&EPA 

United States 

Environmental Protection 

Agency 

United States 

Public Health 

Service 

Office of Air and Radiation (6607J) 

National 

Environmental 

Health Association 

Introduction to 

Indoor Air Quality 

A Reference Manual 

July 1991 

EPA/400/3-91/003 

Introduction to 

Indoor Air Quality 

A Reference Manual 

United States 

Environmental Protection 

Agency 

July 1991 

United States 

Public Health 

Service 

National 

Environmental 

Health Association 

Reference Manual Table of Contents 

TABLE OF CONTENTS Section 4.4 Biological Contaminants 102 

INDOOR AIR QUALITY REFERENCE 

MANUAL SECTION 5. CONTROL OF INDOOR AIR 

CONTAMINANTS 115 

ACKNOWLEDGEMENTS ix Section 5 .1. Residential Heating Systems 

and Moisture Control 116 

Section 5.2. Evaluation of Air Cleaners 131 

SECTION 1. OVERVIEW OF THE 

REFERENCE MANUAL 1 Section 5.3. Public and Private Sector 

Organizations Involved In II Indoor Air Quality Activities 135 

SECTION 2. FACTORS AFFECTING INDOOR 

AIR QUALITY 3 

SECTION 6. INDOOR AIR QUALITY 

Section 2 .1. Indoor Air Quality Modeling 4 MEASUREMENTS 141 

Section 2.2. Sources of Indoor Air Section 6.1. Indoor Air Quality Sampling 

Contaminants 20 Methods 143 

Section 6.2. Accuracy, Precision, and 

SECTION 3. DEFINING HEALTH EFFECTS Related 1lerms 168 

AND RISK ASSESSMENT 29 

Section 6.3. Representative Sampling 170 

Section 3 .1. Defining Adverse IJealth Effects 30 

Section 6.4. Calibration 172 

Section 3.2. 1lhe Respiratory 1lract 31 

Section 6.5. Passive Samplers 180 

Section 3.3. Risk Assessment 36 

Section 6.6. Air Exchange Rates 181 

Section 3.4. EPA Cancer Risk Assessments 

for Indoor Air Contaminants 43 SECTION 7. STANDARDS AND GUIDELINES 

FOR VENTILATION AND 

SECTION 4. SOURCES AND HEALTH HEALTH EFFECTS 185 

EFFECTS OF SELECTED 

CONTAMINANTS 47 SECTION 8. INVESTIGATION 

Section 4.1. Combustion Contaminants 49 TECHNIQUES 203 

Section 4.2. Pesticides 66 Section 8.1. General Investigation 

1lechniques for Residences 205 

Section 4.3. Formaldehyde and Other 

Volatile Organic Compounds 85 Section 8.2. Investigation 1lechniques for 

Combustion Sources 217 
Table of Contents Reference Manual 

Section 8.3. Investigation Techniques for LIST OF EXHIBITS 

Pesticides 242 

Section 8.4. Investigation Techniques for SECTION 2. FACTORS AFFECTING ~NDOOR 

Formaldehyde and Other AIR QUALITY 3· 

Volatile Organic Compounds 258 

Section 8.5 

Exhibit 2-1 .. Major sources of in~ltration 

Investigation Techniques for measured during weatherization 

Biological Contaminants 277 studies. 10 

II 

Exhibit 2-2 Effective leakage area of building 

components (0.016 inches 

water). 11 

Exhibit 2-3. Values for wind coefficient. 12 

Exhibit 2-4. Source emission rates for 

selected contaminants. 13 

Exhibit 2-5. Decay rates for selected 

contaminants. 17 

Exhibit 2-6. Deposition velocities for selected 

contaminants on various surfaces 

and indoor areas. 18 

Exhibit 2-7. Sources of indoor air 

contaminants. 21 

SECTION 3. DEFINING HEALTH EFFECTS 

AND RISK ASSESSMENT 29 

Exhibit 3-1. Structure of the respiratory tract. 35 

Exhibit 3-2. Commonly used ventilatory 

measurements. 36 

Exhibit 3-3 EPA cancer risk assessments. 44 
Reference Manual Table of Contents 

SECTION 4. SOURCES AND HEALTH Exhibit 4-9. Measurements of pesticides in 

EFFECTS OF SELECTED buildings. 79 

CONTAMINANTS 47 

Exhibit 4-10. Potential sources of 

Exhibit 4-1a. Relationship between carbon formaldehyde indoors. 91 

monoxide (CO) concentrations 

and carboxyhemoglobin Exhibit 4-11. Measurements of formaldehyde 

(COHb) levels in blood. 54 concentrations in different 

types of buildings. 92 

Exhibit 4-1b. Carboxyhemoglobin levels and 

related health effects. 55 Exhibit 4-12. Health effects and sources of 

selected volatile organic II Exhibit 4-2. Controlled studies of the effects compounds. 94 

of human exposure to nitrogen 

dioxide. 56 Exhibit 4-13. Examples of volatile organic 

compound measurements in 

Exhibit 4-3. Effects of exposure to nitrogen indoor air. 96 

dioxide plus other gas stove 

combustion products in the Exhibit 4-14a. Examples of selected volatile 

home on the incidence of organic compound emission 

acute respiratory disease in rates for materials and typical 

epidemiology studies involving household products indoors. 99 

gas stoves. 59 

Exhibit 4-14b. Additional examples of volatile 

Exhibit 4-4. Selected studies of human organic compound emission 

exposure to carbon dioxide. 61 rates for selected materials 

found indoors. 100 

Exhibit 4-5. Selected studies of asthmatic 

subjects exposed to sulfur Exhibit 4-15. Molds identified in 68 homes 

dioxide. 62 in southern California. 110 

Exhibit 4-6. Composition of mainstream Exhibit 4-16. Fungi reported as allergenic. 111 

and sidestream smoke. 63 

Exhibit 4-7. Summary of health effects, SECTION 5. CONTROL OF INDOOR AIR 

products, and uses of 50 CONTAMINANTS 115 

active ingredients in household 

pesticides. 69 Exhibit 5-l. Oil furnace installation. 118 

- Exhibit 4-8. Selected weighted summary Exhibit 5-L Gas-fired forced-air furnace 

statistics for indoor air configurations. 119 

concentrations of pesticides in 

Jacksonville and Exhibit 5-3. Forced-air distribution systems. 120 

Springfield/Chicopee (ng/m3). 75 

Exhibit 5-4. Installation of a vapor retarder 

in the attic. 125 
Table of Contents Reference Manual 

Exhibit 5-5. Installation of a vapor retarder Exhibit 6-3. Battery-powered personal air 

in the crawl space or floor. 126 samplers. 159 

Exhibit 5-6. Installation of a continuous Exhibit 6-4: Properties of filters used in 

vapor retarder. 128 particulate sampling. 160 

Exhibit 5-7. Attic ventilation strategies. 129 Exhibit 6-5. Some storage properties of gases 

in plastic bags. 163 

Exhibit 5-8. Sizing factors for different vent 

coverings. 130 Exhibit 6-6. Limitations of selected solid 

adsorbents. 164 

II Exhibit 5-9. Comparative performance of 

viscous impingement and Exhibit 6-7. Sources for testing and 

dry media filters. 132 calibration procedures 

applicable to indoor air 

Exhibit 5-10. Estimated percentage of quality sampling. 165 

particle removal for portable 

air cleaners by CADR and by Exhibit 6-8. National Institute of 

room size. 134 Standards and Technology 

(NIST) Standard Reference 

Exhibit 5-11. Minutes to achieve 90% Materials (SRMs) for the 

removal of airborne particles. 135 calibration of instruments and 

procedures utilized in air 

Exhibit 5-12. Public interest organization quality analysis. 166 

indoor air activities. 136 

Exhibit 6-9. Precision and accuracy. 169 

Exhibit 5-13. Professional and trade 

association indoor air activities. 137 Exhibit 6-10. Example calibration or audit 

form for a direct reading 

carbon monoxide or carbon 

SECTION 6. INDOOR AIR QUALITY dioxide monitor. 176 

MEASUREMENTS 141 

Exhibit 6-11. Different types of airflow 

Exhibit 6-1. Collection and analytical meters. 177 

methods for quantitative 

monitoring of some Exhibit 6-12. Sample rotameter calibration 

contaminants. 146 form. 178 

Exhibit 6-2a. Commercially available indoor Exhibit 6-13. Calibration using the 

air monitoring equipment. 147 soap-bubble meter. 179 

Exhibit 6-2b. Identification codes for 

methods in Exhibit 6-2a. 155 

Exhibit 6-2c. Identification codes for 

manufacturers in Exhibit 6-2a. 156 
Reference Manual Table of Contents 

SECTION 7. STANDARDS AND GUIDE· Exhibit 8-6. Examples of chimney caps. 235 

LINES FOR VENTILATION 

AND HEALTH EFFECTS 185 Exhibit 8-7. Potential consequences when 

more than one appliance 

Exhibit 7-1. Air quality standards and is connected to the same flue. 236 

guidelines for selected 

contaminants. 186 Exhibit 8-8. Combustion inspection form. 237 

Exhibit 7-2. Outdoor air requirements for Exhibit 8-9. Features of proper stove 

ventilation of commercial installation. 238 

facilities (offices, stores, shops, 

hotels, sports facilities). 195 Exhibit 8-10. Suggested chimney sizes for II residential wood-burning 

Exhibit r-3. Outdoor air requirements for equipment. 239 

ventilation of residential 

facilities (private dwellings, Exhibit 8-11. Safety guidelines for unvented 

single, multiple). 199 gas-fired heaters. 240 

Exhibit 7-4. Uniform Building Code Exhibit 8-12. Safety guidelines for unvented 

ventilation requirements. 200 kerosene heaters. 240 

Exhibit 7-5. Acceptable ranges of Exhibit 8-13. Sources of termiticide 

temperature and humidity contamination and mitigation 

during summer and winter. 202 methods. 249 

Exhibit 8-14. PestiCides that can be 

SECTION 8. INVESTIGATION measured using low volume 

TECHNIQUES 203 PUF sampling with GC/ECD. 250 

Exhibit 8-1. Indoor air quality health Exhibit 8-15. Useful sources of information 

effects form. 206 on pesticides. 251 

Exhibit 8-2. Indoor air quality residential Exhibit 8-16. Guidelines for using pesticides 

inspection form. 211 safely. 252 

Exhibit 8-3. Location and operation of Exhibit 8-17. First aid guidelines for pesticide 

typical backdraft diverter. 232 poisonings. 255 

Exhibit 8-4. CABO Building Code Exhibit 8-18. Guidelines for cleaning 

combustion air requirements pesticide spills and residues. 256 

for residential fuel-burning 

equipment. 233 Exhibit 8-19. Examples of biological control 

of pesticides. 257 

Exhibit 8-5. Separation guidelines to 

prevent downdrafts into Exhibit 8-20. Selected passive formaldehyde 

chimneys. 234 measurement methods. 270 
Table of Contents Reference Manual 

Exhibit 8-21. A dose-effect relationship 

between formaldehyde (HCHO) 

exposure and selected health 

effects in mobile and 

conventional homes. 271 

Exhibit 8-22. Effect of temperature and 

relative humidity on formaldehyde (HCHO) levels in a 

mobile home under controlled 

conditions. 272 

II Exhibit 8-23. Advantages and disadvantages 

of nonspecific and specific 

detector systems for VOC and 

SVOC analysis. 273 

Exhibit 8-24. Commercially available 

portable VOC detection 

instruments. 274 

Exhibit 8-25. Characteristics of sorption 

collection methods. 275 

Exhibit 8-26. Environmental survey form 

for evaluating the presence 

of potential sources of 

allergens. 290 

Exhibit 8-27. Commonly used samplers for 

collecting indoor bioaerosols. 295 
Reference Manual 

ACKNOWLEDGEMENTS 

The Indoor Air Quality Learning Module and 

the Indoor Air Quality Reference Manual were developed under a cooperative arrangement between the 

National Environmental Health Association, the 

Bureau of Health Professions of the U.S. Public 

Health Service, and the Indoor Air Division of the 

Environmental Protection Agency. 

The documents were written by: 

Ingrid Ritchie, Ph.D., Associate Professor 

School of Public and Environmental Affairs 

Indiana University 

The following persons are gratefully acknowledged 

for their contributions: 

Barry Stern had the foresight to recognize the 

importance of indoor air quality issues and the need 

to strengthen the competency of practicing environmental health professionals in this area. His 

initiative in developing this project, his support, 

and his patience have been fundamental to the 

success of this work. 

David Mudarri was the principal technical advisor 

for this project. He provided expert technical 

guidance and made extensive and invaluable 

editorial contributions. His insight and thoughtful 

assistance provided the framework for both documents, and his tireless effort and encouragement 

helped steer the project through many difficult 

times. 

Edward Culver (Bureau Administrator, Bureau of 

Environmental Health, Health and Hospital 

Corporation of Marion County, Indianapolis, 

Indiana) contributed Lesson 9 of the Learning 

Module, "Establishing an Indoor Air Quality 

Program." 

Geraldine Struensee spent many hours typing 

complex tables and initially formatting the documents. Her forbearance through innumerable 

revisions is sincerely appreciated. 

Acknowledgements 

Reviewing Organizations 

Individuals from the following organizations 

reviewed and commented on all or part of the two 

documents. 

Federal Agencies 

Bonneville Power Administration, 

Department of Energy 

Consumer Product Safety Commission 

Department of Health and Human Services 

National Institute of Environmental Health 

Sciences 

National Institute for Occupational Safety 

and Health 

Department of Housing and Urban Development 

Office of Policy Development and Research 

Environmental Protection Agency 

Office of Air and Radiation 

Office of Pesticides and Toxic Substances 

Office of Research and Development 

Office of Water 

General Services Administration 

Public Buildings Services 

State and Local Government Agencies 

Association of Local Air Pollution Control Officials, 

Washington, DC 

Central District Health Department, Boise, ID · 

Clark County Health Department, Las Vegas, NV 

Connecticut Department of Health Services, 

Hartford, CT 

Division of Environmental Services, Toledo, OH 

Forsyth County Environment Affairs Department, 

Winston-Salem, NC 

Health and Hospital Corporation of Marion County, 

Indianapolis, IN 

Illinois Department of Public Health, 

Springfield, IL 

Lincoln-Lancaster County Air Pollution Control 

Agency, Lincoln, NE 

Mansfield Health Department, Mansfield, MA 

Maryland Department of Education, Baltimore, MD 

(continued next page) 

II 
II 

Acknowledgements 

Minneapolis Department of Environmental Health, 

Minneapolis, MN 

Montgomery County Public Schools, Rockville, MD 

Plano Health Department, Plano, TX 

Southeastern Health District, Pocatello, ID 

State College Health Department, State College, PA 

Other Organizations 

Department of Environmental Health, East Carolina 

University, Greenville, NC 

Indoor Air Quality and Safety Research, 

Gas Research Insti.tute, Chicago, IL 

Reference Manual 

Sponsoring Organizations 

National Environmental Health Association 

Executive Director: 

Project Coordinators: 

Grants Assistant: 

Nelson Fabian 

Terry Johnson 

Latty Marcum 

Geraldine Struenesee 

U.S. Department of Health and Human Services 

Project Officer: Barry Stern, M.P.H., R.S. 

Bureau of Health Professions 

Health Resources and Services 

Administration 

U$. Public Health Service 

U.S. Environmental Protection Agency 

Project Officer: David H. Mudarri, Ph.D. 

Indoor Air Division 

Office of Air and Radiation 
SECTION 1. 

OVERVIEW OF THE 

REFERENCE MANUAL 

The Indoor Air Quality Reference Manual is 

the companion document to the Indoor Air Quality 

Learning Module. The purpose of the Reference 

Manual is to provide an opportunity for continuing 

education plus useful reference material on selected 

indoor air quality topics. 

The Reference Manual is divided into 8 sections . 

corresponding to the first eight lessons of the 

Learning Module. Section 1 provides an overview of 

the Reference Manual and suggests ways that the 

Reference Manual can best be used as an adjunct to 

the Learning Module. Sections 2-8 contain information that supplements the corresponding lessons in 

the Learning Module. For example, Lesson 2 of the 

Learning Module describes the factors that affect 

indoor air quality, while Section 2 of the Reference 

Manual shows how those factors are combined in 

indoor air quality modeling to simulate indoor 

environments; Section 2 also provides specific 

information and data on individual factors. 

~ections 3 and 4 of the Reference Manual correspond· 

to Lessons 3 and 4 of the Learning Module and · 

contain information on the nature of human responses as well as health effects from specific 

contaminants. Section 5 contains information about 

air cleaning devices and residential heating and air 

mover systems. 

The Reference Manual also contains information and 

exhi~its which can be directly used in field investigations. For example, Section 4 contains tables 

which relate symptoms, contaminants, and sources 

in a way that could assist in diagnosing indoor air 

quality problems; Section 6 provides information on 

~pecific measurement techniques and equipment, 

mcluding availability of equipment from various 

manufacturers; Section 7 provides a listing of public 

health and occupational standards which can be 

useful in interpreting measured data; and Section 8 

includes specific forms and questionnaires which can 

be used to collect data during field investigations. 

II 

SECTION 2. 

FACTORS AFFECTING 

INDOOR AIR QUALITY 

Section 2.1 discusses the general mass 

balance equation and its use in indoor 

air quality modeling. Exhibits 2-1 

through 2-6 provide some examples 

of empirical data for parameters 

which are used in the model. Section 

2.2 contains Exhibit 2-7 which is a 

detailed listing of sources and contaminants potentially released by 

those sources. 

Taltle of Contents 

Section 2.1. Indoor Air Quality Modeling 

Section 2.2. Sources of Indoor Air Contaminants 

List of Ex:hibits 

Exhibit 2-1. 

Exhibit 2-2. 

Major sources of infiltration measured 

during weatherization studies. 

Effective leakage area of building components 

4 

20 

10 

(0.016 inches water). 11 

Exhibit 2-3. 

Exhibit 2-4. 

Exhibit 2-5. 

Exhibit 2-6. 

Exhibit 2-7. 

Values for wind coefficient. 

Source emission rates for selected 

contaminants. 

Decay rates for selected contaminants. 

Deposition velocities for selected 

contaminants on various surfaces and 

indoor areas. 

Sources of indoor air contaminants. 

12 

13 

17 

18 

21 

II 
II 

Section2 

2.1. INDOOR AIR QUALITY MODELING 

Indoor air quality models describe the 

transport and dispersion of air contaminants 

throughout a structure and the variation of indoor 

air contaminant concentrations as a function of 

source strengths, air-exchange rates, removal 

mechanisms, and other parameters. 

Most models are hi!Sed on either the principles of 

conservation of energy or the conservation of mass in 

a compartment or zone. Some models are based on 

empirical methods in which test data are evaluated 

statistically and fitted using regression analysis. 

These empirical models may better reflect the 

specific circumstances for which they are calibrated, 

but they do not have the wide applicability of the 

models which are based on first principles. 

In a mass or energy balanc~ model, the term 

compartment or zone refers to a region in which 

spatial variations in contaminant concentration can 

be ignored over the time period of interest. A 

single room, a floor, or a house that is well-mixed is 

usually treated as a single zone. Houses with central 

forced-air heating systems can be considered to be 

well-mixed when the circulation fan is operating. 

Houses with other types of heating systems can also 

be considered to be well-mixed providing interior 

doors remain open and a sufficiently long time 

period is allowed for mixing. For steady-state 

conditions (when generation of contaminants equals 

removal), these models reduce to simple algebraic 

equations. The basic mass balance equation for a 

single zone model is presented below. 

The accuracy of the single zone model depends on 

the degree of mixing, the time period of concern, 

and the extent to which the parameters have been 

characterized. Model performance can be measured 

by comparing predicted data with actual measured 

values. Mter the model has been calibrated, it 

should be evaluated against other data. It is 

important to note that the data set which is used for 

calibrating the model should not be used to evaluate 

the model's general predictive capability. 

lAQ Reference Manual 

Single zone models may not be adequate when 

sources and sinks are not uniformly distl,"ibuted 

throughout the area or when stratification .of 

contaminants occurs, and in these cases multi-zone 

models may be needed. These models may be 

adequate, for example, to describe contaminant 

concentrations when a kerosene heater is operating 

in one room of a house (zone 1) that is separated 

from the remainder of the house (zone 2) by dosed 

doors. 

Multi-zone models might also be used when 

predicting contaminant concentrations in a building 

with multiple floors. These models include separate 

mass balance equations for each zone, and they are 

more complex than single zone models. 

In general, indoor air quality models are useful tools 

that can be used: 1) to understand how the factors 

that affect indoor air quality relate to one another, 

2) to predict concentrations of contaminants for 

places and conditions that cannot be measured, and 

3) to determine required accuracy and precision for 

monitoring studies. 

Available Indoor Air Quality Models 

Numerous models have been developed to estimate 

concentrations of contaminants in indoor air, and 

some of these also estimate inhalation exposures. 

The Air and Energy Engineering Research Laboratory (AEERL) at EPA has developed a multi-zone 

indoor air quality model (Sparks, 1988) which can 

be used on an IBM-PC or compatible computer. 

The AEERL model treats each room as a well-mixed 

chamber that can contain both sources and sinks. 

Source terms which can be included are random on/ 

off sources (for example, cigarettes), sources that are 

on for specific periods of time (for example, kerosene 

heaters), steady-state sources (for example, moth 

crystals), and sources with high initial emission 

rates followed by a low steady-state rate of emission 

(for example, floor wax). The model also allows the 

impact of heating, ventilating, and air-conditioning 

(HV A C) systems, air cleaners, and interroom air 
IAQ Reference Manual 

flows on indoor air quality to be evaluated. The 

model has been verified to a limited extent with 

experimental data from EPA's indoor air quality test 

house. 

The AEERL model is user friendly and has a menudriven user interface. Output from the model can 

be displayed if a graphics adapter and monitor are 

available. Additional information on the model and 

user's manual can be obtained by contacting the Air 

and Energy Engineering Research Laboratory, U.S. 

EPA, Research Triangle Park, NC 27711. 

Further discussion on single zone, multi-zone, and 

exposure models can be found in NAS (1981); 

Wadden and Scheff(1983); Nagda, Rector, and 

Koontz (1987); McNall et al. (1985); Sexton and 

Ryan (1988); Sexton and Hayward (1987); Axley 

(1987); and Repace (1987). 

Mass Balance Equation 

The primary source for the following discussion is 

Nagda et al. 1987; other useful sources include 

NRC (1981) and Wadden and Scheff(1983). 

The generation and removal of contaminants in 

indoor environments can be described mathematically based on the conservation of mass: 

rate of accumulation = (

1

) 

rate of [input + generation- output -sinks], 

or 

~ = race of change [ (infiltration . ) + <~eneracion) de in mass due to of outdoor rur mdoors 

where, 

(

exfiltration ) (indoor removal ) ]' 

- of indoor air - of contaminants 

V = the indoor volume, 

ci = the indoor concentration, and 

t =time 

(2) 

Section 2 

Parameters in the mass balance equation must be 

evaluated independently. Some parameters, such as 

volumes and surface areas, can be measured directly 

or can be easily obtained from blueprints. Others 

such as ventilation rates and source emission/ 

removal rates are more difficult to obtain. 

Infiltration and exfiltration 

The infiltration of contaminants from the outdoors 

depends on the product of the outdoor contaminant 

concentrations (C ) and the volume rate of air 0 

exchange ( vV), where v is the air exchange rate in 

air changes per hour (ach). 

Not all outdoor air contaminants that move into a 

structure reach the inside; some fraction of contaminants, F b' is intercepted by the cracks and crevices in 

the building envelope which decreases the amount 

that actually reaches the indoor air. The overall 

relationship for the change in indoor contaminant 

concentrations due to infiltration from outdoor air 

is, therefore, given by: 

Removal of contaminants due to the exfiltration of 

indoor air is the product of the volume rate of air 

exchange (vV) and the concentration of air leaving 

the structure, c.- In cases of good mixing, Ce is the 

same as C; and the exfiltration term over a period of 

time is given by: 

Generation and removal 

of contaminants 

The generation of contaminants indoors (source 

term) over a period of time can be expressed as Sdt, 

where S is the contaminant emission rate, 

V dCi(gen) = Sdt. 

The removal of indoor contaminants is due to 

chemical reactions, adsorption of contaminants on 

II 
II 

Section 2 

indoor surfaces, and removal by mechanical means 

through air cleaning devices. The rate of decay due 

to chemical reactions and/or adsorption over a 

period of time is given by Adt, where A is the 

overall decay rate of the contaminant. 

Removal by air cleaning devices depends on the 

volume flowrate of air handled by the device, q, and 

on the efficiency of the device, F (that is, the 

proportion of contaminants removed). Removal by 

air cleaning devices can be expressed as qFCidt. 

The expression for total removal over a period of 

time is then given by: 

VdCi(rem> = -Adt- qFCidt. 

Effective Volume 

The concentration of contaminants indoors also 

depends on the indoor volume. The actual volume 

that is available for contaminant dispersal depends 

on the degree of air circulation, and it is known as 

the effective volume (kV), where k is a dimensionless factor. The value of k becomes 1 when the 

entire indoor air volume is available for contaminant 

dispersal. The value of k is less than 1 when there is 

no forced mixing and the degree of circulation 

depends on thermal gradients indoors. 

Generalized Mass Balance Equation 

Equation 2 can be written as a generalized mass 

balance equation for predicting indoor concentrations. Assuming uniformly mixed conditions and 

an effective volume, kV, rather than the total indoor 

volume, V, equation 2 becomes: 

(3) 

or 

(4) 

IAQ ReferenceManual 

where, 

ci = indoor concentration (mass/ 

volume); 

F b = fraction of outdoor concentration 

intercepted by the building envelope 

(dimensionless fraction); 

v = air exchange rate (1/time); 

Co = outdoor concentration (mass/volume) 

S = indoor source generation rate (mass/ 

time); 

kV = effective indoor volume where k is a 

dimensionless fraction; 

A = decay rate (mass/time); 

q = flow rate through air cleaning device 

(volunie/time); and 

F = efficiency of the air cleaning device 

(dimensionless fraction). 

Mixing factor: Because the extent of air mixing in 

the interior varies, a mixing factor, m, may be 

introduced which modifies the air exchange to yield 

an effective air exchange rate for exfiltration of a 

contaminant. The mixing factor is the ratio of the 

concentration of the exiting air to the concentration 

of the indoor air. When the two concentrations are 

the same, the air is said to be completely mixed, and 

m equals one. When contaminants are exhausted 

directly from their source, m will be > 1. However, 

the more usual case is for m to be < 1 because 

mixing is not complete. 

The value of m has been estimated to be in the 

range of0.33- 1.0 (Wadden and Scheff, 1983). In 

general, mixing between rooms in residential 

structures is usually complete in less than 1 hour; 

therefore, the complete mixing assumption is often 
IAQ Reference Manual 

used to estimate average concentrations over time 

periods greater than 1 hour. 

The effective air exfiltration rate for a given contaminant is the product of the mixing factor, m, and 

the air exchange rate, v, and it is given by mv. 

Therefore, equation 4 becomes: 

dC. = (1 - F )vC + S - mvC. - A. - qFC. _1 b 0- 1- 1 (5) 

dt kV kV kV 

Use of the Mass Balance Equation 

The basic mass balance equation can be used for 

many applications, and the solutions to the equation 

will vary depending on initial assumptions. Some 

examples of applications include using the equation 

to predict the buildup of contaminants as a result of 

the infiltration of contaminated outdoor air or from 

using an indoor source for varying time periods; to 

evaluate the effectiveness of mechanical ventilation; 

or to determine the effect of air exchange rates and 

other variables on indoor contaminant concentrations. 

Equilibrium Concentrations 

One application of the model is to compute the 

equilibrium (steady-state) concentrations that would 

be achieved under a variety of conditions. The 

simplest case assumes a nonreactive contaminant, no 

indoor sources (S = 0), no cleaning devices (F = 0), 

no capture of outdoor contaminants by the indoor 

air (Fb = 0), and uniform mixing (m = 1). Under 

these conditions, equation 5 reduces to: 

dC. = v(C - C.) . -1 0 1 

dt (6) 

Thus, in this simple case, when equilibrium is 

reached (that is, when the indoor air concentration 

is constant), dC/dt = 0, and the indoor concentration equals the outdoor concentration. 

Section 2 

Effect of Indoor Sources: If we now introduce an 

indoor source of contaminants, equation 6 becomes: 

~ = v(C0 - C) + ~ , 

dt kV 

and the equilibrium concentration (when dC./dt = 0) 

would be given by: 1 

C.=C+S 1 0 

kvV 

Other terms can be introduced in a similar way. 

Effect ofTime: Another application is to determine under a given set of conditions how much 

time is required to reach equilibrium or what 

concentration will result after a given period of 

time. Using the simple case in equation 6 where we 

assume an initial indoor concentration, C. , and a 

final indoor concentration equal to a cons~ant 

outdoor concentration, C0

, then the indoor concentration at any time, t, is given by: 

c. = c +(C. -c) e-v(c-co). (7) l,t 0 10 0 

For example, we can calculate the indoor concentration of carbon monoxide (CO) after 2 hours in a 

100 m3 space assuming that the outdoor concentration is 9 ppm; the initial CO indoors is 3 ppm; 

there are no indoor sources or cleaning devices; the 

air exchange rate is 0.3 ach; and uniform mixing of 

the indoor air occurs. The solution is: 

c2hc = 9 ppm+ (3 ppm- 9 ppm) (0.55) 

= 5.7 ppm. 

After 2 hours the indoor concentration under the 

stated conditions equals 5. 7 ppm or about 60% of 

outdoor concentration. 

II 
II 

Section 2 

Quantifying Parameters 

Values for the input parameters which are needed 

either to make simple computations or to use 

available indoor air quality models are derived by 

direct measurements or by combining special 

knowledge of specific conditions with values derived 

from the literature or specific research. The following discussion provides some basis for assisting the 

user in defining values for specific applications. 

Infiltration atzd exfiltration: The infiltration rate 

of a given building can vary considerably depending 

on the weather conditions, occupant activities, and 

the operation of appliances and HV AC equipment. 

Weatherization studies on houses in the United 

States have shown that major sources of air leakage 

are walls and floors, ceilings, heating systems, 

windows and doors, and fireplaces. Air leaks 

through vents and diffusion through walls are minor 

sources. The importance of these individual sources 

will vary depending on the region of the country 

and construction techniques. Exhibit 2-1 identifies 

specific sources of air leakage and ranges of infiltration that have been measured for each. 

Air exchange rates: Air exchange rates for input 

into models can be obtained in one of three ways. 

The type of air exchange rate data which are needed 

will depend on the particular situation which is 

being investigated. 

One approach is to use an average number of air 

exchanges per hour that have been developed for 

different types of structures and conditions. This 

method provides only ballpark estimates, since air 

exchange rates cannot be reliably estimated from a 

visual inspection of the building, its age, or construction. Air exchange rates can also be determined using empirical models which are statistical 

fits to measurements over a long period of time at 

specific sites. These models incorporate temperature differentials between indoors and outdoors and 

wind speed with empirically derived regression 

constants to obtain air exchange' rates. The accuracy 

IAQ Reference Manual 

of empirical models is about 40%, but individual 

predictions can vary by 100% (ASHRAE, 1989). 

The best way to obtain air exchange rates is to 

measure them directly using tracer gas methods. If 

direct measurements are not possible, air exchange 

rates can also be determined indirectly by measuring or calculating air leakage rates and converting 

these rates to air exchange rates. 

A model developed by the Lawrence Berkeley 

Laboratory (Sherman and Grimsrud, 1989) has been 

widely used as the basis for indirect calculations and 

it is summarized below. The accuracy of these 

calculations will depend on the accuracy of the 

required inputs. The method of calculating the air 

exchange rates from leakage rate data in residences 

is as follows (ASHRAE, 1989): 

1) Use Exhibit 2~2 to determine the 

effective air leakage area from each 

possible source. For example, the 

leakage area of 100 ft of uncaulked sills 

is: 100ft x 0.19 in2

/ft = 27.0 in2• 

2) Add the individual leakage areas to 

obtain a total effective leakage area. 

The total effective leakage area can also 

be measured using fan pressurization. 

3) Using the effective leakage area, 

calculate the airflow rate due to 

infiltration: 

where, 

Q =airflow rate, cfm; 

L = effective leakage area, in2; 

~t = average indoor-outdoor temperature 

difference for the time interval of 

the calculation, °F; 

A = stack coefficient, cfm2 in-4 °F-1

; 
IAQ Reference Manual 

The stack coefficient for residences is a 

function of the. number of stories: 

A= 0.0156 for one story; 

A = 0.0313 for two stories; 

A 0.0471 for three stories. 

B = wind .coefficient, cfm2 in-4 mph·2·; 

The wind coefficient depends on the 

number of stories and the degree of shielding around the house, and it can be obtained from Exhibit 2-3. 

J.1 average wind speed measured for the 

time interval of interest, mph. 

4) Calculate the infiltration rate by dividing Q by the building volume. 

Example Calculation: 

Estimate the infiltration over the heating season in a 

one-story house with a volume of 10,000 ft3 and a 

leakage area of 50 in2• The average indoor temperature during the heating season is 75°F and the 

average outdoor temperature is 32°F. The house is 

located on a lot that has a thick hedge on one side 

and single story houses on the other sides (heavy 

shielding). The average wind speed during the 

heating season is 5 mph. 

First, calculate the airflow rate due to infiltration: 

Q = 50 ((0.0156 X 43) + (0.0039 X 52)}0

·

5 

= 43.8 cfm 

= 2630 ft3/hr. 

Next, calculate the ach: 

= (2630 ft3/hr)/10,000 ft3 

= 0.26 ach. 

Section 2 

Source and removal terms: A wide range of 

sources and source combinations are possible in 

indoor environments. Some sources may start and 

stop in a random fashion (tobacco products), some· 

_ emit for limited and specified periods of time (gas 

heaters), some emit at rates that are high init.ially 

but reduced over short or long periods of time 

(waxes, formaldehyde), and others may emit at a 

more uniform rate over a period of time (moth 

balls). Different types of sources and source combinations can be modeled, but the equations may 

become more complex. Also, a given source can have 

different emissions at different times depending on 

the conditions of the measurements. For example, 

the rate of emissions from a kerosene heater that 

uses a wick will depend on the burner setting, age 

of the wick, type of fuel used, age of the heater, and 

other factors. In addition, it should be noted that 

different methodologies for the measurement of the 

emission rate can yield different .results. Exhibit 2-

4 gives examples of some emission rates for selected 

sources and contaminants. 

The removal term, R, is often unknown, and for 

some contaminants it may depend on the physical 

and chemical characteristics of the interior space. 

The removal term may be incorporated into the 

source term to give a net source term, or it can be 

evaluat~:td as a function of the decay rate (A) or 

9eposition velocity (vdep); Exhibits 2-5 and 2-6 

provide examples of decay rates and deposition 

velocities for selected contaminants. The caveats for 

the so~rce term also apply to the removal term. 

Removal expressed as a function of the decay rate 

and the contaminant mass (VC) is given by: 

R = A.VC. l 

Removal expressed as deposition is given by: 

where, 

(continued next page) 

II 
Section2 IAQ Reference Manual 

v dep =deposition velocity, length time·1 and 

a= area of contact, length2• 

The relationship between A. and v dep is then: 

vc~ep=A.V. 

a 

Exhibit 2•1. Malor sources of infiltration measured during weatherization studies. 

RELATIVE AMOUNT OF LEAKAGE 

SOURCE RANGE(%) AVERAGE(%) 

walls 18-50 35 

ceiling details 3-30 18 

heating system 3-28 15 

windows and doors 6-22 15 

fireplaces 0-30 12 

vents in conditioned spaces 2-12 5 

diffusion through walls <1 

SOURCE: .ASHRAE (1985) 
IAQ Re/ereiu:e Manual Sel:tion 2 

Exhibit 2·2. ~ffective leakage area of building components (0.016 inches water). 

BEST BEST 

COMPONENT EST. MAXM;IN COMPONENT EST. MAX MIN 

SILL FOUNDATION-WALL DOMESTIC HOT WATER SYSTEMS 

Caulked,in2/ft of pe~imeter 0.04 O,o6 0.02 Gas Water Heater (only if in 

Not caulked, in 21ft of perimeter 0.19 o:19 OJ;>5 conditioned space), in2 per unit 3.1 3.9 2.325 

JOINTS BETWEEN CEILING AND WALLS ELECTRIC OUTLEtS AND LIGHT FIXTURES 

Joints, in2/ft of wall O.Q7 0.12 0.02 Electric Outlets and Switches 

(only if QOt taped or plastered Gasketed, in2 per outlet and switch 0 0 0 

and no vapor bar\ier) Not gasketed, in2 per outlet and switch 0.076 O.i6 0 m Recessed Light Fixtures, in2 per fixture 1.6 3.10 1.6 

WINDOWS 

Casement ·PIPE AND DUCT PENETRATIONS THROUGH ENVELOPE 

W eatherstripped, in2/ft2 of window 0.011 0.017 O.Q0.6 Pipes 

Not weatherstdpped, inWclof window 0.023 0.034 0.011 Caulked or sealed, in2 per pipe 0.155 0.31 0 

Awning Not caulked of sealed, in2 per pipe 9.30 1.55 o.;n 

W eatherstripped, in2/ft2 of window 0.011 0.017 o:Qo6 Ducts 

Not weathe;stripped, in2/ft2of window 0.023 om4 .0.0~1 Sealed or with continuous 

Si~~gle Hung vapor barrier, in2 per duct 0.25 0.25 0 

Weatherstripped, in2/ft2 of window 0.032 0.042 ·o.oz!) Unsealed and without vapor barrier, 

Not weat!;terstripped, in2/ft2 of window 0.063 0.083 0.052 in2 per duct 3.7 3.7 2.2 

Double Hung 

W eatherscripped, in2/ft2 of window 0.043 0.0!53 0.023 FIREPLACE 

Not weacheritripped, in2fft2of window 0.086 0.126 0.046 Without Insert 

Single Slider Damper dosed, in2 per unit 10.7 13.0 8.4 

Weathersrripped, in2/fc2 of window 0.026 0.039 0.013 Damper open, in2 per unit 54.0 59.0 50.0 

Not we!ltherstripped, in2/ft2 of window 0.052 0.077 0.026 With Insert 

Double Slider Damper dosed, in2 per unit 5.6 7.1 4.03 

Weacherstripped, in2/ft2 pf window 0.037 0.0.54 0.02 Damper open or absent, in2 per unit 10.0 14.0 6.2 

Not w~therscripped, in2/ft2 of window 0.074 0.11 0,04 EXHAUST FANS 

DOORS Kh:chenFan 

Single Door Damper dosed, in2 per mn 0.775 1.1 0.47 

Weatherstrip~d, in2/ft2 of door 0.114 0.215 .0:043 Damper open, in2 per mn 6.0 6.5 5.6 

Nor weatherstripped, in2/ft2 of door 0.157 0.243 0 .. 086 Bathroom Fan 

Double Door · · · Damper closed, in2 per mn 1.7 1.9 1.6 

Weatherstripped, in2/ft2 of qoor 0.114 0.215 O.Q43 Damper open, in2 per mn 3.1 3.4 2.8 

Not weatherstripped, in2/fr' of door 0.16 0.32 0.1 Dryer Vent 

Access co Attic 9r Crawl space Damper closed, in2 per mn 0.47 0.9 0 

W eatherstrip,P!!d, in2/ft2 per access 2.8 2.8 1.2 

Not weathers~ripped, in2/ft2 per access 4.6 4.6 . 1.6- HEATING DUCTWORK-FORCED AIR SYSTEMS 

(only in unconditioned space) 

WALL-WINDOW. FRAME Joints taped or caulked, in2 per house 11 11 5 

Wood Frame Wall Joints not taped/caulked, in2 per house 22 22 11 

Caulked, in2/ft2 of window 0.004 0,007 0.004 

No caulking, in2/ft2 of window 0.024 0,039 0 .. ();!2 FURNACE-FORCED AIR SYSTEMS 

Masonry Wall (only if in conditioned space) 

Caulked, in2

/ft2 of winqow 0.019 0,03 . Q,Ot6 Sealed combustion furnace, per unit 0 0 0 

No caulking, in2/ft2 of window 0.093 0,15 0.082 Retention head burner furnace, 

in2 per ·unit 5 6.2 3.1 

WALL-DOOR FRAME Retention head plus stack damper, 

Wood Fr!lllle Wall in2 per unit 3.7 4.6 2.8 

Caulked, in2/ft2 of wi!ldow 0.004 0,004 O:OQl Furna,ce with stack damper, 

No caull<ing, in2/ft2 of window 0.024 0.024 ((.009 in2 per unit 4.6 6.2 3.1 

Masonry Wall 

C(tulked, in2/ft2 of wi~dow 0.0143 Q.0143 0.004 AIR CONDITIONER 

No caulking, in2/ft2 of window 0.072 0.07.2 ().024 Wall or window unit, in2 per unit 3.7 5.6 0 

SOURCE: :ij.eprinted with permission from the 1985 ASHRAE Handbor!k-Frmdammtals published by the American Society of Heating Ref: · · 

!lnd Air-ConditiQning E~~gineers, Inc. · · · ' ngeracmg 
Ill 

Section2 IAQ Reference Manual 

Exhibit 2·3. Values for wind coefficient. 

SHIELDING CLASS 

1- no obstructions or local 

shielding 

2- light local shielding; 

few obstructions, 

a few trees or small shed 

3- moderate local shielding; 

some obstructions within 

two house heights, thick hedge, 

solid fence, or one 

neighboring house 

4- heavy shielding; obstructions 

around most of the perimeter, 

buildings of trees within 30ft 

in most directions; typical 

suburban shielding 

5- very heavy shielding; 

large obstructions 

surrounding perimeter 

within two house heights; 

typical downtown shielding 

SOURCE: ASHRAE (1989) 

HOUSE HEIGHT (STORIES) 

ONE TWO THREE 

0.0119 0.0157 0.0184 

0.0092 0.0121 0.0143 

0.0065 0.0086 0.0101 

0.0039 0.0051 0.0060 

0.0012 0.0016 0.0018 
IAQ Reference Manual Section 2 

Exhibit 2·4. Source emission rates for selected contaminants. 

CONTAMINANT AND SOURCE EMISSION RATE REFERENCE 

MATERIAL 

Formaldehyde 

medium density fiberboard• 1.5 mg/m2

/hr CPSC, 1985 

pardcle board 0.560 mg/m2

/hr initally 

0.1-0.2 mg/m2/hr after 6 to 27 m months 

textiles, resilient flooring ..s.0.01 mg/m2

/hr Matthews et at. 1984 

carpeting, ceiling tiles, 

carpet pad 0.01 mg/m2

/hr 

. fibrous glass insulation, 

softwood plywood 0.02 mg/m2

/hr 

hardwood paneling 0.11-0.28 mg/m2/hr 

particleboard underlayment 0.30 mg/m2/hr 

industrial particleboard 0.31 mg/m2

/hr 

medium density fiberboard 1.5 mg/m2/hr 

UFFI simulated wall panel 0.23 mg/m2

/hr 

gas burner, gas oven 0.67 mg/hr 

kerosene heater, convective 0.33 mg/hr 

kerosene heater, radiant 1.3 mg/hr 

cigarettes 0.5 mg/hr 

ovenb 11.4 (9.9-14.2) J,tg/kcal (n=5) Traynor eta!., 1979 

top burner" 5.2 (2.0-12.0) J,tg/kcal (n=5) 

Perchloroethylentl 

50% polyester, 50% rayon 220 J,tg/m2

/hr Tichenor and Sparks, 1988 d 

rayon 55 J,tglm2

/hr 

polyester knit 430 J,tg/m2

/hr 

acetate 6700 J,tglm2/hr 

acrylic knit 56 J.~glm /hr 

wool blend 990 J,tglm2

/hr; 1200 J,tg/m2/yr 

cotton 440 J,tg/m2

/hr 

linen 570 J,tg/m2

Lhr 

65% polyester, 35% cotton 350 J,tg/m2

/hr 

80% myon, 15% flax 180 J,tg/m2

/hr 

(continued next page) 
Seclion2 IAQ Reference Manual 

Exhibit 2·4. Source omission rates for selected contaminants (eontlnuod}. 

CONTAMINANT AND SOURCE EMISSION RATE REFERENCE 

MATERIAL 

Para-dichlorobenzene 1.44 mg/cm2

/hr Clayton and Stephenson, 1988 

Carbon Monoxide 

m gas stovee 61.7 .±. 3.58 JJ,g!kJ (n=192) Borrazzo et at., 1987 

oven 950 (650-1600) JJ,g/kcal (n=6) Traynor et at., 1979 

stove, top burner 890 (720-1090) JJ,g/kcal (n=4) 

kerosene heater, blue flame 125.9 JJ,g!kJ Porter, 1984 

reduced fuel consumption£ 1.40 JJ,glkJ 

kerosene heater, white flame 23.9 JJ,glkJ 

reduced fuel consumption£ 3.00 JJ,glkJ 

kerosene heater, convective 1.26 .±. 0.49 10"" ft3/Btu/hr Ritchie and Arnold, 1984 

kerosene heater, radiant 1.16 .±. 0.48 10·6 ft3/Btu/hr 

wood stove, airtight 10-140 cm3/hr {n= 7) Traynor et at., 1987 

wood stove, not airtight 220-1800 cm3/hr (n=4) 

Carbon Dioxide 

oven 200,000 JJ,g/kcal Traynor et al., 1979 

(195,000-250,000) JJ,g/kcal (n=6) 

stove, top burner 205,000 JJ,g/kcal 

(196,000-217 ,000) JJ,g/kcal (n=3) 

kerosene heater, convective 1376 .±. 200 10"" ft3

/Btu/hr Ritchie and Arnold, 1984 

kerosene heater, radiant 1379 .±. 240 10·6 ft3/Btu/hr 

Nitrogen Dioxide 

gas stoves 10.5 .±.1.4~ JJ,glkJ (n=192) Borrazzo et.al. , 1987 

oven 62 (44-74) JJ,g/kcal (n=ll) Traynor et. at. , 1979 

stove, top burner 85 (69-100) JJ,g/kcal (n=4) 

kerosene heater, blue flame 4.7 JJ,glkJ Porter, 1984 

reduced fuel consumption£ 1.15 JJ,glkJ 
IAQ Reference Manual Section2 

Ex.iblt 2·4. Source e111ission rates for selected conta~nlnants (coatiauedJ~ 

CONTAMINANT SOURCE EMISSION RATE REFERENCE 

MATERIAL 

Nitrogen Dioxide (continued) 

kerosene heater, white flame 7.2 J.Jglk] 

reduced fuel consumptionf 1.61 JJglkJ 

kerosene heater, convective 0.211 .±. 0.042 10·6 ft3

/Btu/hr Ritchie and Arnold, 1984 111 kerosene heater, radiant 0.025 .±. 0.008 10·6 ft3

/Btulhr 

Nitric Oxide 

gas stoves 16.8 .±. 1.37 J.Jglk] (n=192) Borrazzo eta/., 1987 

oven 29 (14-50) JJg/kcal (n= ll} Traynor et al., 1979 

stove, top burner 31 (21-47).JJg/kcal (n=4) 

kerosene heater, blue flame 0.1JJglkJ Porter, 1984 

reduced fuel consumption f 

kerosene heater, white flame 14.4 JJglkJ 

reduced fuel consumption£ 0.52 JJglkJ 

kerosene heater, convective 0.411 .±. 0.105 10-e ft3/Btulhr Ritchie and Arnold, 1984 

kerosene heater, radiant 0.014 .±. 0.008 10·6 ft3Btulhr 

Sulfur Dioxide 

oven 0.8 (0.5-1.0) JJg/kcal (n= 11) Traynor et al., 1979 

stove, top burner 0.8 (0.6-0.9) JJg/kcal (n=4) 

kerosene heater, convective 0.078 .±. 0.010 10·6 ft3/Btulhr Ritchie and Arnold, 1984 

kerosene heater, radiant 0.079 .±. 0.017 10•6 ft3/Btulhr 

Hydrogen Cyanide 

oven 1.8 (1.6-2.3) JJglkcal (n=3) Traynor et al., 1979 

stove, top burner 0.07 JJg/kcal 

(continued next page) 
Section2 IAQ Reference Manual 

Exhibit 2·4. Source emission rates for selected contaminants (fontlnued). 

CONTAMINANT AND 

MATERIAL 

Total Suspended Particulates 

wood stove, airtight 

wood stove, not airtight 

no stove, background 

Benzo(a)pyrenli' , 

wood stove, airtight 

wood stove, airtight 

no stove, background 

SOURCE EMISSION RATE 

2.5-8.7 mg/hr (n= 7) 

16-230 mglhr (n=4) 

1.1, 1.6 mg/hr (n=2) 

0.02-0.76 J,tg/hr (n= 7) 

2.2-57 J,tg/hr (n=4) 

<0.01J,tg/hr (n=2) 

• based on CPSC analysis of existing data 

b Oven operated ~t 1 hr at 180°C (350°F). 

c Operated with water-filled cooking pots. 

REFERENCE 

Traynor et at., 1985 

Traynor et at., 1985 

d Emissions from dry cleaned fabrics. The reader is cautioned by Tichenor et al. to 

use the results in a qualitative way, not for emissions calculations. 

e Emission factors ate based on a statistical analysis of existing data by various 

investigators. 

£ 75% of normal fuel consumption. 

s Outdoor penetration factor of 0.48 

11 Outdoor penetration factor of 0.30 
IAQ Reference Manual 

Exhibit 2·5. Decay rate$ for selected contaminants. 

CONTAMINANT AND MATERIAL 

Nitrogen Dioxide 

based on steel chamber studies 

• highest removal 

unpainted plaster board 

cement block 

wool carpet 

• high removal 

used bricks 

masonite 

polyurethane foam 

• moderate removal 

cotton/polyester bedspread 

painted plasterboard 

plywood (1/4 in) 

acrylic fiber or nylon 

carpet 

ceiling tile (wood fiber) 

all vinyl wallcovering 

with proper backing 

• low removal 

particleboard 

ceramic tile 

cotton terrycloth 

wool (80%)/polyester (20%) fabric 

window glass 

galvanized metal duct 

formica countertop 

vinyl or asphalt tile 

Formaldehyde 

based on concentration measurements 

based on "fast" chamber studies 

particleboard underlayment 

paneling 

medium density fiberboard 

based on concentration data for Houston 

Particles <1 micron diameter 

Radon 

DECAY RATE 

> 8.4/hr 

8.4/hr 

6.0/hr 

4.2/hr 

4.1/hr 

3.7/hr 

2.7/hr 

2.6/hr 

2.6/hr 

1.9- 2.0/hr 

1.9/hr 

1.9/hr 

0.7/hr 

0.7/hr 

0.3/hr 

0.3/hr 

<0.1/hr 

0 

0 

0 

-0.0182 to -0.0231/mo 

(ave = -0.0195) 

-0.078/mo (ave) 

-0.093/mo (ave) 

-0.053/mo (ave) 

-0.0013 to -0.0028/mo (ave) 

0.05/hr 

1.258 x 104 /min 

Section2 

REFERENCE 

Billick and Nagda, 1987 

Versar, 1985 

U.S. CPSC, 1985 

Stock and Sixto, 

Dockery and 

Kusuda eJ al., 1980 

m 
II 

Section2 IAQ Reference Manual 

Exhibit 2·6. Deposition velocities for selected contaminants on various surfaces and 

Indoor areas. · 

CONTAMINANT AND MATERIAL 

Stt/fttr Dioxide 

carpet 

pink tufted 

pile 

backing 

orange 

pile 

backing 

green 

pile 

backing 

white 

pile 

backing 

mustard 

pile 

backing 

dark green (unused) 

pile 

backing 

dark green (used) 

pile 

backing 

embossed vinyl 

wallpaper 

paint 

gloss 

emulsion 

Nitrogen Dioxide 

flooring materials 

carpet 

(pH= 4.1) 

(pH= 3.5) 

(pH= 6.7) 

(pH= 9.2) 

(pH= 4.8) 

(pH= 4.3) 

(pH- 4.5) 

DEPOSITION VELOCITY REFERENCES 

Walsh et at., 1977 

0.031 em/sec 

0.006 em/sec 

0.053 crp/s'ec 

0.014 em/sec 

0.074 em/sec 

0.016 cmlsec 

0.072. em/sec 

0.012 em/sec 

0.022 em/sec 

0.017 em/sec 

0.020 em/sec 

0.011 em/sec 

0.029 crtJ./sec 

0.014 em/sec 

0.096 em/sec Walsh eta!., 1977 

0.007 em/sec 

Walsh et al., 1977 

0.033 crri/sec 

0.128 em/sec 

0.55 to 3.46 m/hr (n = 5) Miyasaki, 1984 
IAQ Reference Manual Section2 

Exhibit 2·6. Deposition velocities for selected contaminants on various surfaces and 

indoor areas (ttmtlnued}. 

CONTAMINANT AND MATERIAL 

Nitrogen Dioxide (continued) 

tatami facing 

floor sheet 

plastic tile 

ceramic tile 

bath mat 

needle punch 

wall materials• 

wall paper 

printed plywood 

ceiling materials• 

insulation board 

painted insulation board 

plaster board 

wooden cement board 

asbestos cement board 

Nitric Oxide 

flooring materials• 

carpet 1 

tatami facing 

floor sheet 1 

needle punch 

ceiling materials 

insulation board 

painted insulation board 

plaster board 

wooden cement board 

Ozone 

fabrics 

cotton muslin 

lamb's wool 

nylon 

linen 

DEPOSITION VELOCITY 

·0.46 m/hr 

0.04 to 0.09 m/hr (n = 3) 

0.12 m/hr 

0.15 m/hr 

1.97 m/hr 

0.47 m/hr 

0.06, 0.08 m/hr (n=2) 

0.05 m/hr. 

4.31 m/hr 

2.13 m/hr 

0.66 in/hr 

1.17 m/hr 

1.47 m/hr 

0.01 m/hr 

0.01 m/hr 

0.00 m/hr 

0.03 m/hr. 

0.00 m/hr 

0.04 m/hr 

0.11 m/hr 

0.12 m/hr 

0.88 - 6.52 em/min 

0.24 - 6.34 em/min 

0.03 - 1.92 em/min 

0.33 - 0.56 em/min 

REFERENCES 

Miyazaki, 1984 

Miyazaki, 1984 

Miyazaki, 1984 

Sabersky et al., 197 3 

(continued next page) 

Ill 
Section2 IAQ Reference Manual 

Exhibit 2·6. Deposition velocities for selected contaminants on various surfaces and 

indoor areas (1ontinued}. 

CONTAMINANT AND MATERIAL DEPOSITION VELOCITY REFERENCES 

Ozotze (continued) 

building materials Sabersky et al., 197 3 

neoprene 

plywood (1 side varnished) 

polyethylene sheet 

lucite 

aluminum 

plate glass 

0.91 - 5.79 em/min 

0.30 - 1.83 em/min 

0.61 - 1.46 em/min 

0.03- 0.37 em/min 

0.03 - 0.96 em/min 

0.03 - 0.06 em/min 

• average values from the results of experiments at 20-26°C, 40-60% RH 

2.2. SOURCES OF INDOOR AIR 

CONTAMINANTS 

Exhibit 2-7 provides a more detailed 

tabulation of sources and contaminants. Product 

categories and examples of products are identified 

for major source categories including consumer and 

commercial sources, building sources, personal 

sources, and outdoor sources. Examples of contaminants which have been identified for the product 

categories are also given. 

Specific compounds are grouped according to 

general categories of contaminants (for example, 

vinyl chloride is a VOC which has been measured 

from building materials). Examples ofbuilding 

materials are included (pressed wood products, 

construction adhesive, insulating materials, plastic 

piping, and vinyl or plastic wall coverings). The 

reader should not attempt to match specific contaminants 

with specific products. 
IAQ Reference Mdnual Section 2 

Exhibit 2·7. Sources of indoor air contaminants. 

SOURCES CONTAMINANTS 

CONSUMER AND COMMERCIAL PRODUCTS 

Cleaners and waxes 

aerosol bathroom cleaner 

unpressurized aerosol window cleaner 

liquid all purpose cleaner 

powdered abrasive cleaner 

dishwashing detergent 

concentrated spot remover 

liquid floor wax 

aerosol furniture wax 

aerosol and solid room deodorants 

paste furniture wax 

oven cleaners 

Paints and Associated Supplies 

paints (oil, urethane, acrylic) 

varnishes and shellac 

wood stains 

paint thinners 

paint brush cleaners 

paint removers 

Pesticides 

termite treatment of homes 

aerosol all-purpose household pesticides 

roach killer (powder, liquid, spray) 

flea killer (powder, liquid dip, aerosol) 

mold and mildew inhibitors 

houseplant insecticides 

moth repellents 

rodentiddes (rat or mouse killer) 

Particulates 

• nonmetals (phosphates, other inert powders) 

VOCs 

• aromatic hydrocarbons (toluene, 

p-dichlorobenzene) 

• halogenated hydrocarbons (perchloroethylene; 

methylene chloride; 1,1,1-trichloroethane) 

• alcohols 

• ketones (acetone, methyl ethyl ketone) 

• aldehydes (formaldehyde) 

• esters (alkyl ethoxylate) 

• ethers 

Particulates 

• metals (lead, mercury, chromium) 

VOCs 

• aromatic hydrocarbons (toluene) 

• aliphatic hydrocarbons (n-hexane, heptane} 

• halogenated hydrocarbons (methylene chloride, 

propylene dichloride) 

• alchohols 

• ketones (methyl ethyl ketone, methyl isobutyl 

ketone) 

• ester (ethylacetate) 

• ethers (methyl ether, ethyl ether, butyl ether) 

Particulates 

• nonmetals (sulfur, lime) 

VOCs 

• aliphatic hydrocarbons (kerosene) 

• aromatic hydrocarbons (xylene) 

• halogenated hydrocarbons (chlordane, pdichlorobenzene, heptachlor, chloropyrifos, 

diazinon) 

(continued next page) 

II 
II 

Section 2 IAQ Reference Manual 

Exhibit 2·7. Sources of indoor air contaminants (continued}. 

SOURCES CONTAMINANTS 

CONSUMER AND COMMERCIAL PRODUCTS (continued) 

Pesticides (continued) 

fungicides (household disinfectants) 

Adhesives 

rubber cement 

plastic model glue 

floor tile adhesive 

ceramic adhesive 

carpet adhesive 

all~purpose adhesives 

Cosmetic/Personal Care Products 

perfume 

personal deodorants (aerosols, solids) 

body powder (talc) 

shampoo and body soaps 

rubbing alcohol 

hair sprays 

Automotive Products 

hydraulic fluids 

motor oils 

gasolipe 

automotive cleaners 

auto,motive waxes 

Hobby Supplies 

photographic chemicals 

specialty adhesives 

clay dust 

VOCs (continued) 

• ketones (methyl isobutyl ketone) 

• organic sulfur/phosphorous compounds 

(malathion) 

VOCs 

• aliphatic hydrocarbons (hexane, heptane) 

• aromatic hydrocarbons 

• halogenated hydrocarbons 

• alcohols 

• organic nitrogen compounds (amines) 

• ketones (acetone, methyl ethyl ketone) 

• esters (vinyl acetate) · 

• ethers 

VOCs 

• alcohols (propylene glycol, ethyl alcohol, 

isopropyl alcohol) 

• ketones (acetone) 

• aldehydes (formaldehyde, acetaldehyde) 

• esters 

• ethers (methyl ether, ethyl ether, butyl ether) 

VOCs 

• aliphatic hydrocarbons (kerosene, mineral 

spirits) ' 

• aromatic hydrocarbons (benzene, toluene, 

xylene) 

• halogenated hydrocarbons (perchloroethylene) 

• alcohols (ethylene glycol, isopropyl alcohol) 

• ketones (methyl ethyl ketone) 

• amines (triethanolamine, isopropanolamine) 

Particulates 

• nonmetals (fibers, smoke) 
IAQ Reference Manual Section 2 

Exhibit 2·7. Sources of indoor air contaminants (tontinuedJ. 

SOURCES CONTAMINANTS 

CONSUMER AND COMMERCIAL PRODUCTS (continued) 

Hobby Supplies (continued) 

wood fillers 

Furnishings and Clothing 

carpets 

upholstered furniture 

plastic furniture 

shower curtains 

draperies 

blankets 

mattresses 

Building Materials 

pressed wood products 

construction adhesive 

insulating materials 

plastic piping 

vinyl or plastic wall coverings 

VOCs 

• aliphatic hydrocarbons (kerosene, hexane, 

heptane) 

• aromatic hydrocarbons (toluene, xylene, benzene) 

• halogenated hydrocarbons (methylene chloride, 

ethylene chlo.ride) 

• alcohols (benzyl alcohol, ethanol, methanol, 

isopropyl alcohol) 

• aldehydes (formaldehyde, acetaldehyde) 

• ketones (methyl isobutyl ketone, acetone) 

• esters [di-(2-ethylhexyl) phthalate} (DEHP) 

• ethers (ethylene glycol ether) 

• amines (ethylene diamine) 

VOCs 

• aromatic hydrocarbons (styrene, brominated 

aromatics) 

• halogenated hydrocarbons (vinyl chloride) 

• aldehydes (formaldehyde) 

• ethers 

• esters (DEHP) 

BUILDING SOURCES 

Particulates 

• fibers (fiberglass, asbestos) 

VOCs 

• aliphatic hydrocarbons (n-decane, n-dodecane) 

• aromatic hydrocarbons (toluene, styrene, 

ethyl benzene) 

• halogenated hydrocarbons (vinyl chloride) 

• aldehydes (formaldehyde) 

• ketones (2-propanone, 2-butanone) 

• ethers 

• esters (urethane, ethylacetate, DEHP) 

(continued next page) 

m 
II 

Section 2 IAQ Reference Manual 

Exhibit 2·7. Sources of indoor air contaminants (continued}. 

SOURCES CONTAMINANTS 

BUILDING SOURCES (continued) 

Building Materials (continued) 

Heating, Ventilating, and Air-Conditioning 

Systems · 

furnaces (carbon-based fuels) 

air conditioner reservoirs 

Garages 

vehicular exhaust 

stored chemicals (pesticides, paints, solvents, 

gasoline) 

Combustion Appliances 

unvented heaters (kerosene, gas) 

gas cooking stoves 

woodburning stoves and fireplaces 

Radioactive Contaminants 

• radon gas 

Inorganic Gases 

• sulfur dioxide, nitrogen oxides, carbon 

monoxide, carbon dioxide 

Particulates 

• nonmetals (fiberglass, molds, smoke) 

VOCs 

• aliphatic hydrocarbons (methane) 

Polynuclear Aromatic Hydrocarbons 

• benzo(a)pyrene 

Inorganic Gases 

• sulfur dioxide, nitrogen oxides, carbon 

monoxide 

Particulates 

• metals (lead, nickel, platinum, palladium) 

VOCs 

• aromatic hydrocarbons (benzene) 

• chlorinated hydrocarbons, other substituted 

hydrocarbons 

Polynuclear Aromatic Hydrocarbons 

· • benzo(a)pyrene 

Inorganic Gases 

• sulfur dioxide, nitrogen oxides, carbon 

monoxide, carbon dioxide 
lAQ Reference Manual Section 2 

Exhibit 2·7. Sources of indoor air contaminants (fontinueiiJ. 

SOURCES CONTAMINANTS 

BUILDING SOURCES (continued) 

Combustion Appliances (continued) 

Tobacco Smoke 

Human and Biological Origin 

animal feces 

pets 

indoor plants (spores, pollen) 

metabolic products 

pathogens 

VOCs 

• aliphatic hydrocarbons (propane, butane, 

isobutane) 

Polynuclear Aromatic Hydrocarbons 

• benzo(a)pyrene 

Radioactive Contaminants 

• radon 

Aldehydes 

• acetaldehyde, acrolein 

PERSONAL SOURCES 

Over 3800 Compounds Including: 

Inorganic Gases 

Metals 

Particulates 

Radioactive Contaminants 

VOCs 

Organic Nitrogen Compounds 

Ketones 

Polynuclear Aromatic Hydrocarbons 

Inorganic Gases 

• ammonia 

Particulates 

• nonmetals (dander, feces) 

VOCs 

· • aliphatic hydrocarbons (methane) 

• aromatic hydrocarbons (toluene) 

• aldehydes (acetaldehyde) 

(continued next page) 

'• m 
Section2 IAQ Reference Manual 

Exhibit 2 .. 7. Sources of Indoor air contaminants (continued). 

SOURCES CONTAMINANTS 

OUTDOOR SOURCES 

Soils and Rocks 

Outdoor Air 

industrial emissions 

contaminated groundwater 

vehicular exhaust 

Potable Water 

volatilization ofVOCs during showering, 

bathing, other uses of potable water 

Humidifiers 

Contaminated Groundwater 

seepage into basements 

SOURCE: Adapted from U.S. EPA. (1987) 

Radioactive Contaminants 

• radon gas 

Inorganic gases 

• carbon monoxide, sulfur dioxide, nitrogen 

dioxide, ozone 

Particulates 

• metals (lead, other metals of respirable size 

range) 

• nonmetals (fibers) 

VOCs 

• aliphatic hydrocarbons 

• aromatic hydrocarbons 

• halogenated hydrocarbons 

• aldehydes and ketones 

• alcohols 

• esters 

• ethers 

• organic nitrogen compounds 

• organic sulfur/phosphorous compounds 

Radioactive Contaminants 

• radon gas 

VOCs 

• halogenated hydrocarbons (1,1,1-

trichloroethane, chloroform, trichloroethylene, 

tetrachloroethylene) 

Particulates 

• aerosolized asbestos and minerals, biological 

contaminants 

Radioactive contaminants 

VOCs 
IAQ Refe-rence Manual 

REFERENCES 

American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). 1985. "Natural ventilation and 

infiltration." Chap. 22. 1985 ASHRAE Handbook. Fundamentals. ASHRAE: Adant~ GA. 

American Society of Heating, Refrigerating, and Air-Condi-

. tioning Engineers (ASHRAE). 1989. 1989 ASHRAE 

Handbook: Fundamentals. I-P edition. ASHRAE: Atlanta, GA. 

Axley,J.W. 1987. "The NBS multi-zone model." Presented 

at the 1987 Annual Meeting of Pacific Northwest InternatiQnal 

Section of the Air Pollution Control Association." November 

8-10. Seattle, W A. 

Billick, I.H. and N.L. Nagda. 1987. "Reaction decay of 

nitrogen dioxide." Indoor Air '87 Vol. 1. Volatile Organic 

Compounds, Combustion Gases, Particles and Fibers, Microbiological 

Agents. OraniendruckGmbH: Berlin, Germany. pp. 311-

315. 

Borrazzo,J.E., C.I. Davidson, and C.T. Hendrickson. 1987. 

"A statistical analysis of published gas stove emission factors for 

CO, NO, and NO/' Indoor Air '87. Vol. I Volatile Organic 

Compounds, Combustion Gases, Particles and Fibers, Microbiological 

Agents. Oraniendruck GmbH: Berlin, W. Germany. pp. 

316-320. 

Clayton, R. and E. SJ;ephenson. 1988. Indoor Air Quality Test 

House Mothcake Testing. IAB Report 88-5. U.S. Environmental Protection Agency: Research Triangle Park, NC. 

Dockety, D.W. and J.D. Spengler. 1981. "Indoor-outdoor 

relationships of respirable sulfates and particles." Atmos. 

Environ. 15: 335-343. 

Kusuda, T., S. Silberstein, and P.E. McNall, Jr. 1980. 

"Modeling of radon and irs daughter concentrations in 

ventilated spaces."]. Air Poll. Control Assoc. 30: 1201-1207. 

Matthews, T.G., T.J. Reed, B.J. Tromberg, C.R. Daffron, and 

A.R. Hawthorne. 1984. "Formaldehyde emissions from 

consumer and construction products: potential impact on 

indoor formaldehyde concentrations." Indoor Air. Vol. 3. 

Sensory and Hyperreactivity Reaction to Sick Buildings. Swedish 

Council for Building Research: Stockholm, Sweden. pp. 115-

120. 

McNall, P., G. Walton, S. Silberstein,]. Axley, K. Ishiguro, 

P. Grot, and T. Kusuda. 1985. Indoor Air Quality Modeling. 

Phase 1 Report. Framework for Development of General Models. 

Section 2 

NBSIR 85-3265. U.S. Department of Commerce, National 

Bureau of Standards: Gaithersburg, MD. 

Miyazaki, T. 1984. "Adsorption characteristics of NO, by 

several kinds of interior materials." Indoor Air. Vol. 4. 

Chemical Characterization and Personal Exposure. Swedish Council 

for Building Research: Stockholm, Sweden. pp. 103-110. 

Nagda, N.L., H.E. Rector, and M.D. Koontz. 1987. Guidelines 

for Monitoring Indoor Air Quality. Hemisphere Publishing Corp.: 

New York. 

National Research Council (NRC). l981. Indoor Pollutants. 

National Academy Press: Washington, DC. 

Porter, W.K. 1984. "Pollutant emissions from kerosene 

heaters and unvented gas space heaters." Indoor Air. Vol. 4. 

Chemical Characterization and Personal Exposure. Swedish·Council 

for Building Research: Stockholm, Sweden. pp. 265-270. 

Repace, J.L. 1987. "Indoor concentrations of environmental 

tobacco smoke: models dealing with effects of ventilation and 

room size." Chapt. 3. Environmental Carcinogens. Methods of 

Analysis and Exposure Assessment. Vol. 9-Passive Smoking. I.K. 

O'Neill, K.D. Brunnemann, B. Dodet, and D. Hoffman (eds). 

IARC Scientific Publications No. 81. World Health Organization, International Agency for Research on Cancer: Lyon, 

France. pp. 25-41. 

Ritchie, I.M. and F.C. Arnold. 1984. "Characterization of 

residential air pollution from unvented kerosene heaters." 

Indoor Air. Vol. 4. Chemical Characterization and Personal 

Exposures. Swedish Council for Building Research: Stockholm, 

Sweden. pp. 253-258. 

Sabersky, R. H., D.A. Sinema, and F.H. Shalr. 1973. 

"Concentrations, decay rates and removal of ozone and their 

relation to establishing dean indoor air." Environ. Sci. Techno!. 

7: 347-353. 

Sexton, K. and S.B. Hayward. 1987. "Source apportionment of 

indoor air pollution." Atm. Environ. 21(2): 407-418. 

Sexton, K. and P.B. Ryan. 1988. "Assessment of human 

exposure to air pollution: Methods, Measurements, and 

Models." Air Pollution, the Automobile and Public Health. A. 

Watson, R.R. Bates, and D. Kennedy (eds). National Academy 

Press: Washington, DC. pp. 207-238. 

Sherman, M.H. and D.T. Grimsrud. 1980. "Infiltrationpressurization correlation: Simplified physical modeling." 

ASHRAE Transactions. 86(3): 778-807. 
Se&tion2 

Spllt'ks, L.E. 1988. Indoor AirQ11ality Model Version 1.0. EPA600/8-88-097a. U.S. Environmental Protection Agency, Air 

and Energy Engineering Reseuch Laboratory: Reseuch 

Triangle Pllt'k, NC: 

Stock, T.H. and R.M. Sixto. 1985. "A survey of typical 

exposures to formaldehyde in Houston IU'ea residences." Amer. 

Ind. Hyg. Assoc.]. 46: 313-317. 

Traynor, G.W., D.W. Anthon, and C.D. Hollowell. 1979. 

Intkor Air Q11ality: Gas Stove Emissiom. Lawrence Berkeley 

Laboratory: Berkeley, CA. As cited in National Resellt'Ch 

Council (NRC). 1981. Indoor Poli11tants. National Academy 

Press: Washington, DC. 

Traynor, G.W., M.G. Apte, A.R. Carruthers, J.P. Dillworth, 

D.T. Grimsrud, and L.A. Gundel. 1985. "Indoor air pollution 

due to emissions from wood-burning stoves." LBL-17854. 

Lawrence Berkeley Laboratory, Building Ventilation and Indoor 

Air Quality Program: Berkeley, CA. 

Tichenor, B.A., L.E. Spllt'ks. 1988. Eva/nation of perchloroethy!-

me emissiom from dry cleaned fabrics. EP A-600/2-88-061. U.S. 

Environmental Protection Agency: Washington, DC. 

IAQ Reference Manual 

U.S. Consumer Product Safety Commission (CPSC). 1985. 

"Pressed wood products exposure assessment report." U.S. 

CPSC: Washington, DC. 

U.S. Environmental Protection Agency (EPA). 1987. Draft 

Report. Indoor Air Pollution. The Magnit11de and Anatomy of 

Problems and Solutions. U.S. EPA, Office of Air and Radiation 

Programs: Washington, DC. 

Ve!SIU', Inc. 1985. "Formaldehyde exposure in residential 

settings: sources, levels and effectiveness of control options," 

Draft Final Report. As cited in U.S. Consumer Product Safety 

Commission (CPSC). 1985. "Pressed wood products exposure 

assessment program." U.S. CPSC: Washington, DC. 

Walsh, M., A. Black, A. Morgan, and G.H. Crawshaw. 1977. 

"Sorption of S02 by typical indoor surfaces, including wool 

carpets,wallpaperandpaint." Atm. E1tViron. 11: 1107-1111. 

Wadden, R. A. and P.A. Scheff. 1983. Indoor Air Pollution. 

John Wiley&:. Sons: New York, NY. 
SECTION 3. 

DEFINING HEALTH 

EFFECTS AND RISK 

ASSESSMENT 

Section 3.1 contains a discussion of 

what constitutes an adverse health 

effect from. the perspecd:ve of different 

public health organizations; Section 

3.2 provides an overview of the 

structure and function of the respiratory tract and its defense 1;11echanisms; 

Section 3.3 provides an overview of 

the process of risk assessment; and 

Section 3.4 provides a summary of 

EPA cancer risk assessments for 

specific indoor air contaminants. 

Table of Contents 

Section 3.1. 

Section 3.2. 

Section 3.3. 

Section 3.4. 

Defining Adverse Health Effecrs 

The Respiratory Tract 

Risk Assessment 

EPA Cancer Risk Assessments for 

Indoor Air Contaminants 

List of Exhibits 

Exhibit 3-1. Structure of the respiratory tract. 

Exhibit 3-2. Commonly used ventilatory measurements. 

Exhibit 3-3. EPA cancer risk assessments. 

30 

31 

36 

43 

35 

36 

44 
II 

Section 3 

3.1. DEFINING ADVERSE HEALTH EFFECTS 

There is a range of effects that can occur 

from exposure to indoor air contaminants. Some 

exposures result in body burdens which do not 

produce physiologic changes or morbidity. Others 

can produce mild discomfort at one extreme, and 

mortality at the other. Because of these broad 

ranges of effects and variability in susceptibility, it 

is useful to review different approaches to the 

question of whether or not an exposure has resulted 

or can result in adverse health effects. 

The American Thoracic Society (Andrews, et al., 

1985) has developed guidelines which define 

adverse respiratoty effects. These guidelines were 

developed within the context of the Clean Air Act 

as it applies to protection of the public agajnst 

adverse health effects from outdoor air contaminants. In this context, the Society's Scientific 

Assembly on Environmental and Occupational 

Health defines adverse effects as "medically significant physiologic or pathologic changes" that 

interfere with normal activity, cause episodic 

respiratoty illness, incapacitating illness, permanent 

respiratoty injury, and/or progressive respiratory 

dysfunction. 

Recognizing that the determination of adverse 

health effects is not entirely medical, but also a 

subjective societal decision, the Assembly listed 

potential health effects in a hierarchy of severity and 

did not demarcate between adverse and nonadverse 

effects. Thus, the definition of "medically significant" is broadly interpreted and includes: 

asthmatic attacks; 

reports of chronic respiratory symptoms; 

the need to take pulmonary medication; 

decreased pulmonary function; 

increased prevalence of wheezing; 

chest tightness; 

cough/phlegm; 

acute upper respiratory infections; 

eye, nose, and throat irritation; and 

odors. 

IAQ Reference Manual 

This listing provides guidance that recognizes that 

irritation and odor effects can be interpreted as 

adverse health effects. 

The American Society of Heating, Refrigerating, and Air-Conditioning Engineers 

(ASHRAE), in ASHRAE Standard 62-1989, 

defines acceptable air quality as "air in which there 

are no known contaminants at harmful concentrations as determined by cognizant authorities and 

with which a substantial majority (80% or more) of 

the people exposed do not express dissatisfaction." 

ASHRAE also explicitly identifies discomfort effects 

as unacceptable. 

ASHRAE Standard 62-1989 reflects a concern for 

the growing number of sick building syndrome 

complaints by building occupants. This definition 

also reflects the Society's traditional interest in 

occupant satisfaction with the building's thermal 

environment. Thus, the ASHRAE definition and 

the background information to the procedures 

section of the Standard provide considerable latitude 

in determining whether or not adverse effects occur. 

The American Public Health Association's 

Model Housing Code (Mood, 1986) also provides 

latitude in addressing adverse health effects. The 

term "cognizant authority" used by ASHRAE is also 

used in APHA's Model Housing Code. In APHA'S 

model code, the term usually refers to the local 

health officer who has the responsibility of determining whether or not the presence of a contaminant is harmful. 

The World Health Organization's Working 

Group on Indoor Air Quality (WHO, 1983) did not 

explicitly define adverse health effects, but identified the following effects as adverse: odor, irritation, airway effects, carcinogenic effectS, systemic 

effects, and respiratory disease. 

Based on these sources, an adverse health effect 

could be interpreted broadly to include effects 

which are medically significant, physiologic or 

pathologic changes which do not result in the 
IAQ Reference Manual 

expression of symptoms and/or frank disease, and 

discomfort effects, including odors. Decreases in 

productivity should also be added to this list. 

This interpretation reflects an emerging international consensus of individuals and organizations 

involved with indoor air quality. Woods (1986) 

aptly distills the criteria for judging building 

performance based on presentations and discussions 

from Indoor Air 84, the Third International Conference on Indoor Air Quality and Climate. As 

summarized by Woods, these criteria include the 

ability of the building to provide for the health, 

safety, comfort, acceptability, well-being, and 

productivity of occupants. 

3.2. THE RESPIRATORY TRACT 

Eyery person breathes in 10,000 to 20,000 

liters of air each day that contain several million 

particles and gas molecules. It is one of nature's 

wonders that the respiratory tract is able to cleanse 

much of this contaminated air by the time the .air 

reaches the region of the lungs where gas exchange 

takes place. 

The respiratory tract is protected from injury by 

many interrelated defense mechanisms including 

mechanical defenses, fluids that line the airways, 

airway reflexes, and antimicrobial, inflammatory 

and immune defenses. If one or more of these is 

impaired, respiratory damage and disease can result. 

An understanding of the structure and defense 

mechanisms of the respiratory tract is a useful first 

step toward understanding many of the respiratory 

related health effects associated with indoor air 

· contaminants. 

Structure of the Respiratory Tract 

The respiratory tract can be divided into three 

regions: the nasopharyngeal region, the tracheobronchial region, and the pulmonary region (Exhibit 3-1). 

Section 3 

Nasopharyngeal Region 

The nasopharyngeal region is the upper portion of 

the respiratory tract, and it consists of the nose, 

mouth, pharynx, and larynx. A primary function of 

this region is to condition the temperature and 

humidity of the air in the nose. 

As air enters the nose, nasal hairs trap some of the 

larger particles. Another important defense mechanism is the turbulent flow of air in this region. The 

airflow is turbulent because of turbinates and the 

small cross-sectional area in the nasopharynx. 

Larger particles (>8-10 urn) are removed by inertial 

impaction, and there is a rapid drop in the deposition rate of particles having a mass median diameter 

of less than 1 micron. 

Other defense mechanisms include the presence of 

nasal secretions and mucociliary clearance. Highly 

soluble or reactive gases such as sulfur dioxide and 

formaldehyde are effectively absorbed by or interact 

with nasal secretions, which decreases the concentration of these contaminants that reach the lower 

airways. 

Tracheobronchial Region 

The tracheobronchial region includes the trachea 

and bronchi. The trachea, a tube about 4.5 inches 

long and 1 inch in diameter, extends from the 

bottom of the larynx through the neck and into the 

chest. At the lower end, it divides into two tubes, 

the right and left bronchi. These conducting 

airways are lined with ciliated epithelium and 

coated with a thin layer of mucus which is secreted 

by goblet cells and mucus-secreting cells. The 

airway secretions are about 95% water, and the 

remainder consists of carbohydrates, proteins, 

inorganic materials, and small amounts of antimicrobial substances. 

The nasopharyngeal and tracheobronchial regions 

also have "irritant" receptors which are located in 

the epithelium. Inhaled gases or particles can 

ED 
II 

Section 3 

activate the irritant receptors and initiate 

bronchoconstriction, mucus hypersecretion, and 

rapid breathing. Bronchoconstdction is a reaction 

in which the smooth muscles of the airways constrict, causing the airways to narrow. 

Contaminants in this region are removed by impaction onto the airway secretions and removal by the 

action of the cilia. The cilia are hairlike filaments 

that wave back and forth at about 12 times per 

second. They are abundant in the respiratory tract 

from the nose to the terminal bronchioles. Their 

role is to propel mucus that contains contaminants 

from the airways to the upper respiratory tract 

(called mucociliary transport mechanism or 

mucociliary escalator) where the mucus may be 

swallowed or expelled by sneezing or coughing. 

If the cilia become damaged (for example, by 

tobacco smoke), they cannot propel the mucus. It 

remains in the airways until it is coughed up and 

expectorated or· swallowed. (Heavy smokers typically have to cough up mucus in the mornings when 

they arise because of a buildup of mucus during the 

night--as a result of cilia which are not able to 

remove mucus efficiently.) 

Within each lung, the bronchi divide and subdivide, becoming smaller and smaller. The branches 

at the farthermost reaches of the lung (pulmonary 

region) are very small and are called bronchioles. 

This division or bifurcation can be visualized by 

thinking of the trachea as the trunk of an upside 

down tree, and the bronchi and bronchioles as the 

branches which become smaller and smaller. 

The bronchioles do not contain as many ciliated 

cells as the larger airways; they have almost no 

mucus producing cells and a very thin layer of 

airway secretions that line airways. The bronchioles 

appear to be particularly susceptible to injury from 

contaminants, particularly cigarette smoke and 

ozone. 

IAQ Reference Manual 

Pulmonary Region 

The pulmonary region is the area where gas exchange occurs. The bronchioles lead into several 

ducts (alveolar ducts), each of which ends in a 

cluster of air sacs. Each cluster (alveolar sac) 

resembles a tiny bunch of grapes and ends in tiny air 

sacs called alveoli. The walls of the alveoli are thin 

membranes only one to two cells thick through 

which oxygen and other gases can pass freely. 

From top to bottom, the respiratory tract branches 

from the trachea into 25 to 100 million branches, 

and these branches end in about 300 million alveoli. 

These alveoli have a combined cross sectional area of 

about 8.6 ft 2 (an amazingly large area considering 

that the cross sectional area of the trachea is only 

about .31 in2

) (Olishifski and Benjamin, 1988}. 

Gas exchange in the alveolar region is based on the 

principle that gases diffuse rapidly from areas of 

higher concentration to areas of lower concentration. 

In the body, the concentration of oxygen (and any 

contaminants) is higher in the alveolar air than it is 

in the blood coming from the body's tissues. At the 

same time the pulmonary artery brings oxygen 

deficient blood from the body tissues back to the 

capillaries which are in contact with the alveoli. 

Oxygen from the lungs diffuses from the alveoli to 

the body via the pulmonary vein, which carries the 

blood to the heart. Some of the oxygen is carried in 

solution in the plasma, and the remaining is 

combined with hemoglobin in the red blood cells to 

form oxyhemoglobin. The oxygen is then released 

by the hemoglobin whenever the oxygen tension of 

the plasma decreases. As the oxygen diffuses from 

the plasma into the tissue capillaries, it is continually replenished by more oxygen· from the oxyhemoglobin. 

The diffusion of carbon dioxide follows the same 

principle, but the concentration of carbon dioxide is 

higher in the body tissues than in the incoming air. 
IAQ Reference Manual 

Contaminants that reach the air-exchange surfaces of 

the terminal alveoli are intercepted, ingested, and 

processed by alveolar macrophages or polymorphonuclear leucocytes. Once these cells have completed 

their work, they exit the lung via the mucociliary 

escalator or via the lymphatic system. 

Those contaminants (such as carbon monoxide} that 

are not removed by the lung's defense mechanisms 

can enter the blood and lymph systems, resulting in 

the transport of contaminants to the organs· where 

adverse effects can occur. 

The bronchioles and the alveoli appear to be 

particularly susceptible to injury from inhaled 

toxicants. This may occur because under normal 

conditions the bronchioles contain fewer ciliated 

cells than larger airways, almost no mucus-producing cells, and the clearance mechanism of this 

region is relatively slow. 

Modes of Action (Gases, Particles) 

The mode of action of contaminants in the respiratory system depends on the characteristics of the 

gases and particles and on the individual's rate and 

type of breathing (oral, nasal, or combination). 

Particles and gases that reach the conducting 

airways first interact with liquids that line the 

respiratory tract. Reactions with these liquids can 

potentially increase the susceptibility of the underlying airway epithelium to injury. Acute effects 

include inflammation and pulmonary edema; 

chronic effects include bronchitis, bronchiolitis, 

fibrosis, emphysema, alveolitis, and cancer. 

Gases 

Important characteristics of gases which determine 

how they behave in the respiratory tract include 

solubility, reactivity, and concentration. Soluble 

gases are absorbed in the upper airways, where they 

may be buffered, detoxified, diffuse into the systemic circulation, or exert a pathologic effect. 

Section .3 

Extremely water soluble gases such as ammonia and 

sulfur dioxide most often cause upper airway 

irritation and injury. Sulfur dioxide is highly 

soluble, and about 90% of all sulfur dioxide that is · 

irihaled is absorbed in the upper respiratory passages 

with only slight penetration to the lower respiratory 

tract. 

Ozone is several hundredfold less soluble than sulfur 

dioxide, and less of it will be absorbed in the upper 

respiratory tract. If the breathing rate is increased 

or if breathing switches from nose to mouth, less of 

each contaminant is removed in the upper respira-

.tory tract and more will reach the middle and lower 

portion of the lungs. Nitrogen dioxide is less 

soluble and less reactive than ozone. Therefore, it 

could penetrate more deeply into the lungs. 

Insoluble gases such as carbon monoxide,. which are 

not reactive with airway secretions or cells, CaJ:?. 

reach the lower lung and diffuse into the bloodstream in. the same concentrations as they were 

inspired. 

. Particulates 

The action of particulates depends on size, shape, 

density, and reactivity of the particulates. Particles 

will be deposited in one of the three regions of the 

lung depending on the velocity ofthe airstream and 

the size of the particles (Task Group ,on Lung 

Dynamics, .1966). 

Larger particles are deposited primarily in the 

nasopharyngeal region. As particles are inhaled, 

some are deposited as the airstream passes througli 

the nose and pharynx. In this region, the changing 

path of the airstr~ causes larger particles to be 

removed by impaction on the airway walls because 

they cannot negotiate the turbinates. Particles 

greater than about 10 microns in diameter are 

effectively trapped by the nasopharyngeal defense 

mechanisms. About 60-80% of particles in the size 

range 5 to 10 microns in diameter are trapped in 

this zone. Small particles (less than 5 microns in 

m 
II 

Section 3 

diameter) are not e~fectively trapped in this zoneonly 5% are trapped and the remainder can travel to 

the lower regions of the lung (Task Group on Lung 

Dynamics, 1966). 

In the tracheobronchial region, airflow is slower and 

particles are deposited by sedimentation and 

impaction. This region has minimal deposition of 

particles except for very small particles which are 

deposited by diffusion. About 10% of the particles 

in the size range 1 to 10 microns in diameter and 

30% of particles 2 to 5 microns in diameter are 

deposited in this zone (Task Group on Lung 

Dynamics, 1966). 

In the pulmonary region, particles are deposited by 

diffusion, and one method of removal occurs by 

macrophages. In this region there is a maximum 

efficiency of deposition at a size around 0.1 microns 

in diameter or less and between about 1 and 2 

microns in diameter (about 30% deposition), and 

there is a minimum efficiency for particles about 0.5 

microns in diameter (Task Group on Lung Dynamics, 1966). 

The air sac linings are coated with a fluid film that 

serves the same cleansing function as the fluid in the 

breathing tubes. Deposited particles or dissolved 

particles and gases may be removed by the fluid 

which flows upward in the air sacs. The macrophages, in turn, can migrate to the small bronchioles where they are removed by the mucociliary 

escalator, or they may pass through the alveolar 

membrane into the lymph system. Macrophages 

can also be destroyed and release particles into the 

alveolar sac. If particles are not removed by these 

means, they may form a deposit in the air sac which 

may or may not result in health effects. 

The rate of clearance of particles is important in 

determining the responses to contaminants, especially slow acting toxicants such as carcinogens. 

The residence time of particles ranges from minutes 

to hours in the upper respiratory tract, hours to days 

in the tracheobronchial region, and days to months 

in the pulmonary region. 

IAQ Reference Manual 

Pattern of Breathing 

The type and rate of breathing also affect the 

deposition of particles and gases. During mouth 

breathing, larger particles will get deeper into the 

lung if the breathing is slow, deep, and with large 

lung volumes. Mouth breathing bypasses the 

defense mechanisms in the nasopharyngeal region. 

Pulmonary Function Tests 

In many scientific studies pulmonary function tests 

are performed to determine if contaminants can 

adversely affect the respiratory tract, and physicians 

also use pulmonary function tests to determine if 

lung function has been impaired. Large decreases in 

pulmonary function provide evidence of an adverse 

respiratory effect, but small changes may or may not 

be significant. 

The American Thoracic Society's Scientific Assembly on Environmental and Occupational Health 

views pulmonary function tests which seem to reflect 

inflammatory changes of the small airways equivocally~ The Assembly observes that preliminary 

results indicate that these tests may predict susceptibility to respiratory disease or increased responsiveness, but concludes the results should not be 

used as indicators of adverse health effects in 

individuals. The Assembly's ambiguity reflects the 

current scientific data base in this area. 

The ventilatory capacity of the lungs can be measured by a spirometer. The spirometer is an instrument which measures volumes of air and relates 

them to time (Exhibit 3-2 summarizes some of the 

commonly used terms of pulmonary function tests). 

Small, portable spirometers which can be used in 

field work can be purchased. These instruments can 

provide basic ventilatory measurements. More 

sophisticated tests require laboratory spirometry 

equipment. 

Lung function testing is probably most useful in the 

evaluation of lung function after occupational 

exposures or as a component of research, but there 
IAQ Reference Manual 

may be some instances when it may be an appropriate component of an indoor air quality investigation. The investigator should know that lung 

. function tests have limitations. The results of these 

tests vary considerably among normal people of the 

Ex•llait 3·1. Structure of t•• respiratory tract. 

Upper Lobe of Right Lung 

Pulmonary Vein 

Section 3 

same sex, age, and height. Whenever these tests ate 

conducted as part of an indoor air quality assessment, a physician or other knowledgeable person 

should conduct and interpret results . 

Frontal Sinus 

SOURCE: Reprinted with permission of the American Lung Association. 

m 
II 

Section 3 IAQ Reference Manual 

Exhibit 3·2. Commonly used ventilatory measurements. 

TERM 

vital capacity 

forced vital capacity 

one-second forced 

expiratory volume 

one-second forced 

expiratory volume 

expressed as a 

percentage ofFVC 

maximal voluntary 

ventilation 

SYMBOL 

vc 

FVC 

FEV:l X 100 

FVC 

MVV 

SOURCE: West (1980}, Olishifski and Benjamin (1988) 

3.3. RISK ASSESSMENT 

Risk assessment is a tool that has been 

used increasingly in the fields of environmental 

science and health to identify the probability of 

injury, disease, or death from exposure to agents 

(chemical, physical or biological) under specific 

circumstances. Risk assessments attempt to answer, 

either qualitatively or quantitatively, basic questions such as: Is the water, food, or air safe? Will 

acute or chronic effects result? If there is an effect, 

will it occur in months, years, or decades? How 

many people are likely to be affected by exposure to 

the agent? 

Risk assessment can also be used to evaluate the net 

risk and costs associated with a particular policy. 

For example, before water was chlorinated, many 

deaths occurred from infectious disease outbreaks 

DESCRIPTION 

The largest exhaled volume of air measured after a 

maximal inspiration followed by a maximal expiration without forced or rapid effort. 

The vital capacity performed with expiration as 

forceful and rapid as possible. 

Volume of air exhaled during the first second of 

a forced vital capacity; normally, the FEV 1 is about 

80% of the FVC. 

The observed FEV 1 expressed as a percentage of the 

observed FVC. The ratio is typically normal or 

increased in restrictive diseases and reduced in 

obstructive deseases. 

Volume of air which a subject can breathe with 

voluntary maximal effort for a given time (10-15 

sec., if possible, equated to 1 min.). 

such as typhoid and cholera. More recently, the use 

of chlorine to disinfect water is known to increase 

the rate of formation of halogenated hydrocarbons. 

Risk analysis can be used to compare the risk (and 

therefore cost) of illness associated with not chlorinating water to the in<;reased risk of cancer from 

chlorination byproducts. 

The process of risk assessment is not infallible. 

Caution must be used in making assumptions and 

selecting input data for the assessments. When risk 

assessments are used, the uncertainty associated 

with them must always be acknowledged. 

Useful references for additional information on risk 

assessment include several articles on cancer risk 

assessment (Calabrese, 1987; Menzel, 1987; Sielken, 

1987; Severn, 1987; Wilkinson, 1987) and guidelines published by EPA for conducting exposure 
IAQ Reference Manual 

assessments and assessing risks from carcinogens, 

mutagens, teratogens and chemical mixtures (U.S. 

EPA, 1986 a-e). EPA's risk assessment methodologies are currently under review and revised guidelines are anticipated. 

Assessment vs Management of Risk 

Once the risk associated with exposure to an agent 

has been defined, a policy can be developed to 

manage that risk. In the environmental and health 

fields, risk assessments are generally performed by 

scientists and engineers, and the management of 

risk is usually a decision made by a governmental 

agency. 

Risk management is a socio-political decision on 

whether or how much to control futtire exposure to 

the contaminant or activity under consideration. 

The risk assessment portion of the decision-making 

process should be carried out independently from 

considerations of the consequences of risk management. The risk management decision depends in 

part on the risk assessment, but also on the consideration of social, economic, and political factors. 

Measures of Risk 

Risk assessments are used to measure the likelihood 

of a specific effect, such as death from acute hazards 

(in early deaths/year), cancer (in early deaths/year), 

and various types of chronic conditions (in cases/ 

year). 

Risk can be measured for a population or an individual. A population risk is the number of occurrences of a hazard per year within a given population. For example, assume there were 15 million 

automobile accidents in the U.S. in 1988; of these, 

assume that about 1 in 300 resulted in the death of 

an individual. The population risk-/is 11300 x 15 

million, or 50,000 deaths/year. 

The individual risk is the probability of a single 

occurrence affecting an individual during a year. 

For the automobile accident example, the individual 

Section 3 

risk of dying as a result of an automobile accident is 

about 50,000 deaths/year/250 million people. This 

means that an individUal has a 2 in 10,000 chance 

(or 1 in 5000) chance of dying as a result of an 

automobile accident. 

The above examples are quantitative .estimates of 

risk, but risk can also be expressed in qualitative 

terms using categories such as "low," "meditim," or 

"high." 

Perception of Risk 

There Is a difference between the measure of risk 

and the perception of risk. The measurement of risk 

is based upon an estimated likelihood or frequency 

of an effect. The perception of risk is based upon a 

societal-political or personal interpretation and 

acceptance of the hazard posed by a situation or 

chemical exposure. For example, people who drive 

cars, but do not wear seatbelts, may perceive their 

risk to be less than the actual risk of driving 

without wearing seatbelts. On the other hand, the 

perceived risk of flying may be considerably higher 

than the actual risk for those people who are afraid 

to fly. 

Risks can be voluntary or involuntary and may 

result from natural or synthetic substances. In 

general, people are willing to accept higher risks 

from voluntary exposure to agents (for example, 

smoking) than from involuntary exposure (for. 

example, pesticide residues in food). Also, people 

might be willing to accept a cancer risk of 1110,000 

or 1/100,000 as a result of eating peanut butter 

containing low levels of naturally occurring aflatoxin, but they might reject having a synthetic 

chemical with a cancer risk of 1/100,000 in their 

water supply. 

The Risk Assess111ent Process 

EPA has published guidelines for performing risk 

assessments of carcinogens, mutagens, chemical 

mixtures, and developmental toxicants (U.S. EPA 

1966 a-e). The basic elements of risk assessment 

m 
II 

Section 3 

which are identified in the guidelines include one or 

more of the following: hazard identification, doseeffect evaluation, exposure assessment, and risk 

characterization. Examples used in the discussion of 

these elements below are taken predominantly from 

carcinogenic risk assessment, not because it is more 

important, but because this area is the most developed. 

Hazard Identification 

Hazard identification is the process of determining 

whether or not exposure to an agent can cause an 

increase in the incidence of a health condition. This 

involves a review and analysis of available scientific 

information to determine whether or not an agent 

poses a particular risk. 

Information which is used to identify hazards is 

obtained from cellular and tissue studies, animal 

studies, controlled human exposure studies, case 

studies of humans exposed in accidents or in the 

workplace, and epidemiologic studies. 

Carcinogen risk assessment: A hazard identification to determine whether or not a contaminant 

poses a carcinogenic risk should include information 

on the nature of contaminants, degradation products, and metabolites. The available scientific 

literature should be reviewed for the following key 

elements: 

• physical and chemical properties which 

affect the distribution and decay of the 

chemical in the body; 

• routes and patterns of exposure; 

• structural or activity properties of the 

chemical or its metabolites that support or 

argue against the prediction of potential 

carcinogenicity; 

• metabolic and pharmacokinetic properties 

of the chemical which determine how the 

IAQ Reference Manual 

chemical is distributed, metabolized, and 

excreted in the animal or human; 

• toxicologic effects other than carcinogenicity, interactions with other chemicals or 

agents and with lifestyle factors, and other 

factors relating to toxicologic effects; 

• short-term predictive tests which detect 

chemical interactions with DNA and assess 

mutagenic activity; 

• 

• 

long-term animal studies which identify 

the tumorigenic or carcinogenic potential of 

the chemical; and 

human epidemiologic studies which 

examine the association between the 

chemical and the incidence ofcancer. 

Of these elements, animal and human epidemiologic studies have been the most widely used 

sources of data to evaluate hazards, but they do have 

limitations. 

Animal studies are used because it is assumed that 

effects in humans can be inferred from effects in 

animals. This assumption is generally accepted 

because all the chemicals that have been demonstrated to be carcinogenic in humans (except 

possibly arsenic) have been shown to be carcinogenic 

in some, but not all, animal species. Even so, 

caution must be used when animal studies are 

interpreted because there are potential differences in 

the way different species metabolize, distribute, and 

excrete chemicals. 

The overall confidence that an agent which is 

carcinogenic in animals will be carcinogenic in 

humans increases with the following types of 

evidence: 

• an increase in the number of animal species 

and strains showing an effect, and with 

bot'l sexes showing an effect; 
IAQ Reference Manual 

• an increase in the number of tissue sites 

affected by the agent; 

• the presence of a clear-cut dose-effect 

relationship; 

• a high level of statistical significance of the 

increased tumor incidence in treated 

compared to control groups; 

• a dose-related shortening of the time for 

tumors to form or death to occur as a result 

of tumors; and 

• a dose-related increase in the proportion of 

1 tumors which become malignant. 

Human epidemiologic studies which are properly 

designed and conducted provide the most direct 

information about the toxicity of a particular 

contaminant. These studies, however, are not 

available for most chemicals because of the complexity and cost associated with gathering these data. 

Epidemiologic studies require large sample sizes for 

statistical reasons, and long time periods are needed 

to observe effects such as cancer. It is also difficult 

to quantifY exposures because confounding variables 

such as socioeconomic effects, personal habits such 

as smoking and drinking, and other risk factors may 

not be known or cannot be adjusted for in the 

calculations. 

Because of the problems associated with epidemiologic studies, animal studies and the other types of 

evidence listed above are usually used to derive 

estimates of cancer risk in humans. 

The weight of evidence is reviewed carefully for 

technical adequacy and then given an overall 

classification for human carcinogenicity. The 'EPA 

classification system includes 5 groups in descending order of overall weight of the evidence: 

Group A (Carcinogenic to Humans): Used when 

there is sufficient evidence from epidemiologic studies 

Section 3 

to support a finding that a causal relationship exists 

between exposure to the agent and cancer; 

Group B (Probably Carcinogenic to Humans): 

Used when there is enough evidence of carcinogenicity based on animal studies and limited epidemiological evidence (Group Bl) or inadequate or no 

human data (Group B2); 

Group C (Possibly Carcinogenic to Humans): 

Used when there is limited evidence for carcinogenicity in animals and inadequate or no human data; 

Group D (Not Classifiable as to Human Carcinogenicity): Used when there is inadequate animal 

evidence of carcinogenicity and inadequate or no 

human data; and 

GroupE (Evidence of Noncarcinogenicity in 

Humans): Used when there is no evidence for 

carcinogenicity in at least two adequate animal tests 

in different species or in both adequate epidemiologic and animal studies. 

Dose-Effect Assessment 

Dose-effect assessment is a critical part of the overall 

risk assessment process. It attempts to quantifY the 

relationship between the dose and adverse effects 

expected in humans. Ideally, human epidemiologic 

data should be used to develop the dose-effect 

relationship for carcinogenic and noncarcinogenic 

effects. In practice, however, these data are usually 

not available, and data from animal studies are used. 

There are three problems associated with the use of 

animal data which must be considered in the doseeffect assessment. First, animals are usually exposed 

at high doses, which means that effects at low doses 

must be extrapolated. Second, animals and humans 

differ in susceptibility. Third, there are some 

individuals in the population who may be more 

susceptible to effects than the average person. 

The extrapolation of effects at high doses to those at 

low doses usually involves one of two assumptions: 

II 
II 

Sectiotz 3 

1) biological effects occur after a threshold dose has 

been reached, or 2) there is a linear relationship 

between the dose and the effect. Effects which 

involve the alteration of genetic material (genotoxic 

effects), including the initiation of cancer, are 

assumed to be nonthreshold effects; that is, the 

effect is proportional to the dose, and t;here will 

always be an effect unless the dose is zero. A 

threshold dose is assumed for effects which are not 

genotoxic. 

These assumptions, however, may need to be revised 

for some substances as new methods of assessing 

doseweffect relationships are developed. One of these 

new methods is the use of physiological pharmacokinetic modeling, which compares the sensitivity of 

animal and human cells and then relates these via 

dosimetry models to human and animal species 

sensitivity (Menzel, 1987). Whenever these new 

models appropriately simulate real effects, they may 

be preferable co the traditional threshold versus 

nonthreshold models. 

Regardless of the assessment methodology, numerical estimates of the dose-effect relationship should 

not stand alone-assumptions and uncertainties 

should be included. The risk characterization 

should include a discussion and interpretation of the 

numerical estimates that provide the risk manager 

some insight into the degree to which the estimates 

are likely to reflect the true magnitude of the risk to 

humans. 

Noncarcitzogen dose-effect assessment: For 

noncarcinogens, the threshold dose in animal 

studies is approximated by the nowobservedwadverseeffect level, NOAEL (expressed in mg/kg/day). The 

NOAEL is selected in the context of the entire data 

set. Uncertainties in the NOAEL are compensated 

by dividing the NOAEL by an uncertainty factor 

(previously called the safety factor) which may be 10 

(or less), 100, 1000, or 10,000. The uncertainty 

factor dates to the early days of food additive 

legislation when it became dear that there was no 

universally accepted quantitative method of exIAQ Reference Manual 

trapolating from animal data to humans. The 

selection of the uncertainty factor is a professional 

judgment that depends on the nature and quality of 

the data, the seriousness of the effect, the type of 

effect, and the population to be protected. 

The NOAEL can be used to derive the reference 

dose (RID) for humans. The reference dose, which 

was formerly called the acceptable daily intake 

(ADI), can be expressed as an oral reference dose 

(mg/kg/day) or inhalation reference concentration 

(mg/m3

). The RID is a dose (from contaminants in 

food, ·water, and air) that is anticipated to be without 

risk to humans over a lifetime of exposure. The 

RID is derived by dividing the NOAEL for the 

toxic effect appearing at the lowest dose by the 

uncertainty factor. An additional modifying factor 

which comments on the quality of the data may also 

be included. The RID is an estimate of risk (with 

uncertainty that spans perhaps an order of magnitude). It is not a guarantee of absolute safety, and it 

may overestimate the risk in some instances. 

In those instances when the NOAEL cannot be 

identified, the RfD might be calculated with the 

lowest observed-adverse-effect level (LOAEL). 

The assessment should be accompanied by a confidence statement that comments on the quality of 

the study that drives the assessment, the underlying 

data base and the degree to which the selected study 

agrees with the data base, and the overall adequacy 

of the assessment. 

Carcinogen dose-effect assessment: There are three 

main components to the dose-effect assessment for 

carcinogens: 

1) the appropriate data base is selected based 

on the quality of the data, its relevance to 

human modes of exposure, and other 

factors; 

2) mathematical models are used to extrapolate from high to low doses of exposure; and 
IAQ Reference Manual 

3) appropriate scaling factors are used to 

extrapolate from animal studies to human 

exposure. 

In the absence of human data, data are typically 

used from a species that responds most like humans 

or has in the long-term studies shown the greatest 

sensitivity. 

Several mathematical models (linearized multistage 

model, one-hit model, gamma multi-hit model, 

log-probit model, and other time-to-response 

models such as the W eibull model) have been used 

to extrapolate the risks from high doses to those at 

low doses. No single model is recognized as most 

appropriate for all carcinogens (U.S. EPA, 1986a). 

The selection of a specific model depends on the 

underlying mechanism that results in the development of cancer, and if such data are available, the 

selected model should be consistent with these data. 

Unfortunately, the way in which cancer develops is 

not understood for most carcinogens. In the absence 

of these data, EPA recommends the use of the 

multistage model, which assumes that cancer 

originates in a single cell as a result of an irreversible and self-replicating process that involves a 

number of different random biological events. 

EPA uses a linearized modification of the multistage 

model which assumes that the time rate of occurrence of each event is in strict linear proportion to 

the dose. This model, the linearized multistage 

model, is considered to be the strongest of the 

available models (U.S. EPA, 1988). The selection of 

the model for extrapolation is important because at 

low doses the predicted values from the models 

diverge significantly. For example, for a given dose 

there may be a factor of 105 or 108 difference in the 

estimation of lifetime cancer risk at a given concentration by the most conservative and least conservative models. This is an uncertainty equivalent to 

not knowing if one has enough money to buy a cup 

of coffee or pay off the national debt (Cothern, et at. 

1986). Even so, it is highly likely that the projections of the more protective models will not underSection 3 

estimate risk and they may strongly overestimate it 

(U.S. EPA, 1988). 

The risk estimates at low doses derived from animal 

studies must also be adjusted for the differences 

between the human and the animal test species. 

Some of these differences indude body size, genetic 

variability, population homogeneity, health status, 

life span, pharmacokinetic effects such as metabolism and excretion patterns, and the exposure 

regimen. 

The most common approach for making these 

adjustments is to use standardized scaling factors 

which are related to the type of exposure pathway 

and sensitivity of the target organs. Scaling factors 

include mg per kg body weight per day, ppm in the 

diet or water, mg per m2 body surface per day, and 

mg per kg body weight per lifetime. Because 

detailed toxicological, physiological, metabolic, and 

pharmacokinetic data may be limited for a specific 

agent, EPA considers a scaling factor based on 

surface area (mg per m2 body surface area per day) to 

be appropriate because certain pharmacological 

effects scale according to surface area (U.S. EPA, 

1986a). 

Carcinogenic risk assessments must be accompanied 

by a weight-of-evidence statement that is a professional judgment of the quality of the assessment. 

The system for classifying the evidence is given 

under the Hazard Identification section. 

Exposure Assessment 

The exposure assessment estimates the exposures to 

which the population of interest is likely to be 

subjected. It must be combined with the doseeffect assessment in order to obtain a quantitative 

estimate of the risk. 

At the present time there is no single approach to 

exposure assessment that applies to every case. 

Rather, the method that is used must match the 

individual case based on the available data. As in all 

Ill 
II 

Section !J 

phases of the risk assessment process, the assumptions, approximations, and assertions made for the 

exposure assessment should be stated. 

The major elements of the exposure assessment 

which are outlined by EPA include identification 

and characterization of the following areas: 

• Sources. The production, distribution, 

uses, disposal, and environmental releases of 

the chemical should be assessed. 

• Exposure pathways and environmental 

fate. The transport, transformation, 

principle pathways of exposure, and 

predicted environmental distribution 

should be evaluated. 

• Measured or estimated concentrations. 

The concentrations available for exposure 

should be evaluated using measurement, 

mathematical models, or a combination of 

the two. 

• Exposed populations. Populations and 

subpopulations at potentially high exposure 

should be identified, and subpopulations of 

high sensitivity may be studied separately. 

• Integrated exposure analysis. An exposure profile is developed from the estimation of environmental concentrations and 

the description of the exposed population. 

This profile should include the size of the 

exposed population; duration, frequency, 

and intensity of exposure; and routes of 

exposure. 

EPA currently assumes that receiving a high dose of 

a carcinogen over a short time period is equivalent 

to receiving a low dose over a lifetime. This 

assumption is used to calculate a lifetime average 

daily exposure (LADE) that is incorporated into the 

risk characterization. 

IAQ Reference Manual 

Risk Characterization 

The final step in the risk assessment process is the 

characterization of risk. In this step, numerical 

estimates of risk are presented along with a framework for evaluating those risks. The risk characterization section should summarize the hazard 

identification, exposure assessment, and the doseeffect assessment, and the public health risk estimates. Major assumptions, scientific judgments, 

and to the extent possible, uncertainties should be 

included. 

Noncarcinogen Risk Characterization: The risk 

for noncarcinogens may be characterized by a 

margin of safety (MOS) approach that is estimated 

by dividing the reference dose (oral or inhalation) by 

the estimated daily human dose (U.S. EPA, 1988). 

The MOS quantifies the ratio between potential 

exposures and a presumed safe level; it is not an 

absolute statement of risk, but a surrogate for risk. 

The larger the MOS, the smaller the risk. The MOS 

that is needed to protect human health will vaty 

depending on the agent, and its selection is similar 

to the process used to select the uncertainty factors 

for the reference dose calculation. 

Carcinogen Risk Characterization: The numerical 

estimates for carcinogenic risks can be calculated in 

one of three ways. The unit cancer risk, under an 

assumption oflow-dose linearity, is the excess 

lifetime risk due to a continuous constant lifetime 

exposure of one unit of carcinogen concentration. 

Typical exposure units include ppm or ppb in food 

or water, or ppm or J.lg/m3 in air. When the dose, 

expressed as mg/kg/day is used rather than the 

concentration, the term slope factor is used and 

represents the risk per unit dose. One can convert a 

slope factor to unit risk by multiplying the slope 

factor by the inhalation rate (20m3

/day) and 

dividing by body weight (70kg). The dose corresponding to a given level of risk can be used in some 

instances-for example, when using nonlinear 

extrapolation models where the unit risk would 
IAQ Reference Manual 

differ at different dose levels. Finally, risks can be 

characterized either in terms of individual risks, 

population risks, or both. 

Individual risks provide an estimate of the additionallifetime risk for individuals exposed to 

average and maximum levels of an agent. Individual risks can be obtained by multiplying the 

incremental unit risk (from the dose effect assessment) by the lifetime average daily exposure of that 

person (U.S. EPA, 1989). 

Population risk estimates provide a measure of the 

possible total expected excess number of cancers in a 

population during a lifetime of exposure to a given 

agent. The population risk is derived by multiplying the individual risk by the total exposed population over some selected time period (U.S. EPA, 

1989). 

The usefulness of these estimates must be balanced 

with the likelihood that the agent is a human 

carcinogen. The likelihood is reflected by the 

letters A, B2

, B1, C where "A" is the most certain 

risk and "C" is only a possible human carcinogen. 

The availability of a unit risk estimate does not 

modify the uncertainty associated with "B" or "C" 

designations nor are risks for A carcinogens necessarily more accurate than risks for "B" and "C" 

agents. 

3.4. EPA CANCER RISK ASSESSMENTS FOR 

INDOOR AIR CONTAMINANTS 

EPA maintains an online data base, 

Integrated Risk Information System (IRIS), that is a 

primary source of EPA health hazard assessments 

and related information on chemicals of environmental concern. IRIS is intended for users with 

Section 3 

some knowledge of health sciences, but extensive 

training in toxicology is not needed. IRIS is 

maintained by the Environmental Criteria and 

Assessment Office, U.S. EPA, Cincinnati, OH. This 

data base, which includes over 400 chemicals, can 

be accessed by groups outside of EPA through 

diskettes which are updated quarterly or through 

online sources which are updated monthly. The 

user fees are about $130 per quarter for the diskettes, and the online service has a $25 per month 

fee which is applied to a user fee of $25 per hour 

plus an additional charge for each computer screen 

accessed. 

The online data base includes the following information: oral reference dose assessments, inhalation 

reference dose assessments, carcinogenicity assessments (slope factors/unit risk factors), drinking 

water health advisories, EPA regulatory actions, and 

supplementary data. 

Exhibit 3-3 provides a summary of cancer risk 

estimates for selected indoor air contaminants. All 

of the estimates, except radon, are unit risk estimates. which provide an upper bound estimate of 

risk that may occur from continuous lifetime 

exposure per unit of air concentration of the contaminant (U.S. EPA, 1989). These numbers can be 

used to Compare or prioritize hazards in a relative 

sense, and in some special circumstances may be 

useful for evaluating the highest likely cancer 

impact on an exposed population. 

The risk estimate for radon includes an estimate of 

the annual population cancer risk resulting from 

exposure to radon indoors. Estimates of the annual 

population cancer risk resulting from exposure to 

other contaminants are not available at this time. 

m 
m 

Section 3 

Exhibit 3·3. EPA cancer risk assessments.1 

CONTAMINANT 

Radon 

VOCs 

Benzene 

Methylene chloride 

Chloroform 

Carbon tetrachloride 

1 ,2-Dichloroethane 

Trichloroethylene 

Tetrachloroethylene 

Formaldehyde 

PAHs 

Benz( a)-anthracene 

Benzo(a)-pyrene (BaP) 

Dibenzo(a,h)-anthracene 

3-Methylchol-anthrene 

Pesticides 

Aldrin 

Chlordane 

Dieldrin 

Heptachlor 

Lindane 

UNIT RlSK2

•

3 

(CLASSIFICATION) 

8.3 X 10•6

/ Jig/m3 (A) 

4.7 X 10"7

/ Jig/m3 (B2) 

2.3 X w-s; Jig/m3 (B2) 

1.5 x 10"5

/ Jig/m5 (B2) 

2.6 x 10·51 Jig/m3 (B2) 

1.7 X 10"6/ Jig/m3 (B2) 

5.8 x 10"7/Jig/m3 (B2/C) 

1.3 x 10"5/ Jig/m3 (Bl) 

8.9 x 104 / Jig/m3 (B2) 

1.7 x 10·3/ Jig/m3 (B2) 

1.4 x 10·2

/ Jig/m3 (B2) 

2.7 x 10"3/ Jig/m3 (B2) 

4.9 X 10·3/ !J.g/m~ (82) 

3.7 x 104 / !J.g/m3 (B2) 

4.6 X 10"3/ Jig/m3 (B2) 

1.3 x 10·3/ Jig/m3 (B2) 

3.8 x 104 / Jig/m3 (C) 

IAQ Reference Manual 

ESTIMATED 

ANNUAL EXCESS 

CANCER CASES 

20,ooo<9> 
IAQ Reference Manual Section 3 

Exhibit 3·3. EPA cancer risk assessments1(continuedJ. 

CONTAMINANT 

Asbestos 

UNIT RISK2

•

3 

(CLASSIFICATION) 

1.6 x 104 to 

2.3 X 1Q·3f 

ESTIMATED 

ANNUAL EXCESS 

CANCER CASES 

0.01 fibersfml<5

•

6

•

7

> (A) 

1

SOURCE: U.S. EPA (1989a) 

1.8 X 10·3 tO 

2.7 X 10·3/ 

0.01 fibers/ml<7

•

8

> (A) 

2

Unit risk of the contaminant is an upper bound estimate of the lifetime risk of contracting cancer per unit exposure. Upper bound 

means that the true risk which can't be defined is not likely co be higher than the upper bound value and may be lower. 

3The risk estimates for radon, asbestos, and benzene are based on epidemiological data. The risk estimates for the organic contaminants, except benzene, are based on animal bioassay data and represent the "upper-bound" estimate of the risk. The alpha designation 

i.e A, B2

, B1, C, is the weight-of-evidence classification which indicates the certainty that the agent is a human carcinogen. 

4U .S. Environmental Protection Agency (EPA). 1986. Risk Assessment Methodology Environmental Impact Statement: NESHAPs for 

Radionuclides. Background Information Document. Vol. I. U.S. EPA, Office of Radiation Programs: Washington, DC. 

sFibers as measured by phase contrast microscopy. 

6

Lung cancer in male and female smokers and nonsmokers. 

7

U.S. Environmental Protection Agency (EPA). 1985. Airborne Asbestos Health Update. EPA-600/8-84-003F. U.S. EPA Office of 

Health and Environmental Assessment: Research Triangle Park, NC. 

"Mesothelioma in male and female smokers and nonsmokers. 

9Fucure downward revision to approximately 16,000 annual excess cancer cases is likely. 

REFERENCES 

American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). 1989. ASHRAE Standard 62-

1989. Ventilation for acceptable indoor air quality. ASHRAE, Inc: 

Atlanta, GA. 

Andrews, C., S. Buist, B.G. Ferris,Jr.,J. Hackney, W. Rom,]. 

Samet, M. Schenker, C. Shy, and D. Strieder. 1985. "American 

Thoracic Society guidelines as to what constitutes an adverse 

respiracoty health effect, with special reference co epidemiologic 

scudiesofairpollution." Am. Rev. Resp. Dis. 131 (4): 666-668. 

Calabrese, E.J. 1987. "Animal extrapolation. A look inside 

the toxicologist's black box." Environ. Sci. Techno/. 21(7): 

618-623. 

Cothern, C.R., W.A. Coniglio, and W. L. Marcus. 1986. 

"Estimating risk to human health." Environ. Sci. Techno!. 20(2): 

111-116. 

Deisler, P.F.,Jr. 1988. "The risk management-risk 

assessment interface." Environ. Sci. Techno/. 22(1): 15-19. 

m 
m 

Section 3 

Menzel, D.B. 1987. "Physiological pharmacokinetic modeling." Environ. Sci. Techno!. 21(10): 944-950; 

Mood, E. (ed). 1986. APHA-CDC Recommended Minimum 

HoiiSing Standards. American Public Health Association, 

Committee on Housing and Health: Washington, DC. 

Olishifski, J .B. and G.S. Benjamin. 1988. "The Lungs," Chap. 

2. Fundamentals of Industrial Hygiene. 3rd edition. B.A. Plog 

(ed). National Safety Council: Chicago, IL. 

Severn, D.J. 1987. "Exposure assessment." Environ. Sci. 

Ttchnol. 21(12): 1159-1163. 

Sielken, R.L. 1987. "Cancer dose-response extrapolations." 

Environ. Sci. Ttchnol. 21(11): 1033-1039. 

Task Group on Lung Dynamics. 1966. "Deposition and 

retention models for internal dosimetry of the human respiratory tract." Health Physics. 12(2): 173-207. 

U.S. Environmental Protection Agency (EPA). 1985. Airborne 

Askstos Health Update. EPA-600/8-84-003F. U.S. EPA, Office 

of Health and Environmental Assessment: Research Triangle 

Park,NC. 

U.S. Environmental Protection Agency (EPA). 1986a. 

"Guidelines for carcinogen risk assessment." Federal Register. 

51 (185): 33991-34003. September 24. 

U.S. Environmental Protection Agency (EPA). 1986b. 

"Guidelines for mutagenicity risk assessment." Federal Register. 

51 (185): 34005-34025. September 24. 

U.S. Environmental Protection Agency (EPA). 1986c. 

"Guidelines for the health risk assessment of chemical mixtures." Federal Register. 51 (185): 34013-34025. September 

24. 

IAQ Reference Manual 

U.S. Environmental Protection Agency (EPA). 1986d. 

"Guidelines for the health assessment of suspect developmental 

toxicants." Federal Register. 51 (185): 34028-34040. September 24. 

U.S. Environmental Protection Agency (EPA). 1986e. 

"Guidelines for exposure assessment." Federal Register. 

51 (185): 34041-34054. September 24. 

U.S. Environmental Protection Agency (EPA). 1988. Principles 

of Risk Assessment. A Nontechnical Review. (165.6). U.S. EPA: 

Washington, DC. 

U.S. Environmental Protection Agency (EPA). 1989a. Report to 

Congress on Indoor Air Quality. Vol. II: Assessment and Control of 

Indoor Air Pollution. EPA 400/1-89 001C. U.S. EPA, Office of 

Air and Radiation: Washington, DC. 

U.S. Environmental Protection Agency (EPA). 1986b. Risk 

Assessment Methodology Environmental Impact Statement: NESHAPs 

for Radionuc!ides. Background Information Document. Vol. I. U.S. 

EPA, Office of Radiation Programs: Washington, DC. 

West,J.B. 1980. Respiratory Physiology- The Essentials. 2nd 

edition. Williams & Williams: Baltimore, MD. 

Wilkinson, C.F. 1987. "Being more realistic about chemical 

carcinogenesis." Environ. Sci. Techno!. 21(9): 843- 847. 

Woods,]. ,Jr. 1986. "Building performance assessment." 

Indoor Air. Vol. 6. Evaluations and Conc!IISions for Health Sciences 

and Technology. Swedish Council for Building Research: 

Stockholm, Sweden. 

Working Group on Assessment and Monitoring of Exposure to 

Indoor Pollutants. 1983. Indoor Air Pollutants: Exposure and 

Health Effects. EURO Reports and Studies 78. World Health 

Organization: Copenhagen, Denmark. 
SECTION 4. 

SOURCES AND HEALTH 

EFFEcrS OF SELEcrED 

CONTAMINANTS 

Section 4 provides a discussion of the 

sources and health effects of combustion contaminants, pesticides, microbiological contaminants, formaldehyde, and other volatile organic 

compounds. Each of the sections 

contains exhibits which summarize 

health effects data. In addition, 

Section 4.2 also discusses the regulatory framework for pesticides. 

Table of Contents 

Section 4.1. 

Section 4.2. 

Section 4.3. 

Section 4.4. 

Combustion Contaminants 

Pesticides 

Formaldehyde and Other Volatile 

Organic Compounds 

Biological Contaminants 

List of Exhibits 

Exhibit 4-la. Relationship between carbon monoxide 

(CO} concentrations and carboxyhemoglobin (COHb) levels in blood. 

Exhibit 4-lb. Carboxyhemoglobin levels and related 

heath effects. 

Exhibit 4-2. Controlled studies of the effects 

Exhibit 4-3. 

of human exposure to nitrogen dioxide. 

Effects of exposure to nitrogen dioxide 

plus other gas stove combustion products 

in the home on the incidence of acute 

respiratory disease in epidemiology studies 

49 

66 

85 

102 

54 

55 

56 

involving gas stoves. 59 

Exhibit 4-4. 

Exhibit 4-5. 

Exhibit 4-6. 

Exhibit 4-7. 

Selected studies of human exposure to 

carbon dioxide. 61 

Selected studies of asthmatic subjects 

exposed to sulfur dioxide. 62 

Composition of mainstream and sidestream 

smoke. 63 

Summary of health effects, products, and 

uses of 50 active ingredients in household 

pesticides. 69 

(continued next page) 

m 
Section4 IAQ Reference Manual 

Exhibit 4-8. Selected weighted summary statistics for 

indoor air concentrations of pesticides in 

Jacksonville and Springfield/Chicopee 

(ng/m3). 75 

Exhibit 4-9. Measurements of pesticides in buildings. 79 

Exhibit 4-10. Potential sources of formaldehyde indoors. 91 

Exhibit 4-11. Measurements of formaldehyde 

concentrations in different types of 

II buildings. 92 

Exhibit 4-12. Health effects and sources of selected volatile 

organic compounds. 94 

Exhibit 4-13. Examples of volatile organic compounds 

measurements in indoor air. 96 

Exhibit 4-14a. Examples of selected volatile organic 

compound emission rates for materials 

and typical household products found 

indoors. 99 

Exhibit 4-14b. Additional examples of volatile organic 

compound emission rates for selected 

materials found indoors. 100 

Exhibit 4-15. Molds identified in 68 homes in southern 

California. 110 

Exhibit 4-16. Fungi reported as allergenic. 111 
IAQ Reference Manual 

4.1. COMBUSTION CONTAMINANTS 

There are many possible sources of combustion contaminants in residential and commercial 

buildings. These sources can release contaminants 

which can result in health effects ranging from 

headaches and respiratory tract irritation to death. 

This section provides an overview of health effects 

that have been related to contaminants from 

combustion sources. 

Sources of Combustion Contaminants 

Residential Buildings 

An important concern associated with the use of 

vented and unvented combustion sources is safety 

hazards including fires, burns from contact with hot 

metal surfaces, and poisonings from the accidental 

ingestion of fuel. Fires are also ·a concern with the 

use of tobacco products, hobby, and craft activities. 

A second concern is the release of indoor air contaminants from all fuel-burning unvented appliances and from vented appliances which are improperly installed, poorly maintained, or improperly 

operated. Safety hazards will not be discussed 

further in this section, but potential health effects 

from specific combustion contaminants are summarized below. . 

The primary fuel sources for vented and unvented 

household appliances include natural gas, fuel oil, 

wood, coal, kerosene, and LP gas. Charcoal, newsprint, and other potentially hazardous fuels should 

not be burned indoors. 

Large combustion appliances such as gas, wood, or 

oil-fired central heating systems are used mainly in 

those areas where winter temperatures fall below 

68°F. Smaller appliances such as gas water heaters, 

ranges, and clothes dryers are used all year. Under 

normal conditions the byproducts of these appliances are exhausted outside of the dwelling through 

a flue or chimney. Contaminants can be released 

indoors if there is a blockage in the flue or chimney 

or if the appliance is not vented properly. 

Section 4 

When a combustible fuel burns, heat and light are 

given off along with a broad range of contaminants 

including asphyxiants, irritants, carcinogens, 

teratogens, and mutagens. Carbon monoxide, 

carbon dioxide, water vapor, and the nitrogen oxides 

are the primary contaminants from the combustion 

of natural gas. The combustion of kerosene adds 

sulfur dioxide and inhalable particulates, including 

polycyclic aromatic hydrocarbons to the inventory. 

Tobacco combustion and improperly vented wood 

and coal combustion sources increase the list of 

potential contaminants, and they can release 

aldehydes, a variety of polycyclic aromatic compounds, and other contaminants to the indoor air. 

Tobacco smoke, combustion-related hobby and craft 

activities, and unvented kerosene and gas space 

heaters pose special problems because they release 

contaminants directly into the living space. Tobacco smoke is of particular concern because of the 

many carcinogenic, teratogenic, and mutagenic 

chemicals in the smoke. 

Another potential problem is the release of moisture 

from the combustion of fuel by unvented sources. It 

is possible for water vapor from combustion to 

condense onto window frames and sills and to wet 

surfaces such as wood and insulation which are not 

directly visible. In addition to structural damage 

which can be caused by excessive moisture, these 

wetted materials can provide an excellent substrate 

for microbial growth which can produce a variety of 

effects in sensitive individuals (Section 4.4). 

Commercial Buildings 

In commercial buildings, important sources of 

combustion contaminants include tobacco smoking, 

garages which are attached to working spaces, and 

improperly located air intake vents. Air intake 

vents which are located at ground level or adjacent 

to vehicles or other combustion sources can significantly elevate indoor contaminant levels by transporting contaminants to all areas served by the air 

handling system. 
m 

Sectio11. 4 

Health Effects of Combustion Contaminants 

Symptoms of exposure to combustion contaminants 

can include headaches, decreased alertness, flu-like 

symptoms, nausea, fatigue, rapid breathing, chest 

pain, confusion, impaired judgment, and others. 

Concentrations at which these symptoms will occur 

depend on health status and individual variations in 

sensitivity, so that specific responses at a given 

concentration of a contaminant will vary among 

individuals. 

Each year there are unnecessary deaths due to carbon 

monoxide poisoning from faulty furnaces and other 

combustion sources. When an investigator receives 

a call and the client reports headaches, drowsiness, 

and nausea, especially during the heating season, the 

inspector should be aware of potential problems 

with furnaces or unvented combustion appliances. 

Carbon Monoxide 

Carbon monoxide (CO) is a colorless, odorless, and 

tasteless gas which is produced from the incomplete 

combustion of any carbon-containing fuel. It is a 

chemical asphyxiant that prevents oxygen from 

reaching the body's tissues. Normally, oxygen is 

carried to the body's tissues by hemoglobin in the 

form of oxyhemoglobin (OHb). When CO is 

present, it also combines with hemoglobin to form 

carboxyhemoglobin (COHb). In fact, CO is about 

200 times as effective as oxygen (02

) in combining 

with hemoglobin. This means that when both 0 2 

and CO are present, hemoglobin will not be available to carry 0 2 to the tissues. Once inside the 

body, CO has a half-life of about 5 hrs. 

The health effects of CO exposure are generally 

discussed in terms of the % COHb in the blood 

(Exhibit 4-1a,b). The level ofCOHb is directly 

related to the CO concentration in the air, the 

duration of the exposure, and the activity level of 

the individual. For a given CO dose, the COHb 

level will reach an equilibrium over some period of 

time. As the CO concentration increases or decreases from this point, the COHb level will follow. 

IAQ Reference Manual 

Normally, metabolic processes in the body will 

result in a COHb level of0.5% to 1.0%. Average 

COHb levels among nonsmokers are 1.2%- 1.5%. 

In cigarette smokers this level is about 3% - 4% on 

average, but it may be as high as 10% in heavy 

smokers (WHO, 1987). 

Continuous exposure to 30 ppm CO leads to an 

equilibrium COHb level of 5%; about 80% of this 

value occurs in 4 hours and the remaining 20% over 

the next 8 hours. Continuous exposure to 20 ppm 

CO leads to COHb levels of 3.7% and exposure to 

10 ppm leads to COHb levels of2%. The time for 

equilibrium to be est.ablished is usually 8 hours, but 

this time can be shorter if a person is physically 

active (Doull et al., 1980). 

Carbon monoxide can have detrimental effects on 

the heart, lungs, and nervous system. At COHb 

levels of 10% or less, the major effects are cardiovascular and neurobehavioral. Levels of 2.5% have 

been shown to aggravate symptoms in angina 

pectoris-patients. No adverse health effects have 

been reported below 2.0% COHb; and findings in 

the range of 2.0 to 2.9% are inconclusive (WHO, 

1987). A level of2.5% COHb can result from 

exposure to air with 50 ppm CO for 90 minutes or 

15 ppm for 10 hours (Turiel, 1985). 

Nitrogen Oxides 

There are many chemical species of the oxides of 

nitrogen (NO), but nitrogen dioxide (N02

) and 

nitric oxide (NO) are of greatest concern as indoor 

air contaminants. Nitrogen oxides are produced 

when fossil fuels are burned, and most of the 

emissions occur as NO which can be converted to 

N02

• 

Nitric oxide is a colorless, odorless, and tasteless gas 

that is only slightly soluble in water. The toxicological and health effects data base for NO is 

somewhat limited. There is some evidence of 

inflammatory changes at the cellular level at 2 ppm 

(U.S. EPA, 1982). The formation of methemoglobin (met-Hb), which intereferes with the transport 
IAQ Reference Manual 

of oxygen, has been attributed to the action of 

nitrite ion generated by either NO or N02 in 

solution. Background levels of met-Hb in the blood 

are in the range of0.2 and 0.7% in the absence of 

high NOx levels. Case eta!. (1979) provide evidence 

to show that met-Hb in whole blood can result from 

the direct uptake of NO by hemoglobin in the 

blood. Case eta!. suggest that exposure to NO at 3 

ppm may be physiologically comparable to exposUre 

to CO concentrations of 10 ppm to 15 ppm. 

Nitrogen dioxide is a corrosive and highly oxidizing gas with a characteristic pungent odor which 

has been. described as stinging, suffocating, and 

irritating. The odor threshold has been placed 

between 0.11 ppm and 0.22 ppm by different 

investigators (WHO, 1987). N02 has a pungent 

odor that is described as stinging, suffocating, and 

irritating. The odor threshold has been placed 

between 0.11 ppm and 0.22 ppm by different 

investigators (WHO, 1987). 

N02 is a deep lung irritant which has been shown to 

result in biochemical alterations and histologically 

demonstrable lung damage in laboratory animals as 

a result of both acute and chronic exposures. In 

laboratory animals, biochemical changes occur at 

concentrations as low as 0.2 ppm for 30 minutes 

(WHO, 1987). Long-term animal studies have 

resulted in emphysema-like structural changes and 

increased susceptibility to bacterial lung infections 

(WHO, 1987). Changes at the cellular level occur 

at the time of exposure, but biological effects are 

delayed, which complicates the understanding of 

long term effects. 

In humans, 80% to 90% ofN02 can be absorbed 

upon inhalation. Controlled clinical studies have 

been conducted on susceptible subjects at concentrations in the range ofO.l ppm to 5.0 ppm. Most 

studies show that substantial changes in pulmonary 

function can be demonstrated in normal, healthy 

adults at or above concentrations of 2 ppm (WHO, 

1987). The evidence at lower concentrations is not 

as clear. Asthmatics appear to be responsive at 

Section 4 

about 0.5 ppm, and subjective complaints have been 

reported at that level (WHO, 1987). Below 0.5 

ppm, small but statistically significant, decrements 

in pulmonary function have been reported in 

asthmatics (WHO, 1987). Kagawa and Tsuru 

(1979) reported decrements in the lung function of 

asthmatics at concentrations as low as 0.15 ppm, 

but others have not substantiated these findings. 

Exhibit 4-2 summarizes some of the human exposure studies that have been conducted. 

Epidemiologic studies suggest that children who are 

exposed to combustion contaminants from gas 

stoves have higher rates of respiratory symptoms and 

illness than other children. Nitrogen dioxide 

concentrations in these studies ranged from a low of 

0.005 ppm to about 0.3 ppm (U.S. EPA, 1982; 

WHO, 1987). In general, these results have not 

been supported in studies of adults. Exhibit 4-3 

summarizes some of the studies which have been 

conducted. 

Carbon Dioxide 

Carbon dioxide is a colorless, odorless gas. It is a 

simple asphyxiant, but it can also act as a respiratory 

stimulant. At concentrations above 1.5% respiration is affected, and breathing becomes faster and 

more difficult. Concentrations above 3% can cause 

headaches, dizziness, and nausea. Above concentra,-

tions of 6% - 8% stupor and death can result (NRC, 

1981). 

The lowest level at which effects have been observed 

in both human and animal studies is about 1% 

(U.S. CPSC, 1983). Structural changes in the lungs 

of guinea pigs have been observed along with 

calcification of the kidneys. In humans, effects 

include increases in respiration, changes in blood 

pH and pC02

, and decreases in the ability to 

perform strenuous exercise. The significance of 

these effects is not dear, but a potential increase in 

respiratory and gastrointestinal illness has been 

postulated because these effects were observed in 

submarine crews at concentrations of 0.5%- 1% 

m 
m 

Section 4 

(NRC, 1981). Exhibit 4-4 summarizes the results 

of some studies which have been conducted. 

Sulfur Dioxide 

Sulfur dioxide (502

) is a colorless gas with a strong, 

pungent odor which can be detected at about 0.5 

ppm (NRC, 1981). S02 is very soluble in water and 

exerts its irritant effects primarily on the upper 

respiratory tract, but its site of action depends on 

the presence of particulates, and the rate, depth, and 

type of breathing. 

There is considerable variability in the response to 

so2 among both normal, healthy subjects and 

asthmatics, and this makes it difficult to define a 

no-adverse-effect leveL It has been estimated that 

about 5% of the population may be sensitive to 802 

(WHO, 1987). 

There is good agreement that healthy adults 

experience adverse effects at concentrations of0.75 

ppm to 1.0 ppm, and that asthmatics experience 

increased airway resistance at exposures of about 0.4 

ppm for 10 minutes, both during exercise and at 

rest (WHO, 1987). Discernable effects have been 

reported below that level, but WHO concludes that 

the consequences of those effects are not clear. 

Increased airway resistance has been reported at 

concentrations of 0.1 ppm among mild asthmatics 

who were exercising (Sheppard, 1981a). There is 

also some evidence that sulfur dioxide at levels of 

0.15 ppm appears to act synergistically with ozone 

at levels of0.15 ppm (Kagawa and Tsuru, 1979a). 

Exhibit 4-5 summarizes some of the human exposure studies which have been conducted on asthmatic subjects. 

Particulates 

In addition to the compounds listed above, other 

gases and particulates can be released from indoor 

combustion sources. In homes where wood is 

burned, respirable particulates which include 

IAQ Reference Mamtal 

polynuclear (or polycyclic) aromatic hydrocarbons. 

(P AH) compounds, trace metals, nitrates, and 

sulfates have been measured. P AH compounds and 

chromium (Tu and Hinchliffe, 1983) have also been 

measured from kerosene heaters. 

P AHs are of particular concern because of their 

carcinogenic potentiaL P AH compounds include a 

large number of organic compounds which contain 

two or more benzene rings in their structure. These 

compounds are produced as the result of incomplete 

combustion. They are only very slightly soluble in 

water, but they are very soluble in fat. Although fat 

soluble, these compounds are metabolized rapidly in 

the body and do not tend to bioaccumulate in the 

fatty tissues. It is thought that the metabolites of 

PAH compounds in the body (diol-epoxides) are 

ultimately the carcinogens (WHO, 1987). 

Once P AH compounds enter the air, they can be 

adsorbed onto respirable-sized particles and inhaled 

into the lungs. P AH compounds are also present in 

foods (smoked, broiled, refined) and water; in fact, 

the oral intake of P AH compounds may be much 

higher than the inhaled amount in the general 

population (WHO, 1987). 

P AH compounds have been shown to be carcinogenic in animal tests and mutagenic in short-term 

laboratory rests. Evidence for carcinogenicity is 

supported by epidemiological studies of coke-oven 

workers, coal-gas workers, and workers in aluminum production plants (WHO, 1987). 

Environmental Tobacco Smoke 

Environmental tobacco smoke (ETS) is a term which 

describes the contaminants released into the air 

when tobacco products burn or when smokers 

exhale. The hazards of inhaling mainstream smoke 

(inhaled by the smoker) and sidestream smoke 

(produced at the burning end of the tobacco product) are well documented. The inhalation of ETS is 

known as "involuntary smoking" or "passive 

smoking." 
IAQ Reference Manual 

Studies have shown that cigarette smoke contains 

over 3800 chemical compounds (NRC, 1981); some 

of these compounds are shown in Exhibit 4-6. 

Many of these gaseous and particulate contaminants 

are irritants, and others are carcinogens (43 identified compounds), mutagens, and teratogens. 

Particles in tobacco smoke are especially hazardous 

because they are inhalable (0.1 J.lm to 1.0 J.lm), 

remain airborne for hours after smoking stops, and 

attract radon decay products. Exhibit 4-6 shows 

that concentrations of contaminants in sidestream 

smoke can be several times higher than those in 

mainstream smoke. 

In 1986 two major reports reached similar conclusions about the hazards of passive smoking; these 

-were Environmental Tobacco Smoke. Measuring Exposures and Assessing Health Effects, which was prepared 

by the National Academy of Sciences (NRC, 1986) 

for the Environmental Protection Agency and the 

Department of Health and Human Services, and The 

Health Consequences of Involuntary Smoking, which was 

prepared for the Office of the Surgeon General (U.S. 

DHHS, 1986). 

Both reports concluded that passive smoking 

significantly increases the risk of lung cancer in 

adults. The NAS Report (NRC, 1986) estimates 

that the risk of lung cancer is about 30% higher for 

nonsmoking spouses of smokers than for nonsmokSection 4 

ing spouses of nonsmokers, and that as many as 

20% of lung cancers in nonsmokers may stem from 

exposure to tobacco smoke. The Surgeon General's 

Report (U.S. DHHS, 1986) concludes that simply 

separating nonsmokers from smokers in work 

environments is not sufficient to protect nonsmokers. Although the available studies did not specifically include workplace environments, tobacco 

smoke poses similar risks, regardless of the environment. 

There was also agreement that passive smoking 

substantially increases respiratory illness in children. 

Children who live in households where there are 

smokers are more likely to have respiratory infections (including bronchitis and pneumonia) than 

children in nonsmoking households. Additional 

effects in c~ldren include increases in coughing, 

wheezing, sputum production, slower lung function 

growth, and low birthweight babies in mothers who 

are nonsmokers but are exposed to ETS. The 

prevalence of these effects has been found to increase 

with the number of smokers in the home. 

The evidence for these effects was so strong that the 

National Research Council's Committee on Passive 

Smoking voted to recommend eliminating tobacco 

smoke from any area where there are small children 

or infants. 

m 
m 

Section 4 IAQ Reference Manual 

Exhibit 4·1 a. Relationship between carbon monoxide (CO) concentrations and 

carboxyhemoglobin (COHb) levels in blood. 

14 

13 

12 

11 

10 

9 

- 8 :& 

t: 7 tf. 

A 6 :z: 

0 

u 5 

4 

3 

2 

0 

0 20 40 60 80 

CO, ppm 

100 

Predicted COHb levels resulting from 1- and 8-hr exposures to carbon monoxide at rest (10 1/min) and with light exercise (20 1/min) 

are based on the Coburn-Forster-Kane equation using the following assumed parameters for nonsmoking adults: altitude = 0 ft; intial 

COHb level= 0.5%; Haldane constant= 218; blood volume= 5.5 1; hemoglobin level= 15 g/100 ml; lung diffusivity = 30 ml/torr/ 

min; endogenous rate = 0.007 ml/min. 

SOURCE: Raub,J. A. and L. D. Grant. 1989. "Critical health issues associated with review of the scientific criteria for carbon 

monoxide." Presented at the 82nd Annual Meeting of the Air Waste Management Association. June 25-30. Anaheim, CA. 

Paper No. 89.54.1. Used with permission. 
IAQ Reference Manual Section 4 

Exhibit 4·1 b. Carboxyhemoglobin levels and related health effects. 

%COHb 

IN BLOOD 

80 

60 

40 

30 

7-20 

5-17 

5-5.5 

Below 5 

2.9-4.5 

2.3-4.3 

EFFECTS ASSOCIATED WITH 

THIS COHb LEVEL 

Loss of consciousness; death if exposure continuesa 

Confusion; collapse on exercisea 

Headache; fatigue; impaired judgementa 

Statistically significant decreased maximal oxygen consumption during strenuous 

exercise in healthy young menb 

Statistically significant diminution of visual perception, manual dexterity, ability to 

learn, or performance in complex sensorimotor tasks (such as driving)h 

Statistically significant decreased maximal oxygen consumption and exercise time 

during strenuous exercise in young healthy menb 

No statistically significant vigilance decrements after exposure to cob 

Statistically significant decreased exercise capacity (i.e., shortened duration of exercise 

before onset of pain) in. patients with angina pectoris and increased duration of 

angina attacksh 

Statistically significant decreased (about 3-7%) work time to exhaustion in exercising 

healthy menb 

SOURCE: au.s. EPA (1979); bu.s. EPA (1985) 

m 
Exhibit 4·2. COAtrolled studies of the effects of huata1n exposure to nUrogen dioxide. • 

POLLUTANT CONCENTRATION DURATION OF 

EXPOSURE 

Jlglm' ppm AND ACTIVITY 

9400 5 14 hours 

9400 2 hours+ 

intermittent 

light excercise 

7520 4 75 minutes 

including light 

and heavy 

exercise 

4700 2.5 2 hours 

1880 2hours 

1880 2 hours 

940-9400 0.5-5 3-60 minutes 

940 0.5 2 hours 

NUMBER&: TYPE 

OF SUBJECTS 

8, IIOI:'mal 

11, normal 

25, normal 

23, asthmatic 

8, normal 

16, normal 

8, normal 

63, chronic bronchitic 

25, chronic bronchitic 

10, normal 

7, chronic bronchitic 

13, asthmatic 

PULMONARY EFFECTS 

Increase of Raw during rhe first 

30 minutes of exposure, with decrease 

during tbe following 4 hours. Increase 

of Raw after 6.8 and 14 hours of exposure. Reactivity to acetylcholine 

increased. 

Increase of Raw and decrease in A aDO 2

; 

no further increase when combined with 

200 pg 0 3 per m3 and 13.0 mg 802 per ml 

No effect on SRaw, hearr rate or skin 

conductance 

Increase of Raw, no change ii).Pa02 

otPaC02 

Small changes in PVC 

No increase in Raw 

Increase of Raw at 3.0 mg/m3 

Decrease of Pa02 at 7.5 mg/m3; 

no change at 3.8 mg/m3 

None 

SYMPTOMS REFERENCE 

Not described Beii&Ulmer 

(1976} 

Not described VonNieding 

eta~ (1977) 

Systolic blood Linnet a/. 

pressure different. (1985) 

No Symptoms 

Nor described Beil&Ulmer 

(1976) 

5 subjects Hackney 

complained of chest eta/. {1978) 

tightness 

Not described Beil&Ulmer 

(1976) 

Not described VonNieding 

et al. (1971) 

Not described VonNieding ~ (0, et a/.(1973) :=:J 

7 out ofl3 Kerret al. ~ asthmatic subjects (1979) ~ ~ 

suffered from symptoms ~ 

such as chest tightness 

~ ~ 

~ ...... 
Exhibit 4·2. Controlled studies of the effects of human exposure to nitrogen dioxide• (continued}. ~ lO 

~ POUJ.!l:AID: ~QN!J!NTRATION DURATION OF 

EXPOSURE NUMBER & TYPE '* ~ 

J.lglm3 ppm ANDACfiVITY OFSUBJEcrS PULMONARY EFFEcrS SYMPTOMS REFERENCE ~ 

~ 

~ 

560 0.3 20 minutes at 10, asthmatic N02 plus exercise decrease in None Bauer eta/. " .Iii! 

~ 

rest, followed by FEV1 

10 minutes of !'lites at 

and 

60% 

partial 

TLC. 

expirlltoty 

After exposure 

flow (1984) - moderate at rest, no significant change 

exercise (oral in function 

exposure, 

mouthpiece) 

560 0.3 20 minutes at 13, asthmatic 11% decrease in FEVi Roger 

test, followed by stastically significant . et al. (1990) 

three 10 minute cycles 

of mode!'llte exercise 

(chamber exposure) 

560 0.3 lhour 8, normal Small increase in mean SRaw at Rehnetal. 

2000 1.06 560 llg/m;; no change at 2000 llg/m3 (1982) 

380 0.2 2 hours 31, asthmatic No effect on forced expil'lltoty Fewer symptoms Kleinman 

intermittent function or total respiratory during N02 exposure eta/. (1983) 

light exercise resistance observed with N02 compared to air 

alone. Small exacerbation by 

NO, of meracholine-induced 

bronchoconsrriction in 17 of 21 

subjectS tested 

280 0.15 N02 2 hours 6, normal Decrease in SGaw!Vtg with 0 3 Cough with 0 3 Kagawa& 

290 0.15 o, intermittent for 5 of 6 subjects, and all 6 for and03 + N02

, Tsuru (1979) 

0.15 light exercise combined 0 3 +NO,; vety burnorN02 

N02 +03 small ( <5%) decrease in alone 

SGaw!Vtg with N02 alone in 3 of 

6 subjects 

230 0.12 20minutes 8, normal Normal: small increase in SRaw Bylina a/. 

460 0.24 at rest 8, asthmatic at 460 llg/m3; decrease in SRaw at (1985) 

910 0.48 910 llg/m3

; no change in reactivity c.., 

~ to histamine. Asthmatic: no effects in ~ 

SRaw; increase in reactivity to ~:~· 

~ 

histamine at 910 llg/m; (continued next page) -.!:>. 
Exhibit 4·2. Controlled studies of the eflects of human exposure to nitrogen dioxide• (tOJJtlnedJ. 

POLLUTANT CQNCENl'RATION DURATION OF 

EXPOSURE 

JJ.g/m~ ppm ANDACI1VITY 

190 0.1 1 hour at rest 

190 0.1 1 hour at rest 

190 0.1 1 hour at rest 

190 0.1 1 hour at rest 

190 0.1 1 hour ar rest 

NUMBER & TYPE 

OF SUBJECTS 

20, asthmatic 

20, normal 

9, asthmatic, 

hypersensitive 

to ragweed 

15, normal 

15, asthmatic (atopies) 

7, asthmatic 

20, asthmatic 

PULMONARY EFFECTS SYMPTOMS 

No effect on baseline SGaw, FEV, or None 

V..,.; increased reactivity to carbachol in normal subjects and in 

asthmatics 

No effect on baseline SGaw, FBV1 None 

and V,.. or reactivity to ragweed 

No change in SRaw for either group; None 

no change in sensitivity to 

methacholine 

No change in response to grass pollen 

after exposure to N02 

No effect on SRaw; increased 

sensitivity to carbachol in 

some subjectS 

REFERENCE 

Ahmed eta/, 

{1982) 

Ahmed eta/, 

(1983) 

Hazucha 

eta!. (1983) 

Orehek 

eta!. (1981) 

Orehek 

eta/. (1976) 

a Indication of change only described if statistically significant. Abbreviations are as follow: SRaw, specific airway resisrance; Raw, airway resisrance; SGaw, specific airway conducrance, the 

reciprocal of SRaw; FEV1

, forced expiraroty volume at 1 second; TLC, total lung capacity; Vtg, toral gas volume; V..,. flow volume; Pa02 and PaC02, arterial pactial pressure of oxygen and carbon 

dioxide; AaD02, difference in partial pressure of oxygen in the alveoli as against the arterial blood; FVC, forced vital capacity. 

SOURCE: Air Quality G11idelines f(}f' Europe. Copenhagen, WHO Regional Office for Europe, 1987 (WHO Regional Publications, European Series, No. 23). Used with permission. 
Exhibit 4·3. Effects of exposure to nitrogen dioxide plus other gas stove combustion products in the home on the 

incidence of acute respiratory disease in epidemiology studies Involving gas stoves. 

NO, CONCENTRATION 

Jiglm' (ppm) 

N02 concentration not 

measured at time of study 

N02 concentration nor 

measured in same homes 

studied 

Kitchens: 

9-596 (gas) 

(0.005-0.317) 

11-353 (electric) 

(0.006..0.188) 

Bedrooms: 

7.5-318 (gas) 

(0.004-0.169) 

6-70 (electric) 

(0.003-0.03 7) 

(by triethanolamine 

diffusion samplers) 

Sample of households 24 hr 

average: gas (0.005..0.11); 

elemic (0-0.06); outdoors 

(0.015-0.05); monitoring 

location not reported; 24 hr 

averages by modified sodium 

arsenite; peaks by 

chemiluminescence 

Sample of same households 

as reported above but no 

new monitoring reporting 

STUDY POPULATION 

2554 children from homes 

using gas to cook compared 

to 3204 children from homes 

using electricity; ages 6-11 

4827 children, ages 5-10 

808 6-and-7 -year-olds 

128 children, ages 0-5 

346 children, ages 6-10 

421 children, ages 11-15 

17 4 children under 12 

EFFECTS 

Studies of Children 

Bronchitis, day or night cough, morning cough, cold going to chest, wheeze, 

and asthma increased in children in 

homes with gas stoves 

Higher incidence of respiratory symptoms and disease associated with gas 

stoves after controlling fur confounding 

factors 

Higher incidence of respiratory illness 

in gas-stove homes. No apparent statistical relationship between lung function tests and exposure to NO 2 levels 

in kitthen or bedroom 

No significant difference in reported 

respiratory illness between homes with 

gas and elemic stoves in children from 

birth to 12 years 

No evidence that cooking mode is 

associated with the incidence of acute 

respiratory illness 

REFERENCE 

Meliaet a/. (1977) 

Melia eta/. (1979) 

Florey et al. (1979) 

Companion paper co 

Melia et al. (1979); 

Goldstein et al. (1979} 

Mitchell et al. (1974); 

See also Keller et a/. 

(1979 a,b) 

Keller eta/. (1979b) 

• (continued next page) 
EXhibit 4·3. Effeds of exposure to nitrog~en dioxide plus other gas stove comltustioa products in the bome on the 

incidence of acute respiratory d~isease in epidemiology studies involving gas stoves (tonllllfled}. 

N02 CONCENTRATION 

!lg/m3 (ppm) 

95 percentile of 24 hr indoor 

average; 39-116 J!gfm3 

(0.02-0.06) (gas) vs 

17.6-95.2 J!g/m3 (0.01-

0.05) (electric); frequent 

peaks (gas) > 1100 J!g/m3 

{0.6 ppm); 24 hr by modified sodium arsenite; peaks 

by chemiluminescence 

Preliminary measurements 

peak hourly 470-940 J!g/m3; 

max 1880 J!g/m3(lppm) 

See Mitchell d a/. (197 4) fur 

monitoring 

See Mitchell d a/. (1974) fur 

monitoring 

See Mitchell et al. (197 4) fur 

monitoring 

a Forced expiratory volume at 1 sec. 

b Forced vital capaciry 

SOURCE: U.S. EPA {1982) 

STUDY POPULATION 

8120 children ages 6-10 in 6 different communities; data 

collected on lung function and 

on history of illness 

before the age of 2 

EFFECfS 

Significant association between history 

of serious respitatory illness before age 

2 and use of gas stoves. Small but 

statistically significant decrements in 

lung function tests between lower 

FVC1

, FVC levels from gas 

stove homes compared with children 

from homes with electric stoves 

Studies of Adults 

Adults cooking with gas 

stoves, compared to those 

cooking with electric stoves 

Adults cooking with gas 

. stoves, compared to those 

cooking with electric stoves, 

146 households 

Members of 441 households 

Members of 120 households 

(subsample of 441 households 

above) 

No consistent statistically significant 

increases in respiratory illness 

associated with gas stove usage 

No evidence that cooking with gas is 

associated with an increase in 

respiratory disease 

No significant difference in reported 

respiratory illness among adults in gas 

vs elecrrlc cooking homes 

No significant difference among adults 

in acute respiratory disease incidence in 

gas vs electric cooking homes 

REFERENCE 

Speizeret a/. (1980) 

Spengler, et al. (1979) 

U.S. EPA (1976) 

Keller eta/. 

(1979a, b) 

Mitchell et a!. (197 4); 

See also Keller d a/. 

(1979a, b) 

Keller eta/. 

(1979a, b) 
Exhibit 4·4. Selected studies of human exposure to carbon dioxide. 

EXPOSURE 

CONCENTRATION 

AND DURATION 

4%, 2 wks exposure 

bracketed by two 2-wk 

control periods 

4.2%, 5 days and 11 days; 

3%, 30 days; exposures 

bracketed by two 3-5 day 

control periods 

3%, 5 days bracketed by 

two 5-day control periods 

1.5%, 42 days 

0.7-5%, 50-60 days 

1% and 2%, 30 days 

EXPOSURE 

METHOD 

Chamber, 24 

subjects 

Chamber, 12 

subjects total; 

4 in each of 3 groups 

Space Cabin 

Simulator; 7 

subjects 

Chamber*; 

Submarines (13 

Polaris patrols) 

Chamber, 2 subjects 

in each of 2 exposures 

EFFECTS 

No psychomotor impairment; no decrement in 

complex task performance by healthy young 

subjects 

Increased arterial and cerebrospinal fluid bicarbonate; decreased pH; occasional mild headaches and 

awareness of increased ventilation during first 24-hrs of 

exposure; some ectopic foci noted during excercise but 

small sample size hampered interpretation; decreased 

tolerance to excerdse noted 

No changes in ammonia or titratable acidity; no 

changes in serum electrolytes, blood sugar, serum 

creatinine, or liver function; no significant changes 

in exercise or psychomotor studies 

Increases in respiratory minute volume, tidal 

volume, physiological dead space; decrease in 

viral capacity; respiratory acidosis, increase in 

pC02, decrease in pH; decrease of plasma chloride, 

red cell sodium increase, potassium decrease; decrease 

in plasma calcium metabolism, urine calcium, urine 

magnesium, increase in red cell calcium. In the 

submarine study a decrease in respiratory and 

gastrointestinal disease was noted with decreasing 

C02 (and other pollutants). 

At 2% significant increases inpC02 in blood and 

alveolar air, decrease in ability to perform strenuous 

excerdse; decrease in blood pH, increase in pulmonary 

ventiliation; changes at 1% were not considered to be 

significant; authors conclude that prolonged C02 

exposure causes acidosis, hypodynamia, and fatigue 

but effects are reversible 

*Similar effects were noted in subjects in both the chamber exposure and submarine exposure. 

SOURCE: Adapted from U.S. CPSC (1'984) 

REFERENCE 

Storm and 

Giannetta (1974) 

Sinclair et al. (1969) 

Glatte et.al. (1967) 

Schaefer (1979) 

Zharov et at. (1963) 
Exhibit 4·5. Selected studies of asthmatic su&fects exposed to sulfur dioxide. 

SULFUR DIOXIDE 

CONCENTRATION a 

(ppm) 

1, 3, 5 

1.0 

0.1, 0.25, 0.5 

0.50 

0.5 

0.25, 0.5 

0.30 

DURATION 

OF EXPOSURE 

(min) 

10 

5 

10 

180 

10 

60 

120 

NUMBER AND 

TYPE OF 

SUB]Ecr 

7,normal 

7,atopic 

7' asthmatic 

6, asthmatic 

7, asthmatic 

40, asthmatic 

5, asthmatic 

24, asthmatic 

19, asthmatic 

TYPE OF 

EXPOSURE 

Mouthpiece 

Mouthpiece 

Oral chamber 

Nose clips 

Mouthpiece 

Chamber 

Chamber 

TYPE OF 

ACTIV11Y 

Rest 

Exercise 

Rest 

Exercise 

Exercise 

Exercise 

EFFEcrsb 

SRaw increased significantly at all 

concentrations for asthmatic subjects, 

only at 5 ppm for normal and atopic 

subjects. Some asthmatics exhibited 

marked dyspnea requiring 

bronchodilacion therapy 

SRaw significantly increased in the 

asthmatic group at 0.5 and 0.25 ppm of 

sulfur dioxide and at 0.1 ppm.in the two 

most responsive JUbjecr. At 0.5 ppm 

three asthmatic subjects developed 

wheezing and shortness of breath 

MMFR significantly decreased 2.7%; 

recovery within 30 minutes 

SRaw increases were observed over 

exercise baseline rates for 80% of 

the subjects. 

No sratistically significant changes in 

FVCorSRaw 

No pulmonary effects seen with 0.3 ppm . 

of sulfur dioxide and 0.5 ppm of nitrogen 

dioxide exposure compsred to exercise 

baselin 

ao.l ppm of sulfur dioxide"" 262 J.lg/m3; 0.05 ppm"' 1310 J.!g/m3; 1.0 ppm"' 2620 J.lg/m3

; s.o ppm= 13,100 J.lg/m3; 10 ppm 26,200 ).lg/m3; 50 ppm"' 131,000 ).lg/m3• 

REFERENCE 

Sheppard 

e1 d. (198la} 

Sheppard 

eta/. 

'(1980, 1981b) 

Jaeger 

et al. (1979) 

Linnet a!. 

(1982) 

Linnet al. 

(1982) 

Linnet a/. 

(1980) 

bsignificant increase or decrease noted here refers to "statistically significant" effects, independent of whether the observed effects are "medically significant" or not. Abbreviations are as follows: 

SRaw, specific air way resistance; MMFR, maximum mid-expiratory flow rare; FVC, forced vital capacity. 

SOURCE: World Health Organization (WHO) 1987. Air Q~~ality Guidelines for Europe. Copenhagen, WHO Regional Office for Europe, 1987 (WHO Regional Publications, European Series, 

No. 23). Used with permission. 
IAQ Reference Manual 

Exhibit 4·6. Composition of mainstream ancl slclestream smoke. 

CONCENTRATION, mg/CIGARETI'Ea 

CHARACTERISTIC 

OR COMPOUND 

General characteristics: 

Duration of smoke 

production, s 

Tobacco burned 

Particles, no. per cigarette 

Particles: 

Tar (chloroform extract) 

Nicotine 

Benzo [a} pyrene 

Pyrene 

Fluoranthene 

Benzo [a} fluorene 

Benzo [b/c} fluorene 

Chrysene, benz [a} anthracene 

Benzo [b/k/j} fluoranthrene 

Benzo [e) pyrene 

Perylene 

Dibenz [a, j} anthracene 

Dibenz [a, h} anthracene, 

ideno-(2, 3-ed} pyrene 

Benzo [ghi} perylene 

Anthanthrene 

Phenols (total) 

Cadmium 

Gases and vapors: 

Water 

Carbon monoxide 

Ammonia 

Carbon dioxide 

NO 

Hyclrogen cyanide 

Acrolein 

Formaldehyde 

Toluene 

Acetone 

Polonium-210, pCi 

a Unless otherwise noted 

b Filtered cigarettes 

MAINSTREAM 

SMOKE(l) 

20 

347 

1.05 X 1012 

20.8 

10.2b 

0.92 

0.46b 

3.5 X 10·5 

4.4x w-5 

1.3 X 10-4 

2.70 X 10-4 

2.72 X 10-4 

1.84 X 104 

6.9 X 10·5 

1.91 X 104 

4.9 X 10·5 

2.) X 10·5 

9.0 x 10·6 

1.1 X 10·5 

3.1 x w-5 

3.9 x w-5 

2.2 x w-5 

0.228 

1.25 X 10-4 

7.5c 

18.3 

0.16 

63.5 

0.014 

0.24 

0.084 

0.108 

0.578 

0.04-0.10 

c 3.5 mg in particulate phase; rest in vapor phase 

d 5.5 mg in particulate phase; rest in vapor phase 

SOURCE: NRC (1981) 

SIDESTREAM 

SMOKE(2) 

550 

411 

3.5 X 1012 

44.1 

34.5b 

1.69b 

.1.27 

1.35 X 104 

1.99 ic 104 

3.9 X 10-4 

1.011 x w-3 

1.255 x 10·3 

7.51 X 10-4 

2.51 x w-4 

1.224 X 1Q·3 

2.60 X 104 

1.35 X 10-4 

3.9 x w-5 

4.1 x w-5 

1.04 X 10-4 

9.8 x w-5 

3.9 x w-5 

0.603 

4.5 X 10-4 

298d 

86.3 

72.6 

7.4 

79.5 

0.051 

0.16 

0.825 

1.44 

0.60 

1.45 

0.10-0.16 

Section 4 

RATIO, 

2:1 

27.5 

l.i 

3.3 

2.1 

3.4 

1.8 

2.8 

3.9 

.45 

3.0 

.37 

4.6 

4.1 

3.6 

6.4 

5.3 

5.4 

4.3 

3.7 

3.4 

2.5 

1.8 

2.6 

3.6 

39.7 

4.7 

46.3 

1.3. 

3.6 

0.67 

5.6 

2.5 

1-4 
II 

Section 4 

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Section4 

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Storm, W.F. and C.L. Giannetta. 1974. "Effects of hypercapnia and bedrest on psychomotor performance." Aerospace 

Med. 45(4): 431-433. 

Tu, K.W. and L.E. Hinchliffe. 1983. "A study of particulate 

emissions from portable space heaters." Am. Ind. Hyg. Assoc. j. 

44 (11): 857-862. 

Turiel, I. 1985. Indoor Air Quality and Human Health. Stanford 

University Press: Stanford, CA. 

U.S. Consumer Product Safety Commission (CPSC). 1983. 

"Hazard assessment for pollutants emitted during use of 

kerosene heaters." Kerosene Heater Briefing Package. U.S. CPSC: 

Washington, DC . 
II 

Section 4 

U.S. Department of Health and Human Services (DHHS). 

1986. The Health Consequencef of Involuntary Smoking. U.S. 

DHHS, Office on Smoking and Health: Rockville, MD. 

U.S. Environmental Protection Agency (EPA). 1976. Scientific 

and Technkal Data Base [~tr Criteria and Hazardom Pollutants, 

1975 ERCIRTP Review. EPA-600/1-76-023. U.S. EPA: 

Research Triangle Park, NC. 

U.S. Environmental Protection Agency (EPA). 1979. Air 

Quality Criteria for Carbon Monoxide. EPA-600/8-79-022. U.S. 

EPA: Washington, DC. 

U.S. Environmental Protection Agency (EPA). 1982. Air 

Quality Criteria for Oxides of Nitrogen. EPA-600/8-82-026F. 

U.S. EPA: Research Triangle Park, NC. 

U.S. Environmental Protection Agency (EPA). 1985. "Review 

of the national ambient air quality standards for carbon 

monoxide; final rule. Federal Register. (September 13) 50: 

37484-37501. 

U.S. Environmental Protection Agency (EPA). 1989. lndo~tr 

Air Parts No • .5. "Environmental Tobacco Smoke." U.S. EPA, 

Office of Air and Radiation: Washington, DC. 

von Nieding, G., M. Wagner, H. Krekeler, U. Smidt, and K.. 

Muysel:$. 1971. "Minimum concentrations ofN02 causing 

acute effects on the respiratory gas exchange and airway 

resistance in patients with chronic bronchitis." Internationa!es 

A«hiv fHr Arbtitsmedizin. 27: 338-348. 

von Nieding, G., I.Ollgen, and H. Kreckeler, R. Fuchs, M. 

Wagner, and K.. K.oppenhagen. 1973. "Studies of the acute 

effects ofN02 on lung function: Influence on diffusion, 

perfusion and ventilation in the lungs." lnternationales Archiv 

[HrArkitsmedizin. 31: 61-72. 

von Nieding, G., M. Wagner, H. I.ollgen, and H. Krekeler. 

1977. "Zur akuren Witkung von Ozon auf die Lungenfunktion des Mensc:hen." (Acute effects of ozone on human lung 

function.) VDl-Berichte. 270: 123-129. 

World Health Organization (WHO). 1987. Air Quality 

Guidelinesf~tr Europe. European Series No. 23. WHO: 

Copenhagen, Denmark. 

Zharov, S.G., Y.A. II'in, Y.A. Kovalenko, I.R. Kalinichencko, 

L.I. Kacpova, N.S. Mikerova, M.M. Osipova, and Y.Y. 

Simonov. 1963. "Effect on man of prolonged exposure to 

atmosphere with a high C02 content." Aviation and Space Med., 

Mos(()W. pp. 155-158. 

IAQ Reference Manual 

4.2. PESTICIDES 

Pesticides are chemicals which are used to 

kill or control pests. A pest is any organism that is 

not wanted in a particular location (for example, in 

the home or garden). Termites, cockroaches, fleas, 

rodents, ants, moths, caterpillars, dandelions and . 

other weeds, fungi, bacteria, and molds in buildings 

are examples of pests. Pesticides can be categorized 

into insecticides, herbicides, fungicides, rodenticides, disinfectants or antimicrobial agents, and 

plant growth regulators. 

Because most pesticides are inherently toxic, proper 

use and storage are needed to minimize the potential adverse effects from exposure. Unfortunately, 

consumers tend to be casual about pesticides, 

perhaps assuming they are innocuous since they can 

be purchased in grocery stores, drug stores, and 

hardware stores, and because these products can be 

used without a license or special protective clothing. 

As a result, each year there are cases of poisonings 

by these products which could have been prevented 

through proper use of the products or through the 

application of alternative methods of pest control. 

The use of pesticides is widespread. In 1985 

agricultural uses in the U.S. accounted for 77% of 

the total usage (over 1 billion pounds), and farmers 

spent about $4.6 billion on pesticides (U.S. EPA, 

1987). Nonagricultural uses of pesticides are also 

significant. During 1984, almost 230 million 

pounds of herbicides, insecticides, fungicides, and 

rodenticides were used for nonagricultural purposes 

(U.S. GAO, 1986). Of this total, about 28.7% was 

used in homes and gardens, and the remainder was 

used by industry, government, and commerce. 

According to 1988 estimates, lawn care pesticides in 

the U.S. account for about 67 million pounds of 

active ingredients (about 8% of the total active 

ingredients applied for agricultural purposes), and 

sales have increased to over $700 million annually 

(U.S. GAO, 1990). It is estimated that about 11% 

of single family households use commercial applicators for lawn care. Diazinon and 2,4:D have been 

determined to be the most widely used lawn care 
IAQ Reference Manual 

pesticides; about 6 million pounds of diazinon and 4 

million pounds of 2,4-D are used on residential 

lawns each year (U.S. GAO, 1990). 

Exhibit 4-7 summarizes some general statements of 

the health effects, products, and uses of 50 active 

ingredients in pesticides used in .. and around residences. The actual risks of any of these pesticides 

will depend on a variety of factors including the 

application method, protective measures, and 

ventilation. 

Measured Concentrations In Homes 

A nationwide survey conducted by EPA during 

1976 and 1977 of household pesticide use found 

that about 91% of households use pesticides (U.S. 

EPA, 1987). In the home, pesticides are used to kill 

pests on lawns, trees, shrubs, flowers, and vegetables. Pesticides are almost universally used to 

control termite infestations either before or after 

construction. Pesticides are applied to living spaces 

to rid them of unwanted pests. And, people use 

these products on themselves or their pets to 

prevent the bites of mosquitos, chiggers, flies, ticks, 

fleas, and other pests.· 

In 1985, EPA extended its earlier work by developing a methodology for determining pesticide 

exposures in the general population of the U.S. (U.S. 

EPA, 1990). The methodology used in this study, 

which is known as the Non-occupational Pesticides 

Exposure Study (NOPES), was designed as a means 

of developing estimates of exposure to some of the 

most commonly used household insecticides via air, 

drinking water, food, and dermal contact. In the 

two cities which were studied (Jacksonville, Florida 

and Springfield/Chicopee, Massachusetts), the 

average number of pesticides in the home was 4.2 

for Jacksonville and 5.3 in Springfield/Chicopee. 

Exhibit 4-8 summarizes some of the data (indoor 

concentrations only) from the study. For the 

majority of the 33 target compounds which were 

studied, indoor air concentrations were substantially 

higher than outdoor air concentrations, and personal 

Section4 

air concentrations were usually similar to indoor air 

concentrations. Another finding of this study was 

that seasonal variations existed for many of the 

compounds. This effect appears to be compoUnd 

specific and complex, and it probably reflects the 

interaction of many variables including temperature, patterns of pesticide usage, lise of heating and 

cooling systems, and occupant activities. 

The study also attempted to assess the relative 

contributions of air, food, water, and dermal 

exposure in the two tested cities. Based on limited 

data it appears that exposure from water ingestion 

was negligible. Food appeared to be a dominant 

contributor for some compounds, while air dominated for others. Limited data were collected for 

dermal exposures, and the importance of this 

pathway needs further study. 

Exhibit 4-9 summarizes some additional measurements of pesticides in buildings under different 

conditions. These and other data suggest some 

pesticides which are sprayed will persist for long 

periods at varying concentrations. It is also possible 

for these chemicals, particularly termiticides, to 

migrate up and down through cracks and crevices in 

the building and by air currents. 

Hazards 

Most pesticides are inherently toxic, and the 

potential hazards posed by these chemicals are 

magnified by improper use and storage. During the 

1976 and 1977 nationwide survey, EPA found that 

less than 50% of the people who participated in the 

survey read pesticide labels for application.procedures. About 85% of the people used pesticide 

products without reservation, and only 9% used 

these products with caution (as cited in U.S. 

EPA, 1987). 

In addition to direct exposures as a result of improper use, secondary exposure can also occur when 

people are unknowingly exposed as a result of some 

other activity. For example, pesticides sprayed onto 

fields can drift into homes, schools, or other build-
Sectiotz 4 

ings. Or, if an office area, public building, or home 

is entered before an applied pesticide has cleared, 

people and animals can be exposed to potentially 

hazardous levels. 

Pesticide formulations that have resulted in higher 

concentrations indoors include bug bombs or home 

foggers which are packaged in pressurized containers. These formulations contain pesticides such as 

DDVP (2,2-dichlorovinyl dimethyl phosphate) 

which have a relatively high volatility (vapor 

pressure of1.2 x 10·>mm Hg). Ifhomes are reentered too soon after application, acute health 

problems can occur because initial concentratioqs 

are high (in the range of mg/m3

). 

A widely used product of concern is the pest strip. 

These products contain DDVP as the main ingredient. DDVP, which is an organophosphate pesticide, 

may also be listed in the product literature as 

dichlorvos or Vapona. DDVP is a concern because it 

is classified as a possible human carcinogen, and it 

also causes liver and nerve damage in animals. 

Pesticides from these strips vaporize into the 

surrounding air, and prolonged exposure is likely to 

increase health risks. 

Another concern is the use of use of pest repellents 

which are applied to the skin and clothing as sprays, 

lotions, or sticks. Many of these products contain 

DEBT (diethyltoluamide) which may also be listed 

in the product description as detamide, metaldephene, MGK, or OFF. Regardless of the formulation, DEBT is rapidly absorbed by the skin and into 

the blood system. There have been reports of acute 

neurotoxicity in children exposed to DEBT -containing products, both through heavy normal use and 

accidental ingestion (CU, 1987). Headaches, skin 

irritation, contact dermatitis, and behavioral 

disorders can also result from exposure to DEBT 

(Morgan, 1989). Because of these potential effects, 

the use ofDEET, especially in children should be 

minimized. 

The application of pesticides to control subterranean 

termites is also of concern. Prior to 1987, it was 

lAQ Reference Manual 

thought that when cydodiene termitiddes such as 

chlordane were applied correctly for subterranean 

termite control, the residents of treated homes 

would not be exposed to the pesticide. However, 

studies in 1987 demonstrated that pesticides used 

for subterranean termite control can be found at low 

levels in the air of properly treated homes. As a 

result, EPA has taken a series of actions which have 

led to the withdrawal of cyclodiene termiticides 

from the market. 

Pesticide Formulations 

Pesticides are packaged in a variety of forms including baits, dusts, "bombs," slow-release insecticide 

strips, flea collars, mothballs, dry powders, aerosols 

sprays, solutions, and wettable powders which 

readily mix with water. 

Pesticide products contain both active and inert 

ingredients. Active ingredients are biologically 

active (the pest killer). Inert ingredients are added 

to the formulation to affect its characteristics in 

some w_ay. The term "inert" is misleading because 

it is a legal term, not a chemical term. It does not 

mean that the compound cannot adversely affect 

humans or animals. 

Typically, a pesticide formulation is mostly inert 

ingredients. There are about 1200 inert ingredients 

which can be used to dissolve the pesticide, provide 

a surface on which solids can adsorb, stabilize the 

product, improve handling and application, or 

intensify the killihg power of the pesticide. 

Many insecticides are lipophilic (soluble i~ fat). 

Insecticides are commonly dissolved in petroleum 

distillates which are mixtures of low molecular 

weight aliphatic and aromatic hydrocarbons. 

Toluene or xylene are added to some formulations to 

stabilize the insecticide or make it more emulsifiable. Alcoho!s, glycols, ethers, or chlorinated 

solvents are used as carriers (also called vehicles) for 

insecticides which are not strongly lipophilic. 

These carriers also make the insecticide more likely 

to be absorbed through the skin. 
IAQ Reference Manual 

Classification of Inert Ingredients 

Inert ingredients may be more toxic than some 

active ingredients. However, inert ingredients are 

considered to be proprietaty, and generally are not 

required to be identified by the product label. An 

exception are inerts which EPA classifies as being of 

"immediate toxicological concern" (a list of chemicals including carbon tetrachloride, formaldehyde, 

methylene chloride, and others). Pesticides with 

these chemicals must either be reformulated or have 

a label which states: "This product contains the 

toxic inert ingredient .... " 

In 198 5, EPA established a classification system to 

allow inert ingredients to be regulated according to 

Section 4 

the risks these chemicals pose. List 1 are those 

inerts of immediate toxicological concern; 28 of 

these chemicals are suspected carcinogens. List 2 

includes those which are classified as potenti~ly 

toxic (62 chemicals). List 3 contains those inerts for 

which there is insufficient data for classification 

(over 800 chemicals), and list 4 includes inerts 

which pose a minimal risk (273 chemicals). 

Most of the inert ingredients have not been tested 

for long term effects. Unfortunately, there is 

insufficient information to classify the toxicity of 

about 213 of the inert ingredients, and it is also 

possible for a chemical that has been banned as an 

active ingredient in pesticides to be used as an inert 

ingredient. 

Exhibit 4·7. Summary of health effects, products, and uses of 50 active ingredients in 

household pesticides. 

PESTICIDE COMMON NAME 

(SOME, NOT ALL, 

CONSUMER PRODUCTS) 

Organophosphates 

Acephate (Ortho Orthene Systemic 

Insect Control; Ortho Isorox 

Insect Killer 

Chlorpyrifos (Ortho Flea-B-Gon; 

d-Con Home Pest Control Killer 

Johnsron"s No-Roach, Raid Home 

Insect Killer-prof' nl strength) 

Diazinon (Spectradde products, 

Johnston's No-Roach, Real-Kill 

Ant&Roach) 

Dichlorvos (DDVP) (Black Flag 

Ant & Roach Killer; Raid Wasp & 

Hornet Killer; Bag-A-Bug Gypsy 

Moth Lure; No-Pest Strips) 

Disulfoton (Ortho Systemic 

Rose & Flower Care; Ross Systemic 

Insecticide Root Feeder Cartridges; 

Jobe's Insecticide Spikes; Bonide 

Systemic Granules) 

USES 

INSECTICIDES 

lawns, turf, ornamentals, 

lawns, ornamentals, termites, ants & 

roaches, ticks and chiggers control 

lawns; turf; ornamentals; indoors in 

no-pest strips, flea collars 

indoors and garden 

fruits & vegetables, potted house plants, 

ornamentals 

COMMENTS 

cholinesterase inhibitor; possible human carcinogen 

cholinesterase inhibitor; substitute for chlordane; 

applied in granular form outdoors, as aerosols and 

emulsifiable concentrates indoors; dietary exposure 

exceeds guidelines due to widespread use 

cholinesterase inhibitor; one of the most widely used 

chemicals in consumer pesticides; applied as aerosols 

and in granular form 

cholinesterase inhibitor; possible human carcinogen; 

protective clothing must be worn during use; 

primarily used in "no-pest scrips" by consumers to kill 

flying insects 

cholinesterase inhibitor; > 2% formulations requite 

certified applicator 

(continued next page) 
Se~tiotl4 IAQ. Referen~e Manual 

Exhibit 4•7. Summary of health effects, products, and uses of 50 active Ingredients In 

household pesticides {continued}. 

PESTICIDE COMMON NAME 

(SOME, NOT All, 

CONSUMER PRODUCTS) 

Malathion (Bonide Rose Spray; Ortho 

Ocduu:d Spray; Johnston's NoRooch Spray; Gro-W ell Fruit Tree 

Spray; Sergeant's Flea & Tick Dip 

for Dogs) 

Naled (Bansect Flea & Tick Collars; 

_$ergeant's Flea & Tick Collars) 

Pyrethroids 

Allethrin (d-Con Home Pest 

Control; Gro-Well Ant and Roach 

Spray; Sergeant's Indoor Fogger; 

Sergeant's Skip-Flea Shampoo; 

Raid Yard-Guard Outdoor Fogger) 

Permethrin (Black Flag Roach Ender; 

Raid FumigatOt' Cake; Sudbury Flea 

&Tick Dip) 

Phenothrin (Ortho Home & Garden 

Insect Killer; Combat Flying 

Insect Fogger; d-Con Flea & Tick 

Killer II; Raid Yard Guard Outdoor 

Fogger III) 

Resmerhrin (d-Con Wasp & Hornet 

Killer; Raid Yard Guard Outdoor 

Pogger, Formula II; Rid-A-Bug Flea 

& Tick Killer; Ortho Flea-B-Gon Flea 

Killer) 

Tetramerhrin (Cotpbat Flying Insect 

Killer; Raid Flying Insect Killer; 

Ortho Home & Garden Insect Killer; 

Raid House & Garden, Formula II) 

Rotenone 

(Orrho ,Rotenone Dust; Orrho 

Tomato & Vegetable Insect Spray; GroWell Organic Insecticide; Sergeant's 

Ear Mite Preparation for Ca.ts) 

USES 

INSECTICIDES (continued) 

ornamental t~s & shrubs, orchards, pet 

products, household insecticides 

pet flea collars, mosquito control, 

orchards & vegetables 

house &; garden insecticides, per 

products 

same as. above 

same as above 

same as above 

same as above 

frult & vegetable gardens, pet products, 

human lice & chigger dusts, fish poison 

COMMENTS 

low toxicity cholinesterase inhibitor; 

cancer srudies are not adequate and 

will be redone; widely used in home products; 

one of GAO's top 10 home chemicals; also used 

in mosquito control programs; banned by Florida in 1986 

for community mosquito control . 

metabolizes to dichlorvos 

synthetic pyrethrin of low toxicity; 

widely used by consumers and 

professionals to control household pests; 

also used by professionals as a termiticide 

synthetic pyrethrin; possible human carcinogen 

synthetic pyrethrin 

synthetic pyrethrin 

synthetic pyrethrin; possible human carcinogen 

human exposure has not been measured; widely used; 

viewed as comparatively safe, bur not fully tested; 

natural botanical derivative 
IAQ Reference Manual Section 4 

Exhibit 4·7. Summary of health effects, products, and uses of 50 active ingredients in 

household pesticides (continued}. 

PESTICIDE COMMON NAME 

(SOME, NOT ALL, 

CONSUMER PRODUCTS) 

Pyrethrins 

(Raid Flying Insect Killer; Black 

Flag Triple Action; Raid House & 

Garden; Hot Shot Fly & Mosquito; 

Hartz 2 in 1 Flea & Tick Dip for 

Dogs/Cats; A-200 Pyrinate AntiLice Shampoo) 

Carbamates 

Bendiocarb (TAT Anr Traps; Raid 

Traps) 

Carbaryl (Specrracide Sevin Liquid, 

Ortho Sevin Garden Dust, Sergeant's 

Flea and Tick Powder for Dogs, 

Bonide Rose Spray) 

Propoxur (Black Flag Ant & Roach 

Killer; Combat Ant & Roach Instant 

Killer; Orcho Horner & Wasp Killer; 

Sergeant's Flea & Tick Spray; Daltek 

Flea & Tick Collars) 

Chlordane 

Dicofol (Bonide Rose Spray; 

Ortho Isotox Insect Killer; 

Prate Noculace Insect Spray) 

Lindane (HCH, BHC) (Kwell shampoo; 

Roxo Borerkill; Gro-W ell Borer 

Killer; Orcho Lindane Borer and 

Leaf Miner Spray) 

Methoxychlor (Black Flag Insect 

Spray; Orcho Tomato & Vegetable 

Dust; Sergeant's Cat Flea Powder; 

Gro-W ell Fruit Tree Spray) 

USES 

INSECTICIDES (continued) 

house & garden products, pet products, 

anti-lice shampoos 

ant, roach, and flea control indoors; 

ornamentals; insecticide-impregnated 

shelfpaper; turf 

fruit & vegetable gardens; turf, 

pee produces-flea collars and 

dusts; ornamentals; indoor use 

indoor use; ant & roach killers; 

per products; mosquito foggers 

terruite control 

vegetable gardens, indoor 

insect & mite control 

house & garden use; shelf 

paper; anti-lice shampoos; 

pet produces; termite control 

house & garden use; pet 

products 

COMMENTS 

viewed as comparatively safe, but not fully rested; 

natural botanical derivative 

cholinesterase inhibitor; widely used by professionals for 

control of indoor pests; applied as a dust or wettable 

powder; consumer exposure occurs almost entirely from 

home uses; EPA recommends application of ready-to-use 

products by professional only 

low toxicity cholinesterase inhibitor; commonly used 

insecticide for control of pests indoors and outdoors; 

applied to leaf surfitces as wettable powder and dust; 

should not be used on pregnant dogs because it may cause 

birch defects in dogs 

probable human carcinogen; cholinesterase inhibitor; 

toxic residue for weeks after application; infants crawling 

on treated surfaces may be exposed dermally; widely used 

probable human carcinogen; cancelled in 1988; product 

may still be stored because shelf supplies were allowed co 

be depleted; most widely used termitidde befOre 

withdrawal; applied as a liquid poured or in jeered into 

the soil around the building foundation 

possible human carcinogen; home use is not large; 

DDT & related compounds may he present as 

contaminants 

possible/probable human carcinogen; use against termites 

(house) is restricted to unoccupied buildings; exposure 

from Kwell shampoo can be high if used roo often or 

lefr on skin too long 

many toxicology clara gaps; furcnula used to control 

pantry pesrs; primarily applied as a liquid spray, widely 

used for mosquito and fly control outdoors 

(continued next page) 

II 
m 

Section 4 IAQ Reference Manual 

Exhibit 4•7. Summary of health effects, products, and uses of SO active ingredients in 

household pesticides (fOJJfinuedJ. 

PESTICIDE COMMON NAME 

(SOME, NOT ALL, 

CONSUMER PRODUCI'S) 

Melhoprtme 

(Dexol Red Spider & Mite Killer; 

Dexol White Fly & Mealy Bug 

Spray; Spectmcide Professional 

Flea Control; Raid Flea Killer PIus) 

MGK 264 (BlackJack Ant & Roach 

Killer; d-Con Flea & Tick Killer; 

Ham: 2 in 1 Flea & Tick Dip for 

Dogs/Cats; Orrho High Power Indo 

Fogger; Raid Pogger) 

Piperonyl butoxide (Raid House & 

Garden, Formula II; Orrho Tomato & 

Vegetable Insect Spray; Hartz 2 in 

1 Rid Flea Shampoo for Dogs) 

Benomyl (DuPont Tersan 1991; GroWell Benomyl Systemic Fungicide) 

Captan (Ortho Tomato & Vegetable 

Dun; Orrho Otthocide Garden 

Fungicide; Bonide Rose Spray; 

Gro-W ell Fruit Tree Spray) 

Chlorothalonil (Ortho Liquid Lawn 

Disease Control; Orrho Multi-Purpose 

Fungicide; Ortho Vegetable Disease 

Control) 

Folpet (Ortho Phalran Rose & Garden 

Fungicide) 

Maneb (Dexol Maneb Garden Fungicide; 

Security Maneb Spray) 

USES 

INSECTICIDES 

cockroach, mosquito, and flea 

control; control of mealy bugs 

& spider mites on house plants 

house use; pet products 

house & garden use; pet 

products 

FUNGICIDES 

vegetables & ornamentals; 

lawn& rurf 

fruit, vegetables, ornamentals; 

turf; house plants; paints; materials; 

(pets, human anti-fungal shampoos; 

cosmetics)* 

ornamentals, tnrf, lawns; fruits, 

vegetables; paint & grout additive; 

wood preservative 

paints; plastics 

ornamentals & vegetable 

gardens 

COMMENTS 

considered to be quite safe; chronic data gaps 

inhalation & contact exposure could be significant; widely 

used 

widely used; direct inhalation is an important 

exposure route 

possible human carcinogen; accounts for 55% of fungicides worldwide; many fungi are resistant to it 

probable human carcinogen; EPA estimates shampoos 

may pose cancer risk of 1 in 10,000; registration 

cancelled fur many commercial food crops but home 

pesticide use is permitted; widely used by consumers 

and professionals; usually applied as a wettable powder 

probable human carcinogen; insufficient data on home use 

probable human carcinogen; cancelled on ornamentals 

and in wood preservatives; > 20% formulations cannot be 

sold to consumets; protective clothing required 

erhylthiourea, a metabolite, is a probable human 

carcinogen, teratogen, antithyroid agent, and possibly, a 

mutagen 
IAQ Reference Manttal Section 4 

Exhibit 4·7. Summary of health effects, products, and uses of 50 active ingredients in 

household pesticides (continued}. · 

PESTICIDE COMMON NAME 

(SOME, NOT ALL, 

CONSUMER PRODUCfS) 

Sulfur and Lime Sulfur (Pic Sulfur 

Candle, fumigant; Ortho Orthorix 

Spray Fungicide; Safer Garden 

Fungicide and Miticide) 

TBTO (Cuprinol Stain&:. Wood 

Preservative; Cabot's WoodPreserving Stain) 

Triforine (Ortho Funginex Rose 

Disease Control; Ortho Orrhenex 

Insect &:. Disease Control) 

Zineb (Security Zineb Spray) 

Deer (Off!; Mu.skol Spray; Cutrer 

Stick and Cutter Cream; Blockade 

flea products) 

toxicology 

Metaldehyde (~narol Snail &:. Slug 

Killer Pellets; Ortho Bug-Geta &:. BugGeta PillS; Deadline Slug&:. Snail Bait) 

Methiocarb (Ortho Slug-Geta) 

Ammonium Sulfamate (Ortho Brush 

Killer A; Science Ammate Weed &:. 

Brush Killer) 

Benefin (Greenview Crabicide; 

Rockland Balan Crabgrass Preventer) 

2,4-D (Ortho Weed-B-Gon; Scott's 

Spot Dandelion Control; hundreds 

of others) 

DCP A (Gro-Well Garden Weeder; Ortho 

Garden Weed Preventer; Gro-W ell 

Pre-Vent Weed Control) 

USES 

FUNGICIDES (continued) 

bedbug control, fumigants; insect 

&:. mildew control on ornamentals 

and food plants 

anti-fouling agent in matine paints; 

wood preservatives 

ornamentals &:. vegetables 

ornamentals, fruits, vegetables 

OTHER INGREDIENTS 

insect repellent; pet flea repellent 

slug &: snail baits 

HERBICIDES 

brush control 

crabgrass control 

weed killer; lawns &:. gardens 

lawn &:. garden crabgrass &:. 

weed control 

COMMENTS 

low toxicity, but may cause irritation 

limited data; skin absorption may be significant 

complete data base 

limited data 

rapid skin penetration &: blood absorption; acute 

neurotoxicity possible in children; widely used, 

but long-term toxicity is not known; additional 

data being generated 

inhalation &:. skin absorption not a concern 

complete data base 

many data gaps 

widespread use in lawn care; limited data; new .data 

being generated 

commonly used lawn herbicide for the control of 

broadleaf weeds and dandelions; primary application is 

in granular lawn fertilizers; professionals commonly 

apply as a spray; cancer and epidemiology studies are 

being developed and reviewed 

widespread use in lawn care; considered to be low in 

toxicity; some data gaps 

(continued next page) 

m 
II 

Section 4 IAQ Reference Manual 

Exhibit 4·7. Summary of health effects, products, and uses of 50 active Ingredients in hous~hold pesticides (tontinueiiJ. 

PESTICIDE COMMON NAME 

(SOME, NOT ALL, 

CONSUMER PRODUcrS) 

Dicamba (Spectracide lawn Weed 

Killer; Scott's Spot Dandelion 

Control) 

Fluazifop (Fluazifop-butyl) 

(Ottho Grass-B-Gon-Grass Killer) 

Glyphosate (Ottho Kleenup Spot Weed 

& Grass Killer; Roundup L & G Lawn 

& Garden Formulation; Ortho Fence & 

Grass Edger II) 

Mecoprop (MCPP) {Orrho Weed-B-Gon; 

Spectracide lawn Weed Killer; GroW ell Dandelion & BroadleafWeed 

Killer; Dexol Spot Weeder) 

Methanearsonates (Gro-W ell Crabgrass 

Killer; Ottho Crabgrass & Dandelion 

Killer; Orrho Crabgrass Killer, 

Formula II) 

Pendimethalin (Scott's lawn Pro 

Step 1 Crabgrass Preventer Plus 

Fettilizer) 

Prometon (Gro-W ell No-Gro Weed & 

Grass Killer; Ortho Triox Vegetation 

Killer) 

Simazine {E-Z Cor; Algi-Kleer) 

Triclopyr (Ortho Brusb-B-Gon; Orcho 

Poison Ivy and Poison Oak Killer) 

Trifluralin {Ottho 3-Way Rose & 

Flower Care; Greenview Preen) 

USES 

HERBICIDES 

lawns& turf 

grass control along walks & in gardens 

lawn & garden weed control 

broadleaf control in lawns 

lawn & turf; crabgrass control 

grass &: weed control in lawns 

&:gardens 

grass &: weed conrrol in lawns 

&:gardens 

algae control. in fish ponds, aquaria; 

orchard &: berry-patch weed control 

brush & poison ivy/oak control 

control of grasses &: broadleaf weeds 

in lawns, turf, flower, &: orchards 

* Use of fungicides on humans and pets is regulated by FDA; 

these uses are nor under the purview of FIFRA. 

COMMENTS 

lack cancer study in second species; relatively low toxicity 

minimal data. gaps 

dermal &: eye exposure a concern during 

application & mixing; protective clothing required 

for agricultural uses but not home use; home-use 

data is limited 

widely used; many data gaps 

inhalation &: dermal exposure is a concern; 

limited data 

considered to have low toxicity; limited 

home-use data 

limited data. 

potential exposure in treated pools; limited data 

limited data 

possible nitrosamine contaminant; 

manufacturers are required to guarantee 

minimal levels of contaminant 

SOURCE: Format adapted from Consumers Union {1987); health effects information revised by the U.S, EPA Office of Pesticide Programs (1990). 
Exhibit 4·8. Selected weighted summary statistics for indoor air concentrations of pesticides in Jacksonville and ~ Springfield/Chicopee (ng/m3).a IC 

):1;:1 

'§.. (!). 

PESTICIDE SUMMER SPRING WINTER SUMMER SPRING WINTER ~ ~ 

~ 

~ Jacksonville Springfield/Chicopee ~ 

~ - Gamma-BHC mean 20.2 13.4 6.0 * 0.5 9.5 

max 245.0 1530.0 75.0 5.0 118.0 

Chlorothalonil mean 5.3 2.2 6.7 * 0.1 0.1 

max 264.0 51.0 523.0 35.0 9.2 

Heptachlor mean 163.4 153.9 72.2 * 31.3 3.6 

max 1600.0 2370.0 684.0 253.0 152.0 

Ronnel mean 0.2 0.0 0.0 * 0.2 0.0 

max 20.0 0.0 0.0 8.8 4.8 

Dichlorvos mean 134.5 86.2 24.5 * 4.3 1.5 

max 2280.0 2910.0 1090.0 324.0 158.(1 

Alpha-BHC mean 1.2 1.2 1.1 * 0.2 0.0 

max 32.0 28.0 32.0 8.0 0.0 

Hexachlorobenzene mean 1.3 0.4 0.3 * 0.0 0.1 

max 21.0 7.7 5.3 0.0 5.7 

Chlorpyrifos mean 366.0 205.4 120.3 * 9.8 5.1' 

max 2170.0 4350.0 1043.3 252.0 291.0 

Aldrin mean 31.3 6.8 6.9 * 0.0 0.3 

max 1840.0 320.0 106.0 0.0 3.9 

Dacthal mean 0.2 0.0 0.3 * 1.6 0.3 

max 12.0 0.0 3.2 32.0 15.0 ~ 

~ 

s· 

(continued next page) ~ 

-!:>. 

El 
ExhUtit 4·8. Selected weighfe,d summary statistics for indoor a~ir concentrations of pesticides in Jacksonville and 

Springfield/Chicopee (ng/m3) 8 (foafin.uedJ. 

PESTICIDE SUMMER SPRING WINTER SUMMER SPRING WINTER 
Exhibit 4·8. Selected weighted summary statistics for Indoor air concentrations of pesticides in Jacksonville and ~ Springfield/Chicopee (ng/m3

)• (fonflnuedJ. lC 

)::1 

~ <II 

- PESTICIDE SUMMER SPRING WINTER SUMMER SPRING WINTER ~ ~ 

~ 

Jacksonville Springfield/Chicopee f 

t 

Chlordane mean 324.0 245.6 220.3 * 199.4 34.8 

max 3020.0 4380.0 2050.0 1700.0 735.0 

4,4'-DDT mean ** 1.0 0.5 * 0.0 0.6 

max 13.0 11.0 6.3 15.0 

4,4'-DDD mean ** 0.0 0.0 * 0.0 0.0 

max 0.0 0.0 0.0 0.8 

4,4'-DDE mean ** 0.6 0.2 * 0.9 0.6 

max 15.0 8.8 8.4 3.5 

Orrho-phenylphenol mean 96.0 70.4 59.0 * 44.5 22.8 

max 1040.0 1240.0 1440.0 560.0 286.0 

Propoxur mean 528.5 222.3 162.5 * 26.7 17.0 

max 7920.0 2030.0 1370.0 505.0 669.0 

Bendiocarb mean 85.7 5.5 3.4 * 0.2 0.4 

max 1500.0 89.0 68.0 10.0 38.0 

Atrazine mean 0.0 0.0 0.0 * 0.0 0.0 

max 0.0 0.0 0.0 0.0 0.0 

Diazinon mean 420.7 109.2 85.7 * 48.4 2.5 

max 13700 2370.0 1080.0 1810.0 27.0 

c., 

a 

~· 

(continued next page) 1:1 

..... 

El 
Exhibit 4·8. Selected wei~ghted summary statisti~cs for in,door air coDCentrations of pesticides i1n Jacksonville C11Dd 

Springfield/Chicopee (ng/m3)a (continuetll. 

PESTICIDE SUMMER SPRING 

Jacksonville 

Carbaryl mean 68.1 0.4 

max 3190.0 97.0 

Malathion mean 20.8 15.0 

max 1890.0 240.0 

Resmethrin mean 0.1 0.0 

max 19.0 0.0 

a ng/m3 ; nanograms per cubic meter (1000 ng 1Jlg) 

*These pesticides were not sampled during the summer in Springfield/Chicopee. 

**These pesticides were not sampled during the summer in Jacksonville. 

SOURCE: U.S. EPA(l990) 

WINTER SUMMER SPRING WINTER 

Springfield/Chicopee 

0.0 * 0.3 0.0 

0.0 16.0 0.0 

20.4 * 5.0 0.0 

1660.0 275.0 0.0 

0.0 * 0.0 0.0 

0.0 0.0 0.0 
IAQ Reference Manual 

Exhibit 4·9. Measurements of pesticides in buildings. 

PESTICIDE 

Diazinon (emulsion) 

Bendiocarb (0.5% wettable powder) 

Carbaryl (5% dust) 

Acephate (1% suspension) 

Diazinon (1% suspension) 

Chlorpyrifos (0.5% suspension) 

Fenitrothion (1.0% suspension) 

Propoxur 

CONCENTRATION 

RANGE, !..lg/m3 

38.4 

9.7 

7.1 

0.9 

1.0 

0.4, 0.5 

0.6, 0.4 

7.7 

ND* 

1.3 

0.2 

0.01 

1.3 

2.9 

0.3 

1.6 

0.6 

0.4 

1.1 

1.1 

0.3 

3.3 

1.1 

0.5 

15.4 

2.7 

0.7 

COMMENTS 

Dormitory 

treatment room, day of treatment 

treatment room, 7 days later 

treatment room, 21 days later 

adjacent room, day of treatment 

adjacent room, 21 days later 

rooms above and below treatment 

room; day of treatment 

rooms above and below; 21 days later 

Dormitory 

day of treatment 

3 days later 

day of treatment 

1 day later 

3 days later 

day of treatment 

1 day later 

3 days later 

day of treatment 

1 day later 

3 days later 

day of treatment 

1 day later 

3 days later 

day of treatment 

1 day later 

3 days later 

day of treatment 

1 day later 

3 days later 

Section 4 

REFERENCES 

Leidy eta/. (1982) 

Wright eta/. (1981) 

(continued next page) 
Sectiotz 4 IAQ Reference Manual 

Exhibit 4·9. Measurements of pesticides in buildings (1onfinued). 

PESTICIDE 

Chlordane (1% emulsion) 

Termide11 (0.5% chlordane 

+ 

0.25% heptachlor) 

gamma-HCH (17 houses) 

Dieldrin (16 houses) 

Chlordane/Heptachlor 

Aldrin 

Chlorpyrifos 

Diazinon 

CONCENTRATION 

RANGE, J.lg/m3 

2.75 .±. 1.33 

3.32 ± 1.38 

5.01.±. 0.97 

4.48 .±. 1. 70 

5.81 ± 5.01 

2.77 .±. 2.69 

1.41 .±. 0.64 

1.80± 1.47 

1.00 .±. 0. 70 

0.01 - 2.9; 0.56 (mean) 

0.01- 0.5; 0.11 (mean) 

3.00-87.7 

1.40- 1.55 

0.51- 34.62 

0.51- 34.62 

COMMENTS 

6 Single-family homes 

3 houses, day of treatment 

6 mos. later 

12 mos later 

3 houses, day of treatment 

6 mos later 

12 mos later 

3houses, day of treatment 

6 mos later 

12 mos later 

carpet swatches were contaminated 

with pesticide after application 

17 houses 

concentrations in interior areas other 

than roof voids, from 1 to 10 years 

after treatment 

4368 Houses 

results for initial sampling; considerable 

variability on resampling; time between 

application and sampling not given 

0.89% > NAS guideline 

0 > NAS guideline 

0.02% > NAS guideline 

no NAS guideline 

REFERENCES 

Wright & Leidy 

(1982) 

Dobbs & Williams 

(1983) 

Olds (1987) 
IAQ Reference Manual Section 4 

Exhibit 4·9. Measurements of pesticides in buildings (fontinued). 

PESTICIDE 

Chlordane 

* ND - not detected 

** NDL - nondetectable level 

CONCENTRATION 

RANGE, flg/m3 

NDL** 

• slab (ducts in slab) 

• crawl space 

• slab (ducts in attic) 

NDLto~2 

• slab (ducts in slab) 

• crawl space 

• slab (ducts in attic) 

>2 to~5 

• slab (ducts in slab) 

• crawl space 

• slab (ducts in attic) 

~5 

• slab (ducts in slab) 

• crawl space 

• slab (ducts in attic) 

HEALTH EFFECTS OF PESTICIDES 

Poisonings 

During 1987, 57,430 cases of pesticide 

exposure were reported to poison control centers, 

and 98% of these were due to accidental exposures. 

Insecticides accounted for about 66% of the total 

cases, followed by rodenticides (17%), moth 

repellents (7.7%), herbicides (7.2%), and fungicides 

COMMENTS 

5038 Houses 

%of houses with identical level 

(time between treatment 

and sampling not given) 

REFERENCES 

Lillie & Barnes 

(1987) 

Time of Treatment 

preconstr. 

77% 

84% 

47% 

17% 

11% 

53% 

5% 

4% 

0 

1% 

1% 

0 

postconstr. 

28% 

5% 

96% 

49% 

48% 

4% 

18% 

28% 

0 

5% 

19% 

0 

(2.3%). About 60% of the cases involved children 

less than 6 years of age. (Blondell, 1989) 

During the period 1980 to 1985, at least 46.5% of 

the accidental pesticide related deaths in the U.S. 

occurred in the home (40.9% of the locations were 

not specified). Organophosphate insecticides were 

responsible for about 32% of the deaths. Seventeen 

percent of the victims were under the age of 5; 

29.6% were between 25 and 44 years of age; 23.9% 

m 
Section 4 

were between 45 and 64 years of age; and 22% were 

over the age of 65 (Blondell, 1989). 

Pesticide poisonings are the second most common 

source of childhood poisonings. A new trend to 

develop products with less offensive odors makes 

poisonings more likely. Consumers should know 

that the availability of these products is increasing 

in the marketplace, and the absence of this warning 

signal may lull users into a false sense of security. 

Prevention of poisoning through proper selection, 

storage, and use of pesticides is the key to reducing 

adverse health effects. Although medical treatments 

can counteract the pesticide poisoning, they apply 

to acute exposures and many treatments pose risks 

to the health of patients. 

Symptoms of Acute and Chronic Exposures 

Many pesticides (for example, organophosphates and 

organochlorines) affect more than one organ system 

and produce a variety of symptoms which can 

progress rapidly from mild to fataL Some pesticides 

produce reactions almost immediately while others 

result in delayed reactions. The specific symptoms 

that will result from a given exposure situation 

depend on the pesticide and its site of action, the 

dose received, and the sensitivity of the exposed 

individual. It should be noted that some individuals may be more sensitive to pesticides and other 

chemicals than the general population. 

Irritation of the skin, eyes, and respiratory tract are 

common effects of pesticides. Skin exposure can 

result in itching, redness, swelling, blistering or an 

acne-like condition. The mucous membranes and 

the lining of the respiratory tract are especially 

sensitive, and inhaled pesticides can produce 

stinging, swelling, difficulty breathing, and increased mucous production. Flu-like symptoms are 

common. 

Gastrointestinal tract symptoms include salivation, 

nausea, vomiting, abdominal cramps, and diarrhea. 

Nervous system effects include fatigue, headache, 

IAQ Reference Manual 

dizziness, weakness, behavioral and mood disturbances, decreased or blurred vision, tingling and 

numbness of the extremities, tremors, pinpoint and 

nonreactive pupils, paralysis, coma, and death. 

Shock, hypertension, and arrhythmias of the heart 

can result when the cardiovascular system is 

affected. The kidneys and blood can also be damaged. 

Some pesticides are sensitizers, and they result in 

more severe and potentially life-threatening reactions with subsequent exposures to small amounts. 

Chronic exposure to some pesticides can result in 

damage to the liver, kidneys, and nervous system. 

Typical clinical findings include muscular weakness, 

and numbness and tingling of the extremities 

(peripheral neuropathy). 

A history of recent pesticide use and the presence of 

these types of symptoms should suggest the possibility of pesticide poisoning. 

Health Effects Data 

There are significant gaps and uncertainties in the 

health effects data base. For example, the lowest 

dose that results in acute effects is not known with 

certainty for most pesticides. In addition, the 

effects of chronic exposures and the doses at which 

these effects occur are not well documented. 

Deficiencies in the data base for long-term health 

effects are also important because of the potential 

exposure to pesticides in schools, parks, retail stores, 

mass transit vehicles, or other public areas; and 

nonoccupational exposures, in general, are poorly 

characterized. 

Of particular concern are the carcinogenic, mutagenic, and teratogenic potential of pesticides. The 

data base for assessing these effects is inadequate to 

support definitive conclusions, but some animal and 

short-term tests suggest that many pesticides may 

be carcinogenic or genotoxic (Borzsonyi et al., 1984; 

U.S. GAO, 1986; AMA Council on Scientific 

Affairs, 1988). 
IAQ Reference Manual 

In addition to the animal and cell studies, there are 

epidemiologic studies of occupationally exposed 

workers which suggest that subacute poisoning does 

occur as a result of continuous low-level exposure 

(Sharp et al., 1986; Xue, 1987; Stokes and Brace, 

198S). · Also, a study by Lowengart eta/. (1987) 

underscores the concern for health effects in children 

resulting from of home pesticide use. Although this 

study was not designed to evaluate the relationship 

between household chemicals and cancer, the data in 

the study showed an association between pesticide 

exposure in children and infants and childhood 

leukemia. However, other studies confirming this 

work are needed. 

REGULATORY FRAMEWORK 

Federal 

EPA regulates pesticide formulations 

under the Federal Insecticide, Fungicide and 

Rodenticide Act (FIFRA) of 1947 and its amend., 

ments. All pesticides must be registered with EPA 

before the products can be sold or distributed. Each 

product must have a label which identifies the EPA 

registration number, ingredients, proper use, health 

effects, warnings, and cautions. 

Registration is based on an overall risk/benefit 

standard which requires the EPA to consider the 

economic, environmental, and social costs and 

benefits of pesticide use. Pesticides can be registered if the pesticide performs its stated function 

when used according to label instructions, without 

posing an unreasonable risk of adverse effects on 

human health or the environment. EPA has a 

Science Advisory Panel of outside experts which 

reviews major pesticide decisions or regulations. 

The roxicological data that are required for registering pesticides used in and around the home depends 

on the nature, magnitude, and duration of expected 

exposures if the pesticide labels are reasonably 

followed. Some basic data such as acute toxicity 

studies for labeling the pesticide formulation are 

required routinely. Longer term studies such as 

Section 4 

reproduction carried over 2 generations of breeding 

and cancer studies in rats and mice are required only 

for nonfood uses which could result in high exposures over a significant period of a person's lifetime. 

Pesticides used on food crops have been tested in all 

types of studies including long-term chronic and 

cancer testing. 

An important provision of FIFRA requires EPA to 

review "old" pesticides (previously registered) to 

ensure that these products meet current scientific 

and regulatory standards. Pesticides which were 

considered to be "reasonably safe" were to be 

reregistered, and those which were considered to be 

"unreasonably unsafe" were to be cancelled. Prior to 

1988, EPA was able to evaluate 185 active ingredients of about 600 previously registered pesticide 

active ingredients. The 1988 amendments accelerate and expedite the reregistration process which 

should enable EPA to evalute the remaining 

chemicals more quickly. 

EPA can also place a pesticide into "Special Review" 

if it believes the chemical poses a serious potential 

health or environmental risk. Special Review is an 

intensive investigation of the pesticide's risks and 

benefits. 

EPA can limit the use of a chemical in some 

applications, but may decide its use is safe in others. 

For example, diazinon is one of the most widely 

used ingredients in consumer pesticide products. In 

1988 EPA banned the use of diazinon on sod farms 

and golf courses because of its toxicity to certain 

birds and other nontarget species. Diazinon can 

still be applied to lawns because lawns are not the 

usual habitat for the waterfowl that are at risk. 

If a pesticide is considered to be a significant health 

hazard, EPA or other appropriate agency can take 

one of the following actions: 1) cancel the registration; 2) cancel the registration and withdraw the 

product; 3) place restrictions on use or application 

of the compound; 4) suspend the registration 

pending resolution of the hazard or receipt of data; 

5) set tolerance limits for pesticide residues on 

II 
II 

Section 4 

foodstuffs; or 6) establish maximum permissible 

limits for the pesticide in drinking water. 

As EPA evaluates pesticides, it publishes fact sheets 

which identify the manufacturer, date of registration, uses, toxicity, and regulatory action. These 

fact sheets and registration information for individual pesticides are a useful source of information. 

Warning Labels 

EPA requires pesticides to be labeled according to 

one of four toxicity categories based on a series of 

tests which relate to acute effects such as eye or skin 

irritation and other harmful effects that result 

shortly after the pesticide exposure occurs. 

Depending on the health effects evaluation, products may be labeled DANGER (highly poisonous), 

WARNING (moderately poisonous), or CAUTION (least hazardous). Unfortunately, based on 

EPA's 1987 survey, it seems highly likely that 

many consumers do not discriminate among these 

different labels. 

Registration and labeling, however, have limitations. In 1986 the GAO noted, "The public is not 

told about the uncertainties surrounding chronic 

health risks." (U.S. GAO, 1986). In 1988 the 

California Senate Office of Research echoed the 

GAO's concerns when it concluded that "labeled 

precautions for consumers may often provide only a 

minimal, and in certain instances inadequate, basis 

for avoiding hazards, especially infants and children" Oennings, 1988). 

EPA does require some pesticide products to 

contain warnings about potential chronic effects, 

but the labeling regulations do not require disclosure of chronic health hazards or the lack of full 

assessments of chemicals. 

Local Authority 

Regulation of lawn chemicals is one area in which 

state and local jurisdictions have attempted to 

IAQ Reference Manual 

inform the public about pesticide use. Some state.s 

such as Rhode Island, Massachusetts, Maryland, 

Minnesota, and Iowa have enacted laws which 

require the posting of warnings for the application 

of lawn chemicals. These regulations require 

notifications of pesticide applications, listing of the 

pesticides to be applied, and the disclosure of health 

and environmental effects. 

REFERENCES 

AMA Council on Scientific Affairs. 1988. "Cancer risk of 

pesticides in agricultural workers." ]AMA. 260 (7): 959-966. 

Blondell,]. 1989. Personal Communication: U.S. Environmental Protection Agency, Health Effects Division: Washington, DC. 

Borzsonyi, M., G. Torok, A. Pinter, and A. Surjan. 1984. 

"Agriculturally-related carcinogenic risk." IARC (International Agency for Research on Cancer) Scientific Publication 

Series. Vol. 56.: M. Borzsonyi, N.E. Day, K. Lapis, and H. 

Yamasaki (eds). World Health Organization: Geneva, 

Switzerland. 

Consumers Union. 1987. "What EPA knows about the risks of 

home use products containing 50 common active ingredients." 

Consumers Union: Mt. Vernon, NY. 

Dobbs, A.J. and N. Williams. 1983. "Indoor air pollution from 

pesticides used in wood remedial treatments." Environ. 

Poll.(Series B). 6: 271-296. 

Jennings, B.H. 1988. "Issue Brief. Pesticides at home: 

Uncertain risks and inadequate regulations." California Senate 

Office of Research: Sacramento , CA. 27 pp. 

Leidy, R.B., C.G. Wright, and H.E. Dupree, Jr. 1982. 

"Concentration and movement of diazinon in air."]. Environ. 

Sci. Health. B17(4): 311-319. 

Lillie, T.H. and E.S. Barnes. 1987. "Airborne termiticide 

levels in houses on United States Air Force installations." Indoor 

Air '87. Vol. 1. Volatile organic compounds, combustion gases, 

particles and fibers, microbiological agents. Oraniendruck GmBH: 

Berlin, W. Germany. 

Lowengart, R.A.,J.M. Peters, C. Cicioni,J. Buckley, L. 

Bernstein, S .. Preston-Martin, and E. Rappaport. 1987. 

"Childhood leukemia and parents occupational and home 

exposures." ].N.C.l. 79(1): 39-46. 
IAQ Reference Manual 

Morgan, D.P. 1989. Recognition and Management of Pesticide 

Poisonings. 4th edition. EPA-540/9-88-001. U.S. Environmental Protection Agency, Office of Pesticide Programs: 

W ashingcon, DC. 

National Research Council (NRC}. 1981. Indoor Pollutants. 

National Academy Press: Washington, DC. 

Olds, K.L. 1987. "Indoor airborne co~centrations of 

termitiddes in Department of the Army family housing." 

Indoor Air '87. Vol. 1. Volatile orgaeic compoumJs, combustion gases, 

particles and fibers, microbiological agmts. Oraniendruck GmBH: 

Berlin, W. Germany. 

Rosenberg, M.J., P.J. Feldblum, and E.G. Marshall. 1987. 

"Occupational influences on reproduction: A review of recent 

literature."]. Occ. Med. 29 (7): 584-591. 

Sharp, D.S., B. Eskenazi, R. Harrison, P. Callas, and A.H. 

Smith. 1986. "Delayed health hazards of pesticide exposure." 

Am. Rev •• Public Health. 7: 441-471. 

Stokes, C. S. and K. D. Brace. 1988. "Agricultutal chemical 

use and cancer mortality in selected rural counties in the 

U.S.A."]. Rural Studies. 4(3): 239-247. 

U.S. Enviconmental Protection Agency (EPA}. 1987. A 

Consumer's Gflide /(1 Safer Pesticide Use. OPA 87-013. U.S. EPA, 

Office of Public Affairs: Washington, DC. 

U.S. Environmental Protection Agency (EPA). 1990. 

Nonoccupational pesticide exposure study (NOPES). EP A/600/3-90/ 

003. U.S. EPA, Atmospheric Research and Exposure Assessment Laboratory: Research Triangle Park, NC. 

U.S. General Accounting Office (GAO). 1986. Nonagricultural 

pesticides. Risks and regulations. GAO/RCED-86-97. U.S. 

GAO: Washington, DC. 

U.S. General Accounting Office (GAO). 1990. Lawn Care 

Pesticides. Risks Remain Uncertain While Prohibited Safety Claims 

Continue. GAO/RCED-90-134. U.S. GAO: Washington, DC. 

Wright, C.G., R.B. Leidy, and H.E. Dupree, Jr. 1981. 

"Insec.ticides in the ambient air of rooms following their 

application for control of pests." Bull. Environm. Contam. 

Toxicol. 26: 548-553. 

Wright, C.G. and R.B. Leidy. 1982. "Chlordane and 

heptachlor in the ambient air of houses treated for termites." 

Bull. Environm. Contam. Toxicol. 28: 617-623. 

Xue, S. 1987. "Health effects of pesticides: A review of 

epidemiologic research from the perspective of developing 

nations." Am.]. lndust. Med. 12: 269-279. 

Section4 

4.3 FORMALDEHYDE AND OTHER VOLATILE 

ORGANIC COMPOUNDS 

Sources of Formaldehyde 

Residential Buildings 

Formaldehyde (HCHO) is a flammable, colorless gas 

with a characteristic odor. The odor threshold for 

HCHO is about 1 ppm, but it can be detected at 

levels as low as 0.05 ppm by some people (NRC, 

1981). ·It is one of the most widely used chemicals 

in the United States. About half of the HCHO 

produced annually (6 billion pounds in 1983) is 

used to make urea- and phenol-HCHO resins 

which, in tum, are used to produce adhesives, 

bonding and laminating agents, foam insulation, 

fabrics, CO?-tings, and paper (U.S. HUD, 1984). 

Phenol-HCHO based resins, which are less susceptible to moisture degradation, are used to make 

interior and exterior grade products (softwood 

plywood, waferboard, and oriented strand board). 

Urea-HCHO resins are used only on interior grade 

products because they are susceptible to moisture 

deterioration. 

HCHO can be released from a variety of products 

(Exhibit 4-10), but the primary residentiafsources 

are hardwood plywood, particleboard, mediumdensity fiberboard (MDF), and other pressed wood 

products. All of these pressed wood products are 

produced by combining wood pieces or chips with 

an adhesive and other chemicals (including ureaHCHO resins) and pressing them together in hot 

hydraulic presses. The potential for HCHO emissions is the greatest for MDF, followed by particleboard and hardwood plywood. 

Hardwood plywood is used to make decorative wall 

paneling, furniture, cabinets, doors, and flooring. 

Softwood plywood also has a variety of applications, 

but it does not contain HCHO. Particleboard is 

used primarily as underlayment, mobile home 

decking, and to make industrial board which, in 

turn, is used to make many products including 

furniture and kitchen cabinets. MDF is used 

m 
Section 4 

primarily in furniture and cabinets as a cost effective 

alternative to solid wood. 

During the last several years, manufacturers of 

particleboard, hardwood plywood, and MDF have 

taken measures to reduce the amount of HCHO 

chat is used to make the board. MDF, however, as 

of 1986 was considered to be a relatively higher 

emitter ofHCHO than the other two products 

(U.S. CPSC, 1986). 

Another important use of urea-HCHO resin is in 

the production of urea-HCHO foam insulation 

(UFFI) which is foamed-in-place. Between 1975 

and 1981 about 435,000 homes were insulated with 

UFFI (U.S. CPSC, 1982). Because of concerns about 

UFFI, the CPSC banned the the installation of UFFI 

in homes and schools as of August 10, 1982. This 

ban, which was intended to prevent the risk of 

injury from cancer as well as the occurrence of acute 

illness, was contested by the industry and overturned by the Fifth Circuit Court of Appeals in 

1983. 

Commercial Buildings 

Any commercial building that is newly constructed 

or recently renovated can be a potential source of 

HCHO emissions. Important potential sources of 

HCHO in commercial buildings include any 

materials made ofMDF, particleboard, and hardwood plywood. These materials include flooring 

materials, paneling, and furniture. In addition, any 

fabrics or other fibers that have been treated to be 

permanent press, soil and wrinkle resistant, and 

water repellent may be additional sources. Confined 

areas where smoking is permitted could have 

elevated levels of HCHO and other aldehydes 

because of the buildup of these combustion 

byproducts. 

Measured Concentrations of HCHO 

Formaldehyde is perhaps one of the most widely 

characterized indoor air contaminants. Exhibit 4-11 

summarizes some of the measurements which have 

IAQ Reference Mamtal 

been made in mobile homes, conventional homes, 

offices, and a variety of public buildings. 

These and other studies have shown that manufactured housing could be expected to have higher 

average concentrations of HCHO than conventional 

housing, probably because of the greater number of 

sources and higher surface to volume ratio. It 

should be noted that construction techniques have 

changed for manufactured housing and average 

concentrations in these' homes may be lower than in 

the past. 

HCHO concentrations in conventional houses 

insulated with UFFI are generally higher than in 

houses with other types of insulation. Measurements of HCHO concentrations in nonresidential 

buildings have generally demonstrated lower 

concentrations than in conventional or mobile 

homes. 

Although general trends have been noted, the 

reported data also show that a wide range of concentrations can exist in any type of construction 

depending on the age of the structure, season, time 

of day, climatic factors, and presence of sources. 

Health Effects of Formaldehyde 

Concerns about exposure to HCHO have resulted in 

thousands ofcomplaints to agencies such as the 

CPSC and in numerous lawsuits. These complaints 

have related primarily to effects resulting from acute 

exposures, but increasingly consumers are concerned 

about health effects resulting from chronic exposures and the potential carcinogenicity of HCHO. 

HCHO is a known irritant and sensitizer. The 

frequency and severity of irritant effects from 

HCHO has been shown to increase with concentration and length of exposure. Symptoms of upper 

airway irritation include a tingling sensation in the 

nose, dry throat, and sore throat. These symptoms 

usual coexist with tearing, burning, stinging, and 

pain in the eyes (NRC, 1981). These effects can 

occur within a few minutes after exposure to HCHO 
IAQ Reference Manual 

depending on the exposure concentration and the 

sensitivity of the individuaL At higher levels, 

inhalation of HCHO produces lower airway irritation and pulmonary effects which are characterized 

by coughing, chest tightness, and wheezing. 

Skin contact with HCHO has been reported to 

result in irritation, allergic contact dermatitis, and 

urticaria. These effects may be caused by direct 

contact with HCHO or formalin (HCHO in 

solution with methanol), or by HCHO-releasing 

agents (cosmetics, germicides, incompletly cured 

resins) and the decomposition of HCHO-containing 

resins (textiles). Repeated contact with low concentrations of HCHO can result in sensitization 

reactions. 

Additional reported effects of HCHO exposure 

include nosebleeds and runny noses, persistent 

swelling of nasal turbinates, headaches, fatigue, 

memory and concentration problems, nausea, 

dizziness, and breathlessness (U.S. EPA, 1987a). 

HCHO has also been reported to be associated with 

altered reproductive function in women and 

fetotoxic effects, but additional work is needed to 

validate these findings. It has been shown to be 

mutagenic in a variery of test systems, including 

humans (U.S. EPA, 1987a). 

Irritant effects have been associated with concentrations in the range of0.1 to 3 ppm, and concentrations as low as 0.03 ppm have been reported to 

cause effects in sensitive individuals. It has been 

estimated that 10% to 12% of the U.S. population 

may have hyperreactive airways which may make 

them more susceptible to the irritant effects of 

HCHO; this estimate includes asthmatics (NRC, 

1981). 

The Committee on Toxicology of the National 

Academy of Sciences (NRC, 1980) evaluated data 

available in 1980, and it concluded that there isno 

population threshold effect level for the irritant 

effects of HCHO in humans. Based on its review, 

.. Section 4 

the Committee concluded that less than 20% of the 

population would experience slight to mild irritation and discomfort when exposed to less than 

0.25 ppm HCHO. More recently, CPSC also 

concluded that there may not be a threshold limit 

concentration for HCHO (U.S. CPSC, 1986). The 

WHO Working Group on Assessment and Monitoring of Exposure to Indoor Air Pollutants (1983) 

concluded that indoor HCHO concentrations of less 

than 0.05 ppm were of limited or no concern and 

concentrations greater than 0.10 ppm were of 

sufficient concern to call for corrective action. 

The most controversial health effect from exposure 

to HCHQ is its carcinogenic potential in humans. 

The debate surrounding the role of HCHO as a 

carcinogen began with a study sponsored by the 

Chemical Industry Institute of Toxicology (CUT) in 

1980 in which it was reported that nasal cancer 

developed in 103 of 240 laboratory rats exposed to 

14.3 ppm HCHO and in two rats exposed to 5.6 

ppm HCHO. Nasal cancer also developed in 2 of 

240 mice exposed to 14.3 ppm HCHO (Kerns et al., 

1983). 

Since the results of the CIIT study were made 

available, there have been other animal and human 

epidemiologic studies which suggest that HCHO 

should be presumed to pose a carcinogenic risk to 

humans. The Federal Panel on Formaldehyde (FPF, 

1982), the International Agency for Research on 

Cancer (IARC, 1982), the CPSC (1986), and the 

U.S. EPA (1987a) have concluded that HCHO 

poses a carcinogenic risk to humans. 

In 1987 the U.S. EPA classified HCHO as a 

"Probable Human Carcinogen" (Group Bl) based on 

sufficient animal and limited human evidence and 

other supporting data (U.S. EPA, 1987). In 1989 

EPA, in consultation with EPA's Science Advisory 

Board, undertook efforts to update the 1987 

assessment in light of new hazard data and recent 

advances in risk assessment methodology. The new 

methodology incorporates pharmacokinetic data 

which provides a closer approximation to a delivered 

dose and uses monkey DNA binding data as the 

II 
II • 

Seclion4 

basis for human dosimetry. This update effort will 

likely significantly reduce the 1987 cancer risk 

estimates. 

Sources of Other Volatile Organic 

Compounds 

Sources 

Organic compounds can be divided into three. 

categories based on volatility. Volatile organic 

compounds (VOCs) exist entirely in the vapor phase 

at ambient temperature and have vapor pressures 

greater than about 1 mm Hg. Semivolatile organic 

compounds (SVOCs) have vapor pressures in the 

range of 10'7 to 1 mm Hg and are present both in 

the vapor and particle-bound state. Nonvolatile 

organic compounds are those that are present only as 

particulates and have vapor pressures less than 10·7 

mm Hg (Riggin and Petersen, 1985). 

Over 250 different organic compounds have been 

measured in indoor air at levels greater than 1 ppb 

(Sterling, 1985), and over 900 volatile organic 

compounds have been identified in indoor air (U.S. 

EPA, 1989). These compounds are incorporated 

into almost all materials and products that are used 

in construction materials, consumer products, 

furnishings, pesticides, and fuels. Drinking water 

(typically well water) that is contaminated with 

VOCs can also be an indoor air source when contaminated water is used for showering, bathing, 

cooking, and other uses that potentially result in the 

release ofVOCs. Some examples ofVOCs and the 

products which contain them are given in Exhibit 

4-12. Exhibit 4-13 contains examples of some 

emission rates for selected VOC-containing 

products. 

A national survey conducted by EPA (1987b) on the 

usage of household solvents has provided insight 

into the sources of six solvents contained in consumer products and the usage of those products by 

consumers. The solvents which were studied 

include methylene chloride and five potential 

substitute chemicals: 1,1,1-trichloroethane, 

IAQ Reference Manual 

trichloroethylene, tetrachloroethylene, carbon 

tetrachloride, and 1,1 ,2-trichlorot~ifluoroethane. 

EPA examined a total of 1 0:?6. brands of household 

products, which were grouped into 67 product 

categories, and the use patterns of 5000 adults. 

These studies demonstrated that exposure to VOCs 

is widespread through the use of consumer products, 

but the significance of these exposures is not known. 

Almost half of the brands surveyed contained at 

least one of the six target chlorocarbons. Methylene 

chloride and 1, 1, 1-trichloroethane were the predominant chemicals-34% of the brands tested 

positive for methylene chloride and 14% for 1,1,1-

trichloroethane. Methylene chloride was found in 

78% of the paint removers/strippers and 60% of the 

aerosol spray paints tested. 1,1,1-Trichloroethane 

was found in most of the typewriter correction 

fluids, suede protectors, and brake quieters/cleaners 

tested. 

Less than 4% of the brands tested were positive for 

any of the four remaining chlorocarbons. Trichloro~ 

ethylene was found in 78% of the typewriter 

correction fluids tested. Tetrachloroethylene was 

found in 58% of the brake quieters/cleaners tested. 

Carbon tetrachloride was not found at the 1% level 

in any of the products tested. 

In addition to the findings of specific concentrations 

of chemicals in household solvent products, the 

study found that concentrations ofchlorocarbons 

varied considerably between brands of the same 

product type, and in a few brands, concentrations 

differed by geographic regions of the country. One 

of the most important findings of this study was 

that product labels are often inadequate; only 56% 

of the brands with chlorocarbons were labeled as 

containing these chemicals. 

Extent of Use 

The EPA household solvent products survey (U.S. 

EPA, 1987b) showed that on average people had 

used slightly fewer than 7 products during their 

lifetime. During a 12-month period prior to the 
IAQ Reference Manual 

survey, participants reported that they used almost 

5 products on average. 

Products were ranked according to the incidence of 

"ever used." The most frequently used products 

were contact cements/super glues/spray adhesives 

(60.6% of the population), latex paint (55.2%), arid 

wood stains/varnishes/finishes (42.9%). The lowest 

incidence of ever used products (less than 3%) was 

for automotive products (transmission cleaners, 

brake quieters/cleaners, and gasket removers). 

The 5 most frequently used products during the 

previous ·12-month period were typewriter correction fluid, solvent cleaners, spot removers, specialized electronic cleaners, and tire/hubcap cleaners. 

These products were also used for the shortest 

amounts of time (from 7.5 minutes for typewriter 

correction fluid to 29.5 minutes for solvent cleaners). Latex paint, oil paint, paint removers/stippers, 

adhesive removers, and wood stains/varnishes/ 

finishes. were the 5 products which were used less 

frequently, but for the longest periods of time (from 

117 minutes for wood stains/varnishes/finishes to 

295 minutes for latex paint). 

The survey also showed that respondents were 

somewhat aware of the potential adverse effects of 

using these products. Over 70% of the respondents 

reported that they kept a door or window open to 

the outside when using nonautomotive primers, 

latex paint, outdoor water repellents, and paint 

removers and strippers. 

Measured Concentrations 

The data base for VOCs and other organic compounds includes studies of healthy and sick buildings. Some examples ofVOCs measurements in 

residential and nonresidential buildings are given in 

Exhibit 4-14. 

These data along with the consumer use surveys 

conducted by EPA show that exposure to VOCs is 

Section 4 

widespread and highly variable. In general, VOCs 

can be expected to be higher in buildings immediately after construction or renovation compared to 

older buildings. The use of consumer products can · 

be expected to predominate VOC emissions after 

building-related VOCs decrease in concentration. 

The Team Studies conducted by Wallace and others 

(Wallace, 1987) have provided itrlportant information about actual exposures to VOCs. These studies 

showed that: 

• Indoor personal exposures were greater than 

mean outdoor concentrations for each of 11 

target VOCs. 

• Breath levels correlated significantly with 

personal air exposures but not with outdoor 

air levels for nearly all the chemicals. 

• Inhalation accounted for more than 99% of 

the exposure for all contaminants studied, 

except for the trihalomethanes. 

• Specific sources of exposure were identified 

and included smoking (aromatics such as 

benzene, styrene, ethylbenzene, and m,pxylene in breath); passive smoking (same 

chemicals in indoor air); visiting dry 

cleaners (tetrachloroethylene in breath); 

pumping gas or being exposed to auto 

exhaust (benzene in breath); various 

occupations such as chemicals, plastics, 

wood processing, scientific laboratories, 

garage or repair work, metal work, printing 

(aromatic chemicals in daytime personal 

air). 

• Other sources which were hypothesized 

included room air fresheners, toilet bowl 

deodorizers, or moth crystals (p-dichlorobenzene in indoor air); and use of hot water 

in the home (chloroform in indoor air). 

II 
Section 4 

Health Effects of Other Volatile Or1anlc 

Compounds 

Exposure to VOCs can result in both acute and 

chronic health effects. Exhibit 4-12 summarizes 

some health effects for selected contaminants. Most 

of the available health effects data have been 

developed from animal studies or occupational 

studies. In general, the health effects data base for 

VOCs, especially, low-level or intermittent exposures, is not complete. 

Many of the VOCs are potent narcotics and result in 

the depression of the central nervous system. VOCs 

can also result in irritation of the eyes and respiratory tract and sensitization reactions which involve 

the eyes, skin, respiratory tract, and heart. At 

higher concentrations, many of these chemicals have 

been shown to result in liver and kidney damage. 

Symptoms ofVOC exposure (depending on the 

dose) could include fatigue, headache, drowsiness, 

dizziness, weakness, joint pains, peripheral numbness or tingling, euphoria, tightness in the chest, 

unsteadiness, blurred vision, skin irritation, irritation of the eyes and respiratory tract, and cardiac 

arrhythmias (Rosenberg, 1990). 

The term "solvent encephalopathy" is used to 

describe a group of symptoms (major symptomsheadache, irritability, difficulty concentrating, and 

fine-motor deficits) attributed to VOC exposures. A 

dose-effect relationship has not been described, but 

effects occur at levels well below the threshold limit 

values for individual solvents, and there appears to 

be a relationship between duration of exposure and 

the time required to resolve symptoms after exposure stops. VOCs are present in office environments 

at concentrations that have been associated with 

solvent encephalopathy (Hodgson, 1988). 

Many of the VOCs which have been measured 

indoors are known human carcinogens (benzene) or 

animal carcinogens (carbon tetrachloride, chloroform, trichloroethylene, tetrachloroethylene, and 

p-dichlorobenzene). VOCs such as 1,1,1-trichloIAQ Reference Manual 

roethane, styrene, and ex-pinene are mutagens and 

possible carcinogens. Other VOCs such as ocrane, 

decane, and undecane are possible co-carcinogens. 

Cancer Risk Estimates: Cancer risk estimates 

developed by EPA for exposure to some VOCs are 

given in Exhibit 3-2, Section 3 of the Reference 

Manual. Other investigators have also estimated the 

cancer risk from VOCs. Wallace (1986) estimated 

that six VOCs (benzene and the other 5 animal 

carcinogens listed above) contribute 1000 to 5000 

excess cancer cases per year nationwide. Tancrede et 

a/. (1987) estimated the cancer risk of9 VOCs 

which had previously been measured in New Jersey 

(Bayonne and Elizabeth), 19 VOCs in California 

(Los Angeles), and 44 VOCs in Dutch houses. The 

estimated mean individual risk (the sum of the 

mean individual risks for each of the VOCs) was 

0.019-0.03 for the residents of New Jersey and 

0.002 for the residents of California. The estimated 

· mean risk for the contaminants based on the Dutch 

data was 0.001-0.002. The unit risk estimates were 

computed using human and animal data, by analogy 

with other chemicals, and other methods. 

When the risks were computed bas~d only on those 

chemicals for which rhere was either animal bioassay 

data or human epidemiological data, the estimated 

risk was 0.003 for New Jersey, 0.001 for California, 

and 0.0002-0.001 for The Netherlands. Estimated 

risks for radon (0.0520), passive smoking (0.002-

0.008), and formaldehyde (0.034) were also shown 

for comparison. Tancrede eta/. concluded that even 

though their estimates were conservative, the 

calculations suggested exposure to VOCs through 

indoor air were important. Although there are few 

risk assessments available for VOCs in indoor air, 

VOCs appear likely to pose a significant cancer risk 

(U.S. EPA, 1989). 

Sick Building Syndrome and Multiple Chemical 

Sensitivity: There is some evidence VOCs can 

provoke some of the symptoms typical of sick 

building syndrome. M¢lhave observed increased 

mucous irritation and impaired memory in healthy 

subjects (who previously demonstrated symptoms of 
IAQ Reference Manual 

sick building syndrome) who were exposed to 22 

VOCs at total VOC concentrations of 5 mg/m3 and 

25 mg/m3 <M!lilhave et at., 1987). 

Kjaergaard et at. (1987} also demonstrated a dosedependent response in 63 randomly selected healthy 

subjects who were exposed to n-decane in the range 

of 0 to 100 ppm. Exposed subjects experienced 

mucous membrane irritation, decreased tear film 

stability, and sensation of increased odor intensity 

and reduced air quality. The authors concluded that 

these results support the hypothesis that VOCs can 

provoke some of the symptoms of sick building 

syndrome. 

Individuals who appear to demonstrate multiple 

chemical sensitivity report severe reactions to 

Section 4 

a variety ofVOCs and other organic compounds 

which are released by building materials and various 

consumer products including cosmetics, soaps, 

-perfumes, tobacco, plastics, dyes, and other products. Many of the chemicals contained in these 

products are potent sensitizers. 

These reactions can occur after exposure to a single 

sensitizing dose or sequence of doses, after which 

time, a far lower dose can provoke symptoms. 

Reactions can also be provoked as a result of chronic 

exposure to low doses. Ashford and Miller (1989} 

summarize some of the studies that have been 

conducted that attempt to link multiple chemical 

sensitivity to exposure to VOCs and other organic 

compounds. 

Exhibit 4·1 0. Potential sourc~s of formaldehyde indoors. 

Pressed-wood products 

Insulation 

Combustion sources 

Paper products 

Stiffeners, wrinkle 

resisters, and water repellents 

Other sources 

SOURCE: Adapted from NRC (1981) 

hardwood plywood, particle board, medium-density fiberboard (MDF), 

decorative paneling 

urea-formaldehyde foam insulation (UFFI), fiberglass made with 

HCHO binders 

natural gas, kerosene, tobacco, automobile exhaust 

grocety bags, waxed paper, facial tissues, paper towels, disposable 

sanitaty products 

floor coverings (rugs, linoleum, varnishes, plastics), carpet backings, 

adhesive binders, fire retardants, permanent press textiles 

plastics, cosmetics, deodorants, shampoos, disinfectants, starch-based 

glues, adhesives, laminates, paints, fabric dyes, inks, fertilizers, 

fungicides 
II 

Section 4 IAQ Reference Manual 

Exhibit 4·11. Measurements of formaldehyde concentrations In different types of 

buildings. 

TYPE OF 

BUILDING 

Conventional homes with ~hipboard 

(n•23) 

Conventional homes 

(n•SO) 

All homes 

(n=lOO) 

U-F foamed conventional homes 

(n•l4) 

U-F wood products conventional homes 

(na13) 

Mobile homes 

(n•65) 

Mobile home day care centets 

(n .. 7) 

Permanent day care centers 

(n=2) 

Mobile homes 

(n•39) 

Conventional homes 

(n=489) 

Mobile homes 

(n•l37) 

Conventional homes 

(n=36) 

Energy efficient homes 

(nm7) 

Apartments 

(n= 19) 

Condominiums 

(n=lO) 

CONCENTRATION (ppm) 

MINIMUM MAXIMUM MEAN REFERENCE 

0.07 1.82 0.51 Andetsen eta/. (1975) 

0.4a 8.1a Sardinas eta!. (1979) 

<0.1 3.68 0.35 Dally et al. (1981) 

(median) 

0.1 1.09 0.47 

(median) 

0.1 0.92 0.1 

(median) 

<0.1 3.68 0.1 

{median) 

0.2 0.45 0.35 Olsen & Dossing (1982) 

0.04 0.09 0.07 

0.02 3.69 0.42 Ritchie & Lehnen (1985) 

0.01 5.52 0.15 

0.1 2.84 0.46 Hanrahan et al. (1985) 

<0.008 <0.14 0.04 Stock & Mendez (1985) 

0.04 0.11 0.07 

0.02 0.27 0.08 

<0.008 0.29 0.06 
IAQ Reference Manual Section 4 

a b Draeger tubes 

Office, nursing home, hospital 

c Office, office/school, nursing home 
Exhibit 4·12. Health effects and sowrces of selected volatile organic co,~u11ds. 

COMPOUND 

Formaldehyde 

Benzene 

Xylenes 

Toluene 

Styrene 

Toluene diisocyanate (IDI) 

Trichloroethylene 

Ethyl benzene 

Methylene chloride 

(Dichloromethane) 

HEALTH EFFECTs<•> 

probable human carcinogen; eye and respiratory 

tract irritant; a variety of low-level symptoms 

carcinogen; respiratory tract irritant 

narcotic; irritant; affects heart, liver, 

kidney and nervous system 

narcotic; may cause anemia 

narcotic; affects central nervous system; 

possible human carcinogen 

sensitizer; probable human carcinogen 

animal carcinogen; affects central nervoUs system 

severe irritation to eyes and respiratory tract; 

affects central nerv'ous system 

narcotic; affects central nervous system; 

probable huma.n carcinogen 

SOURCES AND USES 

listed in Exhibit 4-10 

plastic and rubber solvents; cigarette 

smoking; paints, stains, varnishes, filler, 

other finishes; inhalation of gasoline vapor 

adhesives, joint compound, wallpaper, 

caulking compounds, floor covering, floor 

lacquer, grease deaners,shoe dye, tobacco 

smoke, kerosene heaters, varnish, solvent 

for resins, enamels; used in non-lead 

automobile fuels, pesticides, dyes, 

pharmaceuticals 

solvents, solvent-based adhesives, waterbased adhesives, edge-sealing, moulding 

tape, wallpaper, joint compound, 

calcium silicate sheet, vinyl floor covering, 

vinyl coated wall paper, caulking 

compounds, paint, chipboard, kerosene 

heaters, tobacco smoke 

plastics, paints, synthetic rubber, and resins 

polyurethane foam aerosols 

solvent for paints, varnishes, oil and wax, 

cleaning compounds, degreasing products, 

dry-cleaning 

solvents, in styrene-related products 

paint removers, aerosol finishers; acoustical 

office partitions 
. Exhibit 4·12. Health effects and sources of selected volatile or.ganic compounds (tonlinuedJ. 

COMPOUND 

Para-dichlorobenzene 

Benzyl chloride, 

Benzal chloride 

2-butanone 

(MEK) 

· Petroleum distillates 

4-phenylcydohexene 

HEALTH EFFECTS 

narcotic; eye .and respiratory tract irritant; 

affects liver, kidney, and central nervous system 

central nervous system irritants and 

· depressants; affects liver and kidney; 

eye and respiratory tract irritant 

irritant; central nervous system depressant 

central nervous system depressant; affects 

liver and kidney 

eye and respiratory tract irritant; central 

nervous system effects 

SOURCES AND USES 

moth crystals, room deodorizers 

vinyl tiles plasticized with buryl benzyl 

phthalate 

floor/wall covering, calcium silicate sheet, 

fiberboard, caulking compounds, 

particleboard, tobacco smoke 

cleaning products, solvents, paint thinners 

byproduct of sytrene butadiene latex, an 

·adhesive used in most synthetic fibers 

carpets 

1

For many indoor pollutants, there is insufficient data to determine the levels at·which the specific effects listed would actually occur and the extent to 

which these levels are experienced in non-industrial indoor environments. 

·SOURCE: Tucker (1988), Dreisbach (1980), Turiel (1985) 
Section 4 IAQ Reference Manual 

Exhibit 4·13. Examples of volatile organic compound measurements In iniloor air. 

CONCENTRATION (!lg/m;) 

CONTAMINANT MINIMUM MAXIMUM MEAN REFERENCE 

Benzene 

Kitchens (n = 15) 6 7 15 Seifert & 

Ocher rooms (n = 15) 6 14 18 Abraham (1982) 

Outdoors, next to dwellings (n = 5) 4 33 29 

Toluene 

II Kitchens (n = 15) 34 3800a 60 

Other rooms (n = 15) 17 173a 62 

Outdoors, next to dwellings (n = 5) 16 60 35 

m- and p-Xylene 

Kitchens (n = 15) 18 na 29 

Ocher rooms (n = 15) 10 47 21 

Outdoors, next to dwellings (n=5) 4 32 28 

Ethylbenzene 

Kitchens (n = 15) 6 33 15 

Other rooms (n = 15) 1 22 11 

Outdoors, next to dwellings (n = 5) 4 20 13 

Various types ofbuildingsb Wallace 

et al. (1983) 

Benzene 0.4 120 20 

Carbon tetrachloride 0.5 14 2.5 

Trichloroethylene 0.3 47 3.6 

Chloroform 0.2 200 8 

Dichlorobe~enes 0.2 1200 41 

Ethylbenzene 0.3 320 13 

o-Xylene 0.4 49 7.8 

m- and p-Xylene 0.4 120 21 

Styrene 0.1 54 3.1 

l,l,l~Trichloroethane 0.7 880 50 

Tetrachloroethylene 0.2 250 10 

2 Schools, 2 homes, and 1 office vanderWal 

et al. (1987) 

n-and i-Penranal 10 12 

n-Hexanal 2 7 

n-Octanal .1 21 

N-Nonanal 7 50 

m-Decanal 2.5 17 

Benzaldehyde 4 5 

Toluene 13 69 

Higher Aromatic Hydrocarbons 14 600 

n-Alkanes 8 1700 

Chlorinated Hydrocarbons 4 42 
IAQ Reference Manual Section4 

Exhibit 4·13. Examples of volatile organic compound rneasuren~ents in indoor air {tofttl•uedJ. 

CONTAMINANT 

c Total VOCs d 

Aromatic Hydrocarbons 

Aliphatic Hydrocarbons e f 

Chlorinated Hyrocarbons 

Oxygenated Hydrocarbons8 

c Total VOCs . d 

Aromatic Hydrocarbons 

Aliphatic Hydrocarbons e f 

Chlorinated Hyrocarbons 

Oxygenated Hydrocarbonsg 

TotalVOCs 

1,1,1-Trichloroethane 

Benzene 

Ethylbenzene 

a-Xylene 

Toluene 

3-Methylpentane 

Hexane 

1, 2, 3-Trimethylbenzene 

Heptane 

1, 4-Dioxane 

Acetone 

4-Methyl-1-pentanone 

Butylacetate 

Total VOCs 

1 ,1,1-Trichloroethane 

m, p-Dichlorobenzene 

m,p-Xylene 

Tetrachloroethylene 

Benzene 

Ethylbenzene 

a-Xylene 

Trichloroethylene 

Chloroform 

Styrene 

Carbon Tetrachloride 

CONCENTRATION (J.lg/m3

) 

MINIMUM MAXIMUM MEAN 

New buildings, (office, nursing home, hospital) 

21-1100 

11-270 

4.7-810 

3.9-56 

ND-9.6 

Older buildings, (office, office/school, 

nursing home) 

3 Nonresidential buildings h 

18-130 

12-74 

1.9-18 

4.7-46 

ND-4.3 

237-1090 

14.8-214 

12.9-43.2 

1.16-17.2 

3.66-16.8 

7.84-98.7 

1.42-37.6 

4.7-68.7 

<0.02-0.522 

1.24-38.9 

<0.02-20.1 

11.1-62.7 

0.343-27.9 

10.6-48.3 

Homes in 2 cities over the course 

of 3 sampling periods in 3 years 

200-338 

45-94 

45-71 

36-52 

ll,45 

NC1-28 

9.2-19 

12-16 

4.6-13 

4.0-8.0 

2.1.8.9 

ND1-9.3 

REFERENCE 

Sheldon 

et a/.(1988) 

Sheldon, 

et ai. (1988) 

Bayer and 

Black (1988) 

Wallace (1987) 

(continued next page) 
II 

Seclion4 IAQ Reference Manual 

Exhibit 4-13. Examples of volatile org•ic compound measurements In indoor air (continued). 

CONTAMINANT 

n-OctlUle 

n-Decane 

n-Undecane 

n-Dodecane 

a-Pinene 

a-Dichlorobenzene 

1, 1, l· Trichloroethane 

m- and p-Xylene 

m· and p-Dichlorobenzene 

Tetrachloroethylene 

a-Xylene 

Ethylbem:ene 

Trichloroethylene 

Styrene 

Chloroform 

Carbon Tetrachloride 

1, 2-Dichlorobenzene 

p-Dioxane 

a not included in the calculation of the mean 

MINIMUM MAXIMUM 

Homes in 1 dey over the course 

of 3 samplings periods in 1 year 

MEAN 

2.3-5.8 

2.0-5.8 

2.7-5.2 

2.1-2.5 

2.1-6.5 

0.3-0.6 

16-96 

11-28 

5.5-18 

5.6-16 

4.4-13 

3.7-11 

3.8-7.8 

1-3.6 

0.6-1.9 

0.8-1.3 

0.1-0.5 

0.2-1.8 

b overnight air samples, Elizabeth-Bayonne, NJ; additional measurements are given in Wallace (1987) and 

TEAM publications 

c specific levels of individual contaminants are given in Shelden et 41. (1988) 

d benzene; o- and m-xylene; styrene; ethylbenzene; isopropylbenzene; n-propylbenzene; o- and m-toluene; 

1,2,3-trimethylbenzene; 1,2,4-trimethylbenzene; 1,3,5-trimethylbenzene 

e a-pinene, n-decane, n-undecane, n-dodecane 

f 1,2-dichloroethane; 1,1,1-trichloroethane; trichloroethylene; p-dichlorobenzene 

g n-butylacetate; 2-ethoxyethylacetate 

h Atlanta, GA; spring season; additional VOCs are given in Bayer and Black (1988) 

i not calculated~Iligh background contamination 

j not detected in most samples 

REFERENCE 

Wallace (1987) 
IAQ Reference Manual Section 4 

Exhibit 4·14a. Examples of selected volatile organic compound emission rates for 

materials and typical household products found indoors. 

EMISSION RATES OF SELECTED MATERIALS (J.!g/g)a 

Compound Name Adhesives Coating Fabric Foam Lubricant Paint Rubber Tape 

1 ,2-Dichloroethane 0.80 0.75 3.25 

Benzene 0.9 0.6 0.7 0.20 0.90 0.10 0.69 

Catbon Tetrachloride 1.00 0.18 4.20 0.75 

Chloroform 0.15 0.10 0.04 0.20 0.90 0.05 II Ethylbenzene 527.8 0.20 

Limonene 

Methyl Chloroform 0.40 0.20 0.07 1.00 0.50 0.10 0.10 

Styrene 0.17 5.20 0.02 12.54 33.50 0.15 0.10 

Tetrachloroethylene 0.60 0.30 65.00 0.60 0.20 0.08 

Trichloroethylene 0.30 0.09 0.03 0.10 0.10 0.07 0.09 

Sample Size (n) 98 22 30 68 23 4 90 66 

EMISSION RATE OF SELECTED HOUSEHOLD PRODUCTS (J.!g/g)b 

Health 

Compound Deodo- &Beauty Elect. Misc. Ink& Photo Photo 

Name Cosmetics rants Aids Equip. Housewares Pen Paper . Equip. Film 

1,2,-Dichloroethane 0.06 

Benzene 1.85 0.02 1.10 0.40 0.03 1.51 0.04 

Carbon 

Tetrachloride 0.00 0.04 0.20 2.50 

Chloroform 0.23 4.85 10.00 . 0.10 2.50 0.10 

Ethyl benzene 0.80 10.50 0.13 

Limonene 0.40 1.00 1.80 

Methyl Chloroform 0.20 0.01 0.03 0.19 0.10 0.26 0.08 1.90 

Styrene 1.10 0.15 0.17 0.05 0.02 0.30 0.04 0.10 

Tetrachloroethylene 0.70 0.05 2.00 0.42 

Trichloroethylene 1.90 0.11 0.01 0.06 0.07 0.10 0.03 0.13 

Sample Size (n) 5 9 23 71 23 25 12 35 26 

SOURCE: ll()zkaynak et at. (1987) 
111 

Section4 IAQ Reference Manual 

Exhibit 4·14b. Additional examples of volatile organic compound emission rates for 

selected materials found indoors. 

MA~RIALa 

Latex caulk 

Latex paint (Glidden) 

Carpet adhesive 

Vinyl cove molding 

Linoleum tile 

Large diameter 

telephone cable 

Black rubber molding 

Small diameter 

telephone cable 

Carpet 

Vinyl edge molding 

Particle board 

Polystyrene foam 

insulation 

Tarpaper 

Primer/adhesive 

Latex paint (Bruning) 

Water repellant 

mineral board 

Cement block 

PVC pipe 

Duct insulation 

Treated metal roofing 

Urethane sealant 

Fiberglass insulation 

Exterior mineral board 

Interior mineral board 

Ceiling tile 

Red clay brick 

Plastic laminate 

Plastic outlet cover 

Joint compound 

Linoleum tile cement 

ALIPHATIC 

OXYGENATED 

ALIPHATIC 

HYDROCARBONS 

252 

111 

136 

31 

6.0 

14 

24 

33 

27 

18 

27 

0.19 

3.2 

3.6 

1.1 

0.13 

EMISSION RATE ijlg/m2Jhr) 

AROMATIC 

HYDROCARBONS 

380 

52 

98 

26 

14 

35 

78 

26 

9.4 

12 

1.1 

20 

3.1 

2.5 

3.2 

0.43 

0.39 

0.53 

0.15 

0.19 

0.13 

0.08 

0.03 

HALOGENATED 

COMPOUND 

5.2 

86 

b 

1.4 

0.62 

4.0 

0.88 

1.4 

0.41 

0.14 

1.4 

0.15 

0.06 

ALL TARGET 

HYDROCARBONS 

637 

249 

234 

60 

46 

45 

103 

60 

36 

30 

28 

22 

6.3 

6.1 

3.2 

1.5 

0.54 

0.53 

0.28 

0.25 

0.13 

0.80 

0.03 

a emission rates for cove adhesive are not reported; sample was overloaded. It is estimated that cove adhesive is one of the 

emitters ofVOCs with emissions of target compounds >4700 J.lg/m2

• 

b no detectable emissions 

SOURCE: Sheldon et al. (1988) 
IAQ Reference Manual 

REFERENCES 

Andersen, 1., G.R. Lundqvist, and L. Mfl!lhave. 1975. "Indoor 

air pollution due to chipboard used as a construction material." 

Atm. Environ. 9: 1121-1127. 

Ashford, N.A. and C.S. Miller. 1989. Chemical Sensitivity. A 

Report to the New Jersey State Department of Health. December. 

Bayer, C.W. and M.S Black. 1988. "Indoor air quality 

evaluations of three office buildings." lAQ 88. Engineering 

Solutions to Indoor Air Problems. American Society of Heating, 

Refrigerating, and Air-Conditioning Engineers (ASHRAE): 

Atlanta, GA. pp. 284-293. 

Black, M.S. and C.W. Bayer. 1988. "Pollutant measurement 

methods used in IAQ evaluations of three office buildings." lAQ 

88. E'flgineering Solutions to Indoor Air Problems. American 

Society of Heating, Refrigerating, and Air-Conditioning 

Engineers (ASHRAE): Atlanta, GA. pp. 317-353. 

Dally, K.A., L.P. Hanrahan, M.A. Woodbury, and M.S. 

Kananek. 1981. "Formaldehyde exposure in nonoccupational 

environments." Arch. Environ. H. 36(6): 277-284. 

Dreisbach, R.H. 1980. Handbook of Poisoning. lOth edition. 

Lange Medical Publications: Los Altos, CA. 

"Federal Panel on Formaldehyde Report." 1982. Environ. H. 

Persp. 43: 139-168. 

Hanrahan, L.P., H.A. Anderson, K.A. Dally, A.D. Eckmann, 

and M.S. Kanarek. 1985. "Formaldehyde concentrations in 

Wisconsin mobile homes." ]APCA. 35(11): 1164-ll67. 

Hodgson, M.A. 1988. "Health risks of indoor pollurants." 

IAQ 88. Engineering Solutions to Indoor Air Problqms. American 

Society of Heating, Refrigerating, and Air-Conditioning 

Engineers (ASHRAE): Atlanta, GA. pp. 284-293. 

International Agency for Research on Cancer (!ARC). 1982. 

"Formaldehyde." IARC Monographs on the Evaluation of the 

Carcinogenic Risk of Chemicals to Humans. Vol. 29: Some Industrial 

Chemicals and Dyestuffs. Lyon, France. World Health Organization: Geneva, Switzerland. pp. 345-389. 

Kerns, W.D., K.L. Pavkov, D.J. Donofrio, E.J. Gralla, and J.A. 

Swenberg. 1983. "Carcinogenicity of formaldehyde in rats and 

mice after long-term inhalation exposure." Cancer Research. 43: 

4382-4392. 

Kjaergaard, S., L. M¢lhave, and O.F. Pedersen. 1987. "Hutnan 

reactions to indoor air pollution: n-decane." Indoor Air '87. 

Vol. 1. Volatile Organic Compounds, Combustion Gases, Particles and 

Section 4 

Fibres, Microbiological Agents. Oraniendruck GmbH: Berlin, 

Ge~~ny. pp. 97~101. . 

Mfl!lhave, L., B. Bach, and O.F. Pedersen. 1987. "Human 

reactions to low concentrations of volatile organic compounds." 

Env. Inti. 8: 117-127. 

National Research Council (NRC). 1980. Formaldehyde--an 

assessment of its health effects: Report to the U.S. Consumer Product 

Safety Commission. National Academy Press: Washington, DC. 

National Research Council (NRC). 1981. Indoor Pollutants. 

National Academy Press: Washington, DC. 

Olsen, J.H. and M. D¢ssing. 1982. "Formaldehyde induced 

symptoms in day-care centers." Am. Ind. Hyg. Assoc.]. 43: 

366-370. 

Ozkaynak, H., P.B. Ryan, L.A. Wallace, W.C. Nelson, andJ.V. 

Behar. 1987. "Sources and emission rates of organic chemical 

vapors in homes and buildings." Indoor Air '87. Vol. 1. Volatile 

Organic Compounds, Combustion Gases, Particles and Fibres, 

Microbiological Agents. Oraniendruck GmbH: Berlin, Germany. 

pp. 3-7. 

Riggin, R.M. and B.A. Petersen. 1985. "Sampling and 

analysis methodology for semivolatile and nonvolatile organic 

compounds in air." Indoor Air and Human Health. R.B. 

Gammage, S.B. Kaye, and V.A. Jacobs (eds). Lewis Publishers,: 

Chelsea, MI. pp. 351-358. 

Ritchie, I.M. and R.G. Lehnen. 1985. "An analysis of 

formaldehyde concentrations in mobile and conventional 

homes."]. Environ. H. 47(6): 300-305 .. 

Rosenberg,]. 1990. "Solvents." Chap. 27. Ocmpational 

Medicine. J. LaDou (ed}. Appleton & Lange: Norwalk, CT. 

Sardinas, A.V., R.S. Most, M.A. Giulietti, and P.Honchar. 

1979. "Health effects associated with mea-formaldehyde foam 

insulation for Connecticut." ]. Environ. H. 41(5): 270-272. 

Seifert, B. and H.J. Abraham. 1982. "Indoor air concentrations 

of benzene and some other aromatic hydrocarbons." Ecotox. 

Environ. Safety. 6: 190-192. 

Sexton, K., K. Liu, and M.X. Petreas. 1986. "Formaldehyde 

concentrations inside private residences: A mail-out approach 

to indoor air monitoring." ]APCA. 36(6): 698-704. 

Sheldon, L., H. Zelon,J. Sickles, C. Eaton, and T. Hartwell. 

1988. Indoor Air Quality in Public Buildings. Vol. II. U.S. 

Environmental Protection Agency, Environmental Monitoring 

Systems Laboratory, Office of Research and Development: 

Research Triangle Park, NC. 

II 
Section 4 

Sterling, D.A. 1985. "Volatile organic compounds in indoor 

air: An overview of sources, concentrations, and health effects." 

Indtmr Air and Human Health. R.B. Gammage, S.B. Kaye, and 

V.A. Jacobs (eds). Lewis Publishers: Chelsea, MI. pp. 387-

402. 

Stock, T.H. and S.R. Mendez. 1985. "A survey of typical 

exposures to formaldehyde in Houston area residences." Am. 

Ind. Hyg. Assoc.]. 46(6): 313-317. 

Tancrede, M., R. Wilson, L. Zeise, and E.A.C. Crouch. 1987. 

"The carcinogenic risk of some organic vapors: A theoretical 

survey." Atm. Environ. 21(10): 2187-2205. 

Tucker, W.G. 1988. "Emissions of air pollutants from indoor 

materials: An emerging design consideration." 5th Canadian 

Building & Constroction Congress. Montreal, Canada. November 

27-29. 

Turiel, I. 1985. Indoor Air Quality and Httman Health. Stanford 

University Press: Stanford, CA. 

U.S. Consumer Product Safety Commission (CPSC). 1982. 

"Part IV: Ban of urea-formaldehyde foam insulation, withdrawal of proposed information labeling rule, and denial of 

petition to issue a standard." Federal Register. 47(64): 14366-

14421. 

U.S. Consumer Product Safety Commission (CPSC). 1986. 

Briefing Package on Formaldehyde Emissions from Urea-Formaldehyde 

Prmed \Vood Prod11cts. U.S. CPSC: Washington, DC. 

U.S. Department of Housing and Urban Development (HUD). 

1984. "Manufactured home construCtion and safety standards; 

final rule." Federal Register. 49{155): 31995-32013. 

U.S. Environmental Protection Agency (EPA). 1987a. 

Assessment of Health Risks to Garment Workers and Certain Home 

Residenu from Expostm to Formaldehyde. U.S. EPA, Office of 

Pesticides and Toxic Substances: Washington, DC. 

U.S. Envi(onmental Protection Agency (EPA). 1987b. 

Hemehold Solt~tnt Prodtll:ts: A National Usage Survey. Final 

Report. U.S. EPA, Office of Pesticides and Toxic Substances: 

Washington, DC. 

U.S. Environmental Protection Agency (EPA). 1989. Report to 

Congress on ImU!or Air Quality. Vol. II. Assessment and Control of 

lndtmr Air Pollution. EPA 400/1-89-00lC. U.S. EPA: 

Washington, DC. 

van de( Wal,J.F., A. M.M. Moons, and R. Steenlage. 1987. 

uThermal insulation as a source of air pollution." Indoor Air '87. 

IAQ Reference Manual 

Vol. I. Volatile Organic Compounds, Combustion Gases, Particles 

and Fibres, Microbiological Agents. Oraniendruck GmbH: Berlin, 

Germany. pp. 79-83. 

Wallace, L.A., E. Pellizzari, T. Hartwell, C. Sparacino, and H. 

Zelon. 1983. "Personal exposures to volatile organic and other 

compounds indoors and outdoors-The TEAM Study." 

Presented at the 79th Annual Conference of the Air Pollution 

Control Association. Atlanta, GA. Paper #83.912. 

Wallace, L.A. 1986. "Cancer risks from organic chemicals in 

the home." Environmental Risk Management: Is Analysis Useful? 

Proceedings. Air Pollution Control Association: Chicago, II.. 

Publication #50-55. 

Wallace, L.A. 1987. The Total Exposure Assessment Methodology 

(TEAM) Study: S11mmary and Analysis: Vol. I. EPA/600/6-87-

002a. U.S. Environmental Protection Agency, Office of 

Research and Development: Washington, DC. 

World Health Organization (WHO). 1983. Indoor air 

pollutants: Exposure and health effects. WHO Working Group on 

Assessment and Monitoring of Exposure to Indoor Pollutants: 

Copenhagen, Denmark. 

4.4. BIOLOGICAL CONTAMINANTS 

The home and workplace can harbor a 

variety of airborne allergens and pathogens. About 

50% to 60% of all community acquired illness is 

due to respiratory infections and most of these are 

caused by viruses (Feeley, 1985); but, bacterial 

diseases and allergic reactions caused by biological 

sources can pose significant problems in homes and 

public facilities such as day care centers, hospitals, 

hotels, nursings homes, schools, and office buildings 

(Feeley, 1985). 

Pathogens and Illness 

Biogenic agents (those produced by living organisms) in the indoor environment generally have 

limited direct toxicity, and more often, result in 

infection or allergic responses. The term bioaerosol 

refers to biogenic agents that are airborne. 

Most viral and bacterial diseases are spread by direct 

person to person contact (kissing, hugging, touch-
IAQ Reference Manual 

ing) or indirectly as a result of droplets in air which 

are produced by talking, sneezing, and coughing. 

In addition to these modes of transmission, some 

evidence suggests that these diseases can be transmitted through building-related airborne pathways 

(such as the heating, ventilating, and air-conditioning system). For example, an epidemic of measles 

(28 cases after an incubation period of about 10 

days) in an elementary school near Rochester, New 

York was traced to a student in the second grade 

and a ventilation system that served fourteen 

classrooms. The ventilation system recirculated air 

from room to room before being exhausted outside. 

The investigators concluded that the ventilation 

system was responsible for the outbreak since the 

student did not occupy the same room as the other 

children who became infected (Riley et al., 1978). 

In a more recent study, Brundage et al. (1988) 

demonstrated that army trainees who were housed 

in new energy-efficient barracks with mechanical 

ventilation had acute febrile respiratory disease rates 

that were 51% higher, on average, than trainees 

who were housed in older barracks. These results 

support the hypothesis that risks of respiratory 

infection are increased among susceptible populations in buildings that have tightly sealed envelopes 

and closed ventilation systems. 

Infectious agents can also enter the indoor environment from the outside air. Once inside, they can be 

incubated, amplified, and disseminated by humidifiers, air conditioners, and other building components. 

Legionella 

Legionella is a major cause of respiratory illness 

worldwide and accounts for 1-13% of all 

pneumonias seen in hospitals in the United States, 

Canada, England, and Germany (Feeley, 1985). The 

bacteria are ubiquitous and can survive in water for 

long periods of time-up to a year under certain 

conditions (Skaliy and McEachern, 1979). 

Section 4 

Epidemics caused by Legionella occur most commonly during the summer and early fall while 

sporadic cases of disease occur throughout most of 

the year. The characteristics and causes of some of 

these epidemics are discussed in Imperato (1981) 

and Band et al. (1981). 

Sources of Legionella in residences and office buildings include contaminated forced-air heating 

systems, humidifiers, water flooding, hot water 

systems, hot tubs, vaporizers, nebulizers, and 

external sources, primarily cooling towers and 

evaporative condensers but also dusts from construction and landscaping activities. Legionella has also 

been isolated from potable drinking water. 

Two important bacterial diseases which are both 

caused by Legionella pneumophila are Legionnaires' 

disease and Pontiac fever. These two diseases, which 

are referred to as legionellosis, are not spread via 

person-to-person contact. Rather, they can be 

spread both indoors and outdoors through the soil/ 

air or water/air link. 

Legionnaires' disease: One of the most dramatic 

and frightening cases of indoor airborne bacterial 

infections is the mysterious illness that affected 

veterans attending the American Legion Convention 

in Philadelphia in 197 6. A pneumonia-like illness 

was contracted by 182 persons who were either in or 

near the Bellevue Stratford HoteL Twenty-nine 

people died (Fraser et al., 1977). The organism that 

caused the disease, a gram negative bacillus named 

Legionella pneumophila was first isolated in 1977 at 

the Centers for Disease Control. The illness, named 

after the group that was most affected in 1976, has 

come to be known as Legionnaires' disease. 

Legionnaires' disease is a form of legionellosis that is 

a very severe multi -systemic illness that can affect 

the lungs, gastrointestinal tract, central nervous 

system, and kidneys. It is characterized by a low 

attack rate (2-3%), long incubation period (4-10 

days), and severe pneumonia. Hospitalization is 

required and about 2-3% of cases are fatal even with 
Section 4 

proper treatment. It has been estimated that in the 

U.S., Legione!la species account for 8% to 10%, or 

50,000 to 60,000 cases of community-acquired 

pneumonias (Fang, 1988). 

Pontiac fever: Pontiac fever was first recognized in 

1968 when, during a one-week period, 95 of 100 

employees at the Oakland County Health Department in Pontiac, Michigan became ill with a flulike illness (Glick eta!., 1978). Although a causative agent was not conclusively demonstrated, L. 

pneumophila was implicated 10 years later based on 

indirect fluorescent antibody rests on sera from 

patients who came down with the illness. The airconditioning system was identified as the source and 

mode of transmission of the agent. 

Pontiac fever is a milder clinical form of 

legionellosis. It is characterized by a high attack 

rate (90%) and a short incubation period (2-3 days). 

It is not fatal and it can be resolved without hospitalization. Characteristic symptoms include fever, 

chills, headache, and muscle ache; additional 

symptoms may include sore throat, coughing, 

nausea, diarrhea, and chest pain. 

Allergens 

The term "allergic reaction" or "sensitization 

reaction" refers to a condition in which an immune 

response results in exaggerated or inappropriate 

reactions that are harmful to the host. An individual 

typically experiences an allergic reaction after the 

second contact with a specific allergen. In order for a 

substance to produce an allergic reaction, the 

substance or metabolic product of the substance has 

to act as a hapten and combine with an endogenous 

protein to form an antigen. The antigen is capable 

of eliciting the formation of antibodies. The initial 

exposure results in an antigen-antibody interaction 

which results in the manifestation of allergy. 

Allergies are commonly acquired health problems 

which are mediated by a variety of immunologic 

processes. The substances that cause allergies are 

IAQ Reference Manual 

called allergens or antigens. The term airborne 

allergen refers to allergens that are carried by the 

air. 

Allergens do not affect most people; rather, they 

provoke an allergic response in a small subset of the 

population. Allergens that cause reactions include 

both viable and nonviable agents. Viable agents 

include bacteria, fungi, amoebae, and algae. Common nonviable agents include house dust, insect and 

arachnid body parts and hulks, animal danders, mite 

fecal pellets, cockroach feces, remains of molds and 

their spores, pollens, and dried animal excretions. 

Chemicals found in the home or workplace (plastics, 

metals, pharmaceuticals, detergents, hair dyes, 

bleaches) are not biogenic agents, but they have 

been known to produce allergic reactions in sensitive individuals. 

Illness Caused By Allergens 

Several patterns of illness can arise from exposure to 

allergens including allergic reactions on the skin, in 

the nose, in the airways, or in the alveoli. It is not 

known why some people are allergic to otherwise 

harmless pollen grains or other airborne particles, 

but it is presumably due to differences in their 

immune systems. These differences may be partly 

genetic since allergy-based diseases (allergic rhinitis, 

asthma, contact dermatitis) often run in families. It 

has been estimated that about 20% of the U.S. population may have a genetic predisposition toward 

allergies (Burge, 1988). 

In the respiratoty tract, allergic reactions begin with 

a localized inflammatory reaction that may eventually be accompanied by secondary effects such as 

bacterial colonization (NRC, 1981). The airborne 

allergens that have the most potential to affect the· 

lower lung are those with small aerodynamic 

diameters including molds and organic dusts. Most 

pollens have diameters greater than 12 microns and 

will affect the upper respiratoty tract, but some may 

reach the lower portions of the lung. 
IAQ Reference Manual 

Several important conditions are caused by airborne 

allergens including allergic rhinitis, allergic asthma, 

allergic bronchopulmonary aspergillosis, hypersensitivity pneumonitis, and humidifier fever. 

Allergic rhinitis: Allergic rhinitis is an acute 

condition that resolves readily when the source is 

removed. It is commonly called "hay fever" when it 

is related to pollens produced by the change of 

seasons, and it affects about 15% of the population. 

It is characterized by dilation and edema of the nasal 

mucosa a!ld mucus secretion; typical symptoms 

include sneezing, itching, excessive mucus secretion, 

and obstruction of nasal passages. Conjunctivitis 

(irritation, itching, and reddening of the eyes) may 

also be associated with allergic rhinitis. Secondary 

bacterial infections may result from blocked sinuses 

and eustachian tubes. 

Allergic asthma: Allergic asthma affects about 3% 

to 5% of the population in the U.S. (Reed, 1981). 

It is characterized by bronchospasm, edema of the 

bronchial mucosa, accumulation of bronchial 

mucus, or any combination of these conditions. The 

narrowing of the airways and production of mucus 

can block the airways. Typical symptoms include 

wheezing, shortness of breath, sneezing, itching of 

the nose, and rhinorrhea. Repeated attacks can lead 

to a narrowing of the airways which is reversible 

over short periods of time (spontaneously or with 

treatment). 

Allergic asthma can be caused by a variety of viable 

and nonviable biological agents. Factors related to 

indoor air quality such as cigarette smoke, sulfur 

dioxide, and other particles and gases can precipitate 

attacks. Emotional stress and exposure to cold have 

also been shown to result in asthmatic attacks. 

Allergic bronchopulmonary aspergillosis (ABPA): 

ABPA is an uncommon, progressive disease that is 

caused by an allergic reaction to the inhalation of a 

widely distributed soil fungus, Aspergillus fumigatus. 

Spores are about 3 microns in diameter and grow at 

Section 4 

body temperatures. Episodes of ABPA most 

frequently occur during the winter when the counts 

of Aspergillus fumigatus are highest. 

Other species of Aspergillus can also result in a 

variety of syndromes. ABPA is characterized by 

recurrent episodes of pulmonary eosinophilia, 

usually associated with asthmatic attacks. As the 

disease progresses, bronchiectasis (dilation of the 

bronchial tubes associated with significant mucus 

production), irreversible airway narrowing, and 

pulmonary fibrosis may occur in the upper lobes of 

the lung. Typical symptoms include coughing, 

wheezing, difficulty breathing, and low-grade fever. 

Hypersensitivity pneumonitis: Hypersensitivity 

pneumonitis (also called extrinsic allergic alveolitis) 

is primarily an occupational disease of agricultural 

and industrial workers who are exposed to sensitizing agents in organic (especially fungal spores) and 

inorganic dusts. However, it can and does occur as a 

result of exposures to sensitizing agents in residential and office environments. Some examples of 

hypersensitivity pneumonitis include pigeonbreeder's or bird-fancier's lung which is caused by 

the inhalation of serum proteins in the droppings of 

pigeons and parakeets. The attack rate has been 

estimated to be between 0.1% and 21% in pigeon 

breeders (Parkes, 1982). The inhalation of thermophilic actinomycetes (a group of filamentous 

bacteria that superficially resemble fungi) growing 

in moldy hay can produce farmer's lung. Exposure 

to inorganic compounds such as toluene diisocyante 

(isocyanate lung) and copper sulfate (vineyard 

sprayer's lung) can also produce pneumonitis. 

Expsoure to thermophilic actinomycetes in residential or office ventilation systems can result in 

ventilation pneumonitis. Fungi which have been 

implicated in ventilation pneumonitis include 

Aspergillus, Pencillum, Alternaria, Rhizopus, 

Paecilomyces, and Aureobasidium. Regardless of the 

agent, estimated rates of pneumonitis in office 

workers range from 1.2% (Arnow et al., 1974) to 

4% (Gamble et. al., 1986). 
Section 4 

Hypersensitivity pneumonitis can result from 

intermittent exposure to high concentrations of 

allergens or continuous exposure to low concentrations of allergens. The symptoms and progression 

of the disease are the same, regardless of the agent 

causing the disease (NRC, 1981). Continuous 

exposure to low concentrations of allergens often 

does not result in the appearance of overt symptoms, 

but at a later time, less reversible stages of the 

disease can develop. 

Sensitization causes an inflammatory reaction in the 

alveolar walls and peripheral bronchioles due to an 

allergic reaction between the agent and circulating 

antibodies and sensitized lymphocytes. The diagnosis of hypersensitivity pneumonitis is made by the 

physician based on the patient's history and results 

of some tests. These include restrictive pulmonary 

function tests, decreased exercise tolerance, granulomas and interstitial fibrosis on lung biopsy, reproduction of symptoms upon bronchial challenge with 

the suspected agent, and response to corticosteriod 

medications (Kreiss, 1989). 

An acute attack causes symptoms which are similar 

to the flu: chills, fever, dry cough, shortness of 

breath, tightness in the chest, and fatigue. Symptoms typically occur within 4 to 6 hours after 

exposure, and may persist for 12 hours to 10 days. 

Changes in lung function can return to normal over 

a period of about a month after the condition 

develops. Between attacks, the individual may be 

symptom free and feel fine. Over a period of time, 

the lung gradually develops fibrous scar tissue. 

Irreversible pulmonary fibrosis, followed by pulmonary failure, and death can occur in severe cases. 

Humidifier fever is a type of pneumonitis that is 

probably due to allergic reactions of the alveolar 

wall. It has been related to amoebae, bacteria, and 

fungi. Bacillus subtilis (Parrot and Blyth, 1980), 

amoebae including A. polyphaga and N. gruberi 

(Edwards, 1980), and bacterial endotoxin (Rylander 

et al. 1978, 1984) are specific agents which have 

been implicated in this condition. Sources of the 

these agents include humidifier rese~oirs, air 

IAQ Reference Manual 

coolers, air conditioners, spas, and aquaria. 

The disease is characterized by episodes of flu-like 

symptoms (chills, muscle aches, malaise) and fever 

without prominent pulmonary symptoms and signs. 

Symptoms develop 4 to 8 hours after exposure and 

resolve spontaneously, usually within 24 hours 

without long-term effects. Lung function changes 

may include a restrictive ventilatory defect with a 

decrease in gas transfer that improves over a period 

of days. Pulmonary fibrosis does not occur and 

chest x-rays do not show abnormalities (NRC, 

1981). 

Chronic humidifier fever has been reported from 

residential humidifiers (Kreiss and Hodgson, 1984), 

but the prevalence of the disease (acute and chronic 

forms) in the home environment has not been 

evaluated. In Great Britain, an attack rate of 2% to 

3% has been estimated in office buildings with 

mechanical ventilation based on reports of symptoms (Finnegan et al. 1984). Epidemics in the 

workplace are rare, but when they do occur, attack 

rates are high (30% to 75%). 

An additional potential problem associated with the 

use of some types of humidifiers is the formation of 

fine particles during the operation of the humidifier. 

Highsmith et al. (1988) measured fine particle 

concentrations greater than 590 !Jg/m3 when an 

ultrasonic humidifier was operated in a kitchen 

using tap water containing 303 mg/1 total dissolved 

solids. Using distilled water does reduce, but not 

eliminate, the formation of fine particulates. Even 

when the ultrasonic humidifier was operated using 

purchased distilled water, whole house fine particulate concentrations greater than 40 !Jg/m3were 

measured. Fine particle concentrations greater than 

6300 !Jg/m3 were measured when the ultrasonic 

humidifier was operated in a closed room situation. 

Even when distilled water was used by the manufacturer, fine particles were generated. Impeller units 

generated less than one-third of the aerosol mass 

compared to the ultrasonic units, and steam units 

generated no measurable increase in fine particles. 
IAQ Reference Manual 

The health consequences of these particulates have 

not been evaluated. 

Allergenic Agents 

House Dust Mite 

One important agent that has been implicated in 

allergenic conditions such as allergic rhinitis or 

allergic asthma is the house dust mite. It is not the 

actual house dust mite that causes disease, but 

allergens which are probably present in the excreta 

of the mite, some of which is of inhalable size 

(Tovey eta!. 1981). The highest levels of allergens 

from house dust mites that occur indoors have been 

shown to be associated with respirable particles in 

the size range 0.8 to 1.4 microns (Reed and 

Swanson, 1984). 

The house dust mite, which is an arachnid, is about 

300 microns long, and it can be found in almost 

every home. Mites are translucent and cannot be 

seen with the naked eye. The most commonly 

found mites include Dermatophagoides pteronyssinus (in 

Europe) and D. farinae (in North America) (NRC, 

1981). 

Mite populations vary depending on atmospheric 

moisture and food sources. Growth is favored by a 

temperature of 25 oc and a relative humidity greater 

than 45%. Below 45% RH at 20 oc to 22 oc, 

almost no house dust mites are able to survive 

(Korsgaard, 1982). 

House dust mites are important causes of allergic 

rhinitis and asthma in climates with hum1d, mild 

conditions (NRC, 1981). In North America, the 

mite population is at a maximum during the 

summer when windows are open and ventilation is 

good; levels drop in winter when the heating season 

begins and the relative humidity drops to 10% to 

20% (Arlian eta!., 1982). 

Dust mites feed on the skin scales of humans and 

other animals. The mites, however, cannot feed on 

Section 4 

new skin; rather, they require skin scales that have 

been defatted. This explains why these mites are 

found in mattresses, bedclothes, and heavily used 

upholstered furniture. High concentrations of other 

specialized mites that cause allergic conditions can 

also be found in interior spaces that are used to store 

or process agricultural products. 

Fungi 

Fungi are a major group (over 100,000 species) of 

chlorophyll-less eukaryotic organisms which are 

formed by hyphae with chitinous or cellulosic rigid cell 

walls. Most fungi are saprophytic (live off dead organic 

matter for food), and some fungi require specific 

substrates for growth and reproduction (dung and 

wood-rotting fungi, for example). Many can use any 

nonliving organic matter, providing temperature and 

moisture conditions are met. 

Fungi reproduce either by specialized cells (spores) 

that are produced on fruiting branches or by 

fragmentation of the fungus body (mycelium). 

Fungi have both sexual and asexual stages which can 

result in allergenic effects, and there may be more 

than one spore type for each stage. The identification of fungi and spores can be difficult. Many 

fungi cannot be identified without fruiting structures. Another complicating factor is that fungal 

names have undergone changes, and the names for 

the various life cycle stages may be different because 

they were described at different times (Burge, 

1985). 

Major fungi classes of interest include Zygomycetes, 

Ascomycetes (powdery mildews), Basidiomycetes 

(rusts, smuts, mushrooms), and a fourth class 

Deuteromycetes or Fungi Imperfecti, which is an 

artificial grouping of asexual fungus stages (Burge, 

1985). The imperfect fungi are perhaps the most 

important class from an indoor air quality perspective because this dass includes Aspergillus, 

Cladosporium, Alternaria, Penicillium, and other 

saprophytes which are commonly found indoors. 
Section4 

Any organic material that is wet can support the 

growth of fungi. In the outdoor environment fungi 

can utilize soil, animal and bird droppings, dead 

leaves, grass, tree bark, dead wood, and fallen fruits. 

Indoors, any damp, nonliving organic surface can be 

colonized by fungi; these surfaces include carpet, 

upholstery fabric and fillers, wood, concrete, painted 

surfaces, wall coverings, soap scum on tiles and 

porcelain surfaces. Humidifiers and air conditioners 

can also serve as reservoirs for fungi. Some fungi 

have even become adapted to growth in dry house 

dust environments (Rijckaert, 1981) and carpeting 

that is not water damaged (Gravesen et al., 1986). 

ltfeamred concentrations: The most abundant 

spore types are produced continuously outdoors 

during the growing season at concentrations 

ranging from 103 to 105

/m3; these fungi can reach 

levels of 10° to 104

/m3 indoors. In the outdoor 

environment, airborne spore concentrations are 

reduced in areas with snow cover (dispersion of 

spores is prevented) and where temperatures fall 

below freezing (spore production is decreased). 

Spore counts are usually highest in late summer and 

autumn, although Aspergillus fumigatus is more 

common in autumn and winter (NRC, 1981). 

Spores may be introduced into the home from the 

outside or result from unrestrained growth inside if 

conditions are favorable. Exhibit 4-15 identifies 

some fungi which have been isolated indoors. 

In the ambient air, concentrations of Aspergillus 

fitmigatrts rarely exceed 150 spores/m3, but concentrations in specific sources such as compost piles can 

exceed several million spores/m3• The concentration 

in dean interiors is also low, ranging from 0 to 200 

spores/m3 (NRC, 1981). Recoveries of thermophilic actinomycetes (filamentous bacteria) in 

domestic air are generally less than 3000 counts/m3 

while occupational exposures can be 10 times higher 

(Burge eta!., 1980). 

Factors such as shading of homes"and organic debris 

outdoors have been found to be significantly 

associated with higher spore concentrations indoors 

IAQ Reference Manual 

(Kozak eta!., 1985). Indoors, there is a direct 

relationship between mold growth and airborne 

spore levels and humidity levels between 25% and 

70% (Burge, 1985). Mold growth is suppressed 

below 25% RH, and humidities above 70% are 

optimal for growth. 

Kozak et al. ( 198 5) reported on sources of fungi 

problems in 186 homes that were surveyed using 

rotorod and Anderson samplers over a period of 4 

years in southern California. Of the 80 homes 

sampled with both types of sampling devices, 63 

had a history of water damage and were suspected of 

having an endogenous mold problem. Forty-nine 

percent of these homes had more than one problem 

area. 

The most likely areas with mold problems were the 

bathroom (31% of cases), living room (18.4%), 

family room/den (16.5%), and a bedroom (11.7%). 

The most likely materials were jute-backed carpeting and baseboards (53.5% of problems), wicker 

straw baskets (17 .5%) and walls, ceilings, and 

window frames (13.6%). The most frequent causes 

were chronic water spills (35% of problems), 

followed by recurrent water leaks from plumbing 

(20.4%) and one-time disasters such as roof leaks 

and structural defects (10%). Exhibit 4-15 provides 

a list of molds identified in 68 California homes. 

Disease-producing fungi: Alternaria, Cladosporium, 

Aspergillus and Merulius lachrymans have been 

identified as important causes of allergic asthma and 

rhinitis. Other spores which may colonize the 

airways include Candida, Scedosporium, Scopulariopsis, 

Geotrichium, and Paecilomyces (NRC, 1981). Exhibit 

4-16 includes a list of fungi that have been reported 

as allergenic. Contact with the respiratory tract 

may be brief, followed by clearance out of the 

airways, or it may be prolonged and followed by 

colonization of the airways. 

Elimination of fungal growth is necessary for sporesensitive individuals, but there is no consensus on 

dose-response relationships. Holmberg (1987) 

found that airborne levels greater than 50 CFU/m3 
IAQ Reference Manual 

of thermotolerant Aspergillus spp. were a significant 

risk factor for irritation of the eyes and respiratory 

symptoms. 

Some clinicians caution allergic patients against 

keeping living plants or processed plant materials in 

their homes because they have been implicated as 

substrates for saprophytic fungi which are allergens. 

However, Burge eta/. (1982), in a study of 10 

homes and 3 greenhouses in Michigan, concluded 

that healthy undisturbed houses are not a major 

exposure source for airborne fungus spores. Samples 

were collected before and after watering and also 

while plant foliage was disturbed by a small fan. 

This study, however, was done in a colder climate 

and the limited results may not apply to continuous~y warm and/or humid environments. 

Other Allergenic Agents 

Insect excretions are strong sensitizers that can 

result in allergic responses. Roach fecal pellets are 

Section 4 

important sensitizers, but carpet beetles, houseflies, 

and bedbugs may also be implicated. 

Domestic animals, particularly cats, but also dogs, 

rabbits, guinea pigs, birds, and horses can be 

important causes of allergic rhinitis and asthmatic 

attacks. It is generally accepted that the source of 

the allergen is animal dander, small scales of 

feathers or hair, or saliva (cat). Animal danders are 

very strong sensitizers, and highly sensitive people 

may develop allergic eczema or urticaria (hives) as a 

result of direct contact with the allergen. The feces 

of birds (parakeets and pigeons) can also result in 

allergic rhinitis, asthma, and hypersensitivity 

pneumonitis; the original source of the allergen is 

serum proteins which are secreted in the gut (Reed 

and Swanson, 1984). 

Some individuals may also be allergic to components in tobacco smoke, chemical cleaners, dyes in 

carpeting, hair sprays, evergreen Christmas trees, 

and other chemical agents. 
rm 

Section 4 IAQ Reference Manual 

Exhibit 4·15. Molds identified in 68 homes in southern California. 

PERCENT OF HOMES 

IN WHICH RANGE OF MEAN OF 

MOLD GENERA GENERA ISOLATED SPORES/m3 SPORES/m3 

Cladospi:ff'ium 100.0 12-4,637 437.7 

Penidllium species 91.2 0 4,737 168.9 

Nomporulating mycelid' 89.7 0-494 44.3 

Alternaria 87.0 0-282 30.7 

Streptomycu 58.8 0-212 28.1 

Epicoccum 52.9 0-153 9.6 

Aspergillus species 48.5 0-306 15.0 

Aureobasidium 44.1 0-294 8.0 

Drechslera (Helminthosporium) 38.2 0-94 6.9 

(;ephalosporium 36.7 0-59 5.3 

Aeremonium 35.3 0-188 3.6 

Fusarium 25.0 0-47 4.5 

Botrytis 23.5 0-54 2.9 

Aspergillus niger 19.1 0-59 2.9 

Rhizopm 13.2 0-24 1.4 

Rhodotorula 11.8 0-29 1.5 

BMm'tra 10.3 0- 12 0.7 

Chaetomium 8.8 0-47 1.2 

Unknot1.1n 8.8 0-34 1.2 

Scopulariopsis 8.8 0-25 0.9 

Mil lOr 7.4 0 41 1.4 

Curvularia 7.4 0 12 1.1 

Rhinocladitlla 4.4 0- 12 0.5 

V trtid/Jium 4.4 0- 12 0.4 

Plenozythia 4.4 0-6 0.3 

Pithomycu 2.9 0 25 0.4 

Zygosporium 2.9 0- 18 0.4 

Paedlomycu 2.9 0- 12 0.3 

Stachybotrys 2.9 0-12 0.3 

Aspergl/lus fumigatm 2.9 0-5 0.2 

Nigrospora 2.9 0-5 0.1 

Styranm 2.9 0-6 0.1 

Pleospora 1.5 0-18 0.3 

Botryosporium 1.5 0-12 0.2 

Trichoderma 1.5 0- 12 0.2 

Chrysosporium 1.5 0-6 0.1 

Phoma 1.5 0-6 0.1 

Sporobo/omy(ts 1.5 0-6 0.1 

Trkhothecium 1.5 0-6 0.1 

Ulocladium 1.5 0 5 0.1 

YMSt 1.5 0-5 0.1 

Geotrichum 1.5 0-3 0.04 

a Subcultures of nonsporulating mycelia from one home (grown on Moyer's multiple media) subsequently produced Torula herbarium 

colonies. 

SOURCE: Kozak P.P.,J. Gallup, L.H. Cummins, and S.A. Gillman. "Factors of importance in determining the prevalence of indoor 

molds." Annals of Allergy. 1979; 43:88-94. Copyright©, The American College of Allergists. Used with permission. 
IAQ Reference Manual 

Exhibit 4·16. Fungi reported as allergenic. 

Myxomycetes 

Fuligo 

Stemonitis 

Lycogala 

I>euteromycetes 

Alternaria 

Cladosporium 

Aspergillus 

Sporobolomyes 

Penicillum 

Epicoccum 

Fusarium 

Candida 

Rhodotorula 

Tilletiopsis 

Phoma 

Botrytis 

Helminthosporium 

Monilia 

Paecilomyces 

Sporotrichum 

Stemphylium 

Trichothecium 

Cephalosporium 

Gliocladium 

Aureobasidium 

Trichoderma 

Coniosporium 

Dicoccum 

Nigrospora 

Torula 

Spondylocladium 

Curvularia 

Epidermophyton 

Trichophyton 

Zygomycetes 

Mucor 

Absidia 

Rhizopus 

Ascomycete - sexual stages 

Xylaria 

Eurotium 

Erysiphe 

Daldinia 

Chaetomium 

Claviceps 

Microsphaera 

Saccharomyces 

Basidiomycetes 

Heterobasidiomycetes 

Puccinia 

Ustilago 

Tilletia 

Urocytis 

Dacrymyces 

Holobasidiomycetes 

Chlorophyllum 

Podaxis 

Agaricus 

Armillaria 

Coprinus 

Hypholoma 

Ganoderma 

Merulius 

Polyporus 

Stereum 

Pleurotus 

Cantharellus 

SOURCE: Adapted from Burge, H. A. 1985. "Fungus Allergens." Clin. Rev. Allergy, 3: 319-329. Used with permission. 

Section4 

1111 
Section 4 

REFERENCES 

Arlian, L.G., I.L. Bersl:ein, andJ.J. Gallagher. 1982. "The 

prevalence of house dust mites, Dermatophadoides spp, and 

associated environmental conditions in homes in Ohio." 

]. Allergy Clin. lmmunot. 69: 527. 

Arnow, P.M.,J.N. Fink, D.P. Schlueter,J.J. Barboriak, G. 

Mallison, S.I. Said, S. Marrin, G.F. Unger, G.T. Scanlon, and 

V.P. Kurup. 1974. "Early detection of hypersensitivity 

pneumonitis in office workers." Am.]. Med. 64: 236-242. 

Band, J.D., M. LaVenture, J.P. Davis, G.F. Mallison, P. Skaliy, 

P.S. Hayes, W.L Schell, H. Weiss, D.J. Greenberg, and D.W. 

Fraser. 1981. "Epidemic Legionnaires' Disease." ]AMA. 245 

(23): 2404-2407. 

Burge, H.A. 1985. "Fungus allergens." C/in. Rev. Allergy. 3: 

319-329. 

Burge, H.A. 1988. "Environmental Allergy: Definition, 

Causes, Control." IAQ 88. Engineering Solutions to Indoor Air 

Problems. ASHRAE: Washington, DC. 

Burge, H.A., W.R. Solomon, and M.L. Muilenberg. 1982. 

"Evaluation of indoor plantings as allergen exposure sources." 

]. Allergy Clin.lmmunol. 70 (2): 101-108. 

Burge, H.A., W.R. Solomon, andJ.R. Boise. 1980. "Microbial 

prevalence in domestic humidifiers." Appl. Environ. Microbial. 

39(4): 840-844. 

Brundage,J.F., R. Scott, W.M. Lednar, D.W. Smith, and R.N. 

Miller. 1988. "Building-associated risk of febrile acute 

respiratory diseases in army trainees." ]AMA. 259 (14): 

2108-2112. 

Bdwards,J.H. 1980. "Microbial and immunological investigations and remedial action afi:er an outbreak of humidifier fever. 

Br.]. Ind. M«i. 37: 55-62. 

Fang, G.D., M.J. Fine,J.J. Orloff, V.L. Yu, J.T. Grayston, S.P. 

Wang, R.B. Kohler, D. Arisumi, R.R. Muder, and W. Kapoor. 

1988. (abstract) "A prospective multi-center study of 359 

cases of communiry-acquired pneumonia." American Society of 

Infet:tious Dittases. 

Feeley,J.C. 1985. "Impact ofindoor air pathogens on human 

health." Chapter 12. Indoor Air and Human Health. R.B. 

Gammage and S.V. Kaye (eds). Lewis Publishers: Chelsea, MI. 

Finnegan, M.J., C.A.C. Pickering, and P.S. Burge. 1984. "The 

sick building syndrome: prevalence studies." Br. Med. ]. 289: 

1573-1575. 

IAQ Reference Manual 

Fraser, D.W., T.R. Tsai, W. Orenstein, W.E. Parkin, H.J. 

Beecham, R.G. Sharrar,]. Harris, G.F. Mallison, S.M. Martin, 

J.E. McDade, C.C. Shepard, and P.S. Brachman. 1977. 

"Legionnaires' disease. Description of an epidemic of pneumonia." N. Engl.}. Med. 297: 1189-1203. 

Gamble,]., P. Morey, T. Richards, M. Petersen, and R.M. 

Castellan. 1986. "Building-related respiratory symptoms: 

problems in identification." IAQ 86. Managing Indoor Air for 

Health and Energy Conservation. ASHRAE: Arlanta, GA. pp. 

16-30. 

Glick, T.H., M.B. Gregg, B. Berman, G.W. Mallison, W.W. 

Rhodes, I. Kasanoff. 1978. "Pontiac fever: An epidemic of 

unknown etiology in a health department. I. Clinical and 

epidemiologic aspects." Amer.]. Epidemiol. 107: 149-160. 

Gravesen, S., L. Larsen, F. Gyntelberg, and P. Skov. 1986. 

"Demonstration of microorganisms and dust in schools and 

offices." Allergy. 41: 520-525. 

Highsmith, V.R., C.D. Rodes, and R.J. Hardy. 1988. "Indoor 

particle concentrations associated with the use of tap water in 

portable humidifiers." Environ. Sci. Techno!. 22(9): 1109-1112. 

Holmberg, K. 1987. "Indoor mould exposure and health 

effects." Indoor Air '87. Vol. 1. Volatile Organic Compounds, 

Combustion Gases, Particles and Fibers, Microbiological Agents. 

Oraniendruck GmbH: Berlin, W. Germany. pp. 637-645. 

Imperato, P.J. 1981. "Legionellosis and the indoor environment." Brt!l. N.Y. Acad. Med. 57 (10): 922-935. 

Korsgaard,J. 1982. "Preventive measures in house-dust 

allergy." Amer. Rev. Resp. Dis. 125: 80-84. 

Kozak, P.P., J. Gallup, L.H. Cummins, and S.A. Gillman. 

1979. "Factors of importance in determining the prevalence of 

indoor molds." Ann. Allergy. 43: 88-94. 

Kozak, P.P., J. Gallup, L.H. Cummins, and S.A. Gillman. 

1985. "Endogenous mold exposure: Environmental risk to 

atopic and nonatopic patients." Indoor Air and Human Health. 

R.B. Gammage and S.V. Kaye (eds). Lewis Publishers: 

Chelsea, MI. 

Kreiss, K. 1989. "The epidemiology of building-related 

complaints and illness." Occupational Medicine: State of the Art 

Reviews. 4(4): 575-592. 

National Research Council (NRC). 1981. Indoor Pollutants. 

National Academy Press: Washington, DC. 
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Parkes, W.R. 1982. Occupational Lung Disorders. 2nd edition. 

Butterworths: London, England. 

Parrott, W.F. and W. Blyth. 1980. "Another causal factor in 

the production ofhumidifer fever." ]. Soc. Occup. Med. 30: 

63-68. 

Reed, C.F. 1981. "Allergic agents." Bull. N.Y. Acad. Med. 57 

(lO): 897-906. 

Reed, C.E. and M.C. Swanson. 1984. "Indoor allergens: 

identification and quantification." Indoor Air. Vol. 1. Recent 

Advances in the Health Sciences and Technology. Swedish Council 

for Building Research: Stockholm, Sweden. pp. 99-108. 

Riley, E.C., G. Murphy, and R.L. Riley. 1978. "Airborne 

spread of measles in a suburban elementary school." Amer.J. 

Epidemiol. 107: 421-432. 

Rijckaert, G. 1981. "Exposure to fungi in modern homes." 

Allergy. 36: 277-279. 

Section 4 

Rylander, R., P. Haglind, M. Lundholm, I. Mattsby, and K. 

Stenqvist. 1978. "Humidifier fever and endotoxin exposure." 

Clin. Allergy. 8: 511-516 .. 

Rylander, R. and P. Haglind. 1984. "Airborne endotoxins and 

humidifier disease." Clin. Allergy. 14: 109-112. 

Rylander, R., P. Haglind, M. Lundholm, I. Mattsby, and K. 

Sarsfield. 1974. "Mite-sensitive asthma of childhood: Trial of 

avoidance measures." Arch. Dis. Childhood. 49: 716-721. 

Skaliy, P. and H.V. McEachern. 1979. "Survival ofLegionnaires' disease bacterium in water." Ann. Intern. Med. 90: 662-

663. 

Tovey, E.R., M.D. Chapman, and T.A.E. Platts-Mills. 1981. 

"Mite faeces are a major source of house dust allergens." Nature. 

289: 592-593. 

SECTION 5. 

CONTROL OF INDOOR AIR 

CONTAMINANTS 

This section supplements Lesson 5 of 

the Learning Module, which covers 

various options for controlling indoor 

air quality, and Section 8 of the 

Reference Manual, which provides 

inspection techniques for specific 

contaminants. Section 5.1 contains 

an overview of heating and distribution systems, and a general discussion 

of moisture control in residences. 

Section 5.2 describes types of air 

cleaners and methods for testing their 

efficiency. It provides a summary of 

the ASHRAE (Standard 52-1976) and 

ANSI/AHAM (~dard AC-1-1988) 

methods for evaluating air cleaners. 

Section 5.3 consists of Exhibits 5-12 

and 5-13, which are referenced in the 

Learning Module, and which provide 

listings of public interest, professional, and trade associations that are 

involved in controlling indoor air 

contaminants. 

Table of Contents 

Section 5 .1. Residential Heating Systems and Moisture 

Control 

Section 5.2. Evaluation of Air Cleaners 

Section 5.3. Public and Private Sector Organizations 

Involved In Indoor Air Quality Activities 

Lists of Exhibits 

Exhibit 5-l. Oil furnace installation. 

Exhibit 5-2. Gas-fired forced-air furnace configurations. 

Exhibit 5-3. Forced-air distribution systems. 

Exhibit 5-4. Installation of a vapor retarder in the attic. 

Exhibit 5-5. Installation of a vapor retarder in the 

crawl space or floor. 

Exhibit 5-6. Installation of a continuous vapor retarder. 

Exhibit 5-7. Attic ventilation strategies. 

Exhibit 5-8. Sizing factors for different vent coverings. 

Exhibit 5-9. Comparative performance of viscous 

impingement and dry media filters. 

Exhibit 5-10. Estimated percentage of particle removal 

for portable air cleaners by CADR and by 

room size. 

Exhibit 5-11. Minutes to achieve 90% removal of 

airborne particles. 

Exhibit 5-12. Public interest organization indoor air 

activities. 

Exhibit 5-13. Professional and trade association indoor 

air activities. 

116 

131 

135 

118 Ill 

119 

120 

125 

126 

128 

129 

130 

132 

134 

135 

136 

137 
Sectiotz 5 

5.1. RESIDENTIAL HEATING SYSTEMS AND 

MOISTURE CONTROL 

RESIDENTIAL HEATING SYSTEMS 

Types of Heating Systems 

The purpose of heating and cooling 

systems is to provide sufficient warmth during the 

winter and adequate ·cooling during the summer 

without discomfort to the occupants. There ate 

many potential heating and cooling system configurations for residential use. These include conventional gas or oil furnaces, continuous condensing 

furnaces, electric furnaces and heaters, heat pumps, 

fireplaces and woodstoves, coal furnaces, and 

hydronic (hot water) heating systems. 

Older homes (more than 50 years old) are likely to 

have a gravity furnace, hot water, or steam system. 

Homes built during the last few decades are likely 

to have forced-air systems, but some may have 

hydronic systems in which water is pumped 

through pipes and radiators. Hydronic systems 

were used after World War II in houses built on 

concrete slabs. Newer houses may have heat pumps 

or continuous condensing furnaces. And houses of 

all types and ages could have fireplaces and/or wood 

stoves for primary or supplementary heating. 

Hot Air Systems 

Gravity systems: Gravity-air systems consist of a 

furnace that heats air which is circulated through a 

ducting system. The gravity-air system has a 

furnace (often called an octopus) that occupies a 

large portion of a basement with large "arms" 

(delivery and return ducts) that extend from the 

furnace. 'The furnace is basically a metal box inside 

a larger one. As fuel burns, air in the larger box is 

heated and flows through individual ducts to the 

heat registers in different rooms. As the air cools, it 

sinks and travels back through the return air ducts 

to the furnace where the air is heated again. Combustion gases are exhausted through a chimney. 

Since there are no moving parts, this system is very 

IAQ Reference Manual 

quiet. Humidifiers can be attached, but this system 

cannot accommodate other air cleaning equipment. 

Cold spots typically result along outer walls during 

cold days in houses that are not well insulated. 

Forced-air systems: The forced-air system is similar 

to the gravity system, but it has a blower driven by 

an electric motor which pulls the cold air into the 

return ducts, blows it through the heat exchanger in 

the furnace, and back into the hot air ducting. 

Another difference is that the cold air ducts tun to a 

main return duct from each room return rather than 

to the individual ducts as in a gravity system. 

Forced-air systems are more efficient than gravity 

systems; the furnace does not need to be centrally 

located, and smaller furnaces can be used. The 

furnace can be located in a basement, attic, garage, 

or first floor of the house. Humidifiers and aircleaning equipment can be accommodated. Forcedair systems are generally more comfortable because 

. heat stratification is reduced. 

Hot Water (Hydronics) Systems 

Gravity systems: Hydronic gravity systems (hot 

water or steam) work on the same principle as the 

gravity-air system. Hot water (or steam) rises up 

though a boiler into pipes that connect to radiators. 

Water flows through the radiators and back to the 

boiler where it is heated again. These systems 

provide even heat, but they may be slow to respond 

to demands for more heat. 

Pump driven systems: The hydronic pump driven 

system is the hot water equivalent of a forced-air 

system. This system is more efficient than the hot 

water gravity system and the boiler and pipes can be 

smaller. The boiler can be installed anywhere. . 

Water can be carried through the radiators by a 

series loop, one-pipe, or two-pipe systems. I 

I 

Electric Baseboard Heating Systems 

Electrical baseboard heating systems can be installed 

for whole house heating or localized heat. The 
IAQ Reference Manual 

system usually has one or more baseboards in each 

room, and each unit in a room can be individually 

controlled. This system does not require flues or 

chimneys. Baseboard units are typically resistance 

coils or antifreeze units. 

Gas/Oil Furnaces 

Conventional gas and oil furnaces are similar except 

that the burners (and fuel) are different. Most gas 

furnaces have a burner with a number of jets; some 

have a single large jet in which the flame is spread 

by a deflector plate. Both types commonly have a 

pilot light which heats a thermocouple that holds 

open an electrical valve that supplies gas to the 

furnace. Oil furnaces have a combustion chamber 

into which -oil is pumped through a spray nozzle 

and mixed with air which is blown into the chamber. The oil burner does not have a pilot light; 

instead, it is ignited by a high-voltage spark across a 

pair of electrodes positioned directly in the stream 

of oil and air. Exhibit 5-1 shows typical installations for oil furnaces in older homes. 

In conventional natural-draft furnaces, the gas is 

supplied to the burner at low pressure and mixed 

with the required amount of air for combustion. 

The hot gases pass through a heat exchanger where 

air (or water) is heated, and the waste gases are then 

vented through a chimney to the outside. These 

systems are inefficient (flue gas ·temperatures are 

300°F to 500°F) and large quantities of hot air can 

escape up the chimney even when the chimney is 

not operating because the draft hood and combustion chamber are open to the flue. 

Mechanical (also called powered) combustion 

furnaces utilize a small electric fan to move the 

combustion gases; they do not need a chimney or 

draft hood, which increases efficiency. Combustion 

gases exit through a small vent, usually to an 

outside wall. If the blower is located upstream of 

the heat exchanger, the system is called a forceddraft system. If the blower is located downstream, 

the system is called an induced-draft system. Either 

of these furnaces can be configured as a direct-vent 

Section 5 

furnace in which combustion air is obtained from' 

outside the structure. 

Continuous condensing furnaces are very efficient 

(up to 95%) because they have two or more heat 

exchangers that capture most of the heat that 

normally goes up the flue. The first heat exchanger 

operates in the same way as a conventional furnace; 

the additional exchangers condense the water vapor 

in the flue gases to extract the latent heat, and 

condensate is drained to a house sewer. The temperature of flue gases is lower (100 to 180"F) and 

the gases are exhausted through a small flue (often 

PVC pipe) by an induced draft fan. Standard 

features include spark ignition and a direct outside 

air feed to the combustion chamber. 

All furnaces (gas, oil, or water) need safety devices 

which switch off the gas Qr power to the pump/ 

blower motor in case the air or water reaches a 

temperature that exceeds the design temperature. 

Exhibit 5-2 illustrates different configurations of 

gas-fired, forced-air furnaces that may be encountered in residential heating systems. 

Forced-Air Delivery Systems 

Forced-air delivery systems include extended 

plenum and graduated trunk systems for basements, 

radial and crawl space plenum systems for crawl 

spaces, and slab-on-grade forced-air systems (Exhibit 5-3). Basement forced-air systems typically 

use an extended plenum duct system or a graduated 

trunk system. Crawl space systems include a radial 

system in which supply ducts radiate out from a 

supply plenum. Slab-on-grade forced-air systems 

consist of a down-flow furnace connected to radial 

supply ducts which are set in place before the 

concrete is poured. 

Regardless of the type of system used, warm air 

supply registers should be located against outside 

walls, preferably beneath windows so that rising 

warm air counteracts the falling cold air. Cold air 

rerum grills should be located in or near inside 
Section 5 

Exhibit 5·1. Oil furnace installation. 

Piping Hook·up for Burled Outside Tank 

Note: Enough air for combustion must enter 

furnace room. Provide 15-square-inch opening 

for each gallon of oil burned per hour. 

To Wiring 

To Flue 

---

Draft 

Regulator 

Stack Relay 

....-++ Furnace May 

Be located 

Here 

Antisiphon Valve 

(Underwriter Listed) 

Pipe 311 Below Floor 

rVentCop 

Foot Valve 

Piping Hook-up for Inside Tank Installation 

Filler Cap 

Fuel Tank 

I Note: Enough air for combustion must enter Vent line · 11,4 11 Pipe 

Draft furnace room. Provide 15-square-inch opening 

Regulator for each gallon of oil burned per hour. rr 

To Wiring Fill line 2

11 Pipe - C1{ ~ 

IAQ Reference Mamtal 

Fill Line 211 Pipe 

" :I 

:: 

" II " 

::.1 " 5"4 

. ,,.. 

.... ¥"" I J Ven!Ca~~ Fill Cap •;_ 

\1;• 

.~~ Stack Relay Tank Gage-

~ ~~~ .;:· 

Tank Tank !~t• 

Furnace 7'0" Minimum ,~ 

·"" b\Q r,_ r--- / ---.... rr:l! 

~'J 

Afrt ~ :.;: 

vBurner "."::: 

:-% ... "\.(;·· 

1 T 1.;·" 

;.---~ -Pump· .o 

Drain Plug '"'"' -:.:1 

I' :4!-. •" ·"'"'• ·...;:~l!,:~., ... fh.~~·~·• .•#":ft. ... , " ,.,t',!l cr:·-:.t;·~·""-'· 1>· ~ ~ J~:' c.· ~~r--:"1.,~"'~-.·h"' 'lf.-"''~!!1;;.)!. '•""a,:>' 'If,. '<!J'~.,.!:...J.: .. :<'..,':'~ 'i'* 

Y, 11 OD Soft Copper • Tubing 

SOURCE: U.S. HUD (1976) 
IAQ Reference Manual Section 5 

Exhibit 5·2. Gas.fired forced•air furnace configurations. 

Circulating 

Air Blower 

Gas Burner 

Heal 

Exchanger 

Circulating 

Air Blower 

Filter 

Draft Oiverler 

Relief Air 

Control 

Compartment 

~~~~C:~t- Combustion Air 

Gas Supply Manifold 

Circulating Air 

Upflow Forced-Warm-Air Furnace 

Circulating Air Plenum 

Vent Pipe 

Combustion 

Air 

Gas Burner Gas Supply Manifold 

Basement (Low-Boy) Forced-Warm-Air Furnace 

Vent Pipe 

Hori,ontal Forced·Warm·Air Fumace 

Gas Burner 

Vent Pipe 

Draft Diverter 

Control 

Compartment 

~~§a;:=~ ... Combustion Air 

Gas Supply Manifold 

Circulating Air Plenum 

Downflow (Counterflow) 

Forced·Warm·Air Furnace 

SOURCE: Reprinted with permission of the American Society of Heating, Refrigerating, and Air-Conditioning Engineers from the 

1988 ASHRAE Handbook-Equipment. 
Section5 

Exhibit 5·3. ••rced•air distribution systems 

Heated Air to Rooms 

Furnace Heated Air 

to Rooms 

Extended Plenum Duct System 

Graduated Trunk Duct System 

IAQ Reference Manual 

Extended Plenum System 

• This system is typically installed in basements where headroom 'is important, 

and is one of the commonly used systems. 

• It is a relatively simple but flexible · 

system, although generally limited to 

small- and medium-sized installations. 

• A rectangular plenum, usually located 

alongside the main supporting beam, 

is extended from one or both sides of the 

furnace. 

• Individual room'' takeoff ducts" extend 

at right angles the plenum and can often 

be hidden in the space between floor 

joists for an unrestricted headroom. 

• Either a single floor-level central cold-air 

return or a matching extended plenum 

return air duct with several pickups can 

be used. 

Graduated Trunk System 

• This is similar to the extended plenum 

system but has a main supply trunk that is 

graduated in size to help balance 

delivery pressure after each takeoff. 

• This is an ideal but expensive system and · is generally used only for larger or more 

complex installations. 

SOURCE: Peter A. Mann, P.A. 1989. lllustrateJ Residmtial and Commercial Construction. ©1989, Figures 14-11, 14-12, 14-13. 

Reprinted by permission of Prentice Hall, Inc. Englewood Cliffs, NJ 07632. 
IAQ Reference Manual 

Exhibit 5·3. Forced·air distribution systems (continued}. 

Radial Duct System 

Down-Flow Furnace 

Cold-Air Return \ 

Section 5 

Radial System 

• This system requires a" down-flow" type 

offurnace that blows warm air downward 

to a distribution plenum beneath the floor. 

• Individual room supply ducts radiate out 

from the supply plenum, as shown at the 

left, and are positioned below the floor 

ioists. 

• This system is generally used only in 

crawl space or slab-on-grade 

construction, where headroom below 

the supply ducts is of no concern. 

• The cold-air return is usually through a 

single grille on or near the furnace head. 

• In an unheated crawl space the supply 

ducts must be sealed and well insulated. 

~~~~~~ 

Crawl Space Plenum System 

Crawl Space Plenum System 

• In this system the crawl space itself is used as a plenum to distribute the warm air to the individual rooms. 

Heated-Air Discharged 

Into Crawl Space 

• A down-flow furnace is located on the first floor and discharges warm air into the crawl space, where a positive pressure is created. The 

warmed air then flows upward through the open floor registers into the first-floor rooms. In addition to the connection effect, the floor is 

warm and rdiates heat. This increases the mean radiant temperature and raises comfort levels. 

• Variations in crowl space depth have little effect on the sy~tem' s overall efficiency, and any type of foundation construction can be used. 

• The foundations and crawl space floor must be treated as a fully heated basement and insulated to suit. The crawl space must be mode 

airtight using a continuous and sealed air/vapor barrier. 

• System costs are relatively low since no supply ducts are required and overall system efficiency tends to be quite high. 

SOURCE: Peter A. Mann, P.A. 1989. Illustrated Residential and Commercial Construction. ©1989, Figures 14-11, 14-12, 14-13. 

Reprinted by permission of Prentice Hall, Inc. Englewood Cliffs, NJ 07632. 

(continued next page) 

II 
Section 5 IAQ Reforence Manual 

Exhibit 5·3. Forced·air distribution systems (tonfinuedJ. 

Perimeter Loop System 

Perimeter Loop System 

This is similar to the radial system shown opposite with the addition of a perimeter loop connected to the radial supply ducts. 

• Supply registers ore located in the outer loop at suitable room positions. 

• Fewer radial .feeder ducts ore needed, and the slob perimeter is kept relatively worm provided that the perimeter loop is not insulated. 

• The feeders and loop ore set in place before the concrete floor slab is poured. Ensure that the ducts ore sloped downward toward the 

supply plenum for the collection of any water that may accumulate in the system. 

The radial system con also be used in slab-on-grade construction buttends to result in cold floor areas at the slab perimeter. 

SOURCE: Peter A. Mann, P.A. 1989. Illustrated Residential and Commercial Constrnction. ©1989, Figures 14-11, 14-12, 14-13. 

Reprinted by permission of Prentice Hall, Inc. Englewood Cliffs, NJ 07632. 
IAQ Reference Manual 

partition walls. Ducts should not be located in cold 

spaces such as outside walls. 

A crawl space plenum system could also be used in 

which air from the furnace discharges into the crawl 

space. This creates a positive pressure and warm air 

flows upward through open floor registers. The 

foundation and crawl space floor must be insulated 

and the crawl space must be made airtight using a 

continuous and sealed air/vapor retarder. These 

systems may be susceptible to microbial or soil gas 

contamination of the ventilation air. 

MOISTURE CONTROL 

This section provides an overview of 

sources and solutions to moisture problems; the 

basis of this discussion is Moisture and Home Energy 

Conservation (NCAT, 1983). This document is a 

useful reference, and it is available at minimal cost 

from the National Center for Appropriate Technology. In addition, books on the construction of 

energy efficient homes or retrofits of existing homes 

will also be helpful. 

Moisture problems can occur in any part of the U.S. 

as a result of improper construction and control 

methods, but some areas, such as the coastal states 

or areas where winter temperatures average 3 )°F or 

less, have special problems. Moisture problems 

result from a combination of these climatic factors 

and many activities and situations inside and 

outside the home. 

Sources inside the home can result in significant 

releases of water vapor (humidity). For example, the 

water vapor produced by a humidifier could be 

about 48 pounds in 24 hours; gas appliances 

produce about 88 pounds for each 1000 ft3 of gas 

burned; washing and rinsing an 8 ft x 10 ft room 

produces about 2.5 pounds; drying 10 pounds of 

clothes produces about 10 pounds; and 4 occupants 

in the home produce about 3 pounds of water vapor 

each day (Hedden, 1982): 

Section 5 

As moisture is produced it can be present as a vapor 

(gas), liquid, or solid. Water vapor travels through 

the home by air movement and diffusion, and liquid 

water travels by capillary action. This movement is 

largely controlled by differences between pressure 

inside of the house and outside of the house and the 

movement of water vapor from an area of higher 

pressure to an area of lower pressure. 

Capillary action refers to the movement of liquid 

water from a source through a porous material such 

as soil. Capillary action can be an important route 

of water vapor entry through basements and crawl 

spaces. Diffusion is the direct movement of water 

vapor through the building materials; it occurs as 

interior sources contribute to the buildup of water 

vapor and the interior pressure increases. Water 

vapor is primarily transferred through air movement 

caused by wind or temperature and pressure differences between the interior and exterior of the 

structure. 

During the winter, warm interior air may pass to 

the outside through cracks and openings in the 

building. If the warm, moist air comes into contact 

with cooler surfaces, the water vapor will condense 

onto the cooler surfaces (condensation). During the 

summer when the outside air is warmer and moister 

than inside air, the air flows into the house carrying 

moisture with it. Wind can also cause pressure 

differentials, and the downwind side of a house may 

show more signs of moisture because water vapor is 

being forced through this side. 

The movement of moistute in, around, and through 

the envelope of the house is a prime consideration in 

the design and construction of the house. This is an 

area that is especially important in the design of 

energy efficient homes because of the relatively low 

air exchange rates in these homes. If water vapor is 

not controlled, many problems can result. 

Too much water vapor can cause window sweating 

when warm, moist air contacts cold surfaces. Warm 

air holds more water vapor than cold air, and the 
Section 5 

water in the warm air will condense on the cold 

surface as the air comes in contact with the window. 

Even if a storm sash is used, problems can result. If 

condensation appears on the inside window, the 

storm sash may be leaking cold air which cools the 

inner pane causing condensation; or there is simply 

too much moisture in the house. If the outside sash 

has condensation, the inside window is leaking 

warm, moist air which condenses on the cold 

exterior pane. 

A problem which is not immediately obvious is 

condensation which occurs inside walls. Condensation can occur in exterior walls without vapor 

retarders or in those that have vapor retarders on the 

cold side of the wall or on both the cold and warm 

sides. If a home is uninsulated, water vapor is 

released from warm interior air as it passes through 

the building envelope, and if the temperature is 

cold enough, this moisture freezes. Over the course 

of the winter, the ice builds up and melts as the 

weather warms. Over time, serious structural 

damage can result. If a house has insulation (loose, 

batt, or foam), but no vapor retarder, the same 

process occurs. The insulation does not prevent the 

moisture from passing through the envelope, and 

water vapor will condense inside the wall and also 

pass through the wood and lift paint off the surfaces. 

(Lifting paint is, therefore, one sign of moisture 

problems). 

There must be sufficient humidity in the home to 

prevent drying and cracking of wood and irritation 

to mucous membranes, but it must be controlled to 

prevent: mold, mildew, and structural damage to 

building components and furnishings. Striking a 

balance between these two extremes can be difficult, 

but it is not impossible. Most moisture problems 

can be solved by minimizing unnecessary sources, 

minimizing temperature differences, increasing air 

circulation and ventilation, and altering the moisture transfer rate with the use of vapor retarders. 

• Controlling the source of moisture problems is usually a cost effective solution. 

IAQ Reference Manual 

Strategies include fixing water leaks, 

ducting clothes dryer exhaust outdoors, 

reducing humidifer use, improving drainage, and using kitchen and bathroom 

exhaust fans. 

• Since condensation depends on temperature 

differences, minimizing these can solve 

some problems. Strategies include insulating metal window frames, insulating 

heating and cooling system ducting, 

improving heating patterns, and installing 

a vapor retarder. 

• The moisture transfer rate can be reduced 

by weatherizing before insulating, sealing 

all air leaks from the inside, using a vapor 

retarder for interior surfaces and in crawl 

spaces, using moisture resistant exterior 

wood or waterproofing it, using waterproofing on the exterior or interior of basement 

walls, installing exterior drainage systems, 

and eliminating any exterior moisture 

accumulation. 

• Air circulation and ventilation strategies 

include venting moisture out of enclosed 

spaces (using existing fans); using ceiling 

fans to improve circulation; installing wall, 

roof, and crawl space vents; installing heat 

recovery ventilators; and installing whole 

house fans and roof ventilators. 

Installation of Vapor Retarders 

The effectiveness of th~ vapor retarder is measured 

in permeance (perms) of the material. One perm 

equals one grain of water per square foot per hour 

per unit vapor pressure difference. The lower the 

perm rating ofa material, the better it is at reducing the transfer of moisture. For example, 6 mil 

(1 mil = .001 inch) polyethylene (provides good 

control) has a perm rating of0.06 perm compared to 

concrete, which has a rating of 3.2 perm (NCAT, 

1983). 
IAQ Reference Manual 

The purpose of a vapor retarder is to keep warm, l 

moist air from coming in contact with surfaces that 

are below the dew point of the water vapor (the 

temperature at which condensation occurs). For this 

reason, a vapor retarder must be located on the 

warm side of the wall, floor, or ceiling, and it must 

be tight to prevent the transfer of water vapor. 

Conventional Retrofits 

In the attic or ceiling, vapor retarders may be the 

only way to prevent moisture problems if sufficient 

Section5 

ventilation cannot be provided. It is important to 

install the vapor retarder carefully. Batt insulation 

can be tightly stapled to the rafters; or in attics with 

loose fill insulation, polyethylene can be cut into 

strips and tightly fitted between the joists (Exhibit 

5~4). Regardless of the type of installation, there 

must be sufficient attic ventilation (eave, ridge, or 

vent). 

In both warm and cold climates, crawl spaces 

carefully fitted with ground cover and floor vapor 

Exhibit 5 .. 4. Installation of a vapor retarder in the attic. 

Avoid gaps which 

increase the 

potential for air 

movement and 

condensation or 

frost 

Polyethylene 

Vapor Retarder 

Partition wall 

framing underneath 

_,_'r"'____ Ceiling Joists 

Battens hold 

.---- polyethylene tight 

Qgainst framing 

Ceiling 

Polyethylene strips can be installed prior to loose-fill or blown-in ollie insulation, 

One Inch 

Minimum 

SOURCE: NCAT (1983} 

When insulaling rafters, 

take care to insure 

ventilation occurs 

For thick ceiling insulation, 

ollie ventilation can occur 

through vent troughs 

Insulation work should no! block ollie ventilation at the eaves, 

Vent Trough 
Section 5 

retarders can prevent moisture problems. Ground 

vapor retarders are installed over the soil and can be 

held in place with weights or bricks; a more secure 

method is to cover the retarder with a layer of sand. 

Floor vapor retarders can also be added to provide 

greater protection and insulation. The installation 

differs depending on the climate. In cold climates, 

IAQ Reference Manual 

the vapor retarder is installed on the warm side of 

the floor; in warm climates, the warm side is the 

bottom of the floor (Exhibit 5-5). 

The most cost effective strategy for minimizing 

moisture problems in walls in retrofit installations 

is to seal air leakage points from the inside and 

Exhibit 5·5. Installation of a vapor retarder in the crawl space or floor. 

Vaporre!arder -----tl'l 

face inside 

Foundation 

Vapor retarder ----IM!e:~ 

face outside 

Foundation 

SOURCE: NCAT (1983) 

Insulation installed 

with vapor retarder 

face upward 

Cold Climate 

AR· ...... .M...- Sand cover 

to protect 

vapor 

retarder in 

traffic 

areas 

Hot Climate 

..•• '7:.··:~o,..:;;.- Sand cover 

to protect 

vapor 

retarder in 

traffic areas 
IAQ Reference Manual 

outside of the wall. After ensuring that the leakage 

points have been sealed, a vapor retarding paint can 

be applied to the wall surfaces to provide some 

resistance to water vapor diffusion. In some instances it may be necessary to install a vapor retarder 

on interior walls. 

Weeping windows should be weatherstripped and 

caulked inside first, and then weatherproofed 

outside. If an interior-side storm window is used, it 

must be sealed tightly around all edges. If an outer 

storm window is added, weep holes at the bottom 

are recommended. In very cold climates, tripleglazing is recommended. 

Vapor Retarders In New Construction 

When moisture problems are encountered in new 

construction, problems are sometimes due to an 

improperly installed retarder. Exhibit 5-6 shows 

elements of a properly installed retarder. Any holes 

or other leakage points will allow moisture to be 

transferred. Seams must be carefully overlapped and 

sealed, gaps around windows, doors, floor/ceiling/ 

wall joints, and electrical and plumbing installations must be sealed. This can be done with 

polyurethane foam and other sealants and products. 

Ventilation 

Providing adequate ventilation to the living space 

can solve and prevent many indoor air quality 

problems. Adequate ventilation is necessary to 

maintain comfort and to prevent the buildup of 

indoor contaminants, moisture accumulation, and 

odor problems. Ventilation requirements are given 

in model and local building codes for conditioned 

and unconditioned spaces and combustion appliances (Lesson 7 of the Learning Module and Sections 

7 and 8 of the Reference Manual). 

Ventilation requirements can be expressed in cfm 

(lps) per person or cfm (lps) per unit area of floor 

space. ASHRAE recommends outdoor ventilation 

rates of 0. 3 S ach but not less than 15 cfm (7. S lps) 

per person in residential construction (includes 

Section 5 

single and multiple units) <4-SHRAE, 1989). 

ASHRAE does not address v~ntilation requirements 

of combustion appliances or unconditioned spaces; 

these are given in building codes and codes developed by prof~ssional associations for specific appliances. 

Attic and Crawl Space Ventilation 

Ventilation is needed in the attic during the 

summer to remove excess heat (temperatures of 

15 oaF or more can be reached) and during the 

winter to remove excess humidity that moves 

through the ceiling and condenses in the insulation 

of a cold attic. Attics can be ventilated using 

natural or mechanical vents. Natural vents take 

advantage of the natural flow of air while mechanical ventilation relies on electrically powered exhaust 

fans. 

The needed area for ventilation is determined by the 

area of the attic space, climate, and the presence of a 

vapor retarder in the attic. Four types of vents are 

generally used to provide natural ventilation in 

attics. Ridge vents provide a continuous opening 

along the ridge line of a pitched roof. Air can pass 

through, but rain and snow cannot enter the attic. 

Roof vents are rectangular or circular openings at 

intervals along the flat portion of the roof. Under 

, eaves or soffit vents are installed under the eaves in 

discrete or continuous vents. Gable end vents are 

located in the gable and they can be rectangular, 

round, or triangular openings. 

A ridge vent plus soffit vent configuration is 

considered to be the best system for naturally 

ventilating the attic. A roof and gable-end system 

are typically used in older homes (Exhibit S-7). 

Houses with cathedral ceilings require a continuous 

air space above the insulation with continuous eave 

and ridge vents or individual vents in the eave as 

well as near the ridge for each 'rafter space. 

The second most effective way of providing natural 

ventilation in roofs is a combination of turbine 

ventilators and soffit vents. Turbine ventilators that 
Section5 lAQ Reference Manual 

Exhibit 5·6. Installation of a continuous vapor retarder. 

Ceiling vapor 

retarder laps 

over wall vapor 

retarder 

Wall framing 

Exterior 

Sheathing --11tl 

Wall Cavity Insulation --+HWall Vapor ---I"Hifo+ 

Retarder 

Caulk Under 

Bottom Plate 

Wall vapor 

retarder overlaps 

floor vapor retarder 

approximately' 6 inches 

Flap seals to 

waUvapor 

retardre 

Staple 

through 

nylon ...-4-11>1! 

reinf.tape 

Double-fold technique for 

wrapping window frame 

with vapor retarder 

Vapor reto rder sealed 

at overlap on framing 

stud with acoustical 

caulk. 

Sealing vapor retarder 

seams and overlaps 

--:::.;liiliiiS' Ceiling Insulation 

Ceiling Covering 

Ceiling Vapor Retarder 

.., ______ WafiCovering 

Floor Joists 

To Outside 

framing Stud 

Vapor 

Note: Retarder ~~lDol'l1oCaulk window 

frame prior 

to wrapping 

Vapor retarder sealed 

to low-perm rigid 

insulatipn at i(llerior 

partition joint (similar 

detail at ceiling} 

Technique for sealing 

vapor retarder without 

using window wrap. 

House Wire 

Sealing vapor retarder at 

electrical outlet box 

Framing Stud 

Commercial 

"Poly Pan" 

Electrical Box 

Acousticai 

Sealant 

(All vapor retarders should be sealed with a flexible, non-hardening, 

acoustical sealant. Pay special attention to seal window and door frames. 

All penetrations such as outlet boxes, plumbing and electrical lines, etc.) 

Note:. Put a bead of acoustical 

sealant on nail head and house 

wire penetration through 

"poly pan" 

SOURCE: NCAT (1983) 
IAQ Reference Manual 

Exhibit 5·7. Attic ventilation strategies. 

Flat Roofs 

Vents shoudl be placed 

evenly at the eaves. 

Gable Roofs 

Half of vent area 

should be in the gables 

or at the ridge vent, 

with the other half at 

the cornice or eaves. 

Hip Roofs 

Vent area should be 

equally divided between 

eaves and ridge with all 

vents spaced evenly. 

Placement of Attic Vents 

SOURCE: NCAT (1983) 

Wind 

Poor 

Avoid single 

vents only. Air 

at roof peak is 

not vented out. 

Wind+ 

~~ ,-1 1~ 

Good 

Roof cap and soffit vents. 

Air enters at soffit and exits 

at roof cap and opposite soffit. 

+wind 

Good 

Goble end and soffit vents. 

Air enters at soffit and gable 

and exits at opposite gable. 

Wind 

Best 

Continuous ridge vent and 

soffit vents. Air enters at 

soffits and exits at ridge vent. 

Ventilation Strategies to Reduce Trapped Air in Attics 

Section 5 

are 12 and 14 inches in diameter are typically used, 

and they ventilate about 600 ft2 and 700 ft2, 

respectively (Hedden, 1982). 

Powered ventilation in conjunction with natural 

airflow can also provide adequate ventilation; the 

fans can be installed in gables or on the roof. Whole 

house fans, which are installed in the ceiling, draw 

air in through windows and exhaust the air into the 

attic and out the vents. There must be enough vent 

area to exhaust the gases (1 ft 2 net free area for each 

750 cfm of fan capacity) [Hedden, 1982}. It is 

important for any other ventilating fans (including 

kitchen and bathroom funs) to be exhausted directly 

outside and not into the attic space, otherwise air 

will be forced from the attic back into the living 

space. 

Sizing attic vents: The area needed for venting 

depends on the area to be vented, location, presence 
Section 5 

of a vapor retarder, and the type of vent obstructions. More vent area is needed if a vapor retarder is 

not used. Based on moisture control requirements, 

NCAT (1983) recommends the following procedure 

for determining the minimum area required for 

attic ventilation: 

1) measure the area to be vented; 

2) multiply the area by 0.0067 if there is no 

vapor retarder or 0.0034 if there is a vapor 

retarder in place; 

3) multiply the area obtained in step two by 

one of the sizing factors in Exhibit 5-8 for 

the type of vent covering to obtain the total 

gross vent area needed; and 

4) Determine the proper vent location 

(Exhibit 5-7). 

The CABO code is less stringent and specifies a net 

free ventilating area of at least 11150 of the area of 

the space to ventilate unless other conditions are 

met (CABO, 1989). This area may be reduced to 

11300, providing that at least 50% of the required 

area is provided by ventilators located in the upper 

portion of the space to be ventilated at least 3 feet 

above eave or cornice vents. If a vapor retarder 

having a transmission rate less than 1 perm is 

installed on the warm side of the ceiling, the net 

free cross-ventilation area must be at least 11300 of 

the space ventilated (CABO, 1989). 

Sizing crawl space vents: The NCAT recommendation for moisture control in the crawl space is 

similar to the procedure for attics. The area to be 

ventilated is measured, and whether or not there is a 

ground cover in place, the area is multiplied by 

0.0067 (or 1/150). Then this area is multiplied by 

one of the factors in Exhibit 5-8. 

The CABO code requirements potentially result in 

less ventilating area whether or not a ground cover 

is in place, but the difference is particularly greater 

IAQ Reference Manual 

Exhibit 5·8. Sizing factors for different 

vent coverings.1 

TYPE OF VENT COVERING 

Y<l inch mesh hardware cloth 

Ys inch (8 inch mesh screen) 

No. 16 mesh insect screen (with or 

without plain metal louvers) 

Wood louvers and ~ inch mesh 

hardware cloth2 

Wood louvers and Ys inch mesh screen 

Wood louvers and No. 16 mesh insect 

screen 

FACTOR 

1 

IV<! 

2 

2 

2~ 

3 

1 In crawlspace ventilators, screen openings should not be larger 

than 1/4 inch; in attic spaces, no larger than 1/8 inch. 

2 If metal louvers have drip edges that reduce the opening, use 

the same ratio as shown for wood louvers. 

SOURCE: NCAT (1983) 

if a vapor retarder is in place. The CABO code 

specifies that the number of openings should not be 

less than 1 ft2 for each 150 ft 2 of crawl space area, 

and there should be one opening within 3 feet of 

each corner of the building unless the building 

qualifies for an exemption. The CABO code allows 

the openings to be omitted on one side. Another 

exemption is that the total required area can be 

reduced to 1/1500 of the under-floor area when 

there is an approved ground floor vapor retarder and 

one opening is within 3 feet of each corner of the 

building (the vents can have operable louvers). In 

addition to these exemptions, ventilation openings 

can be vented to the interior of buildings where 

warranted by climatic conditions: 
IAQ R.Bference Manual 

5.2. EVALUATION OF AIR CLEANERS 

The evaluation of air cleaners requires 

information on the efficiency, airflow resistance, 

dust-holding capacity, effect of dust retention on 

efficiency and on resistance, and the maintenance 

which is required to maintain the air cleaner at top 

efficiency. There is no single test which adequately 

characterizes all filters or air cleaners. Testing is 

complex and there are many factors that affect the 

performance of air cleaners in actual use. 

Ideally, testing procedures should approximate the 

conditions and contaminant concentrations which 

can be expected to exist during actual use of the 

devices. The use of standardized tests do allow the 

performance of different air cleaners and filters to be 

compared. 

Test methods for evaluating air cleaner performance 

are contained in ASHRAE Standard 52-76 

(ASHRAE, 1976) and Military Standard 282 (U.S. 

DOD, 1956), which is also referenced by ASHRAE. 

These tests are used to evaluate in-duct systems 

(filters .and electronic air cleaners). Recently, the 

American National Standards Institute (ANSI) and 

the Association of Home Appliance Manufacturers 

(AHAM) have developed a standard for evaluating 

portable air cleaners. 

A useful publication, Residential Air-Cleaning 

Devices: A Summary of Available Information, which 

summarizes the available information on residential 

air cleaners, is available from the Public Information 

Center, Environmental Protection Agency, 

Washington, DC. 204?0. 

ASHRAE Test Methods 

The ASHRAE Standard 52-76 test method specifies 

the evaluation of in-duct air cleaners based on 

collection efficiency (for total mass and by particle 

size), pressure drop across the filter, and dustholding capacity. 

Fractional Efficiency Or 

Penetration Test 

Section 5 

This test is used for high efficiency filters (efficiencies greater than 98%) which are used in dean 

rooms and nuclear applications. The Thermal DOP 

(di-octyl phthalate or bis-(2-ethylhexyl] phthalate) 

test is conducted by feeding a cloud of uniform 

particles (0.3 micron DOP) into the filter and 

determining the percentage of particles removed by 

the filter (U.S. DOD, 1956). The concentration of 

particles upstream and downstream of the filter is 

measured using a light-scattering photometer or 

condensation nuclei counter. Results are usually 

expressed in percent penetration (equal to 100 

minus the percent efficiency) rather than efficiency 

because HEPA filters are almost 100% efficient. 

Weight Arrestance Test 

The weight arrestance test measures the mass 

collection efficiency of a filter based on a standard 

synthetic dust of various particle sizes. The synthetic dust specified by ASHRAE (1976) is composed of72% standardized dust fine, 23% Molocco 

black, and 5% cotton linters. The synthetic dust 

cloud has a particle size range that is larger than 

typical atmospheric dusts. This test is appropriate 

for evaluating low efficiency filters which remove 

larger particulates. These filters are used in residential furnaces, air-conditioning systems, or as upstream filters for other air cleaning devices. The test 

is not appropriate for evaluating the removal of 

respirable particulates. 

Dust Spot Efficiency Test 

The dust spot efficiency test (ASHRAE, 1976) 

measures how well a filter reduces the soiling of 

residential interiors. The test is conducted by 

passing untreated atmospheric air through filter 

paper targets and measuring the difference in light 

transmittance before and after air is passed through 

the filter being tested. The spot efficiencies are 

II 
Section5 

taken at intervals allowing the efficiency to be 

evaluated as a function of filter loading. This test is 

most appropriate for determining the efficiency of 

high to medium efficiency filters and electronic air 

cleaners. 

Dust-holding Capacity Test 

Dust-holding capacity is the amount of a particular 

type of dust that an air cleaner can hold before its 

efficiency drops significantly as a result of the 

resistance imposed by the collected dust. Airflow 

resistance, or simply resistance, is the static pressure 

drop across the filter at a given airflow rate, and the 

term pressure drop is used interchangeably with 

resistance. 

Because of filter variability, ASHRAE's test 

(ASHRAE, 1976) determines that the dust holding 

capacity has been reached based on the following 

criteria: 1) when the maximum pressure drop 

specified by the manufacturer or when two consecutive measures of arrestance are less than 85%, or 2) 

when one value is equal to or less than 75% of the 

maximum arrestance. 

Efficiency Ratings of Filters 

Control strategies for indoor air contaminants have 

recognized the need for efficiency versus size data for 

submicron particles. Manufacturers have attempted 

to respond to this need by categorizing the removal 

efficiencies of filters based on particle size. However, these data are difficult to interpret because 

there is no standard method for determining the 

efficiency of air cleaners as a function of particle size. 

Exhibit 5-9 summarizes the performance of viscous 

impingement and dry media filters (ASHRAE, 

1988). Note that the percent arrestance, percent 

atmospheric dust spot efficiency, and percent DOP 

efficiency do not correlate with one another. For 

example, a filter with a 92% arrestance may be 

f 20% efficient based on the dust spot test. This 

lack of correlation is explained by the types of 

particles that each test measures. 

IAQ Reference Manual 

Exhibit 5·9. Comparative performance of 

viscous impingement and dry 

media filters. 

L PERCENT AlliESTANO:(ASHIAESloodO<d 52·76 TEST METHOD) 

so 60 76 80 90 92 97 98 '19 J I J. %AlMOS.DUSTSPOIEFFICIENCYIASHWSlon®.dl2·7<1l 

GROUP! ~ • • ~ oo ro oo 90 95 98 

-, GROUP II I ~ II OOP EFFICI~CY (Mit.~-28!) 40 50 60 00 

I GROUP Ill 

GROUP IV !J 

Group-1 

Panel-type filters of spun glass, open cell foams, 

expanded metal and screens, synthetics, textile 

denier woven and nonwoven, or animal hair. 

Group II 

Pleated panel-type filters of fine denier nonwoven 

synthetic and synthetic-natural fiber blends, or all 

natural fiber. 

Group III 

Extended surface supported and nonsupported 

filters of fine glass fibers, fine electret synthetic 

fibers, or wet-laid paper of cellulose-glass or allglass fibers. 

Group IV 

Extended-area pleated HEPA-type filters of wet-laid 

ultra-fine glass fiber paper. Biological grade air 

filters are generally 95% DOP efficiency; HEPA 

filters are 99.97 and 99.99%; and ULPA filters are 

99.999%. 

Notes: 

1. Group numbers have no significance other than their use in 

this figure. 

2. Correlation between the test methods shown are approximations for general guidance only. 

SOURCE: Reprinted with permission of the American Society 

of Heating, Refrigerating, and Air-Conditioning 

Engineers from the 1988 ASHRAE HandbookEquipment .. 
IAQ Reference Manual 

Potential applications of these filters can be summarized in terms of efficiency ratings from the 

ASHRAE tests. Based on the atmospheric dust spot 

test to evaluate efficiency, the following applications 

and limitations apply (ASHRAE, 1979). 

Efficiency Rating < 10%: applications include 

window air conditioners; protection of heat exchanger from lint accumulations; relatively ineffective on smoke, settling dust, and pollen. 

Efficiency Rating of 10% to 20%: applications 

include window air conditioners, packaged air 

conditioners, domestic warm air heating; effective 

on lint; somewhat effective on common ragweed 

pollen; relatively ineffective on smoke and staining 

particles. 

Efficiency Ratingof20% to 40%: applications 

include air conditioners, domestic heating, central 

systems; at 20% efficiency, fairly effective on 

ragweed pollen; relatively ineffective on smoke and 

staining particles; effective as a prefilter for final 

cleanup filters for clean room; same applications at 

40%, but with greater degree of effectiveness; 

somewhat effective in removing smoke and staining 

particulates. 

Efficiency Rating of 40% to 60%: applications 

include building recirculated and fresh-air systems; 

domestic heating and air-conditioning; use as 

prefilters to high efficiency types; effective on finer 

airborne dust and pollen; reduce smudge and stain 

materially; slightly effective on fume and smoke; 

ineffective on tobacco smoke at 40%; slightly 

effective on tobacco smoke at 60%. 

Efficiency Rating of 60% to 80%: 60% includes 

same uses as for 40%, but with better effectiveness; 

80% used in hospitals and other controlled areas; 

effective on all pollens, majority of particles causing 

smudge and stain, fume, coal and oil smoke; 

partially effective on tobacco smoke; some types 

reasonably effective on bacteria, but filters (especially in large buildings) can become a medium for 

growth. 

Section 5 

Efficiency Rating of80% to 95%: applications 

include hospital surgeries, pharmaceutical preparation areas, and other controlled areas; very effective 

on particles causing smudge and stain, coal and oil 

smoke and fume; highly effective on bacteria but 

filters (especially in large buildings) may become a 

medium for growth; quite effective on tobacco 

smoke. 

Efficiency Rating> 95%: applications include 

hospital surgeries, intensive care wards, dean rooms, 

pharmaceutical packaging; excellent protection 

against bacteria, radioactive dusts, toxic dusts, all 

smokes and fumes; filters above 98% efficiency are 

generally rated using the DOP test method (Military Standard 282). 

ANSI/AHAM Test Methods 

The ANSIIAHAM AC-1-1988 standard rates 

(AHAM, 1988) the "clean air delivery rate" (CADR) 

of portable cleaners. The CADR is a measure of 

how much air a unit is delivering. The delivery of 

"fresh" air is given in cfm. The fresh air is not 

100% fresh because some contaminants may not be 

removed from the airstream. A cleaner with a 

CADR rating of 100 can reduce the concentration of 

a given contaminant equivalent to reductions 

achieved by adding 100 cfm of fresh air. 

Air cleaners with CADR certifications based on the 

ANSI/ AHAM standard are evaluated in terms of the 

removal of dust (10 to 350 CADRs), tobacco smoke 

(10 to 300 CADRs), and pollen (25 to 400 

CADRs). 

Exhibit 5-10 shows a comparison of the removal of 

smoke, dust, and pollen for portable units as a 

function of CADR and room size, as estimated by 

AHAM. These figures are representative of air · 

cleaning results based on tests in an airtight room, 

and they should only be used as guides. At higher 

CADRs, the importance of fallout from gravity 

becomes less important. 

II 
II 

Section 5 IAQ Reference Manual 

Exhibit 5·1 0. Estimated percentage of particle removal for portable air cleaners by CADI 

and room size. 

PERCENTAGE OF PARTICLES REMOVED 

Smoke Dust Pollen 

(20 min) (20 min) (10 min) 

Room Size CADR Aca Tb Aca Tb Aca yb 

5x6 10 49% 68% 49% 70% 

40 89% 97% 88% 98% 57% 93% 

80 95% 100% 95% 100% 75% 99% 

9x 12 40 53% 71% 52% 72% 24% 78% 

80 76% 89% 75% 89% 40% 86% 

150 89% 98% 89% 98% 58% 94% 

12x 18 80 53% 71% 52% 72% 24% 78% 

150 74% 87% 73% 88% 38% 85% 

300 89% 97% 

350 91% 99% 

450 69% 97% 

18x24 150 51% 70% 50% 71% 23% 78% 

300 73% 87% 

350 77% 91% 

450 50%" 91% 

20x 30 300 63% 79% 

350 67% 84% 

450 40% 86% 

a Removal by the air cleaning device 

b Removal by air cleaning device plus natural seeding 

Note: Estimates ignore the effect of incoming air. For smoke and, to a lesser extent, dust, che more drafty che room, the smaller the 

CADR required. For pollen, which enters from outdoors, a higher CADR is needed in a drafty room. 

SOURCE: U.S. EPA (1990). Adapted from Association of Home Appliance Manufacturers (AHAM). 1990. AHAM Consumer Guide for 

Room Air Cleaners. AHAM, 20 North Wacker Drive, Chicago, IL 60606. Used with permission of AHAM. 
IAQ Reference Manual 

Exhibit 5-11 compares the amount of time required 

to achieve 90% removal of airborne particles based 

on CADRs. As a general rule the higher the 

CADR, the less time needed to remove the same 

amount of contaminants from a room of identical 

size because all things being equal, the more air a 

cleaner processes, the faster it can remove contaminants. 

5.3 PUBLIC AND PRIVATE SECTOR 

ORGANIZATIONS INVOLVED IN 

INDOOR AIR QUALITY ACTIVITIES 

Section 5 

Several public and private sector organizations have activities associated with the control of 

indoor air quality. Exhibit 5-12 lists the activities 

of public interest organizations. Exhibit 5-13 

identifies activities of professional and trade organizations in the private sector. 

Exhibit 5·11. Minutes to achieve 90% removal of airborne particles.1 

No air cleaner 

operating 

CADRs-air cleaner 

operating 

25 

40 

80 

150 

300 

DUST 

128 

49 

36 

21 

12 

6 

'includes removal by fallout from natural forces 

SMOKE POLLEN 

144 22 

51 17 

37 15 

21 12 

12 8 

6 5 

SOURCE: Association of Home Appliance Manufacturers (AHAM). 1990. A.HAM Consumer Guirk for Room Air Cletmers. A.HAM, 20 

North Wacker Drive, Chicago, IL 60606. Used with permission. 
Section5 IAQ Reforence Manual 

Exhibit 5·12. Public interest organization Indoor air activities. 

ORGANIZATION AcriVITIES 

American Lung • Developed a slide-tape presentation on 

Association (ALA) indoor air pollution 

• Issued a position paper on indoor air pollution 

• Distributes information sheets on indoor air 

pollution hazards 

• Aggressive "Stop Smoking" campaign 

II Americans for Nonsmokers' • Develops and distributes model clean indoor air 

Rights (ANR) legislation 

American Public Health • Conducting study on validity and prevalence of 

Association (APHA) multiple chemical sensitivity 

• Publishes a model housing code that includes 

indoor air quality 

Consumer Federation of • Testifies before Congress about indoor air 

America (CFA) concerns 

• Publishes quarterly newsletter, Indoor Air 

News 

• Convened EPA-cosponsored IAQ conferences, 

1986-1988 

Consumers Union (CU) • Publishes product testing results in Consumer 

Reports - recently tested air cleaners, unvented 

kerosene heaters, air-to-air heat exchangers, and 

radon detectors 

National Coalition Against the • Publishes Chemical Watch fact sheets 

Misuse ofPesticides (NCAMP) • Testifies before Congress about pesticide issues 

National Institute for Building • Improves building regulatory environment 

Sciences (NIBS) and facilitates the introduction of building 

technology 

• Prepared report on building standards related to 

indoor air 

• Provides guidance/information, conducts 

workshops/conferences on building IAQ issues 

Tobacco-Free Young America • Acquires and disseminates information 

Project (TFYA) on state and local smoking regulations 

SOURCE: Adapted from U.S. EPA (1989) 
IAQ Reference Manual Section 5 

Exhibit 5·13. Professional and trade association indoor air activities. 

ORGANIZATION 

Air-Conditioning Contractors of 

America (ACCA) 

Air-Conditioning and Refrigeration 

Institute (ARI) 

Air and Waste Management Association 

(AWMA) 

American Conference of Governmental 

Industrial Hygienists (ACGIH) 

American Gas Association (AGA) 

American Industrial Hygienists 

Association (AIHA) 

American Insurance Association 

American Plywood Association 

(APA) 

American Society of Heating, Refrigerating, 

and Air-Conditioning Engineers (ASHRAE) 

ACTIVITIES 

• Publishes technical manuals on air-conditioning 

design, installation, and maintenance 

• Rates performance of air-to-air heat exchangers, 

filter equipment assemblies, and refrigeration 

systems 

• Convenes a standing committee on indoor air 

quality · 

• Convenes indoor air sessions at A WMA annual 

meetings 

• Convenes specialty conferences on indoor airrelated issues 

• Develops indoor air quality guidelines for 

industrial exposures 

• Convenes a committee on bioaerosols 

• Publishes a manual on air sampling instrumentation 

• Develops standards addressing gas leaks and 

combustion product emissions 

• Convenes an Indoor Environmental Quality 

committee 

• Publishes industrial hygiene guidance documents 

• Monitors environmental issues for liability 

implications to member insurers 

• Recommends practices for handling preservative-treated wood products, using chlorpyrifos, 

and applying subfloor vapor barriers 

• Develops "Ventilation for Acceptable Indoor 

Air Quality," Standard 62-1989 

• Develops thermal comfort and energy conservation standards 

• Publishes technical information 

(continued next page) 
Section5 IAQ Reference Manual 

Exhibit 5·13. Professional and trade association indoor air activities (tontinued}. 

ORGANIZATION 

American Society of Testing and Materials 

(ASTM) 

American Institute of Architects 

(AIA) 

Building Owners and Managers Association 

(BOMA) 

Business Council on Indoor Air 

Chemical Specialties Manufacturers Association 

(CSMA) 

Chemical Manufacturers Association 

(CMA) 

Electric Power Research Institute 

(EPRI) 

Gas Research Institute 

(GRI) 

Hardwood Plywood Manufacturers 

Association (HPMA) 

ACTIVITIES 

• Convenes a technical committee on sampling 

and analysis of atmospheres 

• Develops test methods for atmospheric analysis 

• Publishes technical information 

• Producing an environmental resource guide to 

help architects be more responsive to environmental concerns, including IAQ 

• Provides information on all aspects of building 

ownership, operation and maintenance functions 

• Provides guidance to building owners and 

managers on prevention and mitigation of indoor 

air quality problems 

• Provides information to members on indoor air 

trends and government and legislative activities 

on indoor air 

• Develops and represents positions on indoor air 

quality before government and legislative 

bodies to insure that policy is based on accurate 

and comprehensive information 

• Represents companies involved in the formulation of household and institutional care products 

• Develops and represents policy positions before 

various regulatory and legislative bodies 

• Represents chemical manufacturers before 

various public and private sector bodies 

• Sponsors research of indoor air quality as 

it relates to energy consumption and HV AC 

systems 

• Sponsors research of indoor air quality concerns 

of the natural gas industry 

• Licenses manufacturers of burner inserts for 

nitrogen oxide emission reduction 

• Developed a voluntary standard for 

formaldehyde emissions from wood products 
IAQ Reference Manual Section 5 

Exhibit 5·13. Professional and trade association indoor air activities {fontinuedJ. 

ORGANIZATION 

Home Ventilation Institute 

(HVI) 

National Association of Home 

Builders (NAHB) 

National Association of Realtors (NAR) 

National Center for Appropriate Technology 

(NCAT) 

National Environmental Health Association 

(NEHA) 

National Plywood Association 

(NPA) 

Public Health Foundation 

(PHF) 

Service Employees 

International Union 

Sheet Metal and Air-Conditioning National 

Association (SMACNA) 

Tobacco Institute 

SOURCE: Adapted from U.S. EPA {1989) 

ACTIVITIES 

• Develops standards for heat recovery ventilators 

• Supports research of building components and 

operating parameters which affect indoor air 

quality 

• Conducts an annual survey of construction 

materials 

• Provides technical assistance to home builders 

• Supports comprehensive federal legislation that 

increases the role of government in IAQ 

research and informative dissemination 

• Committed to a new program of education on 

IAQ for its membership 

• Publishes Moisture and Home Energy Conservation 

• Publishes technical information on energy 

conservation 

• Provides grants and technical assistance on 

energy-related topics 

• Provides information to state and local environmental health officials on indoor air 

• Co-sponsored the Indoor Air Quality Learning 

Module and Reference Guide 

• Developed a voluntary standard for formaldehyde emissions from particleboard 

• Developed a directory of state indoor air 

contacts and surveyed state indoor air quality 

programs 

• Surveys and investigates indoor air 

problems of public service workers, educates 

members and promotes legislative and regulatory solutions 

• Provides membership with education 

through manuals and a home study course 

• Conducts programs to preserve the rights of 

smokers and member companies against unwarranted government restraint 
Section 5 

REFERENCES 

American Society of Hearing, Refrigerating, and Air-Conditioning Engineers (ASHRAE). 1976. Method of Testing AirCleaning Devim Used in General Ventilation/or Rfmmving 

Parti<nlate Matter, ASHRAE Standard 52-76. ASHRAE: New 

York, NY. 

American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE}. 1979. 1979 AHRAE Handb(}(}k 

and Product Directory. Equipment. ASHRAE: Atlanta, GA. 

American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE), Inc. 1988. 1988 ASHRAE 

Hat~dbrmk. Equipment. ASHRAE: Atlanra, GA. 

American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE), Inc. 1989. Ventilation for 

A<ctptableltTd(}(}r Air Quality. ASHRAE Standard 62-1989. 

ASHRAE: Atlanra, GA. 

Association of Home Appliance Manufacturers (AHAM). 1990. 

"Consumer guide for room air cleaners.'' AHAM: Chicago, IL. 

Association of Home Appliance Manufacturers (AHAM). 1988. 

American Standard Method for Measuring Performance of Portable 

Household Electric Cord-Connected Room Air Cleaners. ANSI/ 

AHAM AC-1-1988. AHAM: Chicago, IL. 

Council of American Building Officials (CABO). 1989. CABO. 

One and Ttt.1o Family Dwelling Code. CABO: Falls Church, VA. 

IAQ Reference Manual 

Hedden,). 1982. Heating, Cooling, Ventilation. Solar and 

Conventional. Creative Homeowner Press: Upper Saddle River, 

NJ. 

Mann, P.A. 1989. lllnstrated Residential and Commercial 

Construction. Prentice Hall: Englewood Cliffs, NJ. 

National Center for Appropriate Technology (NCAT). 1983. 

Moisture and Home Energy Conservation. NCAT: Butte, MT. 

U.S. Department of Defense (DOD). 1956. Filter Units, 

Protective Clothing, Gas Mask Components and Related Prodttcts: 

Performance-test Methods. MIL-STD-282. U.S. DOD: 

Washington, D.C. 

U.S. Environmental Protection Agency (EPA). 1989. Report to 

Congress on Indoor Air Quality. Vol. II. Assessment and Control of 

Indoor Air Pollution. U.S. EPA, 400/1-89/00lC. U.S. EPA, 

Office of Air and Radiation: Washington, DC. 

U.S. Environmental Protection Agency (EPA). 1990. Residential Air-Cleaning Devices. A Summary of Available Information. 

U.S. EPA, Office of Atmospheric and Indoor Air Programs: 

Washington, DC. 

U.S. Department of Health, Education, and Welfare (DHEW). 

1976. Basic Housing Inspection. HEW (CDC) 80-8315. U.S. 

DHEW, Public Health Service: Washington, DC. 

Wadden, R.A. and P.A. Scheff. 1983. Indoor Air Pollution. 

John Wiley & Sons: New York, NY. 
SECTION 6. 

INDOOR AIR QUALITY 

MEASUREMENTS 

Section 6.1 contains a detailed listing 

of indoor air monitoring equipment 

which can be used for personal or area 

monitoring of various contaminants. 

Section 6.2 discusses terms related to 

the measurement process, and Section 

6.3 provides general information to be 

used in collecting representative 

samples and determining proper 

sampling sizes. Section 6.4 outlines 

basic considerations for calibrating 

field equipment and provides 

examples of forms that could be used 

for calibrations. Finally, Sections 6.5 

and 6.6 provide overviews of passive 

samplers and measurement methods 

for air exchange rates, respectively. 

Table of Contents 

Section 6.1. Indoor Air Quality Sampling Methods 143 

Section 6.2. Accuracy, Precision, and Related Terms 168 

Section 6.3. Representative Sampling 170 

Section 6.4. Calibration 172 

Section 6.5. Passive Samplers 180 

Section 6.6. Air Exchange Rates 181 liD 

List of Exhibits 

Exhibit 6-1. Collection and analytical methods for 

quantitative monitoring of some 

contaminants. 146 

Exhibit 6-2a. Commercially available indoor air 

monitoring equipment. 147 

Exhibit 6-2b. Identification codes for methods in 

Exhibit 6-2a. 155 

Exhibit 6-2c. Identification codes for manufacturers 

in Exhibit 6-2a. 156 

Exhibit 6-3. Battery-powered personal air samplers. 159 

Exhibit 6-4. Properties of filters used in particulate 

sampling. 160 

Exhibit 6-5. Some storage properties of gases in 

plastic bags. 163. 

Exhibit 6-6. Limitations of selected solid adsorbents. 164 

Exhibit 6-7. Sources for testing and calibration 

procedures applicable to indoor air quality 

sampling. 165 

(continued next page) 
Sectiotz 6 

Exhibit 6-8. 

Exhibit 6-9. 

Exhibit 6-10. 

1m Exhibit 6-11. 

Exhibit 6-12. 

Exhibit 6-13. 

National Institute of Standards and 

Technology (NIST) Standard Reference 

Materials (SRMs) for the calibration of 

instruments and procedures utilized in 

air quality analysis. 166 

Precision and accuracy. 169 

Example calibration or audit form for a 

direct reading carbon monoxide or 

carbon dioxide monitor. 176 

Different types of airflow meters. 177 

Sample rotameter calibration form. 178 

Calibration using the soap-bubble meter. 179 

IAQ Reference Manual 
IAQ Reference Man.ual 

6.1. INDOOR AIR QUALITY SAMPLING 

METHODS 

Analytical Methods 

Particle and aerosol detectors and gas and 

vapor detectors were introduced in Lesson 6 of the 

Learning Module. Additional information on gas and 

vapor detectors follows: 

Gas and Vapor Detectors 

In general, there are seven analytical methods that 

can be applied to the analysis of gases and vapors 

(Nader, Lauderdale, and McCammon, 1983). These 

methods can be incorporated into direct reading 

field instruments or laboratory-based instruments 

and techniques. 

Electrical methods are those in which a sensor 

responds to chemical and/or physical properties of 

the contaminant so that the output of the sensor is 

related to the concentration of the contaminant. 

Electrical methods include conductivity, potentiometric, coulometric, and ionization detectors. 

These methods can be used for many contaminants 

including carbon monoxide, sulfur dioxide, oxygen, 

formaldehyde, ozone, and oxides of nitrogen. 

Electromagnetic methods are those in which 

electromagnetic radiation (in the form of ultraviolet, 

visible, or infrared radiation) is scattered or absorbed 

by a contaminant and the energy changes are related 

to contaminant concentrations. Contaminants 

which can be analyzed using these methods include 

carbon monoxide, carbon dioxide, hydrocarbons, 

and a variety of organic chemicals. 

Chemi-electromagnetic methods rely on a chemical 

reaction which is detected through the measurement 

of electromagnetic radiation. One of the most 

widely used methods is colorimetry in which a 

contaminant gas is collected and reacted with a 

reagent to form a unique colored chemical. The 

absorption or transmittance of visible light from a 

source is measured by a detector to determine 

Section 6 

contaminant concentrations. Ultraviolet and 

infrared light sources can also be used. Additional 

chemi-electromagnetic techniques are photometric 

(chemiluminescent) methods, which involve the 

generation and release of radiation followed by 

detection using photometric techniques. These 

methods can be used to analyze sulfur dioxide, 

carbon monoxide, oxides of nitrogen, formaldehyde, 

and a variety of organic chemicals. 

Thermal methods can be used to detect contaminants based on conductivity or combustion or to 

desorb contaminants from a substrate so they can be 

further analyzed using other methods such as 

chromatography. These instrnments can be used to 

detect carhop monoxide, carbon dioxide, and 

combustible gases. 

Gas chromatography is a technique which can 

separate complex mixtures of contaminants into 

individual components. The components of the 

mixture will migrate differentially as they are 

carried by a gas (carrier gas) through a porous 

column which contains a soptive medium. As the 

components are separated they will emerge from the 

column at a unique time, and they can be identified 

by different types of detectors (thermal conductivity, flame ionization, flame photometry, or electron 

capture). 

Gas chromatography can be very useful when 

coupled with passive or active collection systems. 

Portable direct reading chromatographic analyzers 

are also available. These instruments can detect a 

broad range of organic chemicals. They are 

equipped with internal calibrators and libraries 

which are used to identify unknown contaminants. 

These devices must be evaluated carefully to ensure 

that they will be able to detect contaminants in the 

lower ranges typically encountered in nonindustrial 

environments. 

Magnetic methods include mass spectroscopy and 

paramagnetic analyzers. Mass spectroscopy is a 

technique which is used in conjunction with gas 

chromatography to analyze a variety of contamiII 
Section 6 

nants after they have been collected using active or 

passive methods. Mass spectroscopy classifies 

ionized molecules, which have been deflected by a 

magnetic field, according to their mass and charge. 

Very small samples can be analyzed, and the method 

is specific. 

Paramagnetic analyzers are magnetic analyzers 

which allow oxygen to be detected under the 

influence of a magnetic field. 

Radioactive detection methods are based on 

radioactive decay and the release of energy (alpha 

and beta particles; gamma rays) f~om radioactive 

contaminants. Several different types of instruments are available for measuring radon and other 

radioactive contaminants. 

Sampling Methods and Instruments 

A list of sampling methods for individual contaminants is provided in Exhibit 6-1. Exhibit 6-2a 

provides a summary of some of the currently 

available instrumentation along with various 

characteristics of the instruments. The listing is the 

result of a survey of vendors which was conducted 

by the National Environmental Health Association 

and the School ofPublic and Environmental .Affairs 

during 1987 and 1988 (Deal and Ritchie, 1988). 

The list is not inclusive since there were vendors 

who did not respond to the survey. The listing 

reflects those methods and equipment reported by 

the vendors at the time of the survey. 

Products that are listed met two criteria for inclusion. First, the products are either portable or 

personal equipment (not stationary). Second, lower 

detectable limits, sampling ranges, and sampling 

flows (if applicable) are suitable for detecting 

commonly occurring indoor concentrations of 

contaminants. 

Sampling equipment is based on several different 

analytical methods which are abbreviated in the 

listings of equipment. Exhibit 6-2b provides the 

IAQ Reference Manual 

abbreviation for each method and a corresponding 

brief explanation of the method. 

The manufacturer's code number is given in parentheses following each product. A key to the manufacturers, their corresponding code numbers, and 

the prodtJ.cts they manufacture is provided in 

Exhibit 6-2b. Each product listed in Exhibit 6-2a 

includes nine categories of information ,about the 

product. These include: 1) Method; 2) LDL/Range; 

3) Sampling Rate; 4) Training/Maintenance; 5) 

Price; 6) Personal/Portable; 7) Power; 8) Weight; 

and 9) Dimensions. These categories were selected 

for comparison purposes because of their usefulness 

in evaluating specific sampling needs. 

Method refers to the sampling method employed by 

the product; a listing of the methods and corresponding abbreviations is given in Exhibit 6-2b. 

LDL/Range is the lower detectable limit followed 

by the range as indicated by the manufacturer's 

specifications. A blank space preceding or following 

the slash (/) means that this category is not applicable to the product, or that the information was 

not provided by the manufacturer's specifications. 

Samp Rate is the rate at which air is sampled 

through active samplers. Sampling rates are not 

given for passive samplers. 

TIM is the training and maintenance required to 

operate the sampler. The codes "L" and "M," 

limited and moderate, respectively, are intended to 

be general indicators. Limited training is a few 

minutes to a few hours of self-instruction. Moderate 

training includes several hours of self-instruction or 

formal instruction. Limited maintenance refers to 

preventative maintenance as well as procedures such 

as regular filter changes. Moderate maintenance 

indicates occasional trouble-shooting, component 

replacement, and calibration. A blank before or 

after the slash (/) indicates that not enough information was provided to determine the required 

training or maintenance. 
IAQ Reference Manual 

Price is the price listed in the literature provided by 

the manufacturer. Prices are generally subject to 

change at any time and should be regarded as 

approximate for a basic sampler without options. 

Per/Por indicates whether the sampler is personal 

(Per) or portable (Por). Personal samplers are 

actually attached to the person or an article of 

clothing during the sampling period. Portable 

samplers are those that can easily be carried from 

place to place. 

Power indicates whether the sampler operates on ac 

or de power or both. A "p" following the power 

requirements means that the sampler utilizes a 

passive sampling method even though another 

aspect of the sampler requires power. 

Section 6 

Weight and Dimensions indicate the weight and 

dimensions listed in the manufacturer's specifications. 

Additional Reference Tables 

In addition to the tables on sampling methods and 

instruments, this section contains tabulated information on battery-powered personal air samplers, 

properties of filters used in particulate sampling, 

storage properties of gases in plastic bags, limitations on solid adsorbents, sources for testing and 

calibration procedures, and standard reference 

materials. This information is contained in Exhibits 

6-3 through 6-8. 
1m 

Section 6 IAQ Reference Manual 

Exhibit 6·1. Collection and analytical methods for quantitative monitoring of some 

contaminants. 

CONTAMINANT COLLECTION METHOD ANALYTICAL METHOD 

co pump H2SO4 electrolyte; solid 

polymer electrolyte 

diffusion electrochemical 

direct reading infrared 

N02 diffusion tube; 

badge (TEA adsorbent) colorimetric 

pump; absorption colorimetric (automated) 

diffusion electrochemistry 

direct reading chemiluminescence 

direct reading electrochemistry 

502 pump; absorption colorimetric 

diffusion electrochemical 

direct reading electrochemical 

radon and diffusion etching; microscopic 

radon progeny counting 

adsorption (charcoal) scintillation counting 

electrostatic thermoluminescent dosimetry 

filtration alpha counting 

asbestos pump/filter gravimetric and 

spectrophotometry 

respirable particles direct reading optical scattering 

direct reading electrostatic precipitation 

direct reading piezoelectric resonance 

biological aerosols pump/impaction incubation; manual 

counting 

metals pump/filter atomic absorption; 

neutron activation; 

X-ray fluorescence 

volatile organics pump/adsorbent gas chromatography/ 

mass spectroscopy 

organochlorine pump/adsorbent gas chromatography/ 

pesticides (polyurethane foam) mass spectroscopy 

HCHO pump; adsorption colorimetric 

pump; adsorption spectrophotometry 

diffusion; adsorption colorimetric 
Exhibit 6·2a. Commercially available indoor air monitoring equipment. ~ to 

~ SAMP PER/ ~ NAME (MFR. CODE) METHOD LDIJRANGE RATE TIM PRICE POR POWER WT. DIMENSIONS !lS 

~ ~ 

AEROSOLS ~ 

MIE Miniram (19) Ph 0.10mglm31 LIM $2350 per dc,p 0.4 kg 10x10x5 em ~ ~ 

0.10-100 mglm3 ~ 

~ 

Low-Pressure 

Inspec-Aerosol 

Impactor 

Spectrometer 

Model 

(3) 

20-900 (2) 

DD 

I 0.08 !Jm I 0.08-1.0 !Jm 31/m L/L 

LIM por 

por - MIE Model RAS-1 Real Time Aerosol Sensor (19) Ph 0.01 mglm3 1 0-100 mglm3 0.21/m LIM $1975 por ac/dc,p 1 kg px18.8x5.3 em 

Particle Fractioning Sampler (2) 0.4 !Jm I 0.4-10.0 !Jm 28.31/m L/L por ac/dc 8.3 kg 23.5x22.2x12.7 em 

MIE RAM-S Real Time Aerosol Sensor (19) Ph 0.1 mglm3 1 0-200 mglm3 0.21/m LIM $4676 por ac 140g 10.5x6.5x2.5 em 

Series 12A Automatic Syringe Samplers (7) we MIM $3000 por de 14.5 kg 53x30x20 em 

Stainless Steel Syringe (7) F L/L $200-$400/14 per p 20-500 ml 

AMMONIA 

Midget Air Sampler (2) F 0.11/m MIM $1095 por de 2.0kg 20.3x17.8x10.2 em 

3-Gas Sampler (2) AWC 200 ml/m MIM $1315 por ac 10.9 kg 39.2x33.7x21 em 

5-Gas Sampler (2) AWC 200 ml/m MIM $1125 por ac 7.2kg 30.5x32.4x19.7 em 

Model PV Sequential Sampler (2) AWC 200 ml/m MIM $2855 por ac 

SS2000 (30) Ech I 0-75 ppm LIM por de 1.5 kg 21.6x10.9x17.3 em 

Liquid Sorbent Badge (31) D,G,IC 16-148 ppm (8 hr) 0.5-5 ml/m L/L $31/ea per p 

ASBESTOS 

MIE FAM-1 Fibrous Aerosol Monitor (19) Ph 0.01 fiberslcm3 I 1.5-2.5 1/m MIM $14,250 por ac/dc 11.4 kg 53x35x20 em 

0.01-30 fiberslcml 

BDX 74 Asbestos Pump (30) I 1.5-4.51/m L/L per de 1 kg 10.2x11.4x6.1 em 

BDX 99 Respirable Dust Sampler (30) I 1.71/m L/L per 

LV-1 (32) F 15-35 1/m LIM $630 ( por ac/dc 2.7 kg 10.2x10.2x17.8 em 

VM-3 (32) F 3-251/m LIM $800 por ac 5 kg 11.4x14.6x23.5 em 

ASB-II (3) 0.8 !Jm I >0.8 !Jm 111/m L/L $500 por 13.6 kg 33x20.3x19 em 

BIOLOGICAL AEROSOLS' 

Microbial Air Sampler (2) 28.3.1/m por 

Viable Microbial Sampler (2) I 0.65 !Jm 10.65-7.0 !Jm 28.31/m L/L por ac/dc 7.7kg 41.9x16.5x43.1 em 

Stainless Steel Syringe (7) F L/L $200-$400114 per p 20-500ml 

CADMIUM 

BDX 99 Respirable Dust Sampler (30) 1.7 1/m L/L per SAMP ~ 

~ 

~· ~ 

(continued next page) C\ 

II 
II 

Exhi'bit 6·2a. Co;m,m,ercial'ly ava:i:l:able indoor air monifo,ri:n,g equipm~eat {fontinued}. ~ 

~ 

~· 

SAMP PERl ;:: 

C\ NAME (MFR. CODE) METHOD LDIJRANGE RATE TIM PRICE POR POWER WT. DIMENSIONS 

CARBON DIOXIDE 

Gastechtor (18) Ech LIM $670-$1100 por dc,both 

RI-411 (18) NDIR 10-9950 ppm MIM $2100 por de 

RI-411 (5) IRD 20 ppm I 0-9950 ppm MIM $1995 por ac/dc 25.4x19x11.4 em 

RI-550A(5) NDIR 1% full scale I 0-20% 6llm MIM $2495 por ac 9 .5 kg 22x19.8x32 em 

MEXA 211E Portable Gas Analyzer (21) NDIR 10-5% MIM por ae 9.5 kg 22x22.5x52 em 

MEXA 321E Portable Gas Analyzer (21) NDIR I 0-25% MIM por ac 13 kg 33x22.5x52 em 

SS2000 (30) Ech 0-10,000 ppm LIM por de 1.5 kg 21x10.9x17.3 em 

Model APBA-210 C02 Monitor (21) NDIR 10-2000ppm MIM por ac/dc 6kg 31.1x13x17 em 

Model APBA-200E C02 Monitor (21) NDIR I 0-2000 ppm 0-100 mllm MIM por ac 5 kg 18x32x9.1 em 

Gastech Model4776 (18) NDIR I0-3000ppm LIM $2000 por ac, de 39.4x33.0x15.2 em 

CARBON MONOXIDE 

C0-82 (18) Ech 10-500ppm L/L $595 per dc,p 

BSI 210 (12) Ech 1 ppm I 0-1999 ppm LIL $695 per de,p 0.3 kg 14x8.5x3.8 em 

Gastechtor (18) Ech LIM $670-$1100 por de, both 

GX-82 (18) Ech LIM $1295 per dc,p 

lnterscan 5140 (22) Ech 2.5 ppm I 0-1000 ppm LIM $1145 per dc,p 680g 15.2x7.6x5.1 em 

lnterscan CO 1140 (22) Ech 1% full scale I 0-5 00 ppm !.211m LIM $1675 por de 3.6kg 18.4x15.2x2.9 em 

lntersean CO 4140 (22) Ech 1% full scale I 0-5 00 ppm 1.21/m LIM $1895 por de 2.0 kg 17.8x10.2x22.5 em 

Ecolyzer Model 2000 (12) Eeh 0.5 ppm I 0-600 ppm 700mllm LIM $1900 por ac/dc 4.5 kg 17.8x17.8x33 em 

GE CO Detector (20) Ech 1 ppm I 0-1000 ppm 60mllm L/L $1195 por de 290g 7.5x13.5x3.6 em 

Dosimeter Model3140 (22) D 1% full scale I 0-5 00 ppm LIM $1235 per dc,p 680g 15.2x7.6x5.1 em 

Model 4148 Compact Portable (22) Ech 1% full scale I 0-50 ppm LIM $1895 por ac/dc 2.0 kg 17.8x10.2x22.5 em 

PAM Model2140 (22) Ech 1% full scale I 0-500 ppm LIL $695 per dc,p 680g 16.5x7.6x5.1 em 

Model PV Sequential Sampler (2) AWC 200mllm MIM $2855 por ac 

Carbon Monoxide Detector (14) Ech 1 ppm I 0-500 ppm LIM $725 per dc,p 343g 7.9x12.1x2.8 em 

Ecolyzer Model 211 (26) Ech 1 ppm I 0-1999 ppm LIM per de 343 g 14.6x8.9x3.8 em 

Pure Air Monitor (4) Ech MIM $455 por ae 2.7 kg 30.5x10.2x17 .8 em 

Model 1148 Standard Portable (22) Ech 1% full scale I 0-50 ppm LIM $1895 por ac/dc,p 3.6kg 18.4x15.2x29.2 em s: 

RI-550A (5) NDIR 1% full scale I 0-20% 6llm MIM $2495 por ac 9.5 kg 22x19.8x32 em 10 

Carbon Monoxide Indicator Badge (36) Col 110-500 ppm L/L $2.25 per p ~ 

Carbon Monoxide Dosimeter, Model 3 (25) DICol LIL per p 14.3 g 7.6x12.7x0.6 em ~ <!> 

Exorox (27) Ech 1 ppm I 0-999 ppm LIM por de 0.9kg 15.2x8.9x5.3 em ~ ;:! MiniCO Indicator and Alarm model IV (25) Ech 1 ppm I 0-500 ppm LIL $562 per de ~ MiniCO V (25) Ech 10-1999 ppm LIL per dc,p 15.2x8.9x3.8 em 

Neorox Pocket CO Monitor (27) Ech 1 ppm I 0-999 ppm LIL per de 150 g 2.8x6.1x10.2 em ~ Portable CO Indicator, Model 70 (25) Ech 2 ppm I 0-100 ppm MIM $1472 por de 3.2 kg 21.6x16.5x8.9 em ;:! 

~ 

MEXA 321E Portable Gas Analyzer (21) NDIR I 0-1000 ppm MIM por ac 13 kg 33x22.5x52 em >:1 

-
Exhibit 6·2a. Commercially available indoor air monitoring equipment (continued}. ~ 10 

):r.:j 

SAMP PER/ ~ NAME (MFR. CODE) METHOD LDL/RANGE RATE TIM PRICE POR POWER WT. DIMENSIONS (li 

~ ;::! 

CARBON MONOXIDE (continued) .~ 

Lamotte 7782 Carbon Monoxide Test Kit (34) we 10ppm/ L!L $45 por p ;::! 

~ MEXA 201E Portable Gas Analyzer (21) NDIR I 0-1000 ppm M/M por ac 9.5 kg 22x22.5x52 em ~· 

~ Mini 

VaporGard 

Monitor 

Dosimeter 

(30) 

Tube (25) 

Ech 

D/Col specific 

0-400ppm 

to tube L!L 

L!L 

$24/10 per 

per 

p 

de 200g 7.7x2.4x11.8 em 

- CHLORINE 

Model 1340 Standard Portable (22) Eeh 1% full scale I 0-10 ppm LIM $2156 por ac/dc 3.6kg 18.4x15.2x29.2 em 

PAM Model2340 (22) Ech 1% full scale I 0-10 ppm L!L $875 per dc,p 680g 16.5x7.6x5.1 em 

Model 4340 Compact Portable (22) Ech 1% full scale I 0-10 ppm LIM $2156 por ac/dc 2.0kg 17.8x10.2x22.5 em 

SS2000 (30) Ech /0-3 ppm LIM por de 1.5 kg 21.6x10.9x17.3 em 

COMBUSTIBLE GAS 

Scott S-101 (29) /0-100% LIM $483 por de .51 kg 7.9x15.9x4.1 em 

Scott S-105A (with 0,) (29) /0-100%; /0-25% o, LIM $777 por de .51 kg 7.9x15.9x4.1 em 

Gastech Protechtor I & II (18) /0-100%; /0-25% o, LIM por de 

FORMALDEHYDE 

TGM 555 (5) AWC/Col 0.002 ppm I 0-5 ppm 0.51/m M/M $5410 por ac/dc 14kg 51x41x18 em 

Formaldehyde Monitor 3750 (35) D 0.8 ppm-hr I 0.8-72 ppm-hr 65.91/m L!L $35 per p 

PF-1 (1) D 0.01 ppm I 0.01-1.0 ppm 4.1 ml/m L!L $48/2 por p 90x25 mm 

Pro-Tek Formaldehyde Dosimeter (9) D 1.6 ppm-hr /1.6-54 ppm-hr L!L $222/10 per p 17.8 g 7.6x7.1x0.9 em 

ETS Formaldehyde Dosimeter (15) DD 0.03 ppm I 0.03-1.0 ppm L!L $24/2 por p 

PRO-TEK Colorimetric Air Monitoring Badges (9) D 1.6 ppm /1.6-54 ppm L!L per p 17.8g 7.6x7.1x0.9 em 

Formaldemeter (24) Ech 0.1 ppm I 0.1-99.9 ppm LIM per de 200g 12x6.3x3 em 

Lamotte 3408 Formaldehyde-in-Air Test Kit (34) Col 0.1 ppm I 0.1-1.0 ppm L!L $38 por p 

I:amotte 6695 Formaldehyde Test Kit (34) we 0.13 ppm/ L!L $40 por p 

Liquid Sorbent Badge (31) D,Col 0.02 ppm I 0.2-2 ppm 0.5-50 ml!m L!L $30 per p 

Passive BubblerTM Sampler (31) D,Col 0.1/0-1.5 ppm (8 hr,slowcap) 11.6 ml!m L!L $36/5 per p 7.0x2.05 em 

0.5/0-5 ppm(15 min, fastcap) 

PF- 20 (1) D,Col /0.1-3ppm (8 hr) 16 cm3

/m L!L per p 

HYDROCARBONS 

Gastechtor (18) Ech LIM $670-1100 por de, both 

SP-203F (18) Ech /low ppm L!L $500 per c, 

MEXA 221E (21) NDIR I 0-500 ppm M/M por ac 9.5 kg 22x22.5x52 em a 

~-;::! 

(continued next page) 0\ 

R 
II 

Exh,J&.Jt 6·2a. Co••·•rc.iallly avai1la'b'l• indoor a1i'r •o·nifo,rin·g eq,ui.p•·•at (continued}. ~ ~ 

t;· 

SAMP PER/ 

;:s 

0\ 

NAME (MFR. CODE) METHOD LDIJRANGE RATE TIM PRICE POR POWER WT. DIMENSIONS 

HYDROGEN SULFIDE 

Ecolyzer Model 2000 (12) Eeh 0.5 ppm I 0-600 ppm 700ml/m IJM $1900 por ad de 4.5 kg 17.8x17.8x33 em 

Dosimeter Model 3170 (22) D 1% full scale I 0-500 ppm IJM $1270 per dc,p 680g 15.2x7.6x5.1 em 

Model 4170 Compact Portable (22) Ech 1% full scale I 0-1 ppm IJM $2064 por ad de 2.0kg 17.8x10.2x22.5 em 

PAM Model2170 (22) Eeh 1% full scale I 0-100 ppm UL $765 per dc,p 680g 16.5x7.6x5.1 em 

Midget Air Sampler (2) F 11/m MIM $1095 por de 2.0kg 20.3x17.8x10.2 em 

3-Gas Sampler (2) Sa Tr 200mllm MIM $1315 por ac 10.9 kg 39.2x33.7x21 em 

5-Gas Sampler (2) SaTr 200mllm MIM $1125 por ac 7.2kg 30.5x32.4x19.7 em 

Model PV Sequential Sampler (2) Sa Tr 200mllm M/M $2855 por ac 

TGM 555 (5) AWC/Col 0.002 ppm I 0-5 ppm 0.5 1/m M/M $5250 por ac/dc 13.6 kg 50.8x40.6x17.8 em 

Ecolyzer Model 241 (26) Ech 1 ppm/ 0-1000 ppm LIM per de 343 g 14.6x8.9x3.8 em 

Model 1170 Standard Portable (22) Ech 1% full scale I 0-1 ppm LIM $2064 por ac/dc,p 3.6kg 18.4x15.2x29.2 em 

Exotox (27) Ech 1 ppm I 0-500 ppm IJM por de 0.9kg 15.2x8.9x5.3 em 

Gold Film Hydrogen Sulfide Analyzer (23) Ech 1 ppb /1-500 ppb 150ml/m IJM $8500 por ad de 3.6kg 30.5x20.3x20.3 em 

Neotox Pocket H2S Monitor (27) Ech 1 ppm I 0-999 ppm UL per de 150 g 2.8x6.1x10.2 em 

Portable Indicator and Alarm, Model361 (25) Ech I 0-50 ppm 1.51/m· MIM $1685 por de 3.4 kg 17.8x25.4x9.5 em 

Mini Monitor (30) Ech I 0-100 ppm UL per de 200g 7.6x2.4x11.8 em 

SS2000 (30) Ech /0-3- ppm IJM por de 1.5 kg 21.6x10.9x17.3 em 

LEAD 

BDX 99 Respirable Dust Sampler (30) 1.71/m UL per 

MERCURY 

Model411 Gold Film Mercury Vapor Analyzer(23) Ech 0.001 mglm3 0-751/m LIM $3750 por ac/dc 2.3 kg 33.0x16.3 em 

I 0.001-1.999 mg/m3 

Mercury Gas Monitoring Badge (31) D,AA 0.002 mg/m3 (8hr)l UL $22.50110 per p 

Mercury Vapor Badge 3600 (35) D,AA /0.005-0.20 mgfm3 UL per p 

NITROGEN DIOXIDE -~ 

!0 

TGM 555 N02 Analyzer (5) AWC/Col 0.005 ppm I 0-0.25 ppm 0.5 1/m M/M $5340 por ac/dc 14kg 51x41x18 em ):l::j 

CSI 1600 NOx Analyzer (6) Ch 0.002 ppm I 0.002-5 ppm 500mllm MIM $7950 por ac 34kg 43.2x27.7x68.6 em ~ !1) 

Air Check (1) D 0.005 ppm I 0.005-10 ppm UL $4812 por p ~ ;:s 

DuPont PRO-TEK Type C30 Dosimeter (9) D 10 ppm-hr 110-100 ppm-hr UL $259/10 per p 16g 7.6x7.1x0.9 em ~ Toyo Roshi N02 Badge (26) DIAd 66 ppb-hr I 66-1066 ppb-hr UL $12 per p 15 g 5x4x1 em 

MDA Palmes Tube (24) DIS 1 ppm-hr /1-20 ppm-hr 1 mllm UL $8-10 per p 14g 8 em x 1.3 em dia. ~ Ecolyzer Model2000 (12) Ech 0.5 ppm I 0-600 ppm 700mllm LIM $1900 ac/dc 4.5 kg 17.8x17.8x33 em ;:s 

por ~ 

Dosimeter Model 3150 (22) D 1% full scale I 0-500 ppm LIM $1425 per dc,p 680g 16.5x7.6x5.1 em l:l 

....... 
Exhibit 6·2a. Commercially available indoor air monitoring equipment (continued}. ~ to 

~ SAMP PER/ ~ NAME (MFR. CODE) METHOD LDLIRANGE RATE TIM PRICE POR POWER WT. DIMENSIONS (I> 

~ ;::s 

NITROGEN DIOXIDE (ctmtinued) ~ 

Modelll52 Standard Portable (22) Ech l% full scale I 0-10 ppm LIM $2295 por acldc 3.6kg l8.4xl5.2x29.2 em ~ \:t 

Model4152 Compact Portable (22) Eeh 1% full scale I 0-10 ppm LIM $2295 por ac/dc 2.0kg 17.8xl0.2x22.5 em ~ PAM Model2150 (22) Ech 1% full scale I 0-5 0 ppm LIL $860 per dc,p 680g 16.5x7.6x5.1 em ...... 

Midget Air Sampler (2) F 0.11/m · M/M $1095 por de 2.0kg 20.3x17.8x10.2 em 

3-Gas Sampler (2) SaTr 200mllm MIM $1315 por ac 10.9 kg 39.2x33.7x21 em 

5-Gas Sampler (2) Sa Tr 200 rollro M/M $1125 por ac 7.15 kg 30.5x32.4x19.7 em 

VaporGard Dosimeter Tube (25) DICol I specific co tube LIL $24110 per p 

Mini Monitor (30) Ech 10-10 ppm LIL por de 200g 7 .6x2.4xll.8 em 

NITROGEN MONOXIDE 

CSI 1600 NOx Analyzer (6) Ch 0.002 ppm I 0.002~5.0 ppm 500ml/m M/M $7950 por ac 34kg 43.2x27.7x68.6 em 

Ecolyzer Model2000 (12) Ech 0.5 ppm I 0-600 ppm 700 mllm IJM $1900 por acldc 4.5 kg 17.8x17.8x33 em 

Dosimeter Model3540 (22) D 1% full scale I 0-500 ppm LIM $1425 per dc,p 680g 15.2x7.6x5.1 em 

Model 1545 Standard Portable (22) Ech 1% full scale I 0-50 ppm LIM $2247 por ad de 3.6kg 18.4x15.2x29.2 em 

Model 4545 Compact Portable (22) Ech 1% full scale I 0-50 ppm LIM $2247 por . aeldc 2.0kg 17.8x10.2x22.5 em 

NITROGEN OXIDES 

CSI 1600 NOx Analyzer (6) Ch 0.002 ppm I 0.002-5 ppm 500mllm M/M $7950 por ac 34kg 43.2x27. 7x68.6 em 

Toyo Roshi N02 Badge (26) DIS 66 ppb-hr /66-1066 ppb-hr LIL $12 per p 15 g 5x4xl em 

MDA Palmes Tube (24) DIS 1 ppm-hr /1-20 ppro-hr 1 mllm LIL $8-10 per p 14 g 8 em x 1.3 em dia. 

Ambient Air Sampler (2) AWC 311m M/M $520-685 por ac 6.4 kg 20.3x25.4x27.3 em 

Model PV Sequential Sampler (2) AWC 200mllm M/M $2855 por ac 

TGM 555(5) AWC/Col 1% full scale I 0-0.25 ppm 0.51/m M/M $5250 por ac/de 14 kg 51x41xl8 em 

IES Model AlOO (41) AWC /0-0.1 ppm; 0-100 ppm M/M $7995 por ac 18.6 kg 27.9x30.5x36.8 em 

AC 35 NO-NO, (40) Ch 0.01 ppm/0-2 ppm M/M por ac, de 5.5 kg 40x30x13 em 

ORGANICS 

Gas Monitoring Badges (31) D varies varies LIL $48/25 per p 

Charcoal Sampling Tubes (9) s Lit por 50/100 mg6x70 rom 

PRO-TEK G-AA Air Monitoring Badges (9} D 0.2 ppm-hr I 0.2-1300 ppm LIL per p 7.7 g 7.7x0.8xl.4 em 

PRO-TEK G-BB Air Monitoring Badges (9) .D 0.4 ppm-hr I 0.4..4000 ppm LIL per p ll.lg 7.7x0.9xl.6 em 

Ambient Air Sampler (2) AWC 311m M/M $520-685 por ae 6.4 kg 20.3x25.4x27.3 em ~ VaporGard Dosimeter Badges (25) D LIL $74 per p ~ 

~· ;::s 

(continued next page) 0\ 

II 
II 

Exhibit 6-2a. Con~mercially available indoor air monitoring ettuipment tcoalhrued}. (I') 

<II 

~ 

~· 

SAMP PERf ~ 

0\ 

NAME (MFR. CODE) METHOD Ll?lJRANGE RATE TIM PRICE POR POWER WT. DIMENSIONS 

ORGANICS (&Dnlinued) 

Organic Vapor Monitor, Series 3500 (35) D compound specific UL per p 

OVA-108 (17) FIIGC 0.5 ppm I 1-10000 ppm 111m MIM por de 5.5 kg 23x30xl0cm 

OVA-128 (17) FIIGC 0.2 ppm I 0-1000 ppm 111m JJM pot de 5.5 kg 23x30xl0cm 

OXYGEN 

Gasteehror (18) Ech JJM $670-1100 por de, both 

GX-82(18) Ech JJM $1295 per dc,p 

OX-82(18) Ech /0-50% JJL $525 per de,p 

Model 3300 Oxygen Monitor (24) I 0-25% or 0-100% MIM por de 

Ecolyzer Model 260 (26) Eeh 0.1%/0-30% JJM per de 343g 14.6x8.9x3.8 em 

Personal 02 Monitor (14) Ech 1% full scale I 0-100% JJM $695 per de,p 343g 7.9xl2.lx2.8 em 

Portable Oxygen Analyzer (14) Ech 1% full scale I 0-100% JJM $2695 por de 6.4kg 15.2xl9x30.5 em 

Scott-Alert (29) 3% full scale I 0-100% JJL $505 per de 514g 7.9xl5.7x4.1 em 

Exorox(27) Eeh 0.1%/0-35% JJM por de 0.9kg 15.2x8.9x5.3 em 

Neorox Pocket 02 Moniror (27) Ech 0.1%/0-35% UL per de 150g 2.8x6.1xl0.2 em 

Portable Indicator &: Alarm, Model 361 (25) Ech I 0-25% ' 1.51/m M/M $1685 por de 3.4kg l7.8x25.4x9.5 em 

Mini Monitor (30) Ech 10-40% UL per de 200g 7 .6x2.4xll.8 em 

OZONE 

CSI 2000 Portable Ozone Meter ( 6) Ch 0.004 ppm I 0-1 ppm 700 ml/m MIM $6750 por de 7.7 kg 20.3xl7.8x45.7 em 

Ambient Air Sampler (2) AWC 311m MIM $520-685 por ac 6.4kg 20.3x25.4x27.3 em 

RADON AND PROGENY 

Track Etch (33) D 0.2 pCill I 0.2-2000 pCi/1 JJL $20-50 pot p 6.4 sq em 

Mini CON ll (8) GM 2.3 MeV I 0-5000 cpm UM $485 per dc,p 454g 6.7xll.8x2.5 em 

MiniCON-RAD n (8) GM 2.3 MeV I 0-5000 cpm JJM $550 per dc,p 454g 6.7x11.8x2.5 em 

Portable Survey Meter (8) GM ·I 0-0.5 mR/hr MIM $440 por dc,p 1735 g ll.lx22.2x10.8 em ~ RDA-2000 Radon/Radon Daughter Detector (11) Sc I 0-99,999 ets variable MIM $4450 por de Skg l2.7xl6.5x20 em lC 

LV-1 (32) F 15-35 lim UM $550 pot aclde 2.7kg l0.2xl0.2xl7.8 em ~ 

Model442-A (28) DD I 0-1000 cpm 28.3-453 1/m MIM por ac 7.3 kg 27.9x40.6x15.9 em ~ <I> 

WLM-IA (10) Eeh 0.12-0.181/m LIM $2950 por de 2.4kg l4.6x11.8x20.3 em ~ ~-

Model 05-420 AT EASE (39) D 0.1 pCi/l/0.1-999 pCi/1 UL $449 por p ~ Model 05-418 Honeywell Professional (39) D 0.1 pCi/1 /0.1-999 pCi/1 JJL $795 por p 

E-Perm Introductory Kit (42) D I< 1 to 50 pCill (2-7 da) JJL $2500 por p .12 kg 1 0.2x8.3 em (chamber) ~ /50 to 200 pCi/1 (15-30 da) !::! = 

/<7pCill(up to 1 yr) t. 

-
Exhibit 6·2a. Commercially available indoor air monitoring equipment (continued}. s 

~ 

):l::j 

SAMP PERl ~ NAME (MFR. CODE) METHOD LDLIRANGE RATE TIM PRICE POR POWER WT. DIMENSIONS ~ 

~ ;:s 

RESPIRABLES &I 

TSI Pie:tobalance Model 3 500 (3 7) EP 0.001 mglm3 I O.ol-10 mg/m3 11/m M/M $4400 por acldc 4.5 kg 31x13xl7 em ~ l':il 

Low-Pressure Impactor Model20-900 (2) I 0.08 J.lm I 0.08· 1.0 J.lm 311m UL por ~ Marple Personal Cascade Impacror Model 294 (2) 3.5 J.lm I 4 stages 21/m L!L $775 per 170g 7.2x5.7x4.0 em .... Marple Personal Cascade Impactor Model 296 (2) 0.6 J.lm I 6 stages 211m UL $975 per 185 g 8.0x5.7x4.0 em 

Marple Personal Cascade Impactor Model 298 (2) 0.6 J.lm /8 stages 211m L!L $1175 per 200g 8.6x5.7x4.0 em 

Microbial Air Sampler (2) 28.31/m por 

Particle Ftactioning Sampler (2) 0.4 J.lm I 0.4-10.0 J.lm 28.3IIm L!L por acldc 8.3kg 23.5x22.2xl2. 7 em 

PS-4 Particulate Sizing Impactors (19) 1.1 J.lm /1.1-8.0 J.lm 21/m L!L $96014 por 130g 8.8x4.8 em dia. 

Mie Miniram (19) Ph 0.1 mg/m3 1 0.1-100 mg/~ LIM $2350 per dc,p OAkg 10xl0x5 em 

Mie R.AM-1 (19) Ph 0.1 mglm3 I 0.01-200 mglm3 1-3lfm LIM $6250 por de 4kg 20x20x20cm 

BDX30(30) UL per de 600g 10.2xl1.4x6.1 em 

BDX 99 Respirable Dust Sampler (30) 1.71/m UL per 

P-5 Digital Dust Indicator (24) 0.001 mglm3 MIM por acldc 

I 0.001-100 mg/m3 

Personal Dust Monitoring System (24) 0.1 mglm3 / 0.01-100 mg/m3 LIM per de 

Stainless Steel Syringe (7) F L!L $200-$400/14 per p 20-500 ml 

May/R.E. Cascade Impactor (3) G 0.5f.lm I 0.5-32f.lm 5lfm UL $4995 por 12x8.2x8.7 em 

Portable Condensation Nuclei Monitor (13) Ph 0.0025 J.lm I 30-70- mllsec MIM por de 3.6kg 12.7x17.8x40.6 em 

TEOM® Series 1200 (39) Im 5f.lg/m3 (10 min ave)/ 0.5- 51/m MIM pot ac 30g 25x36x46 em (sensor) 

15f.lg/m3 (2 min ave)/ 12kg 36x45xl9cm 

(computer) 

SULFUR DIOXIDE 

Dosimeter Model 3240 (22) D 1% full scale I 0-500 ppm LIM $1425 per dc,p 680g 15.2x7.6x5.l em 

Intersean 5 240 Dosimeter (22) Ech 0.5% full scale I 0-20 ppm LIM $1145 per dc,p 680g 15.2x7.6x5.1 em 

Interscan S02 1240 (22) Ech 1% full scale I 0-10 ppm LIM $1675 per de 3.6kg 18.4x1.5x29 em 

Interscan S02 4240 (22) Ech 1% full scale I 0-10 ppm LIM $1895 per de 2.0kg 17.8xl0.2x22.5 em 

Model 4240 Compact Portable (22) Ech 1% full scale I 0-1 ppm LIM $2211 por acldc 2.0kg 17.8x10.2x22.5 em 

PAM Model2240 (22) Ech 1% full scale I 0-50 ppm L!L $860 per dc,p 680g 16.5x7.6x5.l em 

Midget Air Sampler (2) F O.lllm MIM $1095 por de 2.0kg 20.3x17.8x10.2 em 

3-Gas Sampler (2) AWC 200ml/m MIM $1325 por ac 10.9kg 39.2x33.7x21 em 

5-Gas Sampler (2) AWC 200ml!m MIM $1125 por ac 7.15kg 30.5x32.4xl9.7 em 

Ambient Air Sampler (2) AWC 311m MIM $520-685 por ac 6.4kg 20.3x25.4x27.3 em 

Model PV Sequential Sampler (2) AWC 200ml/m MIM $2855 por ac 

VaporGard Dosimeter Tube (25) D/Col I specific to tube UL $24/10 per p 

· Model1240 Standard Porrable (22) Ech 1% full scale I 0-1 ppm LIM $2210 por ai:/dc,p 3.6kg 18.4x15.2x29.2 em ~ Liquid Sorbent Badge (31) D 0.1 ppm f 0.1-100 ppm 0.5-50 mi/m L!L $30 per p ~ 

~· ;:s 

(continued next page) <:l\ 
II 

Exhibit 6·2a. (o,mmerciai1IJ available itldoor air monitoring equipment (tonlinuedJ. ~ 

~ 

~· 

SAMP PER/ ~ 

0\ 

NAME (MFR. CODE) METHOD LDIJRANGE RATE TIM. PRICE POR POWER wr. DIMENSIONS 

SULFUR DIOXIDE (&tJnlinued) 

TGM555 (5) AWCICol 1% full scale I 0-0.25 ppm 0.51/m MIM $5395 por ac/dc 14kg 51x4lx18em 

SS2000 (30) Ech 10-10 ppm UM par de 1.5 kg 2l.6xl0.9x17.3 em 

Mini Monitor {30) Ech /0-20ppm LIL per de 200g 7 .6x2.4xl1.8 em 

TOTAL SUSPENDED PARTICULATES 

Status 2100 (16) Ph 0.5j.lm I 0.5-5 j.1m 23.3mllm MIM $3950 por ae 7.2kg 15.2x25.4x35.6 em 

StatUS 5000 (16) Ph 0.3 j.1m I 0.3-5.0 j.1m 28.3 mllm MIM $6950 por ac 10.8kg 11.4x29.2x41.9 em 

BDX 74 Asbestos Pump (30) I 1.5-4.51/m LIL per de 1 kg 10.2xll.4x6.1 em 

PCD-1 Direct-Reading Dust Monitor (24) 0.001 mg/rr? MIM por 

I 0.001-9.9 mglm3 

LV-1 (32) F 15-35 lim UM $550 par acldc 2.7kg 10.2xl0.2xl7.8 em 

VM-3 (32) F 3-25llm UM $680 por ac 5kg 11.4xl4.6x23.5 em 

Series 12A Automatic Syrioge Samplers (7) we MIM $3000 por de 14.5 kg 53x30x20em 

Midget Air Sampler (2) Sa Tr O.llfm MIM $1095 por de 2.0kg 20.3x17.8x10.2 em 

SOURCE: Ritchie and Deal (1988) 
IAQ Reference Manual Section 6 

Exhibit 6·2b. ldentificatioa codes for methods ia Exhibit 6·2a. 

ABBREVIATION 

AA 

AWC 

Ch 

Col 

D 

DD 

Ech 

EP 

F 

FI 

G 

GC 

GM 

I 

IC 

DESCRIPTION OF METHOD 

Atomic Absorption-ionized molecules are deflected by a magnetic field 

according to their mass and charge 

Automated Wet Chemistry-reagents are reacted with the contaminant to 

determine its presence or concentration; reagents are automatically 

introduced 

Chemiluminescence-the intensity of light emitted from a chemical reaction 

between the contaminant and a reagent is directly related to the 

contaminant concentration 

Colorimetry-reagents are reacted with the contaminant; the presence or 

concentration of contaminant is based on a color change resulting from the 

chemical reaction 

Diffusion-spontaneous transfer and mixing of contaminant based on 

molecular motion 

Dry Deposition-natural settling of particles due to gravity 

Electrochemical--contaminant concentrations are based on the measurement 

of electrical changes caused by chemical reactions 

Electrostatic Precipitation--concentrations of particles are based on the use 

of an electrical field to charge and separate the particles 

Filtration-physical separation of suspended matter from a gas stream 

Flame Ionization--concentrations are proportional to ion currents which 

are produced by contaminants which are introduced into a flame 

Gravimetric-measurement by weight 

Gas Chromatography--concentrations are proportional to a signal that is 

generated as contaminant gas is separated into its components and measured 

by a detector 

Geiger Mueller-measurement of pulses resulting from the ionizing effect 

of radiation on an enclosed gas 

Impaction--collection by forcing contact 

Ion Chromatography-sequential determination of anions or cations using ion 

exchange and conductivity, amperometric, or colorimetric detectors 

(continued next page) 
liD 

Section 6 IAQ Reference Manual 

Exhibit 6·2b. Identification codes for methods in Exhibit 6·2a (tontinued}. 

ABBREVIATION 

Im 

IR 

NDIR 

Ph 

s 

Sc 

SrTr 

we 

DESCRIPTION OF METHOD 

Inertial mass-direct determination by oscillating microbalance 

Infrared Detection-infrared radiation is passed through the sample, dispersed, and detected; concentration is proportional to the amount of radiation that is absorbed by the contaminant 

Nondispersive Infrared Detection-similar to IR except that a single band of 

infrared radiation is used 

Photometry-measurement of light intensity 

Sorytion-adsorption, absorption, or both 

Scintillation-measurement of flashes from radiation 

Sampling Train-for collection of sample only 

Wet Chemistry-reagents are manually introduced to the sample to deter 

mine the presence or concentration of a contaminant 

Exhibit 6·2c. Identification codes for manufacturers In Exhibit 6·2a. 

CODE ADDRESS CONTAMINANTS CODE ADDRESS CONTAMINANTS 

1 Air Quality Research, Inc. N02

,HCHO 4 Calibrated Instruments, Inc. co 

901 Grayson Street 731 Saw Mill River Rd. 

Berkeley, CA 94710 Ardsley, NY 10502 

(415-644-2097) (914-693-9232) 

2 Anderson Samplers RSP, TSP, AER, 5 CEA Instruments, Inc. HCHO, N02

, 802

, 

4215 Wendell Dr. BIO, AER, 802, NO •• 16 Chestnut St., P.O. Box 303 H2

S,CO,C02 

Atlanta, GA 30336 N02

, H2

S, NH3

, Emerson, NJ 07630 

(800-241-6898) ORG,o,,co (201-967-5660) 

3 BGI,Inc. AER, RSP, ASB 6 Columbia Scientific Industries 0 3

, NO •• NO, N02 

58 Guinan St. 11950 Jollyville Rd. 

Waltham,MA 02154 P.O. Box 9908 

(617-891-9380) Austin, TX 78766 

(800-531-5003) 
IAQ Reference Manual Section 6 

Exhibit 6·2c. Identification codes for manufacturers in Exhibit 6·2a (coatinued}. 

CODE ADDRESS CONTAMINANTS CODE ADDRESS CONTAMINANTS. 

7 Demaray Scientific AER, BIO AER, SE 16 Faley International Corp. TSP 

Instruments RSP,TSP P.O. Box669 

1122 Latah St. El Toto, CA 92630-0669 

Pullman, W A 99163 (714-837-1149) 

(509-332-8577) 

17 Foxboro Company ORG 

8 Dosimeter Corporation Rn 38 Niponset Avenue 

P.O. Box 42377 Foxboro, MA 07039 liD Cincinnati, OH 45242 (714-837-1149) 

9 DuPont Co., Inc. N02

, HCHO, ORG 18 Gas tech CO, C02

, 0 2

, HC 

Barcley Mill Plaza P.O. Box 390726 

Marshall Mill Bldg. Mountain View, CA 94039 

Wilmington, DE 19898 

(215-444-4188) 19 MIE,Inc. RSP, ASB, AER 

213 Burlington Rd. 

10 Eberline Instrument Corp. Rn, Prog Bedford, MA 01730 

P.O. Box 2108 (617 -275-5444) 

Sante Fe, NM 87501 

(505-471-3232) 20 General Electric co 

333 W. Seymour Ave. 

11 EDA Instruments, Inc. Rn Cincinnati, OH 45216 

5151 Ward Rd. (513-948-5065) 

Wheat Ridge, CO 80033 

(303-422-9112) 21 Horiba Instruments co,co,,Hc 

1021 Duryen Ave. 

12 Energetics Science Division CO, N02

, NO, H2

S Irvine, CA 92714 

Six Skyline Dr. (800-446-7 422) 

Hawthorne, NJ 10532 

(914-492-3010) 22 Interscan Corporation CO, N02

, H2

S, S02

, 

21700 Nordhoff St. NO, C02 

13 Environment/One Corp. RSP P.O. Box 2496 

2773 Balltown Rd. Chatsworth, CA 91311 

Schenectady, NY 12309 (800-458-6153) 

(518-346-6161) 

23 Jerome Instrument Corp. H2

S, Hg 

14 Environmental Tectontics co,co2 P.O. Box336 

Corp. Jerome, AZ 86331 

County Line Industrial Park (800-952-2566) 

Southampton, PA 18966 

(800-523-6079) 24 MDA Scientific, Inc. N02, NO,, 0 3

, 502, 

405 Barcley 0 2

, RSP, TSP, HCHO 

15 Envirotech Services, Inc. HCHO Lincolnshire, IL 60069 

547 Park Ave. (800-323-2000) 

Prairie Du Sac, WI 53758 

(608-643-4755) 25 Mine Safety Appliances Co. ORG, CO, S02

, N02, 

400 Penn Center Blvd. 0 2

, H2

S 

Pittsburgh, PA 15235 

(800-672-2222) 

(continued next page) 
Section 6 IAQ Reference Manual 

Exhibit 6·2c. Identification codes for manufacturers in Exhibit 6•2a (tonllnuedJ. 

CODE ADDRESS CONTAMINANTS CODE ADDRESS CONTAMINANTS 

26 National Draeger, Inc. N02

, NO,, CO, H2

S, 35 3M Corporation HCHO, ORG, Hg 

101 Technology Drive 02 220-7W, 3M Center 

Pittsburgh, PA 15275 St. Paul, MN 55144 

(412-787-8383) (612-733-6234) 

27 Neotronics 0 2

,CO,H2

S 36 Tracor Atlas co 

P.O.Box370 9441 Baythorne Drive 

II 411 Bradford St., N.W. Houston, TX 77041 

Gainesville, GA 30503 (713-462-6166) 

(404-535-0600) 

37 TSI RSP 

28 SAI Technology Co. Rn P.O. Box 64394 

4060 Sorrento Valley Blvd. St. Paul, MN 55164 

San Diego, CA 92121 (612-490-2888) 

(619-452-9983) 

38 Rupprecht& TSP,RSP 

29 Scott Aviation 02 Patashnick Co., Inc. 

Lancaster, NY 14086 8 Corporate Circle 

{716-683-5100) Albany, NY 12203 

(518-452-0065) 

30 Sensidyne, Inc. CO, C02

, N02, 0 2, 

12345 Starkey Rd., Suite E S02, Cl2

, RSP, ASB, 39 Nuclear Associates Rn 

largo, FL 33542 TSP 100 Voice Road 

(813-5 30-3602) P. 0. Box 349 

Carle Place, NY 11514-0349 

31 SKC,Inc. ORG, S02

, HCHO (516-741-6360) 

RDl #395 Valley View Rd. 

Eighty Four, PA 15330 40 Environment SA NO-NO. 

(412-941-9701) 111 Bd. Robespierre 

78300 Poissy, France 

32 Sraplex Air Sampler Division ASB, TSP, Rn (1) 39.79.34.57 

777 Fifth Ave. 

Brooklyn, NY 11232 41 IES Systems Corp. NO, N02 , NO., S02, 

(212-768-3333) 4432 N. Kedzie Ave. HCHO 

Chicago, IL 60625 

33 Terradex Corp. Rn (312-459-4655) 

460 N. Wiget Lane 

Walnut Creek, CA 94596 42 Rad Blec. Inc. Rn, Prog 

(415-938-2545) 5330 J. Spectrum Drive 

270 Technology Park 

34 Thomas Scientific HCHO,CO Frederick, MD 21701 

Vine St. at Third (301-694-0011) 

P.O.Box779 

Philadelphia, PA 19105 

(609-467-2000) 

SOURCE: Ritchie and Deal (1988) 

Section 6 IAQ Reference Manual 

Exhibit 6·4. Properties of filters used in particulate sampling. 

PORE FILTER PERMEABIUTY 

SIZE, VELOCITY, em/sec FILTER EFFICIENCY 

FILTER MATERIAL Jl.m (~P = 1 cmHg) RANGE,%* 

A. Cellulose Fiber Filter 

Wha.tman 

No.1 Cellulose Fiber 6.1 49-99.96 

No.2 3.8 63-99.97 

No.3 2.9 89.3-99.98 

II No.4 20.6 33-99.5 

No. 5 0.86 93.1-99.99 

No.40 3.7 77-99.99 

No.41 16.9 43-99.5 

No.42 0.83 92.0 - 99.992 

B. Glass Fiber Filter 

Gelman 

Type A Glass Fiber 11.2 99.2 - >99.99 

Type AlE 15.5 99.6- >99.99 

Spectrograde 15.8 99.5 - >99.99 

Microquattz 14.1 98.5 - >99.99 

MSA Uo6B 15.8 99.5 - >99.99 

Pa.llflex 

2500QAO Quartz Fiber 41. 84-99.9 

E70/2075W 36.5 84-99.95 

T6oA20 Teflon Coated Glass Fiber 49.3 55-98.8 

(another lot) 40.6 52-99.5 

T60A25 36.5 65-99.3 

TX40Hl20 15.1 92.6-99.96 

(another lot) 9.0 98.9- >99.99 

Reeve Angel 934AH Glass Fiber 12.5 98.9 - >99.99 

(acid tceated) 20. 95.0-99.96 

Whacman 

GF/A Glass Fiber 14.5 99.0- >99.99 

GF/B 5.5 >99.99- >99.99 

GF/C 12.8 99.6- >99.99 

EPMlOOO 13.9 99.0- >99.99 

C. Plastic Fiber Filter 

Del bag Polystyrene 

Mictosorban-98 13.4 98.2- >99.99 

D. Membrane Filter 

Millipore 

MF-VS Cellulose acerare/nitrate 0.025 0.028 99.999- >99.999 

MF-VC 0.1 0.16 99.999- >99.999 
IAQ Reference Manual Section 6 

Exhibit 6·4. Properties of filters used In particulate sampling (fontlnueiiJ. 

PORE FILTER PERMEABILITY 

SIZE, VELOCITY, cm!sec FILTER EFFICIENCY 

FILTER MATERIAL Jlm (.W ~ lcmHg) RANGE,%* 

Millipore (continued) 

MF-PH 0.3 0.86 99.999 >99.999 

MF-HA 0.45 1.3 99.999 - >99.999 

MF-AA 0.8 4.2 99.999 - >99.999 

MF-RA 1.2 6.2 99.9- >99.999 

MF-SS 3.0 7.5 98.5 - >99.999 II MF-SM 5.0 10.0 98.1- >99.99 

MF-SC 8.0 14.1 92.0- >99.9 

Polyvic-BD Polyvinyl Chloride 0.6 0.86 99.94 - >99.99 

Polyvic-VS 2.0 5.07 88- >99.99 

PVC-5 5.0 11. 96.7- >99.99 

Celotate-EG Cellulose Acetate 0.2 0.31 >99.95 - >99.99 

Celotate-EH 0.5 1.07 99.989 - >99.999 

Celotate-EA 1.0 1.98 99.99- >99.99 

Mitex-LS Teflon 5.0 4.94 84- >99.99 

Mitex-LC 10.0 7.4 62- >99.99 

Fluoropore PTFE-polyethylene 

reinforced 

FG 0.2 1.31 >99.90- >99.99 

PH 0.5 2.32 ,>99.99 - >99.99 

FA 0.1 7.3 >99.99- >99.99 

FS 3.0 23.5 98.2 - >99.98 

Metricel 

GM-6 Cellulose acetate/nittate 0.45 1.45 >99.8 - >99.99 

VM-1 Polyvinyl chloride 5.0 51.0 49-98.8 

DM-800 PVSI Acrylonitrile 0.8 2.7 ~9.96- >99.99 

Gelman Teflon Teflon 5.0 56.8 85-99.90 

Ghia 

52 37PL02 Teflon 1.0 12.9 >99.97- >99.99 

S2 37PJ 02 2.0 23.4 99.89- >99.99 

52 37PK02 3.0 24.2 92-98.98 

S2 37PF02 10.0 95.4- >99.99 

Zefluor- Teflon 

PSPJ 037 50 2.0 32.5 94.6-99.96 

P5PJ 037 50 3.0 31.6 88-99.9 

(continued next page) 
Section 6 IAQ Reference Manual 

Exhibit 6·4. Properties of filters used in particulate sampling {continued}. 

FILTER 

Cbemplast 

75-F 

75-M 

75-C 

Selas Flotronics 

FM0.45 

FMO.S 

FM1.2 

FM5.0 

Nuclepore 

NOlO 

N030 

N040 

N060 

NlOO 

N200 

N300 

N500 

N800 

NlOOO 

N1200 

MSA Personal 

Air Sampler 

MATERIAL 

Teflon Filter 

Silver 

Polycarbonate 

PORE 

SIZE, 

Jlm 

1.5 

1.0 

1.0 

0.45 

0.8 

1.2 

5.0 

FILTER PERMEABIUTY 

VELOCITY, em/sec 

(AP = 1 cmHg) 

3. 

6.6 

32 

1.8 

6.2 

9.2 

19.0 

E. Nuclepore Filter 

0.1 0.602 

0.3 3.6 

0.4 2.9 

0.6 2.1 

1.0 8.8 

2.0 7.63 

3.0 12. 

5.0 30.7 

8.0 21.2 

12.0 95. 

10.0 161.1 

F. Miscellaneous Filter 

12 

FILTER EFFICIENCY 

RANGE,%* 

83-99.99 

54- >99.99 

26-99.8 

93.6-99.98 

90-99.96 

73-99.7 

25-99.3 

>99.9- >99.9 

93.9- >99.99 

78- >99.99 

53-99.5 

28- 98.1 

9-94.1 

9-90.4 

6 90.7 

1-90.5 

1-46 

1-66 

89-99.97 

*The range of filter efficiency value given generally corresponds to a particular diameter range of 0.035 to l.A, a pressure drop range of 1 to 30 em Hg 

and a face velocity range of 1 to 100 em/sec. 

SOURCE: From Air Sampling lnstrummts for Evaluation of ll.tmospherk Contami11t111tJ, American Conference of Governmental Industrial Hygienists, 

Cincinnati, OH, 1983. Reproduced with permission. 
Exhibit 6·5. Some storage properties of gases in plastic llags. 

PLASTIC FILM 

Mylar 

Mylar and Teflon 

Mylar, Aluminized, 

Mylar Saran, 

Scotchpak& 

Aluminized 

Scotchpak 

Aluminized Scotchpak 

Kel-F 

Polyvinyl 

Saran 

PEP-Teflon 

Tedlar 

GAS OR VAPOR STORED 

Olefins 

Formaldehyde 

Formaldehyde 

Ozone 

N02 

so, 

Acrolein 

Acrolein 

Aliphatic HC 

Toluene 

Ethyl ether 

Benzene 

Methyl alcohol 

Perchloroechylene 

Trichloroethylene 

0 2 deficient atmosphere 

Methyl ethyl ketone 

Amyl Acetate 

Acetone 

Xylene 

Benzene 

Sulfur Dioxide 

Nitrogen dioxide 

Owne 

Hydrocarbons 

Mixtures containing aliphatic 

& aromatic hydrocarbons, 

aldehydes, ketones, olefins, 

sulfur dioxide & nitrogen dioxide 

Carbon monoxide 

Nitrogen dioxide 

Carbon monoxide 

Chlorinated hydrocarbons 

Hydrocarbons 

Hydrocarbons 

CONCENTRATION 

20to400ppm 

2to3ppm 

Irradiated car exhaUSt 

70ppm 

0.2 to 0.5 ppm 

0.5 to5ppm 

Car exhaust 

0.1 to lOppm 

0.1 to 130 ppm 

200ppm 

200ppm 

50 ppm 

200ppm 

100ppm 

100ppm 

10% 

200ppm 

lOOppm 

200ppm 

lOOppm 

25ppm 

0.5 to 1., ppm 

0.5 to 1.5 ppm 

0.5 to 1.5 ppm 

7 to20ppm 

Ranges of approx. 50 ppm to 

lOOppm 

1 to 100 ppm in expired air 

1ppm 

1 to lOOppm 

200ppm 

Irradiated car exhaust 

Irradiated car exhaust 

REMARKS 

5 tolO% loss in 24 hrs 

5% in 24 hrs in air mixture 

5 to 10% loss in 2 hrs 

10% loss in 5 hrs in synthetic air 

5% in 8 hrs in synthetic air 

Stable for 4 hrs in bags reconditioned with S02 

10% loss in 24 hrs 

Stable air mixture 

10% loss for 3 days in air samples 

Data given for conditioned and unconditioned bags for 

up to 288 hr storage 

2% loss after .5 days; 20% loss after 13 days 

Data given for conditioned and unconditioned bags for 

72 hr storage 

Storage data given for periods varying from 16 to 

65 hrs for different combinations of components 

in different plastic containers 

Stable several days 

Stable for 120 hrs 

Storage variable with source of supply 

Expired air and synthetic air standards 

Stable for several hrs 

Stable for several hrs 

SOURCE: Prom American Conference of Governmental Industrial Hygienists, Cincinnati, OH, 1983. Air Sampling Instruments for Evaluation of Ati!Wspheric Contaminants. Used with permission. 
Section 6 IAQ Reference Manual 

Exhibit 6·6. Limitations of selected solid absorbents. 

ABSORBENT 

Charcoal 

Silica gel 

XAD-2 

Carbon 

molecular 

sieve 

SOURCE: U.S. EPA (1989) 

LIMITATIONS 

high surface area causes artifact formation during sampling 

high background contamination if using thermal desorption 

high affinity for water 

high catalytic activity 

incomplete sample recovery 

impurities in solvent extraction may be high 

solvent extraction causes dilution of sample 

limited use in humid areas 

thermal breakdown if using thermal desorption 

solvent extraction causes dilution of sample 

thermal stability questionable 

compounds below c7 lost/breakthrough extensive 

poor desorption of highly polar compounds 

possibly retains oxygen which leads to sample oxidation 

limited to some volatile compounds 

high benzene background 

low breakthrough volume for some organics 

holds onto very volatile compounds 

solvent extraction 

desorption efficiency decreases with b.p. > 100 oc 
IAQ Reference Manual Section 6 

Exhibit 6·7. Sources for testing and caUbration procedures applicable to indoor air 

quality sampling. 

Air Pollution Control Association (APCA) 

Box2861 

Pittsburgh, PA 15230 

(412-232-3444) 

American Conference of Governmental Industrial 

Hygienists (ACGIH) 

6500 Glenway Avenue, Building D-7 

Cincinnati, OH 45211 

(513-661-7881) 

American Industrial Hygiene Association (AIHA) 

475 WolfLedges Parkway 

Akron, OH 44311 

(21<5-762-7294) 

American National Standards Institute, Inc. (ANSI) 

1430 Broadway 

New York, NY 10018 

(212-354-3300) 

American Public Health Association (APHA) 

1015 15th Street, NW 

Washington, DC 20005 

(202-789-5600) 

American Society for Testing and Materials (ASTM) 

Committee D-22 on Sampling and Analysis of 

Atmospheres 

1916 Race Street 

PhiJadelphia, PA 19103 

(215-299-5400) 

National Institute for Occupational Safety and 

Health (NIOSH) 

Centers for Disease Control 

Robert A. Taft Laboratories, MS-R2 

467 6 Columbia Parkway 

Cincinnati, OH 45226 

(513-533-8236) 

U.S. Environmental Protection Agency (EPA) 

Environmental Monitoring Systems Laboratory 

Methods Standardization Branch 

Quality Assurance Division (MD-77) 

Research Triangle Park, NC 27711 

(919-541-2622) 
1m 

Section 6 IAQ Reference Manual 

Exhibit 6·8. National Institute of Standards and Technology (NISI)· Standard Reference 

Materials (SRMs) for the calibration of instruments and procedures utilized in 

air quality analysis. 

SRMID DESCRIPTION COMPONENT CONCENTRATION 

Calibration Gases 

1670 Carbon dioxide in air C02 330 ppm 

1671 Carbon dioxide in air C02 340ppm 

1672 Carbon dioxide in air C02 350 ppm 

2633 Carbon dioxide in nitrogen C02 400 ppm 

2634 Carbon dioxide in nitrogen C02 800ppm 

2619a Carbon dioxide in nitrogen C02 0.5 mole% 

2620a Carbon dioxide in nitrogen C02 1.0 mole% 

2621a Carbon dioxide in nitrogen C02 1.5 mole% 

2622a Carbon dioxide in nitrogen C02 2.0 mole% 

2612a Carbon monoxide in air co 10 ppm 

2613a Carbon monoxide in air co 20 ppm 

2614a Carbon monoxide in air co 45 ppm 

1677c Carbon monoxide in nitrogen co 10 ppm 

2.635a Carbon monoxide in nitrogen co 25 ppm 

i678c Carbon monoxide in nitrogen co 50 ppm 

1679c Carbon monoxide in nitrogen co 100 ppm 

1658a Methane in air CH4 1 ppm 

1659a Methane in air CH4 10 ppm 

2627a Nitric oxide in nitrogen NO 5 ppm 

2628a Nitric oxide in nitrogen NO 10 ppm 

2629a Nitric oxide in nitrogen NO 20ppm 

1683b Nitric oxide in nitrogen NO 50 ppm 

1684b Nitric oxide in nitrogen . NO 100 ppm 

2654 Nitrogen dioxide in air N02 500 ppm 

2657 Oxygen in nitrogen 02 2 mole% 

2658 Oxygen in nitrogen 02 10 mole% 

2659 Oxygen in nitrogen IN PREP 02 21 mole% 
IAQ Reference Manual Section 6 

Exhil:tit 6·8. National Institute of Stan•ar•s an• Technology (NISI) · Stan•ar• Reference 

Materials (SRMi) for the calil:tration of Instruments an• proce•ures utilize• in 

air quality analysis (loJJtiJJued}. 

SRMID 

1693a 

1694a 

DESCRIPTION 

Sulfur dioxide in nitrogen 

Sulfur dioxide in nitrogen 

Permeation Devices 

1625 

1626 

1627 

1629a 

Sulfur dioxide 10 em tube 

Sulfur dioxide 5 em tube 

Sulfur dioxide 2 em tube 

Nitrogen dioxide 10 em tube 

Analyzed Liquids and Solids 

1579 Powdered lead base paint, 35 g 

Sulfur in Fossil Fuels 

1616 Sulfur in kerosene 

Materials on Filter Media 

COMPONENT 

2.8 J.tg/min 

1.4 J.tg/min 

0.56 J.tg/min 

1. 0 J.tg/ min 

Ph 

s 

2676c Metals on filter media (cone in J.l.g/filter) Cd 

Pb 

Mn 

Zn 

2677 Beryllium and arsenic (cone in J.tg/filter) As 

Be 

Asbestos 

1876a Chrysotile asbestos As 

• Formerly the National Bureau of Standards (NBS) 

SOURCE: Seward (1988) 

CONCENTRATION 

50 ppm 

100 ppm 

0.107 ppm- 1.07 ppm 

0.0535 ppm -0.535 ppm 

0.0214 ppm -0.214 ppm 

0.05 ppm-0.5 ppm 

11.87% 

<0.01 - 10.09 

<0.01 - 29.81 

<0.01 - 19.85 

<0.01 - 99.29 

<0.002 - 10.5 

<0.001 - 1.03 

37 fibers/ 0.01 mm2 
Sectiotz 6 

6.2. ACCURACY, PRECISION, AND RELATED 

TERMS 

Measured data can provide an estimate of 

the true value of a parameter which can be thought 

of as the average or center of an interval. In order to 

interpret a measurement, it is necessary to understand the variability associated with the measured 

data, and the overall quality of the data. 

Accuracy and precision are two measures of data 

quality that allow us to identifY the center point or 

average and the variability of a measurement. 

Exhibit 6-9 illustrates these two concepts. 

Accuracy is a measure of how close the measured 

values are, on average, to the true value. The 

concept of accuracy can be easily understood by 

visualizing a dart board; the most accurate player is 

the one whose shots are scattered evenly around the 

hull's eye. A less accurate player may, for example, 

tend co hit one side of the board more frequently. In 

Exhibit 6-9 the most accurate measurements are 

shown in Exhibits 6-9b and 6-9c; in these two 

figures, the true value and the measured value 

coincide. Accuracy can be described mathematically 

as follows: 

where, 

(X -X)(lOO) A= m t 

x, 

A = accuracy in percent; 

xm = measured value; and 

X = true value. t 

Precision describes the variation or scatter among 

the results; it is a measure of the uncertainty of the 

average-it is not related to the true value. Again, 

visualizing the dart board, the most precise player is 

the one who consistently places the darts in the 

same place, even if they are not near the hull's eye. 

In Exhibit 6-9, the most precise measurements are 

shown in Exhibits 6-9a and 6-9b; in these two 

figures the measured values are closely clustered 

around the true value. Figure 6-9c shows measurements that are both precise and accurate. The 

IAQ Reference Manual 

standard deviation, s, or the variance, s2' provide a 

good estimate of uncertainty of the average measurement. The standard deviation for a sample of 

measurements can be calculated from: 

where, 

s standard deviation; 

n = total number of measurements; 

Xi = ith measurement of X measurements; 

and 

X = arithmetic mean of n measurements. 

In many cases, accuracy and precision can be 

obtained with the other method and equipment 

specifications. If measurements are performed in 

the laboratory, the laboratory will evaluate accuracy 

and precision through the use of standard reference 

materials as part of its quality assurance program. 

Ideally, the sampling or analytical method that is 

employed by the investigator will be both accurate 

and precise. However, it is possible for a method to 

have high precision but low accuracy because of 

improperly calibrated equipment or inaccurate 

measurement/dilution techniques. Alternatively, a 

method can be accurate but imprecise because of 

low instrument sensitivity or factors beyond the 

investigator's control. 

Bias (B) is a term that describes the ratio of the 

measured value to the true value: 

B= 

X, 

Reproducibility describes the extent to which a 

measurement method yields the same response to 

the same quantiry of contaminant. It is similar ~o 
IAQ Reference Manual 

Exhibit 6·9. Precision and accuracy. 

True Value of 

Concentration 

1---- Bias 

Measured 

Average 

A. Example of Inaccurate (Positive Bias) but Precise Measurements 

True Value 

and 

Measured Average 

B. Example of Accurate (No Bias) but Imprecise Measurements 

True Value 

and 

Measured Average 

C. Example of Accurate and Precise Measurements 

SOURCE: U.S. EPA (1975) 

Section 6 
Seclion 6 

precision, but it is a function of the instrument that 

is used rather than the entire measurement process, 

and it is evaluated over a long period of time. 

Sensitivity is a measure of the accuracy of the 

output signal of an instrument, usually expressed as 

the ratio of the full-scale output of the instrument 

to the full-scale input value. An instrument with 

high sensitivity reproduces every fluctuation, 

regardless of size, that is received as an input signal. 

For example, a very sensitive thermometer may 

reflect a± 0.01 "C change in temperature, but a less 

sensitive one may only reflect changes of± 2.0 oc. 

6.3. REPRESENTATIVE SAMPLING 

Any sampling program, survey work, or 

research problem should have a study design which 

is contained in the protocol. The study design 

addresses such questions as what contaminants and 

equipment to use, the length of the sampling time, 

the sampling locations, and the sample size. 

A major objective of the study design is to ensure 

that a representative sample is collected. This 

generally implies a random sample of a sufficient 

size that will allow conclusions to be drawn about 

the data. Not all investigations will require the 

collection of many samples. Some indoor investigations may involve the collection of only one or just a 

few samples. Even if only a few samples are collected, the i~vestigator must still be alert to the 

basic principles of collecting representative samples. 

Probability Sampling 

Valid conclusions can be drawn only if all portions 

of a population have a known probability of being 

selected during sampling. Where elements of the 

population have a higher probability of selection 

than others, the selected sample elements must be 

weighted to compensate for this difference during 

statistical computations. This means that some type 

of probability sampling plan must be used to ensure 

that the sample is representative of the population 

being measured. 

IAQ Reference Manual 

The selection of a probability sample can be accomplished in several ways. In one method (used for 

asbestos sampling) the area or volume to be sampled 

is reproduced on paper and divided into numbered 

units. The units to be sampled are selected from a 

table of random numbers which can be found in 

most books on statistics. Random numbers can also 

be generated by computer programs. If random 

sampling is employed, care must be taken to ensure 

that samples are collected at the specified locations 

or times. In large survey work, random sampling 

can be costly. 

An alternative to random sampling is systematic 

sampling in which samples are collected at regular 

intervals both in time and space. This sampling 

scheme may be more cost effective and easier to 

accomplish, but bias can enter into the sample 

selection if there is a pattern in the data which is 

correlated with the structure of the sampling frame. 

Another approach is to stratify the sample (either in 

time or in space) if the population under study is 

known or suspected of being stratified in some way. 

This approach has the advantage of resulting in 

better precision than random sampling (and it may 

be more cost effective). The population is divided 

into strata (parts) that are as uniform as possible in 

the component of interest. Each stratum is sampled 

independently, and the average standard deviation is 

calculated. The strata do not have to be equal in 

size. 

Before any large scale investigation, survey, or 

research is undertaken, it is important to get advice 

from someone who is knowledgeable in statistical 

sampling. Considerable time, expense, and embarrassment can be saved by ensuring that the job is 

done correctly the first time. 

Determining Sample Size 

Deciding on the proper sample size for a given 

project can be a difficult decision because of the 

usual trade-offs between budget constraints and the 

ideal situation. Starting points for the selection of a 
IAQ Reference Manual 

sample size are the overall objectives of the monitoring, and the availability of equipment for sampling 

and laboratory analyses. 

Within these two constraints, the selection of 

sample size depends on many factors including: 

• contaminant(s) to be monitored; 

• length of time each contaminant is to be 

sampled (instantaneous sample, 24-hour, 3-

month, and so forth); 

• type of structure, geographic area; and 

• time when sampling occurs (season, day of 

week, time of day). 

The number of samples to be measured depends on 

the accuracy desired in the data as well as the 

expected variance in the data. When measured data 

are arranged according to frequency, some data may 

fit a symmetrical or normal distribution which is 

defined by the mean or standard deviation. The 

mean is found by dividing the sum of the individual 

observations by the number of observations. In 

many instances, the frequency distributions tend to 

be .nonsymmetrical or skewed in one direction. 

These data can be represented by a geometric mean 

which is defined as the nth root of the product of n 

values: 

where, 

-

x = en rrx. ~1/n g i=l I 

X = geometric mean, and g 

X. = individual data values. I 

The geometric mean can also be defined as the 

antilog of the arithmetic mean of the logarithms of 

the data values. Either common logarithms (log10) 

or natural logarithms (log) can be used to calculate 

the geometric mean. When the data are distributed 

according to the lognormal frequency distribution, 

the geometric standard deviation, s , is used as a g 

measure of dispersion instead of the standard 

deviation, s. The geometric standard deviation is 

Section 6 

defined as the antilog of the standard deviation of 

the logarithms of the measurements. It is computed 

as for the arithmetic standard deviation, after 

transforming each value to its corresponding log 

value. 

The sample size necessary to achieve a given precision (for example, being 95% confident that the 

true value is plus or minus some amount) can be 

approximated using the following equation: 

where, 

t = the number of standard deviations that 

account for the desired confidence level 

(area under the normal curve); for example, 

2.14 standard deviations account for 95% 

of the area under a normal curve 

s = standard deviation of the variable to be 

estimated; and 

d = the margin of error that is acceptable. 

In this calculation, a preliminary estimate of the 

standard deviation is required. The expected average 

may also be desirable for deciding what margin of 

error will be acceptable. 

When the required information is not available for 

calculating the sample size, the expected levels can 

be estimated based on professional judgment and 

experience, or a pilor-program (small-scale sampling 

program) can be used to gather preliminary data 

which are then used to refine the sample size . 

calculations as well as the overall protocol. It is 

important to avoid making the sample so. small that 

the estimate is too inaccurate to be useful, but 

because of cost, a sample that is too large should be 

avoided. Since the determination of sample size can 

be complicated (for example, nonnormal distributions, stratified sampling), the investigator is 

cautioned to consult with a statistician to be sure 

that the proper sample size will be collected in a 

cost efficient manner. 

II 
Section 6 

Example Calculation 

Assume that the average value of a contaminant 

(normally distributed) is to be estimated within 

± 10% of its true value under a given set of environmental conditions with a confidence of95%. From 

previous studies, it is known that the standard 

deviation, s, is 0.20. The required sample size, 18, 

is estimated as follows: 

n = (2.142

)(0.202

) 

.102 

18. 

The effect of the acceptable error can be evaluated 

by comparing the above results to those if a margin 

of error of 20% is acceptable as follows: 

n = (2.142

)(0.202

) 

.202 

5. 

In this example, accepting a greater margin of error 

means that fewer samples must be collected. 

Whether or not this is a good decision depends on 

the consequences of accepting a greater margin of 

error. 

6.4. CALIBRATION 

Calibration methods and quality assurance procedures for equipment and laboratory 

methods are specified in several references (Taylor, 

1987; Katz, 1977; and U.S. EPA, 1975, 1977, 

1980, and 1989). 

Direct reading instruments must be calibrated and 

audited on a routine basis if they remain at a fixed 

site. An audit is simply a check on the calibration 

using one or two calibration points plus zero. Field 

monitors which are routinely moved from site to 

site should be calibrated before use at a new site (onsite) and the calibration should be checked at the 

IAQ Reference Manual 

end of the sampling period. The calibration curve 

should be developed over the concentration range of 

interest and should consist of zero plus 3 to 4 points 

using standard calibration materials. 

Exhibit 6-10 provides an example of a calibration 

data sheet. This form can also be used for audits. If 

the before and after calibrations differ significantly 

from previously identified values(± 5% is a useful 

guideline if a value is not specified in the procedure), the data should not be used, and the contaminant should be resampled. 

Indirect reading methods must also be calibrated. 

This may involve calibration of flowmeters followed 

by laboratory analysis some time after collection. If 

so, the laboratory will have its own procedures for 

calibrating equipment used to analyze the collected 

contaminant. Some samplers such as passive 

diffusion samplers are calibrated by the manufacturer-these calibrations can be checked by the 

investigator who has the appropriate facilities, but 

these checks are not routinely done. 

AIRFLOW MEASURING DEVICES 

Types of Airflow Measuring Devices 

The concentration of a contaminant that is 

collected·(by filter, absorber, adsorber, direct 

reading instrument) depends on the volume of air 

sampled: · 

Concentration = mass of pollutant/volume 

of air sampled. 

The volume of air sampled, in turn, depends on the 

flowrate, and it is the flowrate which must be 

calibrated in both active find passive direct reading 

and indirect reading samplers: 

Volume = flowrate x time. 

Flowrates can be measured by several different types 

of devices (Exhibit 6-11 ): 
IAQ Reference Manual 

a) volume meters that measure the total 

volume of gas over some period of time; 

b) rate meters that measure the time rate of 

'flow through them-the flowrate is 

measured through some property of the gas; 

c) variable area meters that measure the rate of 

flow through a changing cross-sectional 

area; and 

d) velocity meters that measure the linear 

velocity of a gas through a duct. 

Widely used devices for measuring flowrates in 

indoor applications are rotameters, orifice meters, 

and mass flow meters. 

Rotameters 

The rotameter is a device that consists of a float that 

is free to move up and down in a vertically graduated, tapered tube (made of glass, metal, or plastic) 

which is larger at the top than at the bottom. As 

the float moves up and down, a variable ring or 

annulus is created between the outer diameter of the 

float and the inner wall of the tube. As air flows 

upward the float rises until the pressure drop across 

the annular area between the float and the wall of 

the tube is just sufficient to support it. The height 

of the float is noted at the point of maximum 

diameter (by convention) and this position on the 

vertical scale is compared to a calibration chart to 

obtain the flowrate. 

The rotameter is the most commonly used device in 

the laboratory and in commercial instruments. 

Rotameters can be easily calibrated using a bubble 

meter; accuracies are ± 5% using the calibration 

curve supplied by the manufacturer, but accuracies 

of± 1.0% to 2% can be achieved when rotameters 

are calibrated in the sampling system as they will be 

used (Wilson et al., 1983). 

The vacuum pump and rotameter may be combined 

into one unit as in personal sampling pumps. Since 

. 

Section 6 

rotameters are very sensitive to pressure changes, 

they must be calibrated in place with the sampling 

system exactly as it will be used during field 

operation. Also, periodic cleaning of rotameters is 

essential since performance is affected by the 

accumulation of moisture and dust. 

Orifice Meters 

The orifice meter may be noncritical or critical. 

Both types can be easily calibrated using a soapbubble meter. A noncritical orifice can consist of a 

thin plate having one circular hole that is inserted 

into a pipe. The pressure drop upstream and 

downstream of the orifice can be related to the time 

rate of flow. Flowrates from a few ml/min to 50 ml/ 

min can be measured (Wilson eta!., 1983). 

The term critical orifice designates an orifice in 

which the pressure drop across the orifice is increased until the downstream pressure is equal to 

about 0.53 times the upstream pressure. As long as 

this ratio remains constant, the flowrate remains 

constant for a given upstream pressure and temperature, regardless of the pressure drop. 

Critical orifices can easily be fashioned from hypodermic syringe needles by trimming the plastic end 

and inserting the needle into the airflow stream. A 

22 gauge hypodermic needle 25 mm long results in 

a flowrate of about 11/min for a 30 minute sampling time; a 23 gauge needle 16 mm long results 

in a flowrate of about 0.5 1/min. Only one calibration point is needed for a critical orifice, and 

accuracies of± 2% can be expected (Wilson et al., 

1983). Once critical orifices are calibrated, they are 

relatively insensitive to pressure changes and can 

maintain constant flow for a long time, provided 

they do not plug. 

Mass Flow Meters 

The mass flow meter is a device that works on the 

principle that when a gas passes over a heated 

surface, heat is transferred from this surface to the 

gas. The velocity of the gas is measured by the 
Section 6 

amount of current required to keep the surface at a 

constant temperature. The term mass flow rate 

arises because the amount of heat transferred 

depends on the mass and velocity of the gas. Mass 

flow meters are increasingly used in monitoring 

instruments. The mass flow meter must be calibrated with the same gas which will be measured, 

because different gases have different thermal 

properties. Flows do not need to be corrected for 

temperature and pressure, and the soap-bubble 

meter can be used to calibrate the meters. 

Calibration of Airflow Measuring Devices 

Airflow measuring devices can be calibrated using 

primary, secondary, or intermediate standards. 

Primary standards are those for which the volume 

can be determined by measuring the internal 

physical dimensions alone. Accuracies of± 0.30% 

can be reached. Intermediate standards are those 

that are calibrated against primary standards; 1% to 

2% accuracies can be achieved. Secondary standards 

are those that are calibrated against primary or 

secondary standards; accuracies of less than 5% can 

be achieved (Wilson et al., 1983). 

The flowrates of active samplers are typically 

calibrated in the laboratory or in the field by the 

investigator before the sampling devices are used, 

but the flowrates of passive samplers are calibrated 

by the manufacturer. 

Flowrates that are specified by the methods should 

be used. Increasing the flowrate to increase sensitivity may result in sample loss or decrease the collection efficiency. Always consult with a knowledgeable person before changing any parameters in a 

method. 

Flowrates for indoor air measurements must be low 

enough not to affect air movement and air exchange. 

Personal sampling pumps operate at flowrates up to 

4 1/min for 8 hours and are powered by internal 

batteries. Batteries must be fully charged before 

sampling begins or data could be lost if the pump 

quits before the sampling period is finished. 

IAQ Reference Manual 

Standard methods will specify flow rates both as a 

range and acceptable percent change during a given 

sampling period. The flowrate must be measured 

both before and after sampling to ensure that the 

pump was operating properly during the entire 

sampling period. This will also prevent a faulty 

pump from being used for subsequent sampling 

efforts. Routine calibration of the flowmeter is a 

must. 

It is important to perform the calibration with the 

sampling system in place exactly as it will be used 

during operation (that is, impingers should be filled 

with solution, filters should be loaded onto cassettes, and so forth). 

Flowmeters should be calibrated over several points 

(4 to 5); however, devices with a fixed flow (critical 

orifice) would be calibrated at a single point. A 

sample calibration data form for the calibration of 

rotameters is given in Exhibit 6-12. 

Soap-Bubble Meter 

The most commonly used devices to calibrate 

flowrate measurements for indoor environments are 

the soap-bubble meter and the wet test meter. A 

soap-bubble meter is one of the simplest and most 

basic primary standards; it is also relatively inexpensive (less than $100 for the meter) and easy to use. 

It is nothing more than a cylindrical tube that has 

graduated markings to identify volume. Inverted 

burets are commonly used as soap-bubble meters, 

but they can only be used to calibrate vacuum 

pumps. In order to calibrate positive pressure flows, 

the soap-bubble meter must be used. 

The soap-bubble meter must itself be calibrated 

before it can be used to calibrate flows from pumps. 

This is done by the mam,Ifacturer. The calibration 

can be checked by filling the tube with water and 

measuring the liquid from the top graduation to the 

bottom graduation. A temperature correction must 

be applied. The soap-bubble meter should only be 

used to measure volumes between gradations that 

have been calibrated. In an average laboratory 
IAQ Reference Manual 

setting the soap-bubble meter is accurate to about 

± 1 %; accuracy decreases for flows greater than 

1l/min or less than 1 ml/min. The calibration and 

use of bubble meters ll;re discussed in an article by 

Levy (1964). 

The set up for calibrating under vacuum and 

pressure conditions is shown in Exhibit 6-13 for the 

soap-bubble meter and an inverted buret. The 

calibration procedure using either device begins by 

wetti.ng the inside of the tube with a soap solution. 

Commercial surfactant products such as "Snoop" or 

dishwashing soaps such as "Ivory" work well. Some 

experimentation is needed to get the right proportion of soap to water. Next, a bubble is formed by 

either touching the tip of the buret to the soap 

solution (Exhibit 6-13c) or by squeezing the rubber 

bulb until the soap solution is raised above the gas 

inlet (Exhibit 6-13 a,b). 

The bubble is moved up the tube by either a 

vacuum at the top or a slight positive pressure at the 

bottom of the tube. The volumetric flow rate can 

be calculated by measuring the time (with a stopwatch) it takes the bubble to move through a given 

volume: 

Flowrate V /time. meas 

Because of the potential variability in measuring the 

time, each flowrate should be measured five times. 

The average time should be used in the calculation 

of the flowrate. Before the flowrate is calculated, 

the measured volume must be corrected. First, a 

·pressure and temperature correction must be applied 

if the room conditions are different from standard 

atmospheric conditions: 

where, 

V5_; = volume at STP; 

V meas measured volume; 

Section 6 

p atm atmospheric pressure (mm Hg); 

T arm atmospheric temperature (°K). 

Second, the volume must be corrected for water 

content of the air. If the gas behind the bubble has a 

relative humidity greater than 50%, the error is 

small; if the gas is dry, the error can be large and 

must be corrected: 

where, 

Vcorr = volume (STP) corrected for water 

vapor, and 

P w vapor pressure of water at room 

temperature (mm Hg); can be 

found in a handbook of chemistry. 

Wet Test Meter 

The wet test meter is an intermediate standard that 

must be calibrated against a primary standard before 

it can be used. It operates much like a waterwheel. 

The meter consists of a series of inverted traps that 

are mounted radially around a shaft that rotates. 

The traps are partially immersed in water, and gas 

that enters the meter fills the traps which causes the 

shaft to rotate. The volume of gas that enters and 

exits the meter is registered by rotating index 

pointers. 

The meter is prepared by first leveling and then 

filling it to the proper level with water. The water 

should be allowed to equilibrate until it is the same 

temperature as the surrounding air. Gas is passed 

through the meter for several hours to saturate the 

water with the gas. Once the meter water level is 

set and the meter is equilibrated, it is ready to use. 

Enough gas is drawn through the system to move 

the drum, and each point is measured several times. 

Wet test meters should not be used with gases (such 

as sulfur dioxide) which produce a corrosive solution 

with water. Temperature and pressure corrections 

must be made. 
Sectiotz 6 IAQ Reference Manual 

Exhibit 6·1 0. Example calibration or audit form for a direct reading carbon monoxide or 

carbon dioxide monitor. 

________ Audit 

________ Calibration Operational Period -------to -------

Site#--------- Instrument -----------------

Location-------- Serial#-------------------

Date--------- Range Setting ----------------

Operator-------- Zero Setting 

Span Setting 

Cylinder# Standard Response Measured Cone. 

Cone. %Chart 

To determine recorder response when setting span during calibration: 

(cylinder concentration/.5) + baseline = %chart (100% of scale 50 ppm) 

Measured concentration = (Response% chart- baseline) (.5) 

%Difference =Measured concentration -Standard concentration x 100 

Standard Concentration 

SOURCE: U.S. EPA (1977) 

% Diff. Remarks 
IAQ Reference Manual 

Exhibit 6·11 •. Different types of airflow meters. 

A. Volume Meters 

(1) Soap Bubble MeterPrimary Standard 

To Vacuum Shaft 

...., 

(2) Wet-Test-Intermediate Standard 

Water Manometer 

Section 6 

Rotating Partitioned Drum 

lnverted........;J~~o-­

Buret 

~Stopcock 

Moving 

Bubble ....... 

Soap Solution 

/ 

B. Rate Meters 

Filling Funnel 

Drain 

Cock 

Orifice Meter-Secondary Standard 

(b) 

Gas In ---..::;;:-----,.:.,.-:------=-____,.,.. Gas Out 

<:::::: 

Orifice 

C. Variable Rate Meter 

Rotameter-Secondary Standard 

Air Out 

Tapered Tube 

t 

Airln 

SOURCE: Wilson eta!. (1983) 

SectionAA 

A 

Float 

Float Annulus 

Section B B 

· , /Gas Outlet 

,. Direction of 

Rotation 

~ 

Gas Intake 

(c) 
Section 6 IAQ Reference Manual 

Exhibit 6·12. Sample rotameter calibration form. 

Rotameter serial number-----------

Location -------------------

Atmospheric pressure (P .,m), mm Hg ------

Calibrated by--------------

Test 

point 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

Rotameter 

reading 

units 

SOURCE: U.S. EPA (1977) 

Bubble 

displacement 

rime, 

min 

Average 

time (t), 

min 

Calibrated with-------------

Atmospheric (T ) oc + 273 = __ oK 

temperature atm ----

Vapor pressure of H20 (Pw), mm Hg _____ _ 

Date _________________ __ 

Volume 

displaced, 

(V meas) 

ml 

' Volume at 

STP (VSTP)', 

ml 

Flowrate, 

QSTP=~ 

ml/min 

Remarks 
IAQ Reference Manual 

Exhibit 6·13. Calibration using the soap·bubble meter. 

A. Vacuum Mode B. Pressure Mode 

Gos0ut(2) v Bobb~S,k., Gas Out 

+ 

Soap Bubble 

~/Gasln(3) 

C. Calibration of a Critical Orifice and Bubbler Train Using a Soap-Bubble Meter (Inverted Buret) 

Bubble 

t· 1,000o1> 

"Air Flow 

Bubble. 

Meter' 

Trap 

SOURCE: Wilson et al. (1983) 

Membrane filter (Millipore Type AA) 

0 Stopwatch 

Section 6 
Section 6 

Wet test meters are not for field use. They are 

bulky, heavy and require special environmental 

conditions; therefore, they are seldom used outside 

the laboratory. They do have a high accuracy(:::; 0.5%) 

and can be used to calibrate flowrates in the range of 

0.5 to 20 1/min (Lioy, '1983). 

SECTION 6.5. PASSIVE SAMPLERS 

Recent technological advances have 

resulted in the development of a variety of small, 

lightweight devices that can be worn by an individual to measure exposures over varying periods of 

time. These sampling devices include both active 

and passive monitors. Passive monitors have 

expanded the ability of the investigator to collect 

data unobtrusively and at a reasonable cost per 

sample. Results are expressed as the measured 

concentration during a given period of time (ppmhr); the time period for sampling should be included in the reprint of results. 

General descriptions of some types of passive 

samplers are given below; further discussion of 

passive samplers can be found in Wallace and Ott 

(1982) and Berlin et al. (1987). Characteristics of 

specific samplers are given in Exhibit 6-2a. 

Sorbent Badges 

Sorbent badges contain liquid or solid sorbents in a 

reusable badge housing. These are widely used in 

the workplace to collect both organic and inorganic 

contaminants, and some of these may be appropriate 

for indoor air measurements. Sorbent badges can be 

attached to an individual's clothing to approximate 

the breathing zone. 

Liquid sorbent badges: Liquid sorbent badges 

consist of a liquid-filled chamber which has a 

bound-liquid membrane on the sampling face. 

Contaminated air diffuses through a diffusion 

barrier at a previously determined rate and comes 

into contact with the bound-liquid membrane. 

Sorbent badges can be obtained with a collecting 

medium capacity of 5 ml to 25 ml and flowrates 

IAQ Reference Manual 

from 0.5 to 50 mllmin. A variety of analytical 

methods can be used to analyze the contaminantcontaining liquid including direct injection into a 

GC, GC with purge and trap techniques, specific 

ion electrodes, and colorimetric methods. Badges 

can be reused if they are properly cleaned and 

refilled (refill kits can be purchased). The cost is 

about $30-$45 for each badge, and refill kits can be 

purchased for about $30 for 10 kits. Not all of the 

potential applications have been verified with 

validation studies. 

Solid sorbent badges: Sorbent badges with solid 

sorbents also rely on diffusion to transport contaminants at a constant sampling rate into the sorbent. 

These samplers can be purchased with a backup 

sorbent which is located behind the primary 

sorbent. Since sorbents have a finite capacity, the 

use of a backup sorbent or two sorbents in parallel, 

but at different sampling rates, is a recommended 

practice. After the sample has been collected, the 

sorbent capsule is removed, placed into a container, 

sealed, and transported to the laboratory. Both the 

primary and backup sorbents are analyzed. Analysis 

can be accomplished by a variety of methods as 

noted under liquid sorbents. Charcoal, silica gel, 

XAD-2, and other sorbents can be purchased. 

Typical costs are about $10-$15 for the resusable 

capsule holder and about $2 for each sorbent 

capsule. 

Sorbent filters and metallic grids: A variety of 

sorbent devices are available for sampling gases. 

These devices are configured as both tubes and 

badges. One example is the Palmes tube (or simiiar 

device), which has been widely used to sample 

nitrogen dioxide indoors. It is a small acrylic tube 

(1.27 em outside diameter, 0.95 em inside diameter, and 7.1 em long) which has three stainless steel 

grids stacked and held into place by a cap at one end 

of the sampler. The grids are precoated with 

triethanolamine (TEA). The bottom end of the tube 

is open to the air and allows the nitrogen dioxide to 

diffuse upward to the TEA coated grids. After 

exposure the open end of the tube is capped and the 

sampler is sent to the laboratory for analysis. The 
IAQ Reference Manual 

Palmes tube has also been used to sample sulfur 

dioxide and carbon monoxide. 

Color Badges 

Color badges, which provide immediate results, are 

also available. These badges are similar to colorimetric detector tubes. The badges consist of a 

sampling tube that contains a chemical which reacts 

with a specific contaminant to produce a color 

change. The. length of the color stain and the 

sampling time are used to determine concentrations. 

In general, color badges are not sensitive enough for 

indoor air monitoring. 

Passive Bubbler 

Another potentially versatile passive monitor is the 

Passive BubblerTM. It consists of a glass vial sealed 

with a TeflonR-faced Knudsen diffusion disk and 

cap. The disk can be reused up to three times, but a 

new disk for each sample is recommended to 

minimize sampling errors. A sorbing solution is 

placed into the vial and the vial is clipped to the 

clothing of a potentially exposed person or placed on 

a stand to collect an area sample. 

The Knudsen diffusion disk controls the rate of 

sampling, which is accurate over a range of air 

velocities from 25 fpm to 250 fpm without correction. The sampling rate of the bubbler can be 

determined by comparison with a reference method 

or by using a test atmosphere (Miksch, 1989a,b). 

After the sample is collected the disk and septum 

cap are removed and replaced by a solid Teflon-lined 

cap. The collected sample can be analyzed by GC, 

HPLC, ion specific electrodes, colorimetry, or other 

methods. 

SECTION 6.6 AIR EXCHANGE RATES 

Measurements of air exchange rates may 

be needed for some types of modeling studies or to 

evaluate the effectiveness of control strategies. 

Several tracer gas techniques, either short-term or 

long-term, can be used for measuring infiltration in 

Section 6 

residential and commerical buildings. Tracer gas 

techniques and instrumentation for studying 

building air exchanges are reviewed by Persily 

(1988) and Dietz (1988). 

A commonly used method is referred to as the 

tracer-gas decay method. In this procedure a known 

concentration of a gas such as sulfur hexafluoride or 

nitrous oxide is injected into a space and the 

decrease in the concentration of the gas, which is 

referred to as the decay of the gas, is measured over 

time. The concentration of the tracer gas is assumed 

to be negligible outside of the structure, and the 

rate of dilution of the tracer gas is proportional to 

the rate at which outside air enters the structure. 

A portable, nonintrusive passive system based on 

the tracer-gas decay method has been developed at 

Brookhaven National Laboratory (Dietz, et al., 

1986). This method is available commercially 

through the National Association of Home Builders 

(NAHB) National Research Center, 400 Prince 

Georges Center Boulev~d, Upper Marlboro, MD 

20772-8731. 

The NAHB method, which is called the Air 

Infiltration Measurement System (AIMS), uses 

perfluorocarbon tracers (PFTs) to measure infiltration for periods of a few days to 6 months (Song and 

Fan, 1989). The system uses a source emitter which 

releases PFT gas at a rate of 1 to 4 x 10-s Umin. A 

uniform concentration is established within 5 to 6 

hours. The receiver is a capillary adsorption rube 

(CAT) which contains a small amount of activated 

ambersorb to capture the perfluorocarbons. Air 

enters the receiver by diffusion at a constant rate of 

0.21/day. Since the rate of emission is temperature 

dependent, air temperatures should be measured, 

and the emitter and receivers must be placed 

carefully. After exposure, the adsorption tube is 

analyzed by a gas chromatograph using an electron 

capture detector. The cost is about $50 per 500 ft 2 

of floor area or $50 per sampler tube. Multizone 

analysis typically costs $60 per 500 ft 2 of area or 

$60 per sampling tube. 

1111 
Section 6 

Tracer-gas decay methods are relatively accurate, 

but they do have shortcomings. First, they are 

unable to provide much information about the 

location of air leaks in a structure, and second, 

short-term tests cannot determine infiltration under 

weather conditions different from those present at 

the time of the test. EPA has developed standard 

methods for both the PFT -CAT system and the 

sulfur hexafluoride procedure (U.S. EPA, 1989). 

Air exchange rates can be measured indirectly by 

estimating the effective leakage area of the structure. The effective leakage area is equivalent to die 

sum of the areas of all the openings in the building 

shell through which air is able to pass. The effective 

leakage area can then be used in an infiltration 

model to estimate the uncontrolled air exchange 

rates of the structure. These models are outlined in 

Diamond and Grimsrud (1984). 

The fan pressurization method uses a variable-speed 

fan, which is mounted on a door which connects to 

the outside, to move large volumes of air into or out 

of a structure. The fan is used to pressurize and 

depressurize the structure. The flow of air through 

the fan is determined at a given pressure differential 

and fan speed by comparing measurements to a 

calibration curve. A pressure versus flow curve is 

determined by taking measurements at several fixed 

pressure differentials, for example, from 10 pascals 

to 70 pascals, at 10 pascal intervals. These data are 

then used in a mathematical equation to determine 

the effective leakage area of the structure. Additional overviews of these methods can be found in 

Wadden and Scheff(1983) and Diamond and 

Grimsrud (1984). 

REFERENCES 

Berlin, A., R.H. Brown, and K.J. Saunders (eds). 1987. 

Diffmive Sampling. An Alternative Approach to W qrkplace Air 

Monitoring. Royal Society of Chemistry: London, England. 

Diamond, R.C. and D.T. Grimsrud. 1984. Manna/ on Indoor 

Air Quality. EPR.I EM-3469. Lawrence Berkeley La.b.: 

Berkeley, CA. 

IAQ Reference Manual 

Dietz, R.N., R.W. Goodrich, E.A. Cote, and R.F. Wieser. 

1986. "Detailed description and performance of a passive 

perfluorocarbon tracer systell?- for building vencilacion and air 

measurements." Measured Air Leakage of Buildings. H.R. 

Trechsel and P.L. Lagus (eds). ASTM STP 904. American 

Society for Testing and Materials: Philadelphia, PA. 

Dietz, R.N. 1988. "Ovel.'View of tracer technology instrumentation for short-term and real-time building ventilation 

determinations." BNL 41067. Brookhaven National Laboratory: Upton, NY. 

Katz, M. (ed). 1977. Methods of Air Sampling and Analysis. 

2nd Edition. American Public Health Association: Washington, DC. 

Levy, A. 1964. "The accuracy of the bubble meter method for 

gas flow measurements."]. Sci. lnstrum. 41: 449-453. 

Lioy, P .J. (ed). 1983. Air Sampling Instruments for Evaluation of 

Atmospheric Contaminants. 6th edition. American Conference of 

Governmental Industrial Hygienists: Cincinnati, OH. 

Miksch, R.R. 1989. "A new 'Passive Bubbler' personal 

monitor employing Knudsen diffusion: II. Application to the 

measurement of formaldehyde." Submitted for publication. 

Nader,J.S.,J.F. Lauderdale, and C.S. McCammon. 1983. 

"Direct reading instruments for analyzing airbome gases and 

vapors." Chap. V. Air Sampling Instruments. 6th edition. P.J. 

Lioy (ed). Amercan Conference of Government Industrial 

Hygienists: Cincinnati, OH. 

Persily, A.K. 1988. Tracer Gas Techniques for Studying Bttilding 

Air Exchange. NBSIR 88-3708. U.S. Department of Commerce, 

National Bureau of Standards (now NIST): Gaithersburg, MD. 

Ritchie, I.M. and C. Deal. 1988. "Sul.'Vey of commercially 

available indoor air monitoring equipment." SPEA/88-20. 

SPEA: Indianapolis, IN. 

Seward, R.W. (ed). 1988. NBS Standard Reference Materials 

Catalog 1988-89. NBS Special Publication 260. National 

Bureau of Standards (now NIST), Office of Standard Reference 

Materials: Gaithersburg, MD. 

Song, B. and J.C. Fan. 1989. "An easy way to monitor air 

infiltration in homes." National Association of Home Builders 

(NAHB) National Research Center: Upper Marlboro, MD. 

Taylor, J.K. (ed.). 1987. Sampling and Calibration for Atmospheric Measurements. ASTM STP 957. American Society for 

Testing and Materials: Baltimore, MD. 
IAQ Reference Manual 

U.S. Environmental Protection Agency (EPA). 1975. Quality 

Assurance Handbook for Air Pollution Measnrement Systems. Volume 

I- Principles. U.S. EPA, Quality Assurance and Environmental 

Monitoring Laboratory, Office of Research and Development: 

Research Triangle Park, NC. 

U.S. Environmental Protection Agency (EPA). 1977. Quality 

Assurance Handbook for Air Pollution Measurement Systems. V fJlume 

II -Ambient Air Specific Methods. (revised 7/84 and 9/85) EPA600/4-77-027a: U.S. EPA, Environmental Monitoring Systems 

Laboratory, Office of Research and Development: Research 

Triangle Park, NC. 

U.S. Environmental Protection Agency (EPA). 1980. Interim 

Guidelines and Specifications for Preparing Quality Assurance Project 

Plans. EPA QAMS-005/80. U.S. EPA, Office of Monitoring 

Systems and Quality Assurance, Office of Research and 

Development: Washington, D.C. 

Section 6 

U.S. Environmental Protection Agency (EPA). 1989. Compendium of Methods for the Determination of Air Pollutants in Indoor 

Air. Draft. U.S. EPA, Atmospheric Research and Exposure 

Assessment Laboratory: Research Triangle Park, NC. 

Wadden, R.A. and P.A. Scheff. 1983. Indoor Air Pollution. 

Characterization, Prediction, and Control. John Wiley & Sons, 

Inc.: New York, NY. 

Wallace, L.A. and W.R. Ott. 1982. "Personal monitors: A 

state-of-the-art survey.H ]. Air Poll. Cont. Assoc. 32(6): 601-

610. 

Wilson, M.L., D~F. Elais, and R.C. Jordan. 1983. APTI. 

Course 435. Atmospheric Sampling. 2nd edition. Revised by 

K.C. Joerger and B.M. Ray. U.S. EPA, Air Pollution Training 

Institute: Research Triangle Park, NC. II 

SECTION 7. 

STANDARDS AND 

GUIDELINES FOR 

VENTILATION AND 

HEALTH EFFECTS 

This section contains tabulated 

information on available standards 

and guidelines. Exhibit 7-1 provides 

quantitative information on both 

public health and occupational 

concentration limits for various 

chemical contaminants. Exhibits 7-2 

and 7-3, which are taken from 

ASHRAE Standard 62-1989, provide 

outdoor air requirements for various 

indoor spaces. Exhibit 7-4 provides 

ventilation requirements for residential structures which are contained in 

the current Uniform Building Code; 

these requirements may be chariged 

pursuant to the issuance of ASHRAE 

Standard 62-1989. Exhibit 7-5 

summarizes acceptable seasonal ranges 

of temperature and humidity from 

ASHRAE Standard 55-81. 

Unit 2, lesson 7 of the Learning 

Module should be consulted for 

explanations and guidance on the use 

of these standards. 

Table of Contents 

Exhibit 7-1. 

Exhibit 7-2. 

Exhibit 7-3. 

Exhibit 7-4. 

Exhibit 7-5. 

Air quality standards and guidelines for 

selected contaminants. 

Outdoor air requirements for ventilation 

of commercial facilities (offices, stores, 

shops, hotels, sports facilities). 

Outdoor air requirements for ventilation 

of residential facilities (private dwellings, 

single, multiple). 

Uniform Building Code ventilation 

requirements. 

Acceptable ranges of temperature and 

humidity during summer and winter. 

186 

195 

199 

200 

202 
Exhibit 7·1. Air quality standards and gu,idelines for seleded contaMinants. ~ 

~ 

~· STANDARD OR GUIDELINE (m .. mg/m~; J.1"' pglm.l) ;:: 

AVERAGING PUBUC HEALTH OCCUPATIONAL "" 

SUBSTANCE TIME EPA WHO ASHRAE CANADA OSHA NIOSH ACGIH COMMENTS 

.Acetaldehyde 8hr 180m 180m 

15min 270m 270m 

.Acetone 8hr 1800m 1780m 

15 min 2400m 2380m 

.Acrolein 8hr 250J.l. 230f.L 

15 min 800f.L 690f.L 

.Acrylonitrile+ 8hr * 4340J,1 2170J.1 4340j.t OSHA standard is given in 1910.1045 

ceiling 21700Jl. 21700J.1 

.Aldehyde (total) lhr R<l R = sum (ci/Ci) 

d = measured concentration over a 5 min. 

period 

Ci = 120f.L formaldehyde 

50J.L acrolein 

9000J.L acetaldehyde 

.Ammonia 8hr 17m NIOSH ceiling is set for 5 minute exposure. 

15 min 27m 24m 

ceiling 34.8m 

.Atsenic+ 8hr SOOJ.l 200J.1 OSHA standard is for organic compounds. 

ceiling * 2J.L .ACGIH TW .A is set for soluble compounds. 

NIOSHceiling is set for 15 minute exposure. 

.Asbestos+ annual * 0.2f/cc OSHA standard is given in 1910.1001. 

8hr O.lflcc NIOSH level for fibers over 5 um length. 

ceiling O.lflcc .ACGIH levels {TW .A} are 

amosite 0.5flcc ~ 

chrysotile 2.0flcc tO 

l':l croddolite 0.2flcc 

other 2.0flcc ~ flee = fibers per cubic em ~ ;:: 

~ 

Benzene+ 8hr * 3.1m 0.32m 32m NIOSH ceiling is sec for 15 minute exposure. 

ceiling 7.8m 3.2m OSHA standard applies to industry exempt ~ ;jl 

from 1910.1028. ~ -
Exhibit 7·1. Air quality standards and guidelines for selected contaminants (tontinued}. s: 

tO 

STANDARD OR GUIDELINE (m "' mg/m~; J1. = JLg/m3

) );:! 

AVERAGING OCCUPATIONAL ~ ~ SUBSTANCE TIME EPA WHO ASHRAE CANADA OSHA NIOSH ACGIH COMMENTS ~ 

~ 

Beryllium+ 8hr 2J1. 2J1. ~ ceiling 5J.!. 0.51J. ~ 

~ 

Cadmium fume+ annual .01-.02 WHO guidelines are annual: 

- 8 hr lOOJ.!. <1-5 ng/m3 (rutal areas) 

ceiling 3001J. 50J.1. 10-20 ng/m3 (urban areas) 

OSHA standard is 100 (TWA) for cadmium 

fume, and 200 (TWA) for cadmium dust. 

ACGIH proposed TWA is 10. 

NIOSH recommends reducing exposure to 

lowest feasible level. 

In process of rulemalcing for OSHA 

standard. 

Calcium oxide (lime) 8 hr 5m 2m 

Carbon dioxide continuous 1800m ASHRAE guideline is nor considered to be a 

long term 1800m 6300m health risk, but a surrogate for ventilation 

lOhr 18000m 1000 ppm=1800m. 

8 hr 18000m 9000m 

15 min 54000m 54000m 

lOmin 54000m 

Carbon disulfide 24hr .10m WHO guideline of .02m is based on sensory 

10hr 3m effecrs. 

8 hr 12m 31m 

30min .02m lOOm 

15 min 36m 30m 

Carbon monoxide 8hr 10m lOrn 10m 12.6m 40m 40m 57m WHO CO guidelines are designed ro 

1 hr 40m 30m 40m 28.6m protect nonsmokers and prevent COHb 

30min 60m levels exceeding 2.3 -3%. 

15 min lOOm 458m 

maximum 229m 229m 

t.o:l 

Chlordane+ 8 hr 0.5m 0.5m a continuous. .005m ~· 30min 2m ~ 

(continued next page) ....... 

II 
-

m 

ExiHIIit 7·1. Air quality standards and guidelines for seleded contaminants {contf•ueciJ. 

STANDARD OR GUIDELINE (m .. mglm'; J.1. .. pg!ml) 

AVERAGING PUBUC HBAL'lll OCCUPATIONAL 

SUBSTANCE TIME EPA WHO ASHRAE CANADA OSHA NIOSH ACGIH 

Chlorine 8hr l.5m 1.5m 

15min 3m 3.0m 

ceiling 1.45m 

Chloroform+ 8hr 9.78m 49m 

Chlorpyrifos 8hr 0.2m 0.2m 

15 min (0.6m) 

Chromium annual * 

(ll andlli) lOhr O.OOlm 

Shr 0.5m 0.5m 

15 min 0.05m 

Cresol lOhr 10m 

8 hr 22m 22m 

Diazinon Shr O.lm O.lm 

Dichlorvos (DDVP) Shr lm 0.9m 

p-Dichlorobenzene Shr 450m 45lm 

15 min 675 m 66lm 

1 ,2-dichloroethane+ 24hr 0.7m 

(ethylene dichloride) Shr 4m 4m 40m 

ceiling 8m 8m 

di-(2-ethyl hexyl) Shr 5m 5m 

phthalate (DEHP}+ 15 min 10m 10m 

Ethyl acetate 8hr 1400m 1440m 

Ethyl benzene 8hr 435m 434m 

15 min 545m 543m 

Ethyl ether Shr !200m !210m 

15 min 1500m 1520rn 

~ ~ 

~· \lS 

""" 

COMMENTS 

NIOSH 15 minute limit is a ceiling limit. 

ACGIH proposes to delete the 15 min limit. 

NIOSH 10 hr limit is for carcinogenic 

chromium; other chromium compounds 

have a 0.025m 10 hr limit. 

ACGIH limit for Cr (VI) is 0.05m for water 

soluble and certain water insoluble 

compounds. 

~ lO 

)::1 

~ ~ 

~ \lS 

~ 

~ ~ 

t 
Exhibit 7·1. Air quality standards and guidelines for selected contaminants (tontinuedJ. s: 

lO 

STANDARD OR GUIDEUNE (m = mg/m1

; J.1 = J.1g/m1

) ~ 

'§.. 

AVERAGING PUBLIC HEALTH OCCUPATIONAL • <IS 

~ SUBSTANCE TIME EPA WHO ASHRAE CANADA OSHA NIOSH· ACGIH COMMENTS ~ 

~ 

Ethylene dichloride+ 8 hr 4m 40m [ 15min 8m 

~· Formaldehyde+ 8 hr I. 2m I. 2m ACGIH proposed ceiling limit is 0.45m. ...... 

(see. aldehydes) 30min .lm, WHO level set to avoid complaints from · 

15 min 0.12m 2.5m sensitive people exposed in non-industrial 

ceiling 2.5m indoor settings. 

NIOSH level reflectS lowest reliably 

quantifiable concentration. 

OSHA standard is given in 1910.1048. 

1.2m lppm 

Heptachlor+ 8hr 0.5m 0.5m 

Hydrochloric acid ceiling 7m 7.5m 

(hydrogen chloride) 

Hydrogen sulfide 24hr .15m 

8hr 14m 14m WHO guideline of .007m is based on 

30min .007m sensory effects. 

15 min 21m 21m NIOSH ceiling set for 10 minute exposure. 

ceiling 15m 

Leacl+ annual .5-111 OSHA standard is given in 1910.1025. 

3month 1.511 1.5f.L NIOSH limit set so workers' blood lead 

10hr <l00J.1 remains <60 g/lOOg blood. 

8hr 5011 15011 ACGIH limit is for inorganic dusts and 

fumes. 

WHO limit is based on the assumption that 

this limit will result in blood lead levels 

<0.2 JJg/ml fur 98% of the population. 

Malathion 8hr 10m 15m 10m 

Manganese annual .001m WHO: short-term guideline desirable; but 

8hr lm lm lack of data to set short-term limits. 

15min 3m 3m ACGIH limit is for fumes; the 8 hr TWA (;) 

l!t 

for dust is 5m. .... 

s· 

~ 

(continued nextpage) 'I 

II 
Exhibit 7•1. Air quality st•dards and gvideUaes for nlected contaminants (coatluedJ. 

SUBSTANCE 

Mercury 

Methylene chloride+ 

(Dichloromethane) 

Methyl alcohol 

Methyl ethyl ketone 

Methyl isoburyl ketone 

Microbial/biological 

contaminants 

Nickel+ 

Nitrogen dioxide 

AVERAGING 

TIME EPA 

annual 

8 hr 

24hr 

8ht 

ceiling 

lOhr 

8 hr 

15 min 

8ht 

15 min 

8ht 

15 min 

annuai 

lOhr 

8ht 

long term 

annual 

24hr 

Sht 

1 hr 

15min 

lOOp. 

STANDARD OR GUIDELINE (m • mg!m3

; ~"' ~m ) 

PUBUCHEALTH OCCUPATIONAL 

WHO ASHRAE CANADA OSHA NIOSH ACGIH 

1~ 

3m 

* 

lOOJI. 

lOOp. 

150p. 

4001J. 480J1. 

173.8m 

350m 

260m 

310m 

590m 

885m 

205m 

300m 

.lm 

18001J. 

50~ 

174m 

262m 

262m 

1048m 328m 

590m 

885m 

205m 

308m 

0.015m 

.lm 

560op. 

1800p. 9400~ 

COMMENTS 

ACGIH and OSHA standard of 50 is for 

non-alkyl vapor, but limits are 1~ 

(TW .t\) and 3~ (STEL) for alkyl 

compounds. 

WHO guideline is for indoor air. 

NIOSH recommends reducing exposure to 

lowest feasible limit. 

OSHA Standard is in rulemaking. 

No formal guidelines/standards; ACGIH 

guidelines stare that fungi concentrations 

less than 100 CFUs!m3 are nor of concern. 

ACGlH proposed TWA is 0.05m for soluble 

compounds and the metaL 

OSHA and ACGIH standards are for soluble 

compounds. ~ tC 

):l 

~ ~ 

~ C1> 

r 

;t· 

~ 

~ 
Exhibit 7·1• Air quality standards and guidelines for selected contaminants {continued}. ~ tO 

STANDARD OR GUIDEUNE (m = mg/m3; Jl = jlglm3) tJ 

AVERAGING PUBUC HEALTH OCCUPATIONAL ~ 

~ SUBSTANCE TIME EPA WHO ASHRAE CANADA OSHA NIOSH ACGIH COMMENTS ;:s 

~ 

Nitrogen monoxide 10 hr 30m r 

(Nitric oxide) 8 hr 30m 31m ;:s .. ;: 

~ 

Ozone - continuous lOOJ.l ·ASHRAE standard is for indoor sources only. 

8hr 100-200Jl 200Jl 

1 hr 235Jl 150-200Jl 235Jl 240J.1 

15 min 600J.l 200J.l 

Parriculares (PM-10) annual 50J.l 50Jl OSHA standard is for total dust, not 

24hr l50Jl 150J.l otherwise classified. 

8hr 15000J.1 lOOOOJ.l 

Parriculaces (PM-2.5) long term 40Jl OSHA standard is for tespimble fracrion, not 

8 hr 5000J.l otherwise classified. 

1hr lOOJ.l 

Pentachlorophenol Shr 0.5m .0.5m 

Petroleum distillates 8hr 1600m 1370m 

(naphtha) 

Phenol IOhr 20m 

8hr 19m 19m 

15 min 60m 

Polynuclear aromatic ACGIH and OSHA standard for coal tar 

hydrocarbons+ pitch volatiles as benzene solubles is 0.2m 

(carcinogenic fraction) (TWA). 

Propylene dichloride Shr 350m 347m 

15 min 510m 509m 

Pyrethrum Shr 5m 5m 

~ ~ c:.· 

;:s 

(continued next page) -....( 

11 
II 

Exhibit 7•1. Air quality standards and guidelines for selected contalllinunts (tontiniHfdJ. ~ ~ 

STANDARD OR GUIDEUNE (m,. mglm5; J.l• J.1glm1) ~· ;s 

'I 

AVERAGING PUBUC HEALTH OCCUPATIONAL 

SUBSTANCE TIME EPA WHO ASHRAE CANADA OSHA NIOSH ACGIH COMMENTS 

Radon annual 4 pCi/1 2.7 pCi/1 4 pCi/1 21.6 pCill EPA recommends undertaking mitigation 

in homes with levels above 4pCi/l. 

WHO gukleline is for new construction; 

remedial accion should be taken without 

delay at > 10.8 pCi/1. 

Styrene+ 24hr .80m WHO 30 minute guideline is based on odor 

IOhr 213m direCtion. 

8hr 215m 213m 

30min .07m 

IS min 425m 426m 

ceiling 426m 

Sulfur dioxide long term SOJ.l 

annual 80!1 80!1 

24hr 365!1 365!1 

10hr l300J.l 

8hr 5000J.1 5200J.1 

1hr 350J.1 

15 min 10000J.1 1300011 

lOmin 500J.1 

Smin 1000J.1 

Sulfuric acid lOhr lm WHO: more data needed; however, 

8 hr 1m lm repeated exposure at or above 0.1 mg/m3 

15 min 3m is cause for concern. 

Tetrachloroethylene+ 24hr 5m NIOSH recommends minimizing workplace 

(perchloroerhy1ene) Shr 170m 339m exposure and limiting number of exposed 

30min 8m workers. 

15min B68m WHO guideline of 8m is based on sensory ~ lC effects. l:'i:l 

Toluene 24hr 7.5m WHO guideline of lm is based on sensory ~ ~ Shr 375m 375m 377m effeccs. ;s 

30min lm ~ 

15 min 560m S65m 

lOmin 750m ~ ;s 

t 
Exhibit 7·1. Air quality standards and guidelines for selected contaminants (tontinued}. 

SUBSTANCE 

Trichloroethylene+ 

1,1 ,1-Trichloroethane 

Vanadium 

Vinyl acetate 

Vinyl chloride+ 

Water vapor 

(relative humidity) 

AVERAGING 

TIME 

24hr 

10 hr 

8hr 

15 min 

8hr 

15 min 

24hr 

10hr 

8hr 

15 min 

8hr 

15 min 

annual 

8ht 

15min 

Xylene (o, m, p-isomecs) 8 hr 

15min 

lOmin 

Zinc 10 hr 

8 hr 

15 min 

EPA 

1 SOURCE: Adapted from U.S. EPA, (1989) 

STANDARD OR GUIDEUNE (m = mg/m3; J.L = J.Lgfm3) 

PUBUC HEALTH OCCUPATIONAL 

WHO ASHRAE CANADA OSHA NIOSH ACGIH 

1m 

134m 

270m 269m 

1080m 1070m 

1900m 1910m 

2450m 2460m 

lJ.L 

1000J.L 

SO!J. 

50J.L 50!! 

30m 35m 

60m 70m 

* 

1.5m 13m 

7.6m 

20-60% 30-80% summer 

30-55% winter 

435m 434m 434m 

655m 65Im 

868m 

5000!J. 

10000!J. 10000J.1 

15000J.L 

COMMENTS 

OSHA and ACGIH limits ate for vanadium 

respirable dust or fumes. 

NIOSH 10 hr limit set fur metallic 

vanadium and vanadium carbide. 

NIOSH recommends lowest reliable 

detectable level. 

OSHA standard is given in 1910.1017. 

NIOSH cecommends limiting exposure to 

lowest reliably detectable level. 

NIOSH limitS ru:e for zinc oxide. 

OSHA and ACGIH limits ru:e fur zinc oxide 

total dust. Limit for respirable fraction is 

5000J.L 

~ 

~ 

i• 

(continued next page) ..._... 
Exhibit 7·1. Air quality standards and guidelines for selected contam~in~ants. (fonlinu•dJ 

Notes 

Reported values were converted where necessary so that all values for the same chemical are in the same units to fadlitate comparisons. Canadian srandards distinguish between short term or long 

term exposures. Shott retm exposures are listed as 1 hr exposures in this table. 

Abbreviations 

ACGIH 

ASHRAE 

EPA 

NIOSH 

OSHA 

WHO 

References 

American Conference of Governmental Industrial Hygienists 

American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc. 

Environmental Prorection Agency 

National Institute for OccupationaJ Safety and Health 

Occupational Safety and Health Administration 

World Health Organization 

ACGIH, Threshold Limit Va/uqs 1111d Biological Exposure Indices for 1989-1990, Cincinnati, OH. 

ACGIH. 1989. Guide/iiiQS for the A.rseJS111ellt of Biotterosols of the Indeor EIIVironment. Cincinnati, OH. 

ASHRAE Standard 62-1989. Ventilmionfor Ac«jlt11ble lndeor AirQt~~~lity, Atlanta, GA. 

Environmental Health Directorate, Canada. 1987. Exposure Guideli/IQS for Rqsfdenti<tl Indoor Air Quality. Ortawa, Canada. 

NIOSH. 1986. "NIOSH recommendations for occupational safety and health standards." Morhidity and Morutlity Weekly Report, 

35(1S). 

U.S. DOL. 1989. "Occupational safety and health standards." CPR. Title 29, P11rt 1910. 

U.S. EPA. 1989. "National primary and secondary air quality standards." CFR, Title 40. Part 50, Section50.1-50.12. 

WHO. 1987. Air Q~~<~lity Guidelines for E11rope. WHO: Europet~n Seriqs No. 23, Copenhagen, Denmark. 

* WHO does not establish guidelines fur these 

substances; instead, the agency publishes risk 

factors for each substance to indicate potential 

human health risks pet unit of exposure. 

+ Subsrance identified as a suspected or 

confirmed human carcinogen. 

Conversion of Units: To convert mg/m3 to 

ppm, use the following formula: 

ppm= (24.45)(mg/m;) 

(gram molecular weight of the substance) 
Exhibit 7·2. Outdoor air require~nts for ventilation of commercial facilities 

(offtces, stores, shops, hotels,~sports facilities). 

APPUCATION 

Dry Cleaners, Laundries 

Commercial laundry 

Commercial dry cleaner 

Storage, pick-up 

Coin-op laundries 

Coin-op dry cleaner 

Food & Beverage Service 

Dining room 

Cafeteria fast food 

Bars, cocktail lounge 

Kitchens (cooking) 

Garages, Repair 

Service Stations 

Enclosed parking garage 

Auto repair rooms 

Hotels, Motels, Resorts 

Dormitories 

Dormitory sleeping area 

Bedrooms cfm/room 

Living room cfrnlroom 

Baths cfm/room 

Lobbies 

Conference rooms 

Assembly rooms 

Gambling casinos 

OUTDOOR AIR. REQUIREMENI'S I 

ESTIMATED MAX 

OCCUPANCY cfrnl lis! 

P/1000 fr or 100m2 person. person 

10 

30 

30 

20 

20 

70 

100 

100 

20 

20 

30 

50 

120 

120 

25 

30 

35 

15 

15 

20 

20 

30 

15 

15 

30 

30 

35 

15 

20 

15 

30 

13 

15 

18 

8 

8 

10 

10 

15 

8 

8 

15 

15 

18 

8 

10 

8 

15 

cfrnl 

ft2 

1.50 

1.50 

7.50 

7.50 

COMMENTS 

Dry cleaning processes may require more air. 

Supplementary smoke removal equipment may be required. 

Make-up air for hood exhaust may require more ventilating air. 

The sum of the outdoor and rransfer air of acceptable qualiry 

from adjacent spaces shall be sufficient to provide an exhaust 

rate of not less than 1.5 cfmlft2 (7 .5 llslm"). 

Distribution among people must consider worker location and 

concentration of runuing engines; stands where engines ate run must 

incorporate systems for positive engine exhaust withdrawal. Contaminant sensors may be used to control ventilation. 

See also food and beverage services,. merchandising, barber 

and beaury shops, garages. 

Independent of room size. 

Independent of room size; insralled capaciry for intermittent use. 

Supplementary smoke removal equipment may be required. ('.) 

~ 

:t 

~· 

(continued next page) "-1 
E.x.hlbit 7·2. Outdoor air requi~r•ments for vutilation of coMMercial fadltttu 

(offices, stores, shops, hotels, sports fadlities) (coatlnvedJ. 

OUTDOOR AIR REQUIREMENTS I 

ESTIMATED MAX 

OCCUPANCY cfmJ JJsl cfm1 Jist 

APPLICATION P/1000 fr:l or 100m2 person person fr:l m2 COMMENTS 

Off'~ees 

Office space 7 20 lO Some office equipment may require local exhaust. 

Reception areas 60 15 8 Supplementary smoke removal equipment may be required. 

Telecommunication 60 20 10 

centers &: data entry areas 

Conference rooms 50 20 10 

Public Spaces 

Corridors &: utilities 0.5 2.5 

Public restrooms din/we or urinal 50 25 Mechanical exhaust with no recirculation is recommended. 

Locker &: dressing rooms 0.5 2.5 

Smoking lounge 70 60 30 Normally supplied by ttamfer air. Local mechanical exhaust with no 

recirculation is recommended. 

Retail Stores, Sales Floors 

& Show Room Floors 

Basement and street 30 0.30 1.50 

Upper floors 20 0.20 1.00 

Storage rooms 15 0.15 0.75 

Dressing rooms 0.20 1.00 

Malls and arcades 20 0.20 1.00 

Shipping and receiving 10 0.15 0.75 

Warehouses 5 0.05 0.25 

Elevators 1.00 5.00 

Smoking lounge 70 60 30 Normally supplied by rransferilir. Local mechanical exhaust with no 

recirculation is recommended. 

Specialty Shops 

Barber 25 15 8 

Beauty 25 25 13 

Reducing salons 20 15 8 

Florists 8 15 8 Ventilation to optimize plant growth may dictate 

Clothiers, furniture 0.30 1.50 requirementS. 

Hardware, drugs, fabric 8 15 8 

Supermarkets 8 15 8 

Pet shops 1.00 5.00 

~ lC 

~ 

<§.. 

~ 

-= 

~ 

~ -= 

~ ..... 
Exhibit 7•2. Outdoor air requirements for ventilation of commercial facilities 

(offices, stores, shops, hotels, sports facilities) (continued}. 

OUTDOOR AIR REQUIREMENTS 1 

ESTIMATED MAX 

OCCUPANCY 

APPLICATION P/1000 ft2 or 100m2 

Sporrs & Amusement 

Spectator areas 150 

Game room 70 

Ice arena (playing area) 

Swimming pools (pool & deck area) 

Playing floots (gymnasium) 

Balltaoms and discos 

Bowling alleys (seating areas) 

Theaters 

Ticket booths 

Lobbies 

Auditorium 

Stages, studios 

Transportation 

Waiting rooms 

Platforms 

Vehicles 

Workrooms 

Meat processing 

Photo studios 

Darkrooms 

Pharmacy 

Bank vaults 

Duplicating printing 

30 

100 

70 

60 

150 

150 

70 

100 

100 

150 

10 

10 

10 

20 

5 

cfml 

person 

15 

25 

20 

25 

25 

20 

20 

15 

15 

15 

15 

15 

15 

15 

15 

15 

1/s/ 

person 

8 

13 

10 

13 

13 

10 

10 

8 

8 

8 

8 

8 

8 

8 

8 

8 

cfm/ 

ft' 

0.50 

0.50 

0.50 

0.50 

Vsl 

m• 

2.50 

2.50 

2.50 

2.50 

COMMENTS 

When internal combustion engines are operated fur maintenance of 

playing surfaces, increased ventilation rates may be required. 

Higher values may be required for humidity control. 

Special ventilation will be needed to eliminate special stage effect 

(e.g., dry ice vapots, mists, etc.). 

Ventilation within vehicles may require special consideration. 

Spaces maintained ar low temperatUres (-lO"F m + 50"F, or -23"C m 

+ 1 O"C) are not covered by rhese requirements unless the occupancy is 

continuous. Ventilation li:om adjoining sources is permissible. When 

rhe occupancy is intermittent, inflltration will normally exceed the 

ventilation requirement. 

Installed equipment must incorporate positive exhaust and control (as 

required) of undesirable contaminants, (toxic or otherwise). ~ 

9-g· 

(continued next page) --..... 
Exllltit 7·2. Outdoor air req8in•ents for ventilation of cOMMercial facilities 

(offices, stores, shops, hotels, sports fadlities) (contiaedJ. 

OUTDOOR AIR REQUIREMENTS I 

ESTIMATED MAX 

OCCUPANCY cfm/ 1/s/ 

APPLICATION P/1000 fr or 100m2 person person 

INSTITUTIONAL FACILITIES 

Laboratories 

Training shop 

Music rooms 

Libraries 

Locker rooms 

Corridors 

Auditoriums 

Smoking lounges 

Hospitals, Nursing&: 

Convalescent Homes 

Medical procedure 

Operating rooms 

Recovery and ICU 

Autopsy rooms 

Physical therapy 

Correctional Facilities 

Dining balls 

Guard stations 

50 

30 

30 

50 

20 

150 

70 

10 

20 

20 

20 

20 

20 

100 

40 

1 The outdoor air is assumed to be acceptable. 

15 8 

20 .10 

20 10 

15 8 

15 8 

15 8 

60 30 

25 13 

15 8 

30 15 

15 8 

15 8 

20 10 

15 8 

15 8 

cfm/ 

ft2 

0.50 

0.10 

0.50 

2.50 

0.50 

2.50 

COMMENTS 

Special contlllllinant control systems may be required for 

processes or functions including laboratory animal occupancy. 

NormaUy supplied by transfer air. Local mechanical exhaust with no 

recirculation is recommended. 

Special requirements or codes and pressure relationships may determine 

minimum ventilation rates and filter efficiency. 

Procedures generating contaminants may reqnire higher rates. 

Air shall not be recirculated in other spaces. 

SOURCE: ·Reprinted with permission ASHRAE Stand4rd 62-1989, Ventilation for Acceptahk lntkor Air Quality, published by the American Society of Heating, Refrigerating, and AirConditioning Engineers, Inc. 
IAQ Reference Manual Section 7 

Exhibit 7·3. Outdoor air requirements for ventilation of residential facilities (private 

dwellings; single, multiple). 

APPLICATION 

Living areas 

Kitchens 

Baths, toilets 

Garages: 

Separate for each 

dwelling unit 

Common for 

several units 

OUTDOOR 

AIR REQUIREMENTS 

0.35 air changes per hour 

but not less than 15 cfm 

(7 .5 1/ s) per person 

100 cfm (50 1/s) intermittent 

-or25 cfm (12 1/s) continuous 

-orOpenable windows 

50 cfm (25 lis) intermittent 

-or25 cfm (12 1/s) continuous 

-orOpenable windows 

100 cfm (50 1/s) per car 

1.5 cfm/ft2 (7 .5 lls/m2

) 

COMMENTS 

For calculating the air changes per hour, 

the volume of the living areas shall include 

all areas within the conditioned space. The ventilation is normally satisfied by infiltration and natural 

ventilation. Dwellings with tight enclosures may 

require supplemental ventilation supply for fuel 

burning appliances. Occupant loading shall be 

based on the number of bedrooms as follows: first 

bedroom, two persons; each additional bedroom, 

one person. Where higher densities are known, they 

shall be used. 

Installed mechanical exhaust capacity. 

Installed mechanical exhaust capacity. 

Normally satisfied by infiltration or natural 

ventilation. 

See enclosed parking garages, Exhibit 7-2. 

SOURCE: Reprinted with permission from ASHRAE Standard 62-1989, Ventilation for Acceptable Indoor Air Quality, published by 

the American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc. 
Section 7 IAQ Reference Manual 

Exhibit 7·4. Uniform Building Code ventilation requirements. 

OCCUPANCY TYPE 

Group A, Assembly 

GroupE, Educational 

general area ventilation 

toilet rooms 

Group B, Business 

general area ventilation 

toilet rooms 

parking garages 

(other chan open) 

Group H, Educational 

general area ventilation and 

toilet rooms 

rooms containing 

hazardous materials 

VENTILATION REQUIREMENTS 

openable exterior openings with an area not less than 1/20 of total floor space 

-ora mechanical system that supplies a minimum of 5 cfm/outside air/person with a total 

circulated of not less than 15 cfm/person at all times of occupancy 

fully openable exterior windows at least 3 ft2 in area for each room; or a vertical duct not less 

than 100 in2 in area for the first toilet facility, with 50 additional in2 for each additional 

facility 

-ormechanically operated exhaust system capable of providing a complete change of air every 15 

min; exhaust must be connected directly to the outside and the point of discharge shall be at 

least 5 ft from any openable windows 

same as for Group A, unless Class I, II, or III-A liquids (flammable or combustible) are used 

in a portion or all of the building; the use of these materials requires exhaust ventilation 

sufficient to provide 6 ach 

same as for Group A 

ventilation shall be provided capable of exhausting a minimum of 1.5 cfm per ft2 of gross 

floor area 

-oran approved alternate method that can. exhaust a minimum of 14,000 cfm for each operating 

vehicle; automatic CO sensing devices may be employed to modulate the ventilation system 

to maintain a maximum average CO concentration of 50 ppm during any 8-hr period, with a 

maximum concentration of 200 ppm for a period not exceeding l hr; connecting waiting 

rooms, office, ticket booth, etc. shall be supplied with conditioned air under positive pressure 

same as for Group A; when recirculation of air is not permitted, the ventilation system shall 

be capable of providing not less than 15 cfm of ourside air per occupant co the general area 

mechanical ventilation system as required by fire and mechanical codes; must have a manual 

shutoff control for ventilation equipment; control must be outside the room adjacent to the 

principal access door 
IAQ Reference Manual Section 7 

Exhibit 7·4. Uniform Building Code ventilation requirements (fontinuedJ. 

OCCUPANCY TYPE 

Group H, Educational (continued) 

garages for the repair of vehicles 

operating under their own power 

fabrication areas 

service corridors and storage of 

hazardous production material 

Group R, Hotels, Apartment 

Houses, Dwellings, and Lodging 

Houses 

general area ventilation 

toilet rooms, bathrooms, laundry 

rooms, and similar rooms 

VENTILATION REQUIREMENTS 

a mechanical ventilation system capable of exhausting a minimum of 1 cfm/ft2 of floor area; 

each stall must have an exhaust pipe extension which, if over 10ft long, must exhaust 300 

cfm 

connecting offices and waiting rooms shall be supplied with conditioned air under positive 

pressure 

mechanical ventilation, which may include recirculated air, shall be provided throughout the 

fabrication area at the rate of not less than 1 cfm/ft2 of floor area 

the exhaust air duct system of one fabrication area shall not connect to another duct system 

outside that fabrication area within the building 

at least one manually operated remote control switch that will shut down the fabrication area 

ventilation system shall be installed at an approved location outside the fabrication area 

mechanical ventilation shall be provided at not less than 1 cfm/ft2 of floor area or not less 

than 6 ach/hr, whichever is greater 

habitable rooms shall be provided with natural ventilation by means of openable exterior 

openings with an area not less than 1/20 of the floor area of such rooms with a minimum 

~5~ . 

-ormechanical ventilation shall be provided at a rate of 2 ach in all habitable rooms and in 

public corridors; 1/5 of the air supply shall be taken from the outside 

natural ventilation shall be provided by means of openable exterior openings with an area not 

less than 1120 of the floor area of such rooms with a minimum of 1.5 ft2 

-ormechanical ventilation shall be provided at 5 ach/hr; the system must be connected directly 

to the outside; the point of discharge of the exhaust shall be at least 5 ft from a mechanically 

ventilating intake 

SOURCE: International Conference of Building Officials (ICBO). 1988. Uniform Building Code. ICBO: Whittier, CA. 
fiJ 

Section 7 

Exhibit 7·5. Acceptable ranges of 

temperature and humidity 

during summer and winter.1 

RELATIVE 

HUMIDITY 

30% 

40% 

50%" 

WINTER SUMMER 

68.5°F-76.0°F 74.0°F-80.0°F 

68.5°F-75.5°F 73YF-79YF 

68YF-7 4YF 73.0°F-79.0°F 

1

.Applies for persons clothed in typical summer and winter 

clothing, at light, mainly sedentary activity. 

•Humidities greater than 50% are considered unacceptable 

because of the potential for microbial growth. 

SOURCE: .ASHR.AE (1981) 

IAQ Reference Manual 

REFERENCES 

.American Conference of Governmental and Industrial Hygienists (.ACGIH). Threshold Limit Values and Biological Exposure 

Indices for 1989-1990 . .ACGIH: Cincinnati, OH. 

.American Conference of Governmental and Industrial Hygienists (.ACGIH). 1989. Guidelines for the Assessment of Bioaerosols of 

the Indoor Environment. ACGIH: Cincinnati, OH. 

American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc. (ASHR.AE). 1981. Thermal Environmental Conditions for Human Occupancy. ASHRAE Standard 55-

1981. ASHR.AE: Atlanta, GA. 

American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc. (ASHRAE). 1989. Ventilation for 

Acceptable Indoor Air Quality. ASHRAE Standard 62-1989. 

ASHRAE: Atlanta, GA. 

Environmental Health Directorate. 1987. Exposure Guidelines 

for Residential Indoor Air Quality. Health Protection Branch, 

Environmental Health Directorate: Ottawa, Canada. 

International Conference of Building Officials (ICBO). 1988. 

Uniform Building Code. ICBO: Whittier, CA. 

National Institute of Occupational Safety and Health (NIOSH). 

1986. "NIOSH recommendations for occupational safety and 

health standards." Morbidity and Mortality Weekly Report. 

35(1S). 

U.S. Department of labor (DOL). 1989. "Occupational safety 

and health standards." Code of Federal Regulations, Title 29. Part 

1919. 

U.S. Environmental Protection Agency (EPA). 1989. "National 

primary and seaondaty air quality standards." Code of Federal 

Regulations, Title40. Part 50, Section 50.1-50.12. 

World Health Organization (WHO). 1987. Air Quality 

Guidelines for Europe. European Series No. 23. WHO: 

Copenhagen, Denmark. 
SECTION 8. 

INVESTIGATION 

TECHNIQUES 

Section 8 provides a discussion of 

general and specific investigation 

techniques for combustion sources , 

pesticides, microorganisms, formaldehyde, and other volatile organic 

compounds. 

Section 8.1 contains two exhibits which 

can be used in their current form or 

adapted to field investigations. Exhibit 

8-1 is a health effects questionnaire and 

Exhibit 8-2 is a general residential 

building inspection form. 

Sections 8.2, 8.3, and 8.4 provide 

specific guidance for residential 

investigation techniques, sampling 

methods, interpretation of data, and 

mitigation advice for individual 

contaminant categories. 

Table of Contents 

Section 8.1. General Investigation Techniques for 

Residences 

Section 8.2. Investigation Techniques for 

Combustion Sources 

Section 8.3. Investigation Techniques for 

Pesticides 

Section 8.4. Investigation Techniques for 

Formaldehyde and Other Volatile 

Organic Compounds 

Section 8.5. Investigation Techniques 

for Biological Contaminants 

List of Exhibits 

Exhibit 8-1. 

Exhibit 8-2. 

Exhibit 8-3. 

Exhibit 8-4. 

Exhibit 8-5. 

Exhibit 8-6. 

Exhibit 8-7. 

Exhibit 8-8. 

Exhibit 8-9. 

Indoor air quality health effects form. 

Indoor air quality residential 

inspection form. 

Location and operation of typical 

backdraft diverter. 

CABO building code combustion air 

requirements for residential 

fuel-burning equipment. 

Separation guidelines to prevent 

downdrafts into chimneys. 

Examples of chimney caps. 

Potential consequences when more 

than one appliance is connected 

to the same flue. 

Combustion inspection form. 

Features of proper stove installation. 

205 

217 

242 

II 

258 

277 

206 

211 

232 

233 

234 

235 

236 

237 

238 
Section 8 IAQ Reference·Manual 

Exhibit 8-10. Suggested chimney sizes for Exhibit 8-20. Selected passive formalderesidential wood-burning hyde measurement methods. 270 

equipment. 239 

Exhibit 8-21. A dose-effect relationship 

Exhibit 8-11. Safety guidelines for unvented between HCHO exposure 

gas-fired heaters. 240 and health effects in mobile 

and conventional homes. 271 

Exhibit 8-12. Safety guidelines for unvented 

kerosene heaters. 240 Exhibit 8-22. Effect of temperature and 

relative humidity on formalII Exhibit 8-13. Sources of termiticide dehyde (HCHO) levels in a 

contamination and potential mobile home under controlled 

mitigation methods. 249 conditions .. 272 

Exhibit 8-14. Pesticides that can be Exhibit 8-23. Advantages and disadvantages 

measured using low volume of nonspecific and specific 

PUF sampling with GCIECD. 250 detector systems for VOC 

and SVOC analysis. 273 

Exhibit 8-15. Useful sources of information 

on pesticides. 251 Exhibit 8-24. Commercially available 

portable VOC detection 

Exhibit 8-16. Guidelines for using instruments. 274 

pesticides safely. 252 

Exhibit 8-25. Characteristics of sorption 

Exhibit 8-17. First aid guidelines for collection methods. 275 

pesticide poisonings. 255 

Exhibit 8-26. Environmental survey form 

Exhibit 8-18. Guidelines for cleaning for evaluating the presence of 

pesticide spills and residues. 256 potential sources of allergens. 290 

Exhibit 8-19. Examples of biological Exhibit 8-27. Commonly used samplers for 

control of pesticides. 257 collecting indoor bioaerosols. 295 
IAQ Reference Manual 

8.1. GENERAL INVESTIGATION TECHNIQUES 

FOR RESIDENCES 

General techniques for investigating 

indoor air quality problems in residences are 

provided in Lesson 8 of the Learning Module. This 

section also contains examples of indoor air quality 

survey forms which can be used to assist in the 

collection of information. Exhibit 8-1 is a sample 

health symptom questionnaire form. Exhibit 8-2 is 

a general residential building inspection form. Each 

of these forms are freestanding, and each may be 

used directly by the investigator. Alternatively, the 

forms may be used as models and modified to meet 

the needs of the particular investigator or situation. 

For individuals seeking private sector diagnostic or 

mitigation services, a useful resource is a survey of 

Section 8 

indoor air quality diagnostic and mitigation firms 

published by EPA's Indoor Air Division (U.S. EPA, 

1989). This report provides a listing of firms that 

are involved in either migitation or diagnostics, and 

it summarizes the services they offer by the type of 

buildings serviced, the types of evaluation, monitoring, and mitigation services, and the areas of 

expertise for personnel in the firm. It should be 

noted that EPA does not imply approval, recommendation, endorsement, or accreditation of the 

listed firms. Copies can be obtained for a fee from 

the National Technical Information Service, 5285 

Port Royal Road, Springfield, VA 22161. (The 

NTIS report number is PB 90-1304159.) 
Section 8 IAQ Reference Manual 

Exhibit 8·1. Indoor air quality health effects form. 

NOTE: This form contains example questions that apply to residential and nonresidential investigations-it 

can be modified for either application. 

Investigator--------------------------- Date _______ _ 

Client's Name------------------------------------

Address ____________________________________________________________________ __ 

A. Demographics 

1. Male __ Female ___ Age __ _ 

2. What is your occupation? 

3. Have you had a change in occupation or 

position since the onset of your symptoms? 

yes no 

B. Work Environment 

1. How many hours per week do you work? 

2. Does your job require you to photocopy? 

yes no 

3. Do you frequently use a video display 

terminal? 

yes no 

4. Are there old or deteriorating books in your 

primary work area? 

yes no 

5. Have there been any water leaks on ceilings, 

pipes, or walls in your primary work area 

during the last six months? 

yes no 

6. To your knowledge, are you exposed to any 

hazardous substances (chemicals, dusts, 

solvents, gases, minerals) during the course of 

your working day? 

If yes, please describe: 
IAQ Reference Mq,nual Section 8 

Exhibit 8·1. Indoor air quality health effects fornt (1o11finued). 

7. Check as many of the following conditions 

that describe your work area: 

__ temperature too cold 

_ temperature too hot 

_ temperature just right 

__ air too dry 

_air too moist 

_ humidity just right 

__ air too stuffy 

_air too smoky 

_too noisy 

__ too quiet 

_ frequent unpleasant odors 

C. Personal Habits 

1. Do you smoke tobacco products? 

yes no 

If yes, 

how much at home? 

how much at work? 

2. Do you wear contact lenses? 

yes no 

If yes, 

how many hours at home? 

how many hours at work? 

3. Do you regularly drink coffee, tea, colas, or 

eat chocolate? 

yes no 

If yes, 

how much? 

D. Are you currently taking any prescribed 

medicines? 

yes no 

E. Do you have any of the following? 

migraine yes no 

heart problems yes no 

allergies/ 

allergic reactions yes no 

asthma yes no 

F. Check the times when you are most aware 

of your symptoms 

_Winter _Mornings At home 

Summer __ Evenings At work 

__ Spring __ At night _Other place 

Fall __ Weekdays Weekends 

(continued next page) 
Section 8 IAQ Reference Manual 

Exhibit 8·1. Indoor air quality health effects form (tolltinued). 

G. At home, do your symptoms get better or I. Have any of the following events been 

worse when you (check as many as apply): associated with onset of symptoms or 

occurred within the last six months? 

Don't 

Better Worse Know 1. Redecorating yes no 

Open the 

windows? (home 2. Home repairs yes no 

or office?) 

ED 3. Energy 

Turn on the air conservation yes no 

conditioner? 

4. New furniture yes no 

Turn on the 

furnace? 5. New vehicle yes no 

Use a 6. Use of unvented 

humidifier? space heater in a 

recreational 

Use a vehicle yes no 

dehumidifier? 

7. New clothing yes no 

Sleep overnight 

elsewhere? 8. New job yes no 

Go away for the 9. New office/office 

weekend? renovations yes no 

Go away fora 10. Pest control 

week? activities yes no 

Go to school, 11. Working on crafts 

work, or stay or hobbies that 

at home? involve chemicals, 

(circle one) dusts, or heat yes no 

H. Have you seen a physician for your symptoms? 

yes no 
IAQ Reference Manual SectionS 

Exhibit 8·1. Indoor air quality health effects form (IOIIIInued). 

J. Symptom Survey 

Please place a check mark next to each symptom which you have or are experiencing. Indicate the severity and frequency of 

each symptom: 

Mild 

Moderate 

Severe 

Occasionally 

Sometimes 

Frequently 

SYMPTOM 

Eye irritation, burning 

Dry or sore throat 

Skin irritation, dryness, 

or scaling 

Skin rash 

Tightness in the chest 

Runny nose 

Asthma (exacerbation of) 

Cough 

Wheezing or other 

breathing problems 

Chest pain 

Changes in the rate and 

depth of breathing 

Changes in pulse rare 

Visual disturbances 

Dizziness 

Fatigue 

Depression 

noticeable, but no change in routine necessary 

some change in normal routine necessary 

unable to maintain a normal routine 

less than one time per week 

one time per week 

more than one time per week 

SEVERITY 

Mild Moderate Severe 

FREQUENCY 

Occasionally Sometimes Frequently 

(continued next page) 
Section 8 

Exhibit 8·1. Indoor air quality health effects form (tontlnued). 

SYMPTOM 

Clumsiness 

Drowsiness 

Headache 

Fever 

Repeated throat infections 

Sinus irritation or infection 

Muscular pains 

Change in heart rhythm 

Tingling or numbness 

in extremities 

Muscle twitching/ 

convulsions 

Nausea or vomiting 

Abdominal pain 

Diarrhea 

Loss of appetite 

Cold/flu symptoms 

Cold extremities 

Difficulty in sleeping 

Irritability 

Backache/neckache 

Eyestrain 

SEVERITY 

Mild Moderate Severe Occasionally 

IAQ Reference Manual 

FREQUENCY 

Sometimes Frequently 
IAQ Reference Manual Section 8 

Exhibit 8·2. Indoor air quality residential inspection form. 

Indoor Measurements 

Date and time of inspection ___________ _ Relative humidty (%) 

Name of client ________________ _ Temperature (°F) 

Home address'--------------,---- Radon (pCi/1 or WL, 

if tested) 

Telephone (home) _____ _ (work) ____ _ 

Date of test 

Inspector __________________ _ Carbon monoxide (ppm) -----

Other: 

Presence of odor on entering home? If so, describe. 

Client's description of the problem (health effects, odor, event). 

SYSTEMS INVENTORY 

Items applicable to newer homes ( < 5 yrs) are 

indicated with "N", those for recent ( < 3 yrs) 

renovations "R," older homes "0;" if there is no 

designation the item applies to all homes. 

A. Residence Background Information 

1. Type of home: 

Conventional 

Mobile Pre-fab Apartment_ 

Single-story _ Multi-story __ 

Attached garage _ 

2. Date of construction/ 

manufacture----------

3. Manufacturer (if manufactured) 

4. Approximate size--------

5. Move-in date----------

(continued next page) 
Section 8 IAQ Reference Manual 

Exhibit 8·2. Indoor air quality residential inspection form (continued}. 

B. The Site 

1. Attach sketch of house/surrounding obstacles 

with orientation to north. 

2. Check for air pollution and noise sources. 

3. Check for low spots and poorly drained clay 

soil. 

4. Check for trash, food, harborage. 

5. Check for proximity to agricultural fields. 

C. The Building Materials 

1. Type of construction: 

Brick __ Stone_ Concrete_ 

Wood _Earth_ Other_ 

2. Roofing materials (N/R): Are there asphalt 

materials close to doors or operable windows? 

Condition: Are there leaks, damaged shingles, 

and corroded flashings which may lead to 

dampness in the attic? 

3. Exterior finish (N/R): Is there preservative 

treated wood (creosote-black and tarry; 

pentachlorophenol-greenish)? 

Condition: Is there evidence of moisture 

damage (rot, mildew, warping, blistering 

paint)? 

4. Interior materials (N/R): Is there interior 

grade plywood, simulated wood wallboard, or 

vinyl finish wallboard? 

Condition: Is there evidence of moisture 

damage? 

5. Interior finish: (0) Is there lead-based paint? 

(If so, caution about removal by sanding; 

hazards to children.) 

(N/R) Is there new (within 1 month) paint? 

6. Type of insulation: 

None _UFFI _Fiberglass_ 

Cellulose _Other 

IfUFFI, date of installation: 
IAQ Reference Manual Section 8 

Exhibit 8·2. Indoor air quality residential Inspection form (continued}. 

D. Hearing/Cooling Systems 

1. Primary heating System: 

Gas _LP _Wood Oil 

Electric_ Kerosene __ _ 

Other--------

Distribution System: 

Forced-air _Gravity __ 

Other------

2. Secondary heating System: 

W cod-burning stove __ 

Coal-burning stove __ 

Fireplace __ _ 

Unvented space heater __ Btu __ 

Other ___________ _ 

3. Cooling system: 

Central air _Window __ 

Water cooler_ None __ 

E. Inspection of Heating/Cooling Systems 

1. Check all appliances for proper installation, 

damage. 

2. Check venting system for proper separation of 

appliances; damage to flues and ducts; maintenance of all systems; clearance and condition of 

chimneys; combustion air supply to each unit; 

and safety hazards. 

3. Central furnaces should be checked for condition of filters; registers and ducting should be 

checked for accumulation of dust/dirt/fiber 

glass/moisture; inlets and cold air return 

should be dear of obstructions. Interior 

furnace rooms must have adequate air intakes 

to allow for proper draft air for chimney. 

4. Fireplaces and wood stoves should be checked 

for creosote buildup; type of wood/fuel; 

clearance of chimney; presence of unline& 

masonary chimney; procedures for loading/ 

cleaning. 

5. Unvented heaters should be evaluated for 

proper size; ventilation during use; operation 

of heater unattended; proper fuel and fueling 

practices. 

6. Check for the presence of asbestos pipe 

covering, insulation, and other materials 

containing asbestos. Are any friable? 

NOTES: 

(continued next page) 
Section 8 IAQ Reference Manual 

Ex~lbit 8·2. Indoor air q•ality residential.inspection form (continued}. 

F. Ventilation Syst;ems 

1. Mechanical ventilation (check those that are 

present): 

__ Supply air fans. Check for short circuiting 

ventilation and inadequate exit paths. 

_Exhaust fans. Check for backdrafting and 

adequate supply air; ratings (at least 100 cfm 

for bathrooms, 200 cfm for standard cookstove, 400+ cfm for draft stoves). 

__ Fresh air connection on central forced-air 

systems. Check for uncontaminated outside 

air supply. 

_Heat recovery ventilator. Check for type 

of matrix, condensate removal, inlet and outlet 

location, condensaton problems. 

NOTES: 

2. Air Cleaning/Conditioning Devices (Check 

those that are present. Is the equipment sized 

properly?) Determine condition and maintenance. 

_Filters (fiberglass, fabric, electronic, 

plastic) 

_Chemical adsorption devices (activated 

charcoal, alumina) 

_Room air cleaners 

__ Dehu~idifiers 

_Humidifiers Type-------

(Note the presence of slime and crusting.) 

NOTES: 

G. Utilities 

1. Water supply. City_ Well 

2. Sewage removaL City_ Septic_ 

H. Cooking Appliances 

Gas _Electric _Other ___ _ 
IAQ Reference Manual Section 8 

Exhibit 8·2. Indoor air quality residential inspection form (eontinued}. 

I. Chemical Usage (Indicate aerosols with "a"). 2. Vents: Total number 

Note ventilation practices. 

Number opened _ 

1. List cleaning products: 

3. Standing water: 

At time of inspection: yes _no 

2. List pesticides: 

Reported by occupant: yes _no_ 

4. Sump: yes _no_ El 

L. Basement Inspection (note condition) 

3. List personal care products: 1. Damp: yes _no_ 

2. Cracks: In walls-yes_ no _ 

In floor -yes no 

4. List chemicals used in hobbies/crafts: 

3. Floor drain/sump: yes_ no_ 

Sealed drain/sump: yes __ no __ 

4. Wall surfaces (construction): 

J. Foundation Inspection 

concrete - drywall__ plaster 

1. Type: concrete _brick _wood __ 

5. Wall covering: paneling_ paint _ 

poured concrete __ creek rock 

wallpaper __ none __ 

2. Condition: 

6. Floor surface (construction): 

concrete dirt 

K.Crawl Space Inspection (note condition) particleboard sub-floor _ 

1. Floor material: dirt _ pea gravel 7. Floor covering: carpet __ vinyl __ 

plastic over dirt or gravel _ paint_ none_ 

(continued next page) 
SectionS 

Exhibit 8·2. Indoor air quality residential Inspection form (eontlnued}. 

M. Have any of the following occurred during 

the last year? 

1. Energy conservation measures: 

2. Renovations: 

3. New furniture: 

4. Interior redecorating: 

NOTES: 

IAQ Reference Manual 
IAQ Reference Manual 

8.2. INVESTIGATION TECHNIQUES FOR 

COMBUSTION SOURCES 

Guidance for the investigation of indoor 

air quality heating and cooling problems can be 

found in the CABO One and Two Family Dwelling 

Code (CABO, 1989), the ASHRAE handbook 

(ASHRAE, 1989), and books on superinsulated 

design (Lenchek et al., 1987; Mann, 1989). The 

Canada Mortgage and Housing Corporation 

(CMHC, 1988a; 1988b) has several publications on· 

combustion systems that are useful. In addition, the 

standards of the National Fire Protection Association (NFP A) and the American National Standards 

Institute (ANSI) should be consulted for the 

installation of specific appliances. Some of these 

standards include NFPA 31 for oil-burning equipment, NFP A 54 for gas appliances and gas piping 

(NFPA, 1988a), and NFPA 211 for chimneys, 

fireplaces, and venting (NFPA, 1988b). Local codes 

should always be consulted for specific requirements. Section 5 of the Reference Manual also 

provides additional information on the types of 

heating systems and air distribution systems. 

A complete discussion of the different types of 

heating system appliances which could be encountered during residential investigations is beyond the 

scope of this section; however, basic information is 

provided for a limited number of vented and 

unvented systems. The investigator should become 

familiar with the design and correct operation of 

both vented and unvented heating systems and 

accessories which may be encountered in the 

geographical area served by the investigator. 

The inspection provides a good opportunity to 

educate the residents about contaminants from 

combustion sources and the safe use of combustion 

appliances. Public education efforts can be assisted 

by the Consumer Product Safety Commission which 

has several useful publications on the selection and 

use of combustion appliances which can be obtained 

free of charge. Some of these are also written in 

Spanish. 

Section 8 

EMERGENCY SITUATIONS 

High carbon monoxide concentrations and 

leaking fuel are potential emergency situations 

which may be encountered. The investigator should 

be prepared to handle potential emergencies over 

the telephone and in the field. 

During a telephone contact, clients who complain 

about a fuel odor should be instructed to eliminate 

any sources of flame and contact the fuel supplier 

immediately. All potential sources of flame or 

sparking should be avoided; this includes using 

telephones in the home. Clients should be instructed to call the gas company from an outside 

telephone. These situations must be treated as an 

emergency because the investigator cannot determine the nature and degree of the hazard. 

If the investigator is conducting an inspection and a 

fuel odor is detected, the degree of hazard can be 

evaluated with a combustible gas meter. In the case 

of a small, slow leak, all sources of flame should be 

extinguished, windows should be opened, and the 

fuel company should be called from an outside 

telephone. The residence should be evacuated if the 

leak appears serious (for example, caused by a 

broken supply pipe) or as a general safety precaution 

if the degree of hazard cannot be ascertained. If the 

fuel company discovers a leak, the service will be 

disconnected until the repairs are made to prevent 

the possibility of fire or other hazards. If monitoring equipment is not available, the situation must 

be created as an emergency. 

Elevated carbon monoxide concentrations (evaluate 

based on guidelines and length of exposure) from 

leaking furnaces and other sources should also be 

treated as a potential emergency. If sources are 

suspected and the individual appears groggy, 

disoriented, or has reddish-colored skin, emergency 

action should be taken. The individual should be 

taken outside of the building immediately (or 

instructed to leave in case of a telephone contact). If 

the contact is by telephone, emergency assistance 
Section 8 

should be requested because the individual may be 

too disoriented to follow commands. 

The investigator should also be alert to the possibility of chronic carbon monoxide poisoning, particularly in children. A health care evaluation should be 

obtained as soon as possible if chronic exposure is 

suspected. 

BACKGROUND INFORMATION FOR 

INVESTIGATING COMBUSTION SOURCES 

Usefitl Definitions 

Chimney and F lrte: A chimney is a masonry or 

concrete channel which extends above the roof and 

carries combustion gases away from the appliance to 

the outside air. The chimney may be lined with a 

pipe (fireclay or other approved material), called the 

flue or chimney flue, which carries the combustion 

gases from the appliance to the outside air. The flue 

connector is that portion of the ducting that 

connects the appliance to the chimney. The flue 

collar is that portion of the appliance designed for 

the attachment of a draft hood, vent connector, or 

venting system. 

Vent: Vent is a term that refers to a passageway 

(pipe or duct) that conveys flue gases (or plumbing 

gases) from appliances (or vent connectors) to the 

outside atmosphere. The vent connector is the pipe 

or duct which connects a gas-burning appliance to a 

vent or chimney. In woodstove installations, the 

vent connector may also be called the stovepipe. 

Draft: Draft refers to the flow of gases through the 

chimney, flue, or vent caused by pressure differences. Draft may be natural (caused by temperature 

or pressure differences) or mechanical. 

Volume Damper: A volume damper is any device 

which when installed will slow or direct the airflow 

in any duct, or the products of combustion in any 

heat-producing equipment, vent connectors, vents, 

or chimneys. 

IAQ Reference Manual 

Draft Regulator: A draft regulator is a device 

which maintains a desired draft in the appliance by 

automatically reducing the draft. Draft regulators 

are generally used to maintain combustion stability 

on appliances that require negative static draft at 

the appliance flue gas outlet. These devices bleed 

air into the chimney automatically when pressure 

decreases (Section 5, Exhibit 5-1). 

Vent Damper: A vent damper (also called automatic vent damper device) is a device in the venting 

system, in the outlet or downstream of the appliance 

draft hood of a fuel-burning appliance, which 

automatically opens the venting system when the 

appliance is in operation and automatically closes 

the venting system when the appliance is in a 

standby or off condition. These devices control the 

draft and can reduce energy consumption and 

improve the seasonal efficiency of gas- and oilburning appliances, and they can be manually 

operated, mechanically activated, electrically 

operated, or thermally actuated, depending on the 

system. 

Draft Hood or Backdraft Diverter: The draft hood 

or backdraft diverter (Exhibit 8-3) is a device built 

into an appliance, or part of a vent connector from 

an appliance. The draft hood ensures that the 

natural-draft furnace operates safely (without 

generating carbon monoxide) if the chimney is 

blocked, if there is a downdraft, or if there· is an 

excessive updraft. The draft hood neutralizes the 

effect of stack action of the chimney or gas vent 

while the appliance is operating, and it allows gases 

to escape easily from the appliance if there is no 

draft, backdraft, or stoppage beyond the draft hood. 

In general, inlet and outlet flue pipe sizes of the 

draft hood should be the same as that of the appliance outlet connection. Spillage can result if 

combustion air is not adequate for a gas appliance 

with a draft hood. 

Plenum: A plenum is a compartment or chamber 

to which one or more ducts are connected and which 

forms part of the air distribution system. 
IAQ Reference Manual 

Combustion Air 

It is important for an appliance to have sufficient air 

for fuel combustion, draft hood dilution, and 

ventilation of the enclosure for the appliance; this 

air is called combustion air. It is not the same as 

circulating air which is air that moves into and out 

of a conditioned space by means· of a circulating 

system. In construction that is not energy efficient, 

combustion air is normally supplied by infiltration. 

If there is insufficient combustion air, incomplete 

combustion and backdrafting will result. To 

determine the required combustion air, the air 

requirements for exhaust fans, kitchen vents, clothes 

dryers, fireplaces, and other combustion appliances 

must be considered. 

In energy efficient homes, inadequate combustion 

air can be a significant problem which can be solved 

in several ways. In new construction, appliances 

that have sealed combustion units can be used, or 

the appliance can be located in an unheated and 

unsealed room (typically, exterior to the house). In 

existing construction, the appliance can be connected to a combustion air intake, providing the 

unit is designed for such a remedy. A relatively easy 

solution (but not an energy efficient one) is to crack 

open windows on the floor where the appliance is 

operating. This is a potential solution for infrequently used fireplaces that may be subject to 

backdrafting when fires are low or smoldering. 

If woodburning stoves and furnaces do not have a 

sealed air intake, they should have a 3-inch diameter 

(minimum) outdoor-air inlet, ducted close to the air 

control of the appliance. A sealed damper or 

gasketed door that will not leak air when the stove 

or furnace is not in use is also needed. Combustion 

air requirements from the CABO code are given in 

Exhibit 8-4 for residential fuel-burning equipment. 

Supply and Return Ducts 

Ducts carrying supply air into the building from the 

outside or from evaporative coolers should be 

Section 8 

constructed of galvanized steel or corrosion-resistant 

metal. Although sheet metal is the preferred 

material for both supply and return air ducts, 

alternatives are permitted under most codes. 

Flexible material (fiberglass sandwiched between 

plastic) is also used. Another technique is to use the 

spaces between studs in walls or floor joists to form 

an air channel by nailing sheet metal or fiberboard 

over the openings (called open joist ducts). When 

these spaces are used to create ducts, the duct space 

should be sealed from unused portions by tightfitting stops of sheet metal or wood. Gypsum 

products should not be exposed in ducts serving 

evaporative coolers. Although these approaches are 

permitted in some codes, they can allow the release 

of organics such as formaldehyde into the living 

space as hot supply air comes into contact with floor 

joists, subflooring, or plastic. 

An underfloor space can be used as a supply plenum 

providing the entire ground surface is covered with 

a vapor retarder having a maximum permeability of 

1 perm and all loose combustible scrap material is 

removed. In addition, fuel gas lines and plumbing 

waste cleanouts should not be located within the 

space. Foil-coated fiberboard is also used to create 

ducts in floor joists--this practice should be discouraged in crawl spaces because of the possibility of 

moisture damage to the fiberboard which would 

create a substrate for microbial growth. In addition, 

any openings in ducts can allow termiticides to 

enter the living space. 

All ductwork instalJ:ed in an attic should be insulated to prevent condensation. All metal supply 

ductwork installed in a ventilated crawl spac~ or 

other nonconditioned area should also be insulated. 

When ducts used for cooling are insulated, the 

insulation should be covered with a vapor retarder 

having a maximum permeance of 0.05 perm or 

aluminum foil having a minimum thickness of 2 

mils. Exterior ducts must be protected by an 

approved weatherproofed vapor retarder. 
Section 8 

Venting of Appliances 

There are two basic types of problems related to 

venting of appliances which can result in the release 

of contaminants indoors. Backdrafting is the flow 

of combustion gases back into the house as a result 

of outside air being drawn into the flue or chimney. 

Flue gas spillage (or spillout) is the flow of combustion gases back into the house as a result of a 

blockage in the flue or chimney or because flue 

gases do not have sufficient velocity to clear the 

backdraft diverter of the combustion appliance. 

There are many causes of these problems including 

defective or unsafe equipment; improper installation 

of combustion appliances; blocked chimneys or 

flues; inadequate combustion air; and downdrafts in 

chimneys or flues. Depressurization caused by 

operating too many appliances that exhaust air out 

of the house (fans, fireplaces, and so forth) can be a 

significant cause of backdrafting and spillage in new 

energy-efficient construction. 

Useful publications about combustion spillage and 

backdrafting can be obtained from the Canada 

Mortgage and Housing Corporation (682 Montreal 

Road, Ottawa, Ontario K1A OP7) which has done 

extensive research in this area. 

The CMHC (1988b) has published a manual that 

describes a series of procedures for testing the 

performance of a residential chimney system. These 

tests are used to identify houses in which spillage of 

combustion gases from fireplaces, natural-draft oil 

and gas furnaces, and hot water heaters. The 

manual includes five test procedures which are 

described in detail and are complete with checklists 

and report forms. The tests include house and 

venting systems tests (described as follows) which 

are designed to detect the susceptibility of the 

chimney system to spillage caused by the combined 

operation of fans, fireplaces, and any other exhausts. 

Furnace and flue tests are included which are 

designed to detect spillage caused by a leaky heat 

exchanger, weak chimney draft due to leaks or 

constrictions within the flue, or maintenance 

IAQ Reference Manual 

problems that can be detected through careful 

inspection of the system. 

The venting system pre-test consists of making a 

visual inspection and simple calculations which 

include estimating the exhaust flow and leakage 

area which are combined into a maximum house 

depressurization estimate which is compared to a 

house depressurization limit (HDL). If the estimated maximum depressurization is larger than the 

HDL, more detailed testing is needed. If it is 

smaller, the system is alright, and no further 

testing is needed. The test requires 10 to 15 

minutes. 

The venting system test is a detailed test that can be 

used to test the effect of fans and fireplace operation 

on the chimney serving the furnace and the hot 

water appliance, and it can also be used to evaluate 

the effect of fans and furnace operation on the 

chimney serving a fireplace. This test also includes 

a procedure for determining spillage under depressurization. The test requires about 40 to 80 

minutes to complete. 

Vents 

Appliances which require venting must be vented to 

the outside. Vents should be installed with an 

upward slope to maintain the velocity of the 

escaping gases, prevent moisture, and reduce the 

chances of backdrafting. Even if the vent slopes 

upward, it is possible for hot gases to flow downward (or horizontally) under some conditions. 

Vents that slope downward should be corrected. 

Too many and/or sharp elbows or bends in the vent 

will prevent it from drawing properly. A general 

rule of thumb is to have no more than two 90° 

elbows; ideally elbows should be limited to 45° 

which will result in an upward slant of about 4SO. 

The vent vertical length should be at least 5 feet 

above the highest vent collar for gravity-type 

systems with the exception of venting systems 

which are integral to the appliance or Type BW 

vents (vented wall appliances). 
IAQ Reference Manual 

To prevent contamination of indoor air, direct vents 

(vents in sealed systems) should be at least 9 to 12 

inches from any door, window, or gravity air inlet. 

The bottom of the vent terminal and air intake 

should be at least 12 inches above grade. In addition to these requirements, the venting system 

should end at least 3 feet above forced air inlets 

. located within 10 feet (CABO, 1989; NFPA, 

1988a). 

The horizontal run of a gravity vent (circulation of 

air by gravity) and its connector should not be more 

than 75% of the vertical height of the venting 

system measured from the appliance outlet, and the 

rise of the connector should not be less 1/4 inlft of 

length measured from the appliance vent collar to 

the vent. 

Two or more appliances (oil or gas fuel only) may be 

connected to gravity-type venting systems providing .they have the required safety controls and listed 

safety shutoff devices. The appliances should 

typically be located on the same story of the building, the connectors should be offset (should not 

enter directly opposite one another), and the venting 

area should be no less than the area of the largest 

vent connector plus 50% of the areas of the additional vent connectors. 

Chimneys 

Appliances can be vented with unlined masonry 

chimneys, metal pipe, or factory-built chimneys. 

Whichever is used, it must be installed and maintained according to local and national building 

codes. A masonry chimney' should be checked to 

make sure the mortar is intact between the bricks or 

stones. Metal chimneys should be checked for rust 

damage or spaces between the joints. These checks 

should be made both inside and outside (a flashlight 

and mirror are useful; smoke can also be used). 

Clients should be instructed to seal any openings 

which would allow combustion gases to seep back 

into the dwelling. 

SectionS 

The chimney must be sized properly to prevent 

spillage and condensation problems. The correct. 

size can be determined in several ways. In the case 

of venting a solid fuel burning appliances, the crosssectional area of the flue should not be less than the 

cross-sectional area of the appliance flue collar, or 

n;10re than 3 times the cross-sectional area of the 

appliance flue collar (NFPA, 1988b) . 

In the case of sizing a single gas-burning appliance, 

the effective areas of the vent connector and the 

chimney flue should not be less than the area of the 

appliance flue collar or draft hood outlet .. A chimney that is connected to more than one gas-burning 

appliance is sized properly if the effective area of the 

chimney flue is not less than the area of the largest 

vent connector plus 50% of the area of additional 

flue collars or draft hood outlets (NFPA, 1988a). 

Avoiding Backdrafts on Chimneys: Chimneys 

should extend above the roof to avoid possible 

downdrafts into the chimney in windy weather and 

to prevent overheating of the roof from the hot flue 

gases. Local codes specifY required clearances. A 

general guideline is that the residential chimney 

should extend at least 3 feet above the highest point 

where it passes through the roof of a building and at 

least two feet higher than any portion of the roof 

within a horizontal distance of 10 feet (Exhibit 8-5). 

Another potential problem is overhanging tree 

limbs which can result in significant downdrafts. 

The chimney should be properly capped to prevent 

rain water from entering (Exhibit 8-6). The 

chimney should also be checked (at least yearly) to 

prevent the buildup of soot and debris which could 

cause improper functioning. Birds' nests, in · 

particular, can cause blockage. 

Chimney connections must be checked to ensure 

that backdrafts and other problems will not result 

(Exhibit 8-7). A gas or an oil furnace should not be 

connected to a chimney that serves a separate 

appliance that burns solid fuel because the draft to 

the furnace may be significantly reduced. No two 
Section 8 

appliances should enter the chimney in the same 

location at the sam~ level; rather, they should be 

staggered along the vertical shaft. This prevents 

fumes from blowing across the chimney rather than 

up and out the other appliance. Another problem 

associated with shared chimneys is the possible 

release of sparks or burning creosote from an open 

wood-burning appliance into the room. 

It should be noted that exterior chimneys are more 

likely to have problems with backdrafting than 

interior chimneys because the gases are quickly 

cooled and draft is lost. 

INSPECTION OF COMBUSTION APPLIANCES 

The main fuels for central heating appliances in the U.S. are natural gas (97% methane), 

liquid petroleum gas or LPG (propane, butane, or a 

combination of these), fuel oil, or electricity. In 

addition to these fuels, wood and coal are also used 

for central heating. 

All of these appliances (except electricity) can 

become sources of indoor air contaminants including carbon monoxide, carbon dioxide, nitrogen 

oxides, inhalable particulates, and in the case of fuel 

oil, kerosene, coal, and sulfur dioxide. Improper 

installation and maintenance are most often the 

causes of fires and the release of contaminants into 

the living space. 

On routine investigations, the evaluation begins 

with a visual inspection of the appliance. The use of 

a standard form is recommended (Exhibit 8-8 is an 

abbreviated form). The following types of questions 

should be answered: 

• Does the appliance work? If not, is the 

equipment faulty or is there insufficient 

fuel. If the fuel correct for the equipment? 

• Is the appliance vented properly? Is there 

any obvious damage to the appliance or 

venting system? 

IAQ Reference Manual 

• Is there sufficient combustion and circulating air? 

• Is the appliance maintained and operated 

properly? 

Fuel-fired heating appliances should be inspected 

and cleaned on an annual basis. Regular inspection 

and maintenance will improve efficiency and 

prevent problems. In some cases regular inspection 

and maintenance can be performed by the homeowner who carefully follows the manufacturer's 

instructions; in other CiJSes, a professional will be 

required. During the visual evaluation, the investigator can usually determine if a service call by a 

professional is needed. 

The following general guidelines for vented appliances include checks that the investigator can make 

and general recommendations which can be given to 

the client. These guidelines only provide an 

introduction to this important area, and the investigator should become familiar with local codes for 

specific requirements. 

Central Forced-Air Fuel-Fired Furnaces 

A properly installed central heating system will not 

result in safety or indoor air quality problems. The 

evaluation should determine if the unit is properly 

installed and operated so that harmful contaminants 

are not emitted indoors. The unit should also be 

checked for other safety hazards. 

One of the first clues that can be obtained in an 

investigation is the presence of any smoke, odor, 

black dust, or ash. If any of these exist, the cause 

should be determined. Next, the location of the 

appliance should be noted. Warm-air fuel-fired 

furnaces should not be installed under stairways, in 

a room used as a bedroom or bathroom, in a closet, 

or in any small space with access only through a 

bedroom or bathroom. These installation requirements, however, do not apply to direct vent furnaces 

or enclosed furnaces. 
IAQ Reference Manual 

Natural Gas Appliances: Appendix G of the 

National Fuel Gas Code contains tables for sizing 

venting equipment serving appliances equipped 

with draft hoods and appliances listed for use with 

Type B vents (Category I furnaces). These tables 

indicate the maximum appliance input rating for 

different vent sizes. 

It should be noted that the Tables in Appendix G 

can result in flue gas condensation in some installations. This is most likely to occur in new midefficiency furnaces that have fan-assisted combustion 

systems rather than draft hoods. Like the dtaft hood 

appliances, the fan-assisted furnaces still rely on the 

buoyancy of the hot combustion gases tp vent the 

flue gases. However, since these appliances operate 

with reduced dilution air, the vent gas volume is 

reduced for a given input and smaller vents can 

therefore be used .. The flue gases in this instance 

will have a higher dew point temperature which 

increases the potential for condensate formation. 

This, in turn, increases the corrosion of the vent 

materials. The 1988 version of the National Fuel 

Gas Code does not address this problem (it will in 

updated versions), but expanded tables have been 

developed by the Gas Research Institute and these 

can be consulted to ensure that vents at;e properly 

sized (tables can be obtained from any gas utility). 

The investigator should make the following obser-. 

vations for gas-fired appliances: · 

1) Check the position and condition of the 

blower doors; doors that have been removed 

or which are ajar can allow contaminants 

from the burner chamber to enter the living 

space. This problem must be fixed immediately. 

2) Examine the furnace filters. This is 

accomplished by disconnecting the power 

and removing the blower access door or 

filter assembly door. Clients should be 

instructed to replace soiled disposable 

filters with filters of the same size every 

four to six weeks during the heating season 

Section 8 

or according to the manufacturer's instructions. Filters that are not disposable should 

be cleaned (by vacuuming or washing with 

detergent acc:ording to the manufacturer's 

instructions) twice a month during periods 

of heavy use and once a month during other 

times. 

3) Examine the burn chamber for the accumulation of lint and the heat exchangers for 

soot and .rust. If any of these are present, 

the furnace should be cleaned so that the 

fuel will burn properly. 

4) Check the flame in the burn chamber to 

determine if combustion is optimum. 

Natural gas furnaces should not have yellow 

tipped flames; LP units may have some 

light yellow tipping of the outer mantle, 

. but the inner mantle should be bright blue. 

A service call is needed if yellow tipping 

exists. 

5) Check the combustion air inlet and air 

openings in the casing of the furnace for 

any obstructions which could, reduce 

airflow. The combustion chamber opening 

side should not be less .than 6 inches for 

fuel-burning appliances. 

6) Check the venting system for evidence of 

corrosion, leaks, and proper sizing. Problems should be corrected. 

7) Check heat inlet registers and cold air 

returns to ensure that they are free and dear 

of carpets, furniture, and other obstructions. Any obstructions should be removed. 

8) Check the cooling coil condensate drain of 

air-conditioning units if negative air is 

created inside the furnace or if the drain is 

connected directly to the structure's sewer 

system. Condensate should be discharged 

outside of the building. Condensate 
Section 8 

drained to the sewer system must be 

drained through an observable airbreak. If 

the drain is not draining freely, it should be 

cleaned. The outside condensing unit 

should have a clearance of 3 inches above 

grade; manufacturer's clearances for proper 

airflow should be strictly observed. 

Oil~FiredAppliances: Oil furnaces are similar to 

gas furnaces in size, shape, and function; they are 

available as upflow, downflow, horizontal, and lowboy configurations for ducted systems. However, 

the heat exchanger, burner, and combustion control 

system are different. Oil-fired forced-air ducted 

systems are usually forced-draft furnaces and 

equipped with pressure-atomizing burners. The hot 

flue products flow through the inside of the heat 

exchanger into the chimney; conditioned air flows 

over the outside of the heat exchanger and into the 

air supply plenum. A barometric draft regulator is 

used in lieu of a draft hood. The checks for an oilfired furnace are ·similar to those for the gas-fired· 

system. 

Oil-fired furnaces must also be checked for proper 

location of the fuel tank and sizing of the tanks 

(Section 5, Exhibit 5-1). If tanks are located inside 

the building the tanks should be evaluated for 

proper separation from boilers, furnaces, stoves, or 

exposed flames. Tanks must be vented to the 

outside. Sufficient combustion air must enter the 

furnace room; i general rule of thumb is to provide 

15 in2 of opening for each gallon of oil burned per 

hour. 

Any odors, particulates, or staining in the furnace 

room suggest problems. The burner jets should be 

checked for cleaning. The blower compartment 

door should be tight. Filters and burner fan should 

be checked to determine if they need cleaning. The 

barometric damper should be checked for lubrication and the need for balancing. The air supply 

should be evaluated for adequacy and the unit 

should be evaluated for clearance from combustibles. In addition to these checks, the guidance 

listed under flues and chimneys also applies. 

IAQ Reference Manual 

Coal~Fired Appliances: Coal-fired appliances are 

still used in some areas; these appliances include 

boilers, furnaces, and space heaters (resemble potbellied stoves). Coal should be burned only in those 

appliances specifically designed for coal. These 

units should be carefully checked for condition and 

possible leaks through the venting system. 

Coal-fired furnaces and boilers must be sized 

properly for the particular supply of coal; improperly sized furnace grates and flues can result in 

excessive coal gas. Owners of coal-fired appliances 

should be questioned about procedures used to fire 

the unit. Sufficient time must be allowed to pass 

before damping to prevent the release of excessive 

coal gas; this is most likely to be a problem at night 

or other periods when full drafds not needed. 

Proper ventilation is needed to provide adequate 

combustion air and prevent heat buildup. 

Wood-Burning Stoves 

Because of rising fuel costs, many people are turning 

to wood as their main or supplementary fueL 

Fireplaces, with or without an insert, and various 

types of freestanding stoves are the most common 

wood-burning appliances; the term "stoves" will be 

used to refer to these devices. If wood appliances are 

used, they should be approved or listed and the 

NFP A or local code installation guidelines should 

be followed. 

Conventional stoves have a single combustion 

chamber which is not airtight; these stoves have a 

low efficiency compared to airtight stoves which 

have a secondary chamber for combustion unburned 

gases from the primary chamber. Simpler stoves 

typically have a damper in the chimney to control 

the flow of air through or over the fire. More 

complicated stoves have a thermostat-controlled 

damper which controls the draft. 

Improperly installed, maintained, or operated woodburning appliances can create serious indoor air 

quality and safety hazards. The investigator should 

evaluate each stove and installation for proper 
IAQ Reference Manual 

installation, condition, venting to the outside, 

proper clearance to all combustible materials, proper 

fuel supplies, and fire stoking techniques. The 

investigator should initially look for evidence of 

smoke, soot, or creosote in the living spaces; flues 

should be evaluated for evidence of leakage. The 

cause of any of these problems should be determined 

and corrected. 

Installation: Proper installation is the key to the 

safe usage of a wood-burning stove (Exhibit 8-9). 

The stove should be located away from all combustible materials. NFP A 211 recommends a clearance 

of 36 inches at the ceiling, back, and sides from 

combustibles. The use of a fireproof barrier can 

reduce the required clearances, but local codes 

should be consulted for specifics. 

The floor on which the stove is placed should also be 

protected (except concrete, day tile, or ceramic). 

The condition of any asbestos floor protection 

should be noted; if the material is not intact or 

cannot be repaired, it should be removed. The stove 

should not be placed on carpeting or any other type 

of combustible surface. Combustible floors should 

be protected by a sheet of noncombustible material 

under the stove; the sheet should extend out from 

the stove 18 inches in all directions. 

Wood and oil or wood and gas appliances should not 

be served by the same flue or chimney because of the 

possibility of insufficient draft for safe combustion 

in each appliance (Exhibit 8-7). 

Stovepipe refers to the single-wall metal piping that 

is used to connect the appliance to the chimney; 

stovepipe should not be used as a chimney. It 

should not be routed through a ceiling, closet, 

alcove, or concealed space. When it must pass 

through interior combustible material, a ventilated 

thimble must be used. 

The chimney for a stove (also oil appliances, domestic-type incinerators, and solid fuel-burning) should 

be of the right material and sized correctly (see 

Section 8 

NFPA, 1988B for guidance). In residential 

installations, single-walled metal flues should not 

be used; flues must be double- or triple-lined. To 

prevent backdrafts, the chimney should not have a 

flue area more than. twice the size of the stovepipe. 

Exhibit 8-10 provides suggested flue sizes for 

residential wood-burning appliances in the absence 

of manufacturer's instructions. Guidelines for the 

clearance of a stove chimney at the rooftop are 

identical to those for central heating appliances. 

These clearance guidelines should be followed to 

prevent downdrafts in windy weather and to prevent 

roof fires caused by hot flue gases. 

Unlined masonry chimneys should not be used. 

Factory built chimneys should be labeled as "Class 

A," "All-Fuel," or "Solid Fuel." Metal thinner than 

28 gauge should not be used as a chimney because it 

can rust or corrode easily, and it is not a good 

insulator which means that combustion gases will 

condense in the flue and increase creosote formation. 

The stovepipe connection should be as short and 

straight as possible to minimize creosote buildup 

and maximize draft. Lengths up to about 8 feet are 

typical, and the horizontal portion should be less 

than 3/4 of the vertical part of the pipe and should 

rise a minimum of 114 inch per foot (ASHRAE, 

1988; CABO, 1989). Smoke leaks typically occur if 

the stovepipe joint does not overlap properly; the 

crimped end should be pointing down toward the 

stove. 

Long stovepipes increase heat output, but also result 

in more creosote accumulation and less draft. If the 

stovepipe is too small for an attached stove, smoke 

will spill out, or the stove will not be able to get hot 

enough because it does not get enough air. If the 

stovepipe is too large, decreased draft and increased 

creosote can result. 

The connection of the stovepipe to the chimney 

should be examined to be sure that it is secure and 

does not leak creosote or gases. The stovepipe 

shouldn1

t move more than 1-2 inches horizontally. 
SectiotJB 

NFP A requires that horizontal runs slope up from 

the stove. This upward slop maintains draft and 

prevents creosote drip. 

Operation atzd maintenance: Stovepipes and 

chimneys should be checked frequently for creosote 

buildup. Black stains on the exterior of a chimney, 

flue, or stovepipe may indicate creosote buildup or 

water damage. Creosote has an unpleasant, acrid 

odor. It may be pooled on the floor, or it may 

appear as bubbles, flakes, curls, or as a dry or tacky 

shiny glaze on the inside of flues, stovepipes, or 

chimneys. After it dries, creosote is flammable. As 

a general rule, cleaning is needed when creosote and 

soot are more than 114 inch thick. 

Creosote can be minimized by proper installation 

and operation of the stove. One of the best ways to 

minimize creosote formation is to use the correct 

type of fuel. Seasoned hardwood is recommended 

over softwoods because hardwoods burn hotter and 

result in less creosote formation. Resinous woods 

burn quickly, and they can be used in small 

amounts for starting fires. However, they should 

not be used as the primary wood because of creosote 

and smoke formation. Recommended moisture 

content ranges between 15% and 25%. "Green" or 

wet wood is likely to result in smoke and creosote 

problems. 

As a safety precaution, wood should be stored at least 

36 inches away from the stove. No more than 25 

pounds of wood should be stored inside the dwelling at 

any time. Treated wood, railroad ties, plastics, 

charcoal, metal, tires, trash, and other non wood 

materials must not be burned in stoves because·they 

emit harmful contaminants when they burn. 

Wood-burning furnaces and boilers may also be 

used in residential heating systems; some of these 

furnaces are multi-fuel furnaces which have a gas or 

oil burner which provides heat if the fire goes out or 

becomes low. Wood-burning boilers and furnaces 

require more care and maintenance than furnaces 

which are fueled by gas or oil only. Indoor air 

quality problems for wood appliances can result 

IAQ Reference Manual 

from stoking operations, creosote deposits and 

plugging of the chimney, or draft problems. Local 

codes should be consulted for the legality of these 

appliances and specific requirements. 

Space Heaters 

Vented Gas Space Heaters 

Many older homes use large gas-fired room heaters 

to heat the entire living space. Vented heaters 

which are not properly installed or maintained can 

release carbon monoxide, carbon dioxide, and 

nitrogen oxides into the living space. These 

appliances are usually vented through the chimney 

and should be installed in the same way as a fuelfired central heating system. 

The investigator should check the vent installation 

and clearance from the vent to any combustible 

walls. There should be 12 to 18 inches of clearance. 

The condition of exposed ducting should be evaluated. Joints should be examined to be sure that 

screws are present and tight. Any deteriorated or 

loose joints are likely sources of leaks. Vented 

heaters do not burn as efficiently as a central heating 

system, and these flues should be cleaned 2-3 times 

during the heating season. 

Safety features which the investigator can identify 

are certification of the aflpliance by the American 

Gas Association Laboratory. Vented gas space 

heaters manufactured after June 1, 1984 are required to have a thermal shut-off device that will 

activate when the heater is not being vented 

properly. 

U nvented Kerosene or 

Gas Space Heaters 

Unvented fuel-fired space heaters that use kerosene 

or gas are of serious concern to public health 

officials. An important marketing tool used to sell 

these devices is a fuel efficiency that is almost 

100%, compared to 60% for most residential 

furnaces or 80% to 90% for high efficiency furnaces. 
IAQ Reference Manual 

When unvented space heaters burn, the heat 

generated by the burning fuel is released directly 

into the living space, but the byproducts of combustion are also released. Burns from hot surfaces and 

fire hazards are additional concerns when unvented 

heaters are used. 

Fire hazards are of great concern when unvented 

heaters are used. Each appliance should be inspected for obvious damage, improper burner 

settings, improper fuels and storage of fuels, 

distance to combustibles, absence of fuel shut-off 

devices in the event of tip-over or flare-up, and 

other fue safety hazards. 

The combustion byproducts of unvented space 

heaters contain many potentially harmful contaminants such as carbon monoxide, nitrogen oxides, and 

carbon dioxide in the case of gas heaters; sulfur 

dioxide, aldehydes, polycyclic aromatic hydrocarbons, and acid aerosols are additional potential 

contaminants from kerosene heaters. 

Emissions from kerosene heaters depend on a several 

factors including maintenance of the unit, flame 

setting, age of the heater, Btu rating of the heater in 

relation to the space to be heated, type of kerosene, 

and type of heater. Emissions from unvented gas 

heaters also depend on age and maintenance of the 

unit, Btu rating, and other factors. 

The concentrations of these contaminants can be 

reduced, but not eliminated, by using heaters in 

well-ventilated areas. Most manufacturers recommend opening the door to the room with a kerosene 

heater to provide air exchange with the rest of the 

house. This practice does not provide sufficient 

ventilation air. 

Adequate ventilation must be provided by bringing 

fresh outdoor air into the living space. This can be 

accomplished by opening a window(s). A general 

rule of thumb is to open a standard sized window 4 

in2 for every 1000 Btu of heater capacity. Using 

this general rule, an 11,000 Btu heater would 

require a window opening of about 2 inches. 

Section 8 

Additional areas of concern and safety tips for 

unvented gas and kerosene heaters are given in 

Exhibits 8-11 and 8-12. 

Household Appliances 

Gas-fired Ranges 

Gas-fired ranges should not be used as a source of 

heat during cold weather. The use of gas-fired 

ranges and ovens as a' source of heat could result in 

the buildup of potentially fatal concentrations of 

carbon monoxide, and this practice also poses safety 

and fire hazards. Additional contaminants that are 

released by gas-fired ranges include carbon dioxide 

and oxides of nitrogen. 

Local building codes should be consulted for specific 

installation requirements. In general, the back and 

sides of gas ranges are required to have a clearance of 

6 inches to combustible materials. The vertical 

clearance should be at least 30 inches, but this is 

allowed to be reduced to 24 inches if the combustible material is protected by a fireproof material. 

Vents serving range hoods should not terminate in 

an attic, crawl space, or any area inside the building. 

Most ranges that are vented to the outside require a 

ventilation rate of about 100 cfm; updraft or 

downdraft ranges require higher rates (atound :400 

cfm for some models) that vary depending on the 

particular model. The fan ratings can be found on 

identification plates on the hood. Many newer 

single and double family homes and apartmen~ 

buildings have recirculating hoods rather than range 

hoods that vent to the outside. 

Pilot lights must be adjusted properly so that the 

burners will burn efficiently, and gas will be 

prevented from escaping if the pilot light goes out. 

Gas-fired Hot Water Heaters 

Proper venting of hot water heaters is also important to prevent combustion-related contaminants 

from entering the living space. The vent should be 
Section 8 

maintained in a safe condition, and installation 

should follow the same guidelines as for a central 

heating system. The water heater should be located 

as close as possible to the chimney. It should not be 

located in bathrooms or bedrooms, closets, or 

confined spaces opening to the bedroom or bathroom. 

If a water heater is located in a garage, it should be 

installed at least 18 inches above the ground. This 

clearance is required to prevent explosions which 

could occur if gasoline or other flammable volatile 

liquids are spilled onto the floor in proximity to the 

heater. 

Gas-fired Clothes Dryers 

Gas-fired clothes dryers can release nitrogen oxides, 

carbon dioxide, and carbon monoxide if they are not 

vented properly. Clothes dryers should be vented 

directly to the outside and not through a chimney, 

flue, gas vent, or vent connector (or to the attic or 

crawlspace). The duct should not be joined with 

screws or anything else that would project into the 

duct and trap lint because removal efficiency will be 

reduced. 

Devices which can be attached to the dryer vent to 

allow heat to come back into the house should not 

be used with gas-fired clothes dryers because they 

allow passage of the combustion-related contaminants back into the living space. They also increase 

the humidity level in the home. 

Other Combustion Sources 

There are other sources of combustion products in 

homes such as candles, lamps, and certain hobbies 

such as soldering, wood burning, and interior 

combustion engines. These sources can release a 

variety of gases and particulates. Emissions from 

these sources have not been characterized adequately. The investigator should be alert to these 

IAQ Reference Manual 

sources and ensure that adequate ventilation is 

present when they are used. 

Fire Safety 

Every home should have a fire detector and extinguisher, but this is especially important in homes 

that utilize wood-burning stoves. An extinguisher 

and detector is recommended in the room with the 

stove. Other detectors should be placed strategically based on guidance from the local fire department. 

MEASURING COMBUSTION-RELATED 

CONTAMINANTS 

Instrumentation 

Most investigations of combustion-related 

complaints will require a carbon monoxide monitor 

and a combustible gas meter. A carbon dioxide 

monitor may be also be useful, but it should not be 

purchased in lieu of the carbon monoxide monitor 

or combustible gas meter. Instruments for field 

inspections should be portable, lightweight, rugged, 

battery-operated, easily read, and convenient to use. 

The combustible gas meter measures the concentration of a flammable gas or vapor in the air, and the 

results are indicated as a percentage of the lower 

explosive limit (LEL). The LEL is the minimum 

concentration of the gas or vapor in air which will 

propagate the flame if an ignition source is present. 

The upper explosive limit (UEL) is the concentration above which ignition will not occur. The 

flammable range is between the UEL and the LEL. 

The combustible gas meter usually does not specify 

what gas is present, it just warns of a potentially 

dangerous situation with an audible sound or 

flashing light. The meter is not accurate for low 

concentrations, and it must be calibrated to the gas 

of interest. The zero and calibration checks should 
IAQ Reference Manual 

be performed at the location where sampling will 

occur because the response of the instrument is 

affected by temperature. 

Combustible gas meters are available for area 

sampling or can be configured with a probe for 

testing point sources such as gas pipes. Regardless 

of the type of meter, it should be intrinsically safe. 

These instruments are easy to use and require 

minimal training. The cost ranges from about $700 

to over $1000. 

Combination oxygen and combustible gas meters 

are available which can detect oxygen deficiencies 

and combustible gases in a single unit. The oxygen 

content of the air is normally 21 %; 16% oxygen is 

the minimum needed to support life, and air with 

less than 19.5% oxygen is considered deficient. 

Although there are several methods which can be 

used to measure both carbon monoxide and carbon 

dioxide, nondispersive infrared spectrophotometry 

(NDIR) is probably the method of choice for several 

reasons. Current generation NDIR instruments are: 

1) insensitive to variations in flow rates and room 

temperature, 2) require no wet chemicals, 3) sensitive over a wide concentration range, 4) quick 

responding, 5) small and portable_, and 6) require 

minimal training to operate. 

The concentratidn of carbon monoxide is usually 

recorded in ppm while carbon dioxide is given in 

percent. Both instruments should be calibrated 

routinely using zero and multi-point calibration 

gases in the range of concentrations to be measured. 

If measurements are conducted in the range of 0 to 

10 ppm, a single point calibration outside of the 

sampling range may not be adequate. 

Carbon monoxide, carbon dioxide, and combust,ible 

gas meters can handle most situations involving 

combustion-related appliances. But there are 

occasions when concentrations of other gases are 

needed. A variety of active and passive monitors are 

available to test for specific contaminants such as 

Section 8 

sulfur dioxide and nitrogen oxides if this information is necessary. 

Most active samplers are not convenient for routine 

residential investigations of sulfur dioxide and 

nitrogen dioxide levels, but active bubbler methods 

which were developed for ambient air sampling can 

be used to collect 1 hour or 24 hour samples. These 

can be built at a nominal cost (about $150 for each 

sampler). Sample 'collection is relatively 

uncomplicated, but a laboratory is required for 

analysis of the samples l:;ly colorimetric methods. 

Portable electrochemical samplers can also be 

purchased for about $1500 to $3000. Passive 

samplers (at about $30 each) are another potentially 

useful alternative, but they cannot be reused, and 

they do require laboratory analysis which is usually 

included in the cost of the sampler. 

Indoor sampling methods are also available for 

organic particulates from fuel combustion and 

compounds found in cigarette smoke. Further 

information on equipment and methods for these 

contaminants is contained in Lesson 6 of the 

Learning Module, Section 6 of the Reference Manual, 

and EPA's Compendium of Methods for Indoor Air 

Quality (U.S. EPA, 1989). 

It may also be necessary to monitor levels of 

carboxyhemoglobin in cases of acute exposures or 

when low-level chronic exposures are suspected. 

These analyses require a blood sample to be drawn 

by a health care provider. 

Measurement Locations 

The combustible gas meter should be operating 

before entering the residence. Readings are taken 

upon entry. If safe levels are measured, the investigator proceeds to the room with the appliance and 

measures levels next to the appliance. If unsafe 

levels are measured (guidelines are given below), the 

residence should be evacuated and the gas company 

should be notified. 
Section 8 

When fuel leaks are suspected during the course of a 

routine investigation, readings should be taken 

adjacent to the appliance and at any points where 

leaks might occur. If leaks are detected, the gas 

company should be notified; a qualified contractor 

will be needed to correct problems. 

If fuel leaks are not suspected, carbon monoxide and 

other contaminants are usually measured in the 

general living area at breathing height or close to 

the floor if infants are present. Measurements can 

also be taken adjacent to the appliance or heat 

registers. Regardless of the location, measurements 

should be made during routine investigations after 

combustion appliances have been operating for at 

least one hour. 

Interpretation of Combustion-Related 

Contaminant Data 

Combustible Gas 

Combustible gas meters must be calibrated to the 

specific gas of interest. A meter calibrated to 

natural gas should not be used for investigations 

involving liquified propane, butane, or a mixture of 

these compounds (liquified petroleum gas, LPG) 

because the lower explosive limits for these compounds are lower than for natural gas (methane). 

General guidelines which can be used are given by 

EPA (U.S. EPA, 1990) for hazardous materials 

investigations: 

• greater than or equal to 25% ofLELevacuate immediately; explosion hazard!, 

• 10% to 25% ofLEL-proceed with 

extreme caution, 

• less than 10% ofLEL-lower hazard, 

proceed cautiously with investigation. 

Carbon Monoxide 

Indoor levels of carbon monoxide (CO) vary considerably depending on the sources that are present and 

IAQ Reference Manual 

consumer use patterns. Concentrations of 1 ppm to 

2 ppm can result indoors from using a normally 

operating gas-fired central furnace; concentrations 

considerably over 100 ppm have been measured in 

homes with faulty furnaces. Levels of 3 5 ppm to 

120 ppm have been measured after 4 burners on gas 

stoves were operating for 20 minutes (Sterling and 

Sterling, 1979). Kerosene heaters can result in 

concentrations from several parts per million to over 

20 ppm (U.S. CPSC, 1983). Traynor eta!. (1983) 

measured concentrations ranging from 1.9 ppm to 

89.4 ppm in a test house (1150 ft 2

) heated by 

unvented gas heaters. 

Since the potential effects of measured concentrations of CO depend on the % COHb in the blood, 

the WHO recommends a carboxyhemoglobin level 

of 2.5% - 3% for the protection of the general 

population, including sensitive groups (WHO, 

1987). The WHO's air concentration guidelines to 

protect these levels include: a maximum permitted 

exposure of 100 mg/m3 (about 87 ppm) for periods 

less than 15 min.; and time-weighted average 

exposures of 50 ppm (60 mg/m3) for 30 minutes, 25 

ppm (30 mg/m3

) for 1 hour, and 10 ppm (10 mg/ 

m3) for 8 hours. 

The U.S. EPA ambient standard and the Canadian 

indoor exposure guidelines for CO are similar. 

EPA's standards are 9 ppm for 8 hours and 3 5 ppm 

for 1 hour; Canada's guidelines are < 11 ppm for 8 

hour exposures and< 25 ppm for 1 hour exposures. 

It should be noted that these guidelines may not 

provide sufficient protection for individuals who are 

chronically ill with heart and/or lung problems. 

Nitric Oxide 

Nitric oxide will be present whenever combustion 

products are emitted directly iO:to the living space. 

Undersized and oversized kerosene heaters have 

resulted in nitric oxide concentrations of0.21 ppm 

and 0.43 ppm, respectively, when burned for a 4 

hour period in a townhome (Ritchie and Oatman, 

1983). Concentrations as high as '0.94 ppm were 
IAQ Reference Manual 

measured when a convective kerosene heater was 

operated in a room with the door opened 1 inch 

(Ritchie and Arnold, 1984). Concentratioqs of 0.00 

ppm to 5 .14 ppm were measured by :r'rayrior et al. 

(1983) in a test house heated. by unvented gas space 

heaters. 

There are no guidelines fot acceptable concentrations of nitric oxide indoors. 

Nitrogen Dioxide 

Nitrogen dioxide concentrations be~ween 01003 

ppm and 0.540 ppm have been measured in homes 

with gas-fired stoves, ovens, or unvented heat~rs 

(Spengler and Cohen, 1985). Steady-state levels up 

to 0.250 ppm have been measured a home with a 

radiant kerosene heater op,erating in a room, with a 

door opened 1 inch; levels .of 0.057 ppm we,re , 

measured when a convective heater was operated in 

a room with the door 'open (Ritchie and Arnold, 

1984). Nitrogen dioxide concentrations ranging 

from 0.225 ppm to 1.35 ppm were measured in a 

test house heated by unvente<f gas space heaters 

(Traynor et al., 1983). 

Based on i~s review oft~~ nitrogen dioxide .literature, the WHO recommends nitrogen dioxide 

guidelines of0.21 ppm (400 Jlg/~ ) ~d 0.08 ppm 

(150 Jlg/m3) for 1 hour and 24 hour ambient 

exposures, respectively. The Canadian exposure 

guidelines for residential indoor air quality are 

<0.25 ppm for 1 hour and < 0.05 ppm for longterm exposures. The U.S. EPA standard for ambient air is 0.053 ppm (0.1 mg/m3) as an annual 

arithmetic average. 

Carbon Dioxide 

Outdoor concentrations of carbon dioxide are 

generally in the range of 300 to 330 ppm (multiply 

by 104 to convert to%). In homes without sources, 

concentrations might be in the range of 0.07% -

0.20% (NRC, 1981). Concentrations in homes 

with kerosene heaters can reach concentrations 

Section 8 

above 0.3% within several hours, and concentrations 

greater than 0.5% have been measured (Ritchie and 

Arnold, 1984). Concentrations of0.177% to 

0.815% were measured by Traynor et al. (1983) in a 

test house heated by unvented gas heaters. 

The Canadian exposure guidelines for residential 

indoor air quality are <3500 ppm ( <0.35%). 

ASHRAE's guideline for acceptable indoor air 

quality is 1000 ppm. ASHRAE, however,. chose 

this level because it is used as an indicator of 

inadequate outdoor air, and not because of the 

potential health effects from carbon dioxide exposure.· 

Sulfur Dio;x:ide 

Outdoor concentrations vary from <0.002 ppm in 

pristine areas to about 0.01 ppm for annual averages 

in urban areas (higher,concentrations do occur). 

Homes without sources are not likely to have · 

measurable sulfur P,ioxide levels unless the qutside 

air is contaminated·. Indoor sources are primarily 

faulty furnaces that burn oil or coal and kerosene 

heate~s. Depending on the concentration of sulfur in 

kerosene, indoor levels have been reported from minimal to over 0.14 ppm (Ritchie and Arnold, ~984). 

The WHO recommends a guideline value for sulfur 

dioxide of0.174 ppm for a 10 minute maximum 

(equivalent to a 1 hour maximum of about 0.122 

ppm). The Canadian exposure guideline is <0.38 

ppm for a 5 minute maximum and <0.019 ppm for 

long term exposures. 

Benzo(a)pyrene 

Benzo(a)pyrene (BaP) is probably the most widely 

known and measured of the several hundred P AH 

compounds which have been detected as byproducts 

of combustion. BaP is a potent carcinogen. The 

ambient air has background BaP levels of nearly 

zero (WHO, 1987); levels of less than 5 ng/m3 were 

measured in the U.S. during the 1970s (Faoro and 

Manning, 1981). 
Section 8 

Indoor levels of BaP have been measured during the 

combustion of wood, coal, kerosene, and tobacco. 

Because BaP and P AH compounds are carcinogens, 

there is no safe level of these compounds indoors. 

Mitigation Advice For Combustion 

Contaminants 

It is important to instruct residents about the 

problem of depressurization of the house when other 

fuel-burning appliances are present and there is 

insufficient oxygen. This problem is particularly 

important in tightly constructed homes. 

It is important for all vented appliances to be 

properly installed, maintained, and operated in 

order to prevent emissions from entering the living 

space. If there are problems with the condition or 

installation of the appliance, flues, chimneys, 

chimney connectors, and so forth, these must be 

repaired, usually by a qualified contractor. 

The most effective method of controlling gaseous 

and particulate combustion products is removal of 

the source or substitution with sources that emit 

fewer contaminants (for example, replacing 

IAQ Reference Manual 

unvented kerosene heaters with electric heaters). 

However, in many instances substitution and/or 

removal will not be possible. In those cases, 

increased ventilation (local exhaust or whole house) 

will help reduce emissions. 

Whenever local building codes allow unvented 

space heaters, the heaters should be checked for 

proper installation and specific limitations. Some 

jurisdictions allow the sale of kerosene hearers, but 

prohibit their use in single family and/or multiple 

family dwellings. Whenever this situation exists, 

efforts should be made to provide the consumers 

with information about of allo~ed and prohibited 

uses. 

Regardless of the primary purpose of an investigation, if unvented heaters are present and their use is 

allowed by the local code, the investigator should 

take time to educate the occupants on safe usage of 

the appliance. It is important to first determine 

why unvented space heaters are being used in lieu of 

vented appliances. Whenever possible, central 

heating systems or vented appliances should be 

encouraged. 

Exhibit 8·3. Location and operation of typical backdraft diverter. 

,.. t "" Flue lining 

Floe 

t ~Gas Vent 

~ )I. 

"'AirSpace n D raft t t 

HotF umace Hot Water Heater-Gas 

SOURCE: U.S. HEW (1976). 
IAQ Reference Manual Section 8 

Exhibit 8·4. CABO Building Code combustion air requirements for residential fuel-burning 

equipment. 

ONE AND TWO FAMILY DWELLINGS 

A. Combustion air requirements for unconfined spaces (M-1202): 

• No special combustion air source is required for unconfined spaces. Unconfined spaces are those 

with a volume not less than 50 ft3 per 1000 Btu/hr or per the input rating of all appliances installed 

in the space. Rooms which open into the space where appliances are installed are considered part of 

the unconfined space if the openings do not have doors. 

Exception: Sealed combustion system (direct vent) appliances or enclosed furnaces are 

exempt from these requirements. 

B. Combustion air requirements for confined spaces (M-1203): 

• Combustion air requirements are 2 in2 of combustion air opening for each 1000 Btulhr of input rating 

with a total area of not less than 200 in2

• 

Exception: 1 in2 for each 1000 Btu/hr input rating may be permitted if the compartment floor 

area is >2 times the floor area of the appliance and the total area is not less than 100 in2• 

If the outside air is used, it must be supplied through the required cross-sectional area 

extending to the appliance room; the same duct should not serve both the combustion air 

openings; the upper duct must be level or extend upward from the appliance room. 

• One-half of the required opening must extend within the upper 12 in of the room and one-half within 

the lower 12 in of the room. 

Exception: In any room that has gas- or liquid-burning appliances which has more than 2 

times the floor area of all such appliances, the required combustion air supply may be reduced by 50%, but not less than 100 in2

• • 

• The combustion air source can come from outside air or interior spaces. If an interior space is used it 

must have a volume in ft3 that is equal to 1/20 of the input Btulhr rating of all fuel-burning and 

water-heating appliances in the space (M-1204). 

• Each appliance must have its own supply duct, and combustion air openings cannot have volume 

dampers. Requirements for cold climates are given in Section M-1211 of the CABO Code. 

C. Attic combustion air 

• Combustion air can be obtained from an attic if the required volume of combustion air can be provided. 

The combustion air opening must have a galvanized sleeve of not less than No. 26 gauge steel (or other 

approved material) extending from the appliance enclosure to at least 6 in above the top of the ceiling 

joists. 

• Circulating air supplies for blower-type furnaces shall not be obtained from the attic area. 

D. Under-floor combustion air 

• The lower combustion air supply required in M-1203 of the code can be obtained from under-floor 

areas having unobstructed openings to the outside equal to at least 2 times the required combustion 

air openings. 

SOURCE: CABO (1989) 
Sectiott 8 IAQ Reference Manual 

Exhibit 8•5. Separation guidelines to prevent downdrafts Into chimneys. 

!Ill: lOFt.----~~)111.--

To prevent downdrafts, chimney height must T 

be at least 2ft. above any roof surface within 2 Ft. 

10 ft. horizontally 

3 ft:minimum 

from roof 

penetration 
IAQ Reference Manual 

Exhibit 8·6. Examples of chimney caps. 

Turbine 

Disc 

Swivel 

Joint 

Clay 

Chimney Pot 

Plate 

Cone with 

Spark Screen 

SOURCE: Shelton, J.W. 1979. Wood Heater Safety. Garden Way Publishing: Cadotte, VT. Used with permission. 

Section 8 
Section 8 IAQ Reference Manual 

Exhibit 8·7. Potential consequences when more than one appliance is connected to 

the same flue. 

Gas 

Water 

Heater 

Creosote buildup can dog chimney, with serious 

consequences for oil and gas appliances·connected to the 

same flue 

Air leaking info chimney through other appliances or their chimney 

connectors may cause more 

creosote accumulation and will 

result in holler and less controllable 

chimney fires, should such fires 

occur. 

Oil 

Furnace 

Accumulated creosote and ash 

may block furnace breaching 

~1 ,, 

··-.. -

... ., 

Chimney capaci~ even with dean 

chimney, may not be adequate to · handle all appliances together. 

~ Explosions in chimney of oil or gas fumes may blow out stovepipe or 

blow sparks out of air inlet 

\ 

Fumes from furnace may blow 

across chimney and cut through 

another appliance, or impede its 

venting 

Sparks originating elsewhere in 

system may come out through a 

fireplace or fireplace stove 

SOURCE: Shelton,J.W. 1979. Wood Heater Safety. Garden Way Publishing: Cadotte, VT. Used with permission. 
IAQ Reference Manual 

Exhibit 8·8. Combustion inspection form. 

Address: Date: 

HOME HEATING INSPECfiON CHECKLIST 

Fentml Heat: Present? y N 

Fuel Source: 

VISUAL INSPECTION 

Cover on Furnace y N 

Obvious Damage to Any Part y N 

Duct Work Connected y N 

Chimney in Good Condition y N 

Smell Fuel Source/Odor y N 

Registers Clean y N 

Loeation in BA or BR y N 

Cold Air Return Clean/Open y N 

Combustion Air Intake Blocked/ y N 

Dirty 

OTHER SOURCES OF HEAT 

(Specify) 

a) Unvented Gas Space Heater 

b) Kerosene Heater 

c) Gas Cooking Stove 

d) Fireplace 

WATER HEATER 

Present y N 

Gas y N 

If in Garage, 18 in Off Ground N/A y N 

Cover on· Water Heater y N 

Obv:ious Damage/Rust y N 

Located in BA or BR y N 

WOOD/COAL STOVES 

36 in Minimum Floor Protection y N 

Accessible to Children y N 

Combustibles 36 in Away y N 

<25 lbs L?8,s. S~ored Inside y N 

ASBESTOS MATERIALS (List location and note condition) 

Present 

Friable 

y 

y 

N 

N 

Operable? y 

If no, why not? 

(Turn on if not in operation at time of 

inspection, if possible.) 

FLUENENT 

Secure to Chimney y 

Correctly Sized y 

Secure to Furnace y 

Flue/Vent Slopes Upward y 

e) Vented Gas Space Heater 

f) Wood Stove 

g) Coal Stove 

h) ~lectric Space Heaters 

VENT 

In Good Condition y 

Slopes Upward y 

Connected Directly/Securely y 

to Chimney 

Chimney in Good Condition y 

Correctly Sized y 

Use Double/Triple Wall Flue y 

Flqe Correctly Sized y 

Sheet Metal Screws in Flue y 

SectionS 

N 

N 

N 

N 

N 

N 

N 

N 

N 

N 

N 

N 

N 

Comments and Code Violations:-----------------------------------

SOURCE: Adapted from Marion County Health Department (1988). 
Section 8 

Exhibit 8·9. Features of proper stove installation. 

SOURCE: Jenkins and Vacca (1979) 

Cf 

Securely fasten 

joint with sheet 

metal screws. 

IAQ Reference Manual 
IAQ Reference Manual 

Exhi.it 8·10 •. Suggested chimney sizes for residential wood~•urning equlpment.1 

APPLIANCE TYPE 2 

Small stoves4 

SUGGESTED INSIDE 

DIAMETER FOR 

ROUND CHIMNEYS 

OR FLUE LINERS 

(INCHES) 

4-6 

5-7 

Medium and large stoves4 6-8 

Fireplace stoves,3

•

4 

small fireplaces 

furnaces, boilers 

Medium fireplaces5 

Large fireplaces 5 

7-8 

8-10 

10 

10 

12 

15 

SUGGESTED 

RECTANGULAR 

FLUE DIMENSIONS 

(NOMINAL EXTERIOR) 

(INCHES) 

4x8 

8x8 

8x8 

8x8 

8 X 12 

8 X 12 

8 1/2 X 8 l/2a 

8 1/2 X 13b 

8 112 X 13c 

8 1/2 X 18d 

13 X 13e 

13 X 18f 

1 Additional sizes can be found in Sheldon (1979), Self (1980), or other handbooks. 2 Each type of appliance spans a range of collar sizes; thus location of type in table is approximate. 

Section 8 

3 A common rule of thumb for fireplace and fireplace-stove chimneys is that the cross-sectional area of the flue should be about 

1/10 of the area of the fireplace opening if the chimney is 15 feet or more in length from the hearth to the chimney top. If the flue 

is unlined or less that 15 feet tall, the needed flue size is l/8 of the fireplace opening. Bigger is not always better. Oversize flues 

tend to create less draft and accumulate more creosote. 

4 Shelton (1979) 

5 Self (1988) 

!" fireplace opening - 28" x 24" x (16"- 18") 

b fireplace opening (30" - 32") x 28" x 18" 

c fireplace opening 36" x 28" x 18" 

d fireplace opening - 42" x 28" x 18" 

e fireplace opening - 48" x 32" x (18" - 20") 

f fireplace opening - 54" x 36" x 20" 

SOURCE: Shelton (1979); Self (1988) 
Section 8 IAQ Reference Manual 

Exhibit 8·11. Safety guidelines for unvented gas·fired heaters. 

• Turn off the fuel valve whenever there is a strong fuel odor, and call for service. 

• Strike the match before the gas valve is opened. This prevents the possible buildup of fuel vapor 

which could easily ignite. If there is an accumulation of fuel vapor, sufficient time should be 

allowed to pass before relighting to dissipate the fuel. 

• Observe the flame to be sure it is adjusted properly. A yellow flame indicates incomplete combustion and will result in higher carbon monoxide and particulate levels. 

• Always keep a window partially open whenever a fuel-burning unvented space heater is in use. 

Adequate ventilation is needed to reduce contaminant levels and to replace oxygen that is used for 

combustion. One inch of open window space for every 10,000 Btu of heater rating is a general 

rule of thumb (equal to about 4 in2 for every 1,000 Btu of heater rating). 

• Never leave the heater unattended while it is in operation. Never use the heater overnight while 

people are sleeping. 

Exhibit 8·12. Safety guidelines for unvented kerosene heaters. 

TO MINIMIZE INDOOR AIR POLLUTION: 

• Use only water dear, or K-1 kerosene, as a fuel. K-2 kerosene and fuel oil have a grtllater sulfur 

content and will increase emissions. Never use gasoline because of explosion/fire hazards. Do not 

use kerosene that is yellow or that has been stored over a period of time (summer season). 

• Examine wicks and burners for excessive carbon buildup after burning 1 or 2 tanks of fueL 

Carbon buildup is indicative of inefficient combustion. 

• Do not operate the heater in confined areas such as bathrooms. Never operate the heater in 

bedrooms while people are sleeping. 

• Size the heater correctly for the space to be heated. A general rule of thumb for calculating the 

required Btu is to multiply the floor area by 28. The resulting number is an approximation; 

anyone who is contemplating the purchase of a kerosene heater should consult with the sales 

representative to more closely match the space to be heated with the correct size of heater. Avoid 

oversized heaters. 

• Always keep the wick at the proper setting. A wick that is too high or too low can significantly 

increase emissions. Do not "turn down" the flame in an effort to cool a room that is too hot. This 

will only decrease the efficiency of combustion and increase the emissions of carbon monoxide and 

particulates. Do not "turn up" the flame in an effort to generate more heat because this will 

increase the oxides of nitrogen. 
IAQ Reference Manual Section 8 

Exhibit 8·12. Safety guidelines for unvented kerosene heaters (tonllnuedJ. 

• ,Always provide adequate ventilation. Do not use heaters in a closed room. Some manufacturers · 

recommend using the heater in a room that is open to other rooms. Air exchange with other 

rooms in the house does not provide sufficient ventilation air. Fresh outside air must be provided. 

Windows should be opened at least 4 in2 for every 1000 Btu of heater capacity. 

• Consider other heating options if anyone in the house is ill, has allergies or asthma, pregnant, or if 

there are small children in the house. 

TO MINIMIZE SAFETY HAZARDS: 

• Do not leave kerosene heaters unattended. 

• Be sure there is sufficient clearance between the heater and combustibles. 

• Do not move the heater while it is burning or if the flame flares or appears to be uncontrolled. 

Turn off the heater, and if this fails or cannot be done, leave the area immediately and call the fire 

department. 

• Store kerosene in a container labeled "kerosene." Do not store other fuel in this container. Store 

fuel in a safe place, where children cannot reach it. 

• Do not store fuel inside ·the house. Fill heaters with fuel outdoors, never indoors. Never add fuel 

to a heater that is burning or hot. 

• Keep children away from kerosene heaters to protect them from touching hot surfaces. 

• Check the temperature of rooms where heaters are being used to be sure that rooms are not too 

hot. Temperatures over 100°F have been measured. 

REFERENCES 

American Society of Heating, Refrigerating, and Air Conditioning Engineers, Inc. (ASHRAE). 1989. 1989 ASHRAE 

Handbook. Fundamentals. l-P edition. ASHRAE: Atlanta, GA. 

Canada Morrgage and Housing Corporation (CMHC). 1988a. 

Residential Exhaust Equipment. EEE/ESC-88-35. CMHC: 

Ottawa, Ontario. 

Canada Mortgage and Housing Corporation (CMHC). 1988b. 

Chimney Safety Tests Users' Manual. Procedrtres for determining the 

safety of residential chimneys. 2nd edition. CMHC: Ottawa, 

Ontario. 

Council of American Building Officials (CABO). 1989. CABO 

One and Two Family Dwelling Code. CABO: Falls Church, VA. 

Faoro, R.B. andJ.A Manning. 1981. "Trends in benzo-

(a)pyrene, 1966-77." ]. Air. Poll. Cont. Assoc. 31: 62-64. 

Jenkins,]. and R. Vacca. 1979. "Wood for home heating. 

Safety and wood heating systems." G2936. Wisconsin Energy 

Extension Service: Madison, WI. 

Marion County Health Department. 1988. "Home heating 

inspection checklist." Bureau of Environmental Health, Health 

and Hospital Corporation: Indianapolis, IN. 
Section 8 

National Fire Protection Association (NFPA). 1988a. National 

Fnt/GasCOfk. NFPA54. NFPA:Quincy,MA. 

National Fire Protection Association (NFPA). 1988b. Chimm:ys, 

Firep/a(tf1 VtntJ, and Solid Fuel Burning Appliances. NFPA 211. 

NFPA: Quincy, MA. 

Ritchie, I.M. and L.A. Oatman. 1983. "Residential air 

pollution from kerosene heaters." J. Air Poll. Cont. Assoc. 33 

(91): 879-881. 

Ritchie, I.M. and F.C. Arnold. "Characterization of residential 

air pollution from unvented kerosene heaters." Indoor Air. Vol. 

4. Chemketl Characterization and Personal Expos11re. Swedish 

Council for Building Research: Stockholm, Sweden. pp. 253· 

258. 

Self, Charles R. 1982. Wood Heating Handbook. 2nd edition. 

Tab Books, Inc.: Blue Ridge Summit, PA. 

Shelton,J.W.1979. WoodHeaterSafoty. Garden Way 

Publishing: Cadotte, VT. 

Spengler, J.D. and M.A. Cohen. 1985. "Emissions from indoor 

combustion sources." Indoor Air and H11man Health. R.B. 

Gammage and S.V. Kaye (eds). Lewis Publishers: Chelsea, MI. 

Sterling, T.D. and E. Sterling. 1979. "Carbon monoxide levels 

in kitchens and homes with gas cookers." Air Poll. Cont. Assoc. 

29(3}: 238-241. 

Traynor, G.W.,J.R. Girman,J.R. Allen, M.G. Apte, A.R. 

Carruthers,J.F. Dillworth, and V.M. Marrin. 1983. "Indoor 

air pollution due to emisions from unvented gas-fired space 

heaters." LBL-15878. Lawrence Berkeley Laboratory: 

Berkeley, CA. 

U.S. Department of Health, Education, and Welfare (DHEW). 

1976. Betsk HoT1sit1g Inspection. HEW (CDC) 80-8315. U.S. 

DHEW, Public Health Service: Washington, DC. 

U.S. Environmental Protection Agency (EPA). 1990. Air 

Sftrvtillanufor Hazardo11s Materials. (165.4). U.S. EPA, Office 

of Emergency and Remedial Response: Cincinnati, OH. 

World Health Organization (WHO). 1987. Air Quality 

G11ide/inujor ETirope. European Series No. 23. WHO: Copenhagen, Denmark. 

IAQ Reference Manual 

8.3 INVESTIGATION TECHNIQUES FOR 

PESTICIDES 

A routine indoor air quality investigation 

should identify which pesticides are present and the 

potential hazards posed by storage and use practices. 

Education about the prudent control of pests can be 

an important goal of an indoor air quality program 

and individual inspections. Clients should be 

informed about potential hazards of products they 

store or use, encouraged to dispose of products 

which are used infrequently, and encouraged to ·use 

less hazardous products whenever possible. 

During an inspection, the investigator should ask if 

pesticides are used. If so, the following information 

should be obtained: 

• inventory of pesticides which are present; 

• frequency of use and the date of last use; 

• methods of storing, mixing, and disposal; 

• methods of application (for example, spray); 

• ventilation and personal protection used for 

mixing and application; and, 

• for termiticides and large area applications, 

date of application, method, and chemical 

(if known). 

The inventory should include questions to identify 

the use of products such as flea and tick collars, 

insect repellents, disinfectant sprays, no-pest strips, 

roach and rodent baits, insect sprays, and so forth. 

A request to see the location where these products 

are stored can reveal important information about 

storage practices. Products which are stored in areas 

where children have access should be relocated. Any 

evidence of spills or leakage requires removal and 

cleanup. Pesticide products which are in unmarked 

containers or those which are not in original 

containers should be disposed of properly. Any 

products which have been banned should be re-
IAQ Reference Manual 

moved and disposed of properly; a list of these 

pesticides can be obtained from the EPA regional 

office. 

The investigator should also determine the type of 

applicator that is or has been used (aerosol cans, 

foggers, bombs, handsprayers, pressurized hose 

sprayers, brushes/cloths, lawn or garden spreaders, 

hand dusters, or shake containers) and the procedures used to apply the products. If any of the 

equipment appears to be contaminated, the investigator should inform the client of the need to clean 

equipment after application and the procedures to 

be followed. 

Mixing and application practices are important 

factors that affect personal exposures during application and contamination of the indoor environment. 

Asking for a demonstration of how the client uses 

equipment and products (even aerosol or pump 

sprays) can somet.imes reveal more information than 

asking for a simple explanation of procedures which 

are followed. Attention should also be given to the 

ventilation which is provided and reentry after 

application. 

A history of the recent application of pesticides and 

flu-like symptoms should alert the investigator to a 

possible pesticide contamination problem. 

Termiticide Investigations 

Termiticides are applied to the soil in one of two 

ways. Pre-treatment (before a house is built) is done 

by trenching around the foundation. Remedial 

treatment is done by drilling, rodding, and sometimes by trenching chemicals into the soil. 

The levels of the termiticide that might result in 

the indoor air depends on the volatility of the 

termiticide, the method of application and route of 

entry, and environmental factors that affect the 

movement of air and degradation of the termiticide. 

A buildup of termiticide can result when the 

heating system becomes contaminated, when 

Section 8 

building is depressurized, or when there are entry 

points into the living spitee. 

If odors (even faint ones) linger more than a few 

days, structural problems or improper application 

should be suspected. 

All structural elements located between the treated 

soil and the inside of the building should be 

examined if possible. Typical problems include 

cracks or openings in the floor, ductwork in the 

crawl space which leaks, and holes around plumbing 

and utility lines in slab foundations. 

Misapplication problems can include accidental 

contamination of ducts, spraying termiticides onto a 

wooden structure, open or poorly sealed injection 

holes, not cleaning spills that occur during injection; transfer from one hole to another; and applying 

termiticides to areas which provide the termiticide 

access to theindoor air. Potential problem areas 

and mitigation methods are summarized in Exhibit 

8-13. 

Wells and drinking water can also become contaminated during termiticide applications. Common 

problems include wells that are not properly sealed, 

old cistern or dug wells that are not properly filled, 

and tree roots which act as channels for pesticide 

flow. If a well is located within the foundation, the 

house should not be treated with a termiticide. 

Contaminated wells require expert assistance. 

Crawl space coJ,ltamination problems 

If a crawl space is present and odors intensify when 

the heating or cooling system blower operates, the 

crawl space should be evaluated. Problems can 

come from several sources: 

1} openings in the floor between the crawl 

space and the living space; 

2} a furnace which draws combustion air from 

the crawl space; 
Section 8 

3) cold air return ductwork which has faulty 

seams or openings; 

4) contamination of joists, piers, and other 

subflooring members;' 

5) contamin~tion of insulation or water pipe 

wrapping; 

6) contamination of the surface soil of the 

crawl space; and 

7) ducting which uses joists and sheet metal 

and/or fiberboard to make the air channels. 

Termiticides should not be applied to crawl spaces 

when the crawl space is used as a hot or cold air 

plenum. 

lntra*slab or sub-slab contamination 

problems 

A lingering odor in a structure with intra-slab or 

sub-slab ductwork suggests that contaminants from 

the treated soil are entering the living space through 

openings, cracks, or deteriorated sections of 

ductwork. 

Termiticides should not be applied to sub-slab or 

intra-slab floors made with cardboard, defective 

metal, tile, cracked concrete, or fiberglass ducts. 

Application of pesticides in these areas is likely to 

result in duct contamination. 

Accidental injection of termiticide into the 

ductwork should be suspected if odors occur 

immediately after the termiticide has been applied 

and as a result of operating the blower on the 

heating and ventilating system. 

To investigate these problems, ventilate the home to 

clear odors. Then starting with the registers nearest 

to the blower, smell each vent to determine the 

source of the odor. Work from the blower outward. 

If an odor is detected from a particular vent, the 

duct near that vent is the most likely source. If the 

IAQ Reference Manual 

source of the odor cann~t be determined, each 

register should be removed and a light and mirror 

should be used to look for rusty or moisture-stained 

sections of the duct. 

Other surface contamination problems 

Any puddles, seepage, wet or moist surfaces in 

floors, walls, or insulation that have a chemical odor 

suggest contamination with a termiticide, if a recent 

application has occurred. Sampling may be required 

to verifY the contaminant. 

Measuring Pesticide Contaminants 

Pesticide measurements will probably not be taken 

during routine investigations of indoor air quality 

problems. As mentioned previously, a recent 

history of use, lingering chemical odors, and 

symptoms may be sufficent to diagnose a problem. 

There may be instances when measurements of 

pesticides will be useful and surface residues, 

airborne samples, or water can be collected and 

tested. Measurement of airborne residues provides 

as estimate of respiratory exposure to the pesticide; 

water samples and surface residues (soil, wood, 

furniture, household objects) can help identifY 

potential hazards and the sources of contamination. 

Procedures for air and residue samples are outlined 

below. Water samples should be collected as 

instructed by the laboratory doing the analysis. 

Air sampliqg 

Pesticide concentrations can be measured to determine if pesticides are present or to evaluate the 

efficiency of mitigation efforts. Collecting pesticide 

samples is relatively easy, but the analysis is complex and requires highly trained analysts and 

sophisticated equipment. Extreme care must be 

used to prevent contamination problems during 

all phases of sampling and analysis. 

Cooperative agreements between local and state 

agencies can generally be developed for analytical 

capability. Private consulting laboratories can also 
IAQ Reference Manual 

conduct sampling and analysis, but costs are high, 

generally $100 to $200 per sample. The laboratory 

must have a rigorous quality assurance program, and 

the analyst should be experienced not only with the 

general analytical technique, but should also have 

experience with pesticide analysis. 

EPA has developed a method for collecting and 

analyzing several pesticides in ambient and indoor 

air using low volume polyurethane foam (PUF) 

sampling with gas chromatography/electron capture 

detection (GC/ECD) (U.S. EPA, 1989a,b). Exhibit 

8-14 identifies pesticides which have been measured 

using this method. 

The indoor sample is collected by using a personal 

sampling pump to draw air through a polyurethane 

foam-cylinder that is slightly compressed into a 

borosilicate glass tube; these can be purchased 

assembled or fashioned by the user. The sample is 

collected by using low flow rates in the range 1 to 5 

lpm for sampling periods of 4 to 24 hours. Stationary or personal samples can be collected. Mter 

collection, the samples are extracted, concentrated, 

and analyzed using GC/ECD. Gas chromatography 

can also be followed by mass spectroscopy/multiple 

ion detection (GC/MS/MID) for confirmation and to 

quantify nonchlorinated compounds. 

Quality control procedures and proper technique are 

very important in this procedure to prevent the 

possibility of contamination. The laboratory should 

include field, process, and solvent blanks at a level 

of 5%. Blank levels should not exceed 10 nanograms (ng)/sample for single components or 100 ng/ 

sample for mixtures with multiple pesticides. 

Replicate determinations of collection efficiency 

should be made using spiked samples. Relative 

standard deviations for the replicate determinations 

of ± 15% or less are acceptable, and recoveries of 

75% are acceptable (U.S. EPA, 1989b). 

Air samples should be placed at the breathing 

height (3 feet to 6 feet above the floor) for the 

occupants. The sampler should be located at least 

12 inches from any obstacle to insure adequate air 

Section 8 

flow. Sampling is conducted at a rate of 1 to 5 

1/min., and the sampling pumps are calibrated 

before and after sampling in the laboratory. The 

collected samples should be refrigerated until 

analysis. 

Ideally, for complaint and emergency investigations, duplicate samples should be collected from 

each living area for a period of 4 hours to 24 hours. 

A field blank should be included if a single residence is sampled; if more than one residence is 

sampled, field blanks at a rate of 5% should be 

included (U.S. EPA, 1989b). 

Special Samples 

Wipe samples (sometimes called swipe or smear 

samples) can be collected from surfaces such as 

kitchen tops, floor surfaces close to walls and 

injection areas, furniture, walls, and other areas 

where contamination is suspected. Wipe samples 

should not be used in lieu of air samples, but they 

can provide useful information about sources and 

extent of contamination. EPA does not have 

guidelines for wipe samples, but wipe sampling 

procedures developed by OSHA can be used [(29 

CFR 1910.132(a)}. The OSHA procedure is not 

limited to pesticides. 

Clean gloves which are impervious to the contaminant should be worn during all phases of collection. 

Surface samples are collected by wetting Whatman 

42 (7 em) filter paper with acetone, water, or other 

solvent as recommended by the analytical laboratory) and wiping across the suspected area. 

The OSHA procedure is as follows: Moisten the 

filter paper with the solvent, and wipe an area of 

about 100 cm2

• Without allowing the filter to 

contact any other surface, fold it with the exposed 

side in, and then fold it over to form a 90-degree 

angle in the center of the filter. Place the filter, 

angle first, into a dean glass vial (provided by the 

laboratory to minimize contamination problems), 

replace the top, seal it, and send it to. the laboratory 

for analysis. A blank filter also moistened with 

solvent should be submitted in a separate vial along 

with the samples. 
Section 8 

The Wood Protection Council (1987) recommends a 

similar, somewhat abbreviated procedure; a filter 

size of at least 10 em x 10 em is recommended. 

Swipe samples should not be used on carpets or 

furnace filters; instead a 10 em x 10 em section of 

these materials should be collected (Wood Protection Council, 1987). 

Interpretation of Pesticide Data 

Interpreting measured air data can be difficult 

because of the lack of guidelines on acceptable 

concentrations of pesticides. The National Academy of Sciences reviewed the seven most frequently 

used termiticides in the U.S. and recommended the 

following guidelines: aldrin-1 J.Ig/m3; chlordane-5 J.Ig/m3; chlorpyrifos-10 J.Igfm3; heptachlor-2.00 J.Ig/m3 (NRC, 1982). The NAS also 

reviewed the data for lindane and pentachlorophenol, but guidelines were not suggested for these 

contaminants. 

In the absence of guidelines for the general population and the uncertainty about the long-term health 

effects of exposure to pesticides, a conservative 

approach is indicated. The presence of pesticides on 

swipe samples should prompt an investigation of 

possible sources and corrective action. The investigator should attempt to contact and consult with 

physicians in those instances where respiratory, · 

allergic, or other effects appear to be experienced by 

exposed individuals. Every effori: should be made to 

minimize pesticide exposures, even in situations 

where the complaint is limited to odors. 

Mitigation Advice for Pesticides 

General Advice 

It is almost impossible to eliminate pests entirely. 

Regular use of pesticides often initiates a vicious 

cycle of pesticide applications that are m<:Jre frequent and potent in order to maintain the same 

degree of control. The best control strategy is to 

prevent pests from invading in the first place and 

IAQ Reference Manual 

avoid the unnecessary use of pesticides. The use of 

nonchemical pest control methods (particularly 

proper hygiene and removal of food, water, shelter, 

and breeding sites) and maintaining healthy plants 

should be encouraged in place of c.hemical control 

methods. 

If pests become established, nonchemical controls 

may not be sufficient to correct problems, and 

pesticides may be necessary. The use of a combination of methods to control pests is called integrated 

pest management (IPM), and education programs 

which emphasize the prevention ofpest infestations 

and integrated pest management may be available 

from (or could be developed in conjunction with) 

county cooperative extension agencies. Useful 

sources of consumer information on pesticides are 

contained in Exhibit 8-15. 

When pesticides must be used, clients should be 

instructed verbally or by fact sheets about the safe 

use, storage, and disposal of pesticides. In general, 

if pesticide products have not been used during the 

preceding 6 months, the proper disposal of these 

products should be encouraged. (A communitysponsored free drop-off program for the disposal of 

household hazardous waste is an effective way to 

dispose of pesticides and other hazardous materials 

that may be found in the home.) If professional 

applicators are hired, consumers should ask what 

products will be used, what potential health effects 

could result, and what reentry times are needed. 

Exhibit 8-16 contains a list of safety tips for the 

safe use of pesticides in the home. This list can be 

modified easily for other applications. 

Pesticide Spills, Improper Applications, 

and Odors 

If pesticide spills occur in or around the home or 

office, quick action is important. The investigator 

should be prepared to respond if he/she is on scene 

and emergency help is not-available. Exhibit 8-17 

provides guidelines for administering first aid in 

emergencies. 
IAQ Reference Manual 

When spills or accidents occur, the basic response 

includes stopping the sou~;ce, containing the 

pesticide, securing the area, obtaihing first aid if 

needed, removing excess pesticide, cleaning the 

area, disposing of waste, and evaluating the area 

after cleanup. Proper respiratory protection (organic 

vapor and particulate cartridges) and clothing 

(impervious gloves, apron, and shoes; disposable 

coveralls) must be worn during all phases of cleanup 

and residue removal. These should be part of the 

investigator's field equipment. General guidelines 

for cleaning spills and residues which can be given 

to clients as part of an education program are 

summarized in Exhibit 8-18. 

One problem related to pesticide application is 

premature reentry. Safe reenti:y times vary depending on the product, and these must be followed as 

specified by the manufacturer to prevent accidental 

poisonings. · 

If professional applicators are responsible for 

improper applications, they should be contacted to 

provide remedial assistance. If pesticides have been 

applied and odors linger, the area should be ventilated and checked for the presence ofliquid pesticide. If present, liquids should first be absorbed, 

then removed. Manufacturers of products should 

also be contacted to obtain information on proper 

mitigation. Sampling should be conducted to verify 

the effectiveness of ventilation and cleanup. 

Methods for mitigating termiticide contamination 

are given in Exhibit 8-13. 

Pest Management Indoors 

There are some rypes of products that consumers 

could replace with other control measures in order 

to reduce their exposure to pesticides. Solid baits 

can provide a safer alternative ·to sprays, and pumps 

that deliver larger droplets can provide more control 

than aerosolized products. The use of pesticide 

strips (containing propoxur; chlorpyrifos, diazinon) 

and paint-on formulations have been suggested as 

safe alternatives to sprays because sprays (aerosol or 

SectionS 

·compressed) are likely to result in higher concentrations of contaminants compared to paint-on formulations or strips. A two-fold increase was observed 

in one study (Ware and Cahill, 1984). 

Pest strips, however, still release pesticides into the 

living space and over a longer period of time 

because they are formulated as controlled releases. 

A safe alternative to pest strips are sticky paper 

strips which are coated with a sugar attractant 

instead of pesticides. 

The use of insect repellents (containing DEBT or 

other active ingredients) which are applied as a 

lotion 'or spray should not be used on infants and 

young children because of potentially serious health 

effects. 

There are many simple, but often effective, 

nonchemical pest control methods which can be 

used in and around residences. Hand removal, 

vacuuming, and the use of a flyswatter can control 

many flying and crawling insects .. Maintaining 

healthy plants and thorough washing of stems and 

leaves at the first sign of some pests can minimize 

pest problems.on plants. Ants can usually be 

controlled by removing visible ants and eliminating 

all food sources. Diatomaceous earth or a mixture of 

boric acid and sugar can be effective controlling 

roaches, ants, and blister beetles. Rats and mice can 

be controlled by ratproofing structures; Vitamin 

D3 pelleted bait can also be effective. Infestations 

of fleas ·can often be controlled by thorough vacuuming of floors, carpets, and upholstery, followed 

by shampooing. All removable bed and furniture 

coverings should be laundered. Heavy infestations 

may require two of these cleanings, or the use of 

pesticides. 

In general, removing food and water and eliminating shelter and breeding sites are fundamental 

principles to be encouraged. 

Removing food and water sources: All pests need 

food and water to survive, and an important step in 

controllipg pests is to remove needed nutrients. 
Section 8 

Standing water can be eliminated from the home by 

fixing leaky plumbing, removing water collectors 

such as tires from yards, correcting drainage problems, and by removing standing water from trays 

under houseplants. Food sources should also be 

removed. Foods (including pet foods) should be 

stored in sealed containers and should not be 

allowed to stand open for long periods of time. 

Garbage should be placed in tightly covered, heavygauge garbage cans and stored outside. 

Eliminatitzg shelter and breeding sites: Shelter 

and breeding sites can be eliminated by sealing 

cracks and crevices to keep pests from entering the 

building, removing wood and paper debris from the 

yard or under houses in crawl spaces, removing 

standing water, maintaining relative humidity 

below 50% in all areas, and removing pet feces. 

Pest Management Outdoors 

Pesticide use can be reduced significantly by 

keeping grass, yard, and garden plants healthy. 

Healthy plants can be grown by planting new plants 

at the right time of the year to minimize the stress 

of transplantation; watering adequately, but not 

overwatering; and applying mulch to retain moisture, reduce weeds, and maintain even soil temperatures. If pests become well established in gardens, it 

may be necessary to apply pesticides judiciously 

according to instructions on the label. Only the 

minimum required for the job should be used. For 

example, instead of applying an herbicide to an 

entire lawn, weeds can be individually spot-sprayed. 

This can dramatically reduce the amount of pesticide that is applied. 

A new industry is emerging to support and foster 

sustainable gardening and agriculture through 

integrated pest management which focuses on 

preventive cultural practices and nonchemical 

IAQ Reference Manual 

controls. The careful selection of disease-resistant 

seed or plant varieties, ,using plant (crop) rotation 

and diversification, and ensuring good drainage and 

soil aeration are important cultural practices which 

can help prevent pest infestations. Other cultural 

strategies include using "trap" plantings to lure 

pests away from vulnerable plantings, planting 

companion plants which have insect-repellent 

properties, and spacing plants properly. 

Nonchemical alternatives must be tailored to the 

individual pest and location of the problem. Biological controls include using beneficial birds, 

insects, and pathogens such as bacteria, viruses', and 

other microorganisms to limit the pest population 

(Exhibit 8-19). Other biological control methods 

·include pheromones (sexual attractants which lure 

the pest to the trap), release of sterile males, and 

hormones to inhibit the growth of juvenile pests. 

Physical controls can also effectively reduce pest 

populations. A simple, but effective measure for 

residential lawns and gardens is to handpick pests 

from gardens and flowers, and weeds from lawns 

and gardens. Some other examples of physical 

controls include traps to remove insects and rodents, 

vacuums to remove insects from crops, screening 

living spaces to limit mosquito and fly access, and 

the use of oils to prevent mosquito larvae from 

growing to adulthood. 

Healthy lawns, gardens, or commercial crops can be 

achieved through the use of nonchemical controls .. 

While nonchemical pest control generally requires 

more work, attention to timing of the application of 

methods, and a longer period of time for results, 

these methods do not pose a hazard to humans or 

pets. In addition, pesticide-resistent populations are 

not created, and special clothing and respirators are 

not required for application of pesticides. 
Exhibit 8·13. Sources of termiticide contamination and potential mitigation methods. 

GENERAL 

1) Call the man\lf(lcturer for specific information about the appropriateness and 

likely success of a particular method, required personal protective equipment, 

cleaning agents, and other procedures. 

2) Conduct air monitoring after mitigation to determine whether or not the 

method was successful. 

CRAWL SPACE 

1) contaminated crawl space 

• install vents if none exist 

• install fans to create a slight vacuum in the space; fans should be 

installed away from the furnace and ducts inside the space; air should be 

exhausted away from air conditioners, windows, and doors 

• remove contaminated soil; install a plastic vapor retarder-over the soil 

surface and use untreated soil to seal the edges 

• correct site grade problems or install drainage tiles to divert excess soil 

moisture 

• pour a concrete slab at least two inches thick over the soil within the 

crawl space 

2) termiticide enters through faulty ductwork 

• insure that any outside combustion air supply is not located in the crawl 

space 

• repair any, cracks. or openings in the duct work and seal joints with duct 

tape 

• seal or remove ductwork and install an attic ducting system 

INTRA-SLAB OR SUB-SLAB DUCI'WORK 

1) termiticide enters through openings, crack, or deteriorated sections of the 

ductwork 

• install air filters at furnace intake ducts and at the floor vents; a qualified 

contractor should be used; actitivated charcoal filters or polyurethane 

foam (60 pores/in) can be tried; filters should be changed every two 

weeks initially and less frequently after odors are reduced 

• sleeve the ducts by inserting a new liner; a qualified contractor should be 

used 

• plug all duct openings and seal with concrete at least 12 in on both sides 

of vent registers; install an above-floor duct system 

2) termiticide has been injected into ductwork 

• for limited problem, remove affected section and replace with new 

ducting 

• for significant contamination, seal all duct openings with concrete; 

install an above-slab heating system 

FOUNDATION WALL SEEPAGE AND ODORS 

1) termiticide enters through cracks or openings in subflooring members above 

the foundation walls 

• seal all drilled application holes in foundation walls and pillars with 

concrete patching . . 

• cap hollow foundation blocks by filling the top row of blocks with 

expandable polyurethane foam or concrete; the tops can also be coated · 

with roofing cement, followed by a strip of roofing paper on the cement; 

the roofing paper is held in place with a wood strip over the paper which 

is toenailed in place 

2) termiticide seeps through hollow block or masonry wall and causes damp or 

wet surfaces 

• wash and rinse until the wall is clean; apply a commercial basement 

sealer when the wall is dry 

• install drainage tiles and a sump pump 

• correct surface grade 

3) termiticide enters through cracks or openings in the hollow or masonry wall 

• cracks should be cleaned as above, sealed with a silicone-based caulk and 

painted over with polyurethane or silicone-based paint 

~ONTAMINATION OF NON-TARGET SURFACES 

1) joists, piers, and other subflooring members are contaminated 

• wash the affected subflooring and rinse; repeat several several times 

• remove.the affected areas and replace with new materials 

2) insulation is contaminated 

• remove and install new insulation 

SOURCE: Velsicol Chemical Corporation (undated); Velsicol Chemical Corporation (1984); Dow Chemical Corporation (1985) 
Section 8 IAQ Reference Manual 

Exhibit 8·14. Pesticides that can be measured using low volume PUF sampling with 

GC/ECD. 

Aldrin 

p,p,-DDT 

p,p,-DDE 

Dieldrin 

Dicofol 

2,4,5-Trichlorophenol 

Pentachlorophenol 

BHC (- and-hexachlorocyclohexanes) 

Cap tan 

Chlordane, technical 

Chlorothalonil 

2,4,-D esters 

ORGANOPHOSPHOROUS 

Chlorpyrifos 

Diazinon 

Dichlorvos (DDVP) 

Ethyl parathion 

Malathion 

Methyl parathion 

Ronnel 

CARBAMATES 

Bendicarb 

Carbaryl 

Carbofuran 

Mexacarbate 

Propoxut 

Allethrin 

d-trans-Allethrin 

Dicrotophos 

Fenvalerate 

SOURCE: U.S. EPA (1989b) 

ORGANOCHLORINE 

PYRETHRIN 

Methoxychlor 

Mexacarbate 

Mirex , 

trans-N onachlor 

Oxychlordane 

Pentachlorobenzene 

Folpet 

Heptachlor 

Heptachlor epoxide 

Hexachlorobenzene 

Lindane (-BHC) 

UREAS 

Chlortoluron 

Diuron 

Fluormeturon 

Linuron 

Tebuthiuron 

TRIAZINE 

Atrazine 

Propazine 

Simazine 

Pyrethrin I 

Pyrethrin II 

Resmethrin 
IAQ Reference Manual Section 8 

Exhibit 8·15. Useful sources of information on pesticides. 

The following publications are available on request from EPA, Office of Pesticide Programs (TS-766C), 401 

M Street, S.W., Washington, DC. 20450. Additional publications and sources of information are also 

available from EPA. 

• Pesticide Fact Book. Brief summary of EPA pesticide regulatory program. 

• Labeling Fact Sheet. Brief description of EPA requirements for the contents of a pesticide label. 

• Pesticide Safety Tips. Suggested safety tips for consumers. 

• Suspended, cancelled, and restricted pesticides. List of pesticides which are no longer available to the 

public. 

• Recognition and Management of Pesticide Poisoning. Reference manual for health care professionals which 

categorizes pesticides according to toxicity, describes symptoms or signs of poisoning, gives information for confirming diagnosis, identifies antidotes. 

• List of Pesticide Fact Sheets. Lists the different fact sheets that EPA has developed for specific pesticides. 

• Citizen's Guide to Pesticides. Provides general and specific information on the safe use of pesticides and 

an overview of EPA's regulatory programs for pesticides. 

Other Resources 

Bio-Integral Resource Center (BIRC) 

P.O. Box 7414 

~erkeley, CA 94707 

Natural Resources Defense Council 

Toxic Substances Information Line 

(1-800-648-6732) 

Rachel Carson Council, Inc. 

8940 Jones Mill Road 

Chevy Chase, MD 20815 

BIRC publishes a journal, Common Sense Pest Control 

Quarterly, which focuses on the least toxic alternatives to pesticides and pamphlets on specific 

pesticide problems. 

NRDC has additional information on hazards of 

toxic substances. 

This organization has information about pesticides 

and lawns. 
Section 8 IAQ Reference Manual 

Exhibit 8·16. Guidelines for using pesticides safely. 

GENERAL PRECAUTIONS 

• Identify the pest to be controlled and select a pesticide which is effective on that pest; help can be 

obtained from county extension agents or supply houses. 

• Select the least toxic product that has the required active ingredient-help can be obtained from your 

state agencies or EPA regional offices. 

• Do not use restricted pesticides. These are especially dangerous and should only be used by a certified 

applicator. 

• ¥ake sure the product bears an EPA registration number. 

• Look for the signal words on the front of the label and observe warnings: 

DANGER, POISON (Skull &. Crossbones)- "Fatal (poisonous) if inhaled." 

"Do not breathe vapors." 

WARNING- "May be fatal if inhaled." "Do not breathe yapors." 

CAUTION- "Harmful if inhaled." "Avoid breathing vapors." 

CAUTION- (no additional signal words required) 

• Read the entire label for correct application technique, timing of the application, precautions, and 

treatment measures. (Failure to use pesticides in accordance with label directions is subject to civil 

and/or criminal penalties.) 

• Use with adequate ventilation. 

• Use protective clothing and respirators as recommended. Paper masks, canvas, leather, and fabric do 

not provide protection. Information on protective equipment can be obtained from safety supply 

houses, local, or state agencies. 

• Prepare only the amount needed for each application--do not use or store extra material. 

• ·If the pesticide requires mixing or dilution, do this outdoors. Be sure that the product will not 

become airborne because of wind. 

• Keep children and pets away from areas where pesticides are mixed, used, or stored. 

• Never smoke while using pesticides. Some formulations are flammable and residues on the hands can 

be carried to the mouth. 
IAQ Reference Manual Section 8 

Exhibit 8·16. Guidelines for using pesticides safely (tonfinuedJ. 

• Do not transfer pesticides to containers, such as empty soft drink bottles, which were not intended for 

them. 

• Do not store pesticides in living areas. Store outside living spaces, in the original containers, and in 

secure areas not subject to flooding. 

• Shower and shampoo thoroughly after using a pesticide product. Wash all clothes that were worn 

separately from the family laundry. Also, rinse boots and shoes. 

• Clean up spills promptly. Do not wash spills with water. Instead sprinkle with kitty litter, sawdust, 

or vermiculite; sweep into a plastic garbage bag; and dispose with the rest of the trash. Follow 

product instructions for further cleanup. In the absence of instructions, call the local or state poison 

control center. 

• Triple rinse tools or equipment that have contacted the pesticide. This should be done in a toilet or 

sink taking care not to splash water. 

DISPOSAL 

• Follow label directions. 

• Determine if local regulations allow pesticides to be disposed of with municipal waste. Strictly 

comply with local regulations. 

In general, if local regulations allow the disposal of pesticides with municipal wastes, unused containers can be 

handled as follows: Be sure that container caps are tight, then wrap the containers or packages in several layers 

of newspapers and tie securely. Place the package into a covered trash can for collection along with household 

wastes. 

• Empty pesticides containers are hazardous. Handle as above. Do not puncture pressurized containers. 

• If there is no regular trash collection, crush and then bury empty containers at least 18 inches deep in a 

place away from water sources, where food is grown, or where children may play. 

• Do not burn pesticide containers inside or outside of the home. Hazardous fumes, gases, or explosions 

could result. 

• Do not pour unused portions of pesticides dowq the sink! Pesticides can interfere with the operation 

of septic systems and can contaminate waterways. 

(continued next page) 
SectiotzB IAQ Reference Manual 

Exhibit 8·16. Guidelines for using pesticides safely (folltlaued}. 

INDOOR APPLICATIONS 

• Remove all food, dishes, utensils, food wrappings, pots and pans before treating kitchen cabinets. Do 

not let pesticides come in contact with these items. Wait until shelves are dry before refilling them. 

• Make sure that adequate ventilation is provided when applying pesticides indoors. This means fresh 

outdoor air! Vacate the house for at least the length of time given by the label. 

• If pesticides are sprayed outdoors, dose the doors and windows of the home and keep them dosed for 

several hours after spraying. Fresh air intakes should be dosed. 

• Apply surface sprays only to limited areas. Do not treat entire walls, floors, or ceilings. Be sure to 

remove pets and cover aquaria and fishbowls. 

OUTDOOR APPLICATIONS 

• Never spray or dust on windy days. 

• Do not use spray nozzles that deliver a fine mist; a coarse droplet spray is less hazardous. 

• When spraying or dusting outdoors cover fish ponds and avoid wells. 

• Do not spray nontarget plants; use only the smallest amount of pesticides needed to do the job. 

Overspraying can contaminate water supplies and leave harmful residues on home-grown produce. 

• Do not spray plants which are in bloom. 

PERSONAL APPLICATIONS 

• Do not use sprays or lotions on infants or toddlers. Use of these products on small children can result 

in health problems, and the long term health effects are not known. Use these products cautiously on 

older children. Do not use these products routinely. Do not use pesticides on pets which are kept 

indoors. 

LOCAL EMERGENCY TELEPHONE NUMBERS 

Poison Control Center: 

Physician: 

SOURCE: Adapted from U.S. EPA (1987) 
IAQ Reference Manual Section 8 

Ex.ibit 8·17. First aid guidelines for pesticide poisonings. 

GENERAL GUIDELINES 

• Avoid direct contact with heavily contaminated clothing, gloves, or bodily excretions. 

• Give first aid, if it can be rendered without contaminating the responder. 

• Call for immediate emergency aid or transport the victim to a medical facility. 

• Provide accurate information to medical personnel. Do not rely on memory. Bring pesticide containers (with 

labels attached} with the victim. Do not transport pesticide containers in the passenger space. Transport 

containers in the trunk of the vehicle. If medical help is coming, have the pesticide container available. 

• Determine appropriate actions from the "Statement of Treatment" on the container if it is available. If the 

container is not available, contact a poison control center, emergency room, or the National Pesticide Telecommunications Network (1-800-858-7378). 

DERMALOREYECONTACT 

• For skin or eye contact, flood with water and remove contaminated clothing. Wash affected skin and hair with 

soap and water. W eat rubber gloves to prevent secondary contamination. Dry and wrap the victim until 

medical assistance arrives. 

• Do not administer ointments, drugs, eye drops, or other preparations. 

INHALATION 

• Do not attempt rescues in contaminated areas unless protective clothing, respirators, and a "buddy" are available. Call for emergency assistance instead. 

• If the area is not contaminated, move the victim to fresh air immediately. 

• Loosen clothing and give CPR if the victim is blue or is not breathing. 

INGESTION 

• If the victim is unconscious, be sure that no further exposure will occur via skin contact or inhalation. Get 

emergency aid immediately. Do' not attempt to induce vomiting if the victim is unconscious or has convulsions. 

• A conscious victim should rinse his/her mouth with plenty of water and drink up to one quart of milk. Emergency help should be called and information should be obtained to determine if vomiting should be induced. 

Vomiting should not be induced if the poison is corrosive, an oil solution, or an emulsifiable concentrate. 

• Aspiration of vomitous into the lungs is a potentially life-threatening situation, and the victim should be 

monitored carefully to prevent this possibility. 

SOURCE: Morgan (1989); U.S. EPA (1987) 
Exhibit 8·18. Guidelines for cleaning pesticid,e spills and residuesa. 

1) STOP THE SOURCE 

• Stop leaking application rods by shutting off the pump and releasing 

hose pressure. Place the leaking rod into a waste container. 

• Right containers only if it can be done without contamination or if 

protective equipment is available. 

2) CONTAIN THE PESTICIDE AND SECURE THE AREA 

• Prevent spilled liquids from spreading by adsorbing with spill control 

pillows, paper towels, and cat litter. (Cat litter that contains bleach can 

cause stains in some materials). 

• Prevent people and pets from entering the area until the cleanup has 

been completed and determined to be successful. 

3) REMOVE EXCESS PESTICIDE 

• Soak up excess liquid with commercial spill control material, cat litter, 

paper towels, sawdust, or soiL Approach the spill from the outer edges 

and work toward the center. Sweep the contaminated material into 

heavy duty plastic bags. 

• Sweep solid pesticides into plastic bags. 

4) CLEAN UP THE AREA 

• Large areas or the cleanup of liquid pesticides which have dried onto 

porous surfaces such as unfinished concrete or wood flooring require 

expert assistance. 

• Small .areas should be washed using a soft bristle brush and heavy-duty 

detergent followed by rinsing with clean water. Used detergent and 

rinse water should be removed to a separate container befure washing 

and rinsing again. 

5) VENTILATE THE AREA 

• Ventilate the area after the cleanup has been completed by opening 

doors and windows for several hours or more depending on the extent of 

the spilL 

6) REMOVE PESTICIDE RESIDUES 

• Minimize pesticide residues on unfinished wood or concrete by applying 

twO coats of sealant after the area has been washed and rinsed. If large 

areas are-involved, the material should be removed. Sealants which seem 

to be effective include polyurethane and epoxy. Latex painrs should not 

be used. 

• Washing will remove small spills of pesticides from most vinyl flooring. 

If the pesticide penetrates beneath the tile, the tile and the underlying 

floor should be removed and replaced. In some instances it may be 

possible to simply wash and rinse the undedayment and replace only the 

floor tile. 

• If a pesticide is spilled or sprayed on carpeting or padding, they should 

be removed and replaced. Steam cleaning should not be used. 

• Plaster walls and other porous wall surfaces should be washed and rinsed 

to remove residues. Iflarge areas are affected, removal is necessary. 

• Clothing should be washed separately using hot water and the maximum 

wash time. Presoaking and repeat washings may be needed. In the case 

of small spills, it may be possible to professionally clean drapery and 

upholstered furniture (the cleaning company should be informed of the 

pesticide residue). If the affected area is large or if the pesticide has 

penetrated into batting materials, disposal is needed. Other household 

goods such as dishes, silverware, and applicances can be washed and 

rinsed to remove residues. 

7) DISPOSE OF WASTE MATERIALS 

• · -Dispose-of waste according to local, state, and federal regulations; 

8) POST CLEANUP EVALUATION 

• Evaluate the effectiveness of cleanup procedures by monitoring the air. 

aNo action should be attempted without proper protective equipment and clothing. 
IAQ Reference Manual Section 8 

Exhibit 8·19. Examples of biological control of pesticides. 

BENEFICIAL ORGANISM 

ladybugs 

predatory mites 

lacewing larvae 

Trichogramma pretiosuml 

Trichogramma minutum 

(wasps which will 

not bother humans) 

Encarsia formosa 

Cryptolaemus 

Pediobious frwelolatus 

(wasps) 

Bacillus thuringiensis 

(bacteria) 

Bacillus thuringiensis 

israelensis 

(bacteria) 

Nosema locustae 

(disease spore) 

Milky SJ:_o.Je-rfisease 

TARGET PEST 

aphids, mites, and other soft bodied pests 

spider mites, greenhouse mites 

aphids, mealybugs, leafhopper nymphs, 

mites, caterpillar eggs, thirps, scales 

eggs of corn borer, cabbage looper, 

cutworm, codling moth, budmoth, 

leafroller, and many caterpillars 

whiteflies 

mealybugs 

Mexican bean beetles 

cabbage looper, imported cabbage 

worm, tomato hornworm, diamond-back 

moth, gypsy moth, fruit maggots, cotton 

bollworm, tent caterpillars 

mosquito, blackfly midges 

grasshoppers 

Japanese beetle grubs 
SedionB 

REFERE_.CES 

Dow Chemical Company. 1985. Dursban Odor Reduction and 

De<~ctivation. Dow Chemical Company: Midland, MI. 

Morgan, D.P. 1989. Recognition and Management ofPesticitk 

Poisoningr. 4th edition. EPA-540/9-88-001. U.S. Environmental Protection Agency, Office of Pesticide Programs: 

Washington, DC. 

National Research Council (NRC). 1982. "An assessment of 

the health risks of seven pesticides used for termite control." 

National Academy Press: Washington, DC. 

U.S. Environmental Protection Agency (EPA). 1987. A 

Consumtr's Guide to Safer Peslicitk Use. OPA 87-013. U.S. EPA: 

Washington, DC. 

U.S. Environmental Protection Agency (EPA). 1989a. 

Compmdium Method.T0-10. "Determination of pesticides in 

ambient air using low volume polyurethane foam (PUF) 

sampling with gas chromatography/electron caprure detector 

(GCIECD)." U.S. EPA, Office of Research and Development: 

Research Triangle Park, NC. 

U.S. Environmental Protection Agency (EPA). 1989b. 

"Determinacion of organochlorine pesticides in indoor air." 

Chap. IP-8. Compendium of Methods for the Determination of Air 

Pollutants in Indoor Air. Draft. U.S. EPA, Atmospheric 

Research and Exposure Assessment Laborarory: Research 

Triangle Park, NC: 

Velsicol Chemical Corporation. 1984. Safo Application is No 

A«ident. Ruidue Management Guitk for Professional Pest. Control 

Operators. Velsicol Chemical Corp.: Jefferson, WI. 

Velsicol Chemical Corporation. (undated). Termiticide Cleanup 

Manual. Velsicol Chemical Corp: Jefferson, WI. 

Wood Protection Council. 1987. Indoor Sampling Guitkline.r for 

Tmnitkidu. National Institute of Building Sciences: Washington, DC. 

IAQ Reference Manual 

8.4. INYESTI~ATION TECHNIQUES FOR 

, FORMALDEHYDE AND OTHER 

·voLATilE ORGANIC COMPOUNDS 

Investigation Techniques for 

Formaldehyde (HCHO) 

Any new or recently remodeled home or 

office area can be a potential source ofHCHO. 

Although there has been a shift away from particleboard/plywood construction in manufactured homes 

(mobile homes), these homes may still have HCHO 

concentrations which are of concern. The age of the 

structure or time since remodeling is important 

information because HCHO emissions are known to 

decrease over time. The emission rate appears to 

decrease rapidly (probably due to the release of free 

HCHO) just after manufacturing of the HCHOcontaining product. The rate then decreases more 

slowly over a period of months or years. 

Several monitoring and modeling studies have been 

conducted in an attempt to determine the decay rate 

of HCHO. In general estimates range from a halflife of several months to over 5 years. Indoor 

concentrations of HCHO from urea formaldehyde 

foam insulation (UFFI)'and other urea-HCHO 

products depend on changes in ventilation rate, the 

operation of air cleaners, indoor and outdoor 

temperatures, and humidity. The rate of release of 

HCHO from UFFI and other urea-HCHO products 

increases with the temperature, wood moisture 

content, humidity of the surrounding air, and with 

decreased HCHO concentrations in the surrounding 

air (Fisk et al., 1987). HCHO also demonstrates 

diurnal and seasonal variations. HCHO concentrations vary by as much as 50% throughout the day 

and are higher during the summer than during the 

winter (Gammage and Gupta, 1989). 

CPSC staff reviewed data for HCHO emissions from 

particleboard and concluded that a rapid decrease in 

HCHO concentration occurs during the first year 

followed by a "semi-steady" emission rate for at least 

the next four years (CPSC, 1986). CPSC staff 

concluded that there were insufficient data to 
IAQ Reference Manual 

evaluate the decay rates ofHCHO after five years. 

HCHO in mobile homes has been reported to have a 

half-life of about 4-5 years (Cohn et al., 1984). 

One of the first activities in the investigation of 

potential HCHO problems is identifying possible 

HCHO-releasing materials, the age of these materials, and time periods when symptoms appear to get 

worse or better. Because HCHO levels can vary 

diurnally, it is important to characterize adequately 

when and where symptoms occur along with 

occupant activities so that sampling will identify 

worst-case exposures. It should be remembered that 

susceptibility to HCHO varies widely-it is 

possible for some family members to experience 

effects daily, while others are not affected at all. 

Symptoms can vaty from person to person, and 

usually no one has all symptoms. 

Recognizing Formaldehyde•containing 

Materials 

The most likely sources of HCHO (pressed wood, 

particleboard, hardwood plywood, and UFFI) can be 

recognized visually in many instances; Other 

sources which can contribute to elevated indoor 

concentrations and health effects are more difficult 

to recognize visually, and a process of elimination 

may be required to evaluate their impacts. 

In new homes the most likely sources of HCHO are 

those which contain pressed wood or particleboard. 

CPSC staff estimated that about 24% of new singlefamily detached house construction uses some type 

of urea-HCHO pressed wood material (CPSC, 

1986). In new single-family detached homes, 

particleboard may be used as underlayment over a 

softwood plywood (not a urea formaldehyde resin 

product). The particleboard underlayment mighr 

be used throughout the entire house or only in the 

kitchen and bathrooms. The underlayment may be 

covered by carpeting, carpet padding, ceramic tile, 

resilient flooring, and solid hardwood coverings 

which generally reduce emissions into the living 

space, but higher levels of HCHO can still occur. 

Section 8 

The presence of particleboard underlayment can be 

confirmed by lifting the floor covering to expose the 

material underneath (this should be done in an 

inconspicuous area). If the home has floor registers, 

these can be removed and the wood material can be 

inspected. 

Waferboard and oriented-strand board can also be 

present as subflooring material. These products use 

phenol-HCHO as the bonding material and do not 

produce significant HCHO emissions. Waferboard 

and oriented-strand board are characterized by large 

wood flakes in contrast to particleboard which is 

produced from small flakes. 

Cabinets and furniture made of wood products can 

be additional sources ofHCHO. Today's kitchen, 

bathroom, and other "wood" cabinets are typically 

made of wood products-not solid wood. Even top 

grade products advertised as solid wood usually have 

medium density fiberboard (MDF) shelves covered 

by hardwood plywood. In top grade cabinets, wood 

products are used as shelving because solid wood is 

more likely to warp when in contact with moisture. 

These products may have an alkyd urea-HCHO 

finish. Less expensive cabinets usually have a core of 

MDF which is covered by hardwood plywood, vinyl, 

or a paper overlay. Exterior doors of this product 

grade are usually solid wood or hardwood plywood. 

The least expensive grades of cabinets usually have 

all parts made of MDF covered by vinyl or paper 

overl!;ty. 

Lower grades of furniture are typically constructed 

from particleboard or MDF with a paper overlay; 

some components may be plastic. Medium to 

higher grade furniture might be constructed. of 

particleboard or MDF with an overlay of hardwood 

veneers. The particleboard or MDF components can 

usually be identified by examining unfinished 

exposed areas such as the underside of tables, chairs, 

or other pieces. All grades of furniture and some 

hardwood floors may be finished with alkyd ureaHCHO finishes which can increase indoor HCHO 

levels. 
Section 8 

Another important source of HCHO indoot:S is urea 

formaldehyde foam insulation (UFFI); homes 

insulated with UFFI can be recognized by sealed 

openings in the exterior siding which were used to 

inject the UFFI. This clue can, on occasion, be 

misleading because cellulose insulation is also blown 

into similar openings. Another problem is that 

openings may not be visible if the exterior siding 

was replaced. 

If openings are present, a screwdriver or similar tool 

can be used to lift the opening cap or mortar and 

inspect the material underneath. UFFI may be 

present if the material is soft, spongy to granular in 

texture, and white to brown in color. If exterior 

openings are not visible, the presence ofUFFI can 

be evaluated by removing and inspecting electrical 

outlets which are· located on exterior walls. Studies 

of the release of HCHO from UFFI products show 

that even if UFFI is installed under optimum 

conditions, the products can still emit significant 

HCHO and interior levels ofHCHO can be elevated 

for long periods of time. 

In the past, manufactured housing had HCHO 

levels that were significantly higher than conventional housing. This was due to the greater use of 

HCHO-emitting materials in construction and the 

high surface to volume ratio of these homes. In an 

effort to reduce HCHO levels, construction techniques have shifted to include the use of gypsumboard panels rather than plywood paneling. However, manufactured housing is still constructed with 

particleboard decking, and the cabinets and furnirure in these homes are still likely to be made of 

particleboard, hardwood plywood, or MDF. 

Measuring Formaldehdye 

There are many different methods available for 

measuring HCHO concentrations including 

personal and s.tationary methods and active and 

passive methods. Evaluations of some of these 

methods are given in Wallace and Ott (1981), 

Kennedy et al. (1985a, b), and Godish·(1985). 

IAQ Reference Manual 

Both automated and nonautomated measurement 

systems can be purchased ranging in price.from 

several hundred dollars for nonautomated systems to 

over $5000 for a fully automated system. The 

continuous monitors allow longer term real-time. 

measurements to be made, but their usefulness for 

routine residential monitoring is limited by the 

time required for instrument stabilization and 

standardization. 

Regardless of which method is used, it is important 

to use standardized conditions during testing. 

Closed house conditions should be observed for 

short-term samples (112 to 1 hour); this means that 

doors and windows should be kept closed for about· 

12 hours prior to testing. Temperatures before and 

during sampling should be at about 23-25°C (73°-

770F), if possible. 

Because of the seasonal differences in the release of 

HCHO, it has been recommended that sampling 

should not be conducted during the winter months, 

from December to March (Godish, 1985). As a 

practical matter, if an individual appears to have 

symptoms related to HCHO then sampling should 

be conducted regardless of the season, recognizing 

that it may have to be repeated at a later time. 

Since HCHO concentrations vary diurnally, measurements should be taken during the times of the 

day when, and in locations where, symptoms appear 

to be worse. It may be necessary to sample more 

than once or to collect samples over a longer period 

of time in order to sufficiently characterize the 

environment, but for most sampling a single set of 

two samples will be sufficient. Samples should be 

collected at the breathing height and away from 

drafts and impediments to airflow. Outside walls 

should be avoided, and samplers should be located 

6 inches to 12 inches away from inside walls. 

Locations near sources of heat should be avoided. A 

rigorous quality assurance program should be 

maintained throughout sample collection and 

analysis. 
IAQ Reference Manual 

After the samples have been collected, instructions 

given in the method for storage, transport, and time 

to analysis should be followed strictly. Some 

methods require refrigeration of the collecting 

medium and collected samples. 

Regardless of the sampling method which is used, 

the outdoor and indoor temperatures, barometric 

pressure, and indoor relative humidity should be 

measured and recorded. Godish and Rouch (1985) 

have recommended standardizing measured HCHO 

concentrations to a temperature of 25°C and relative 

humidity of 60% RH using the Berge equation: 

where, 

C = C[l + A(H-H )e·R(ltr-l/To)J-1 X 0 

ex= standardized concentration (ppm), 

C = measured concentration (ppm), 

R = temperature constant (9799), 

T = measured indoor temperature rK), 

To= standardized indoor temperature ("K), 

A humidity constant, 

H measured indoor relative 

humidity(%), and 

Ho = standardized relative humidity (%). 

Active Methods 

EPA's Method IP-6A (DNPH HPLC Method): 

This method utilizes solid adsorbent sampling 

followed by high performance liquid chromatographic analysis (HPLC) (U.S. EPA, 1989). HCHO 

gas (and other aldehydes or carbonyl compounds) is 

adsorbed onto acidified DNPH (2,4-dinitrophenylhydrazine)-coated silica gel cartridges to form a 

stable derivative. Commercial cartridges are 

SectionS 

available, but random samples from each lot should 

be analyzed to determine background levels of 

HCHO. 

Samples can be collected at a rate of 5 00-1200 ml/ 

min. Samples should be refrigerated after collection, and they can be stored for not more than 90 

days. The precision of field replicates should be 

±20% or better, and repicate HPLC injections 

should have a precision of± 10% or better. 

This sampling procedure requires a moderate degree 

of skill and training; the analysis requires a highly 

skilled person who is proficient in HPLC techniqes. 

EPA's Method IP-6B (Automated Colorimetric 

Method): This method utilizes a commercially 

available continuous colorimetric gas analyzer 

(Model TGM-555-FD) manufactured by CEA 

Instruments, Inc. or its equivalent (U.S. EPA; 

1989). The method of analysis is based on the 

HCHO selective pararosaniline method in which 

HCHO is absorbed into sodium tetrachloromercurate (II) solution containing a fixed amount of 

sulfur dioxide. Acid bleached pararosaniline is 

added to form a purple dye. The concentration of 

HCHO is proportional to the intensity of the dye. 

This method has been modified (Model TGM-155-

D analyzer) to eliminate the toxic mercuty reagents. 

The instrument can be calibrated using liquid 

formaldehyde standards or certified permeation 

tubes. If permeation tubes are used, alphapolyoxymethylene is recommended rather than 

paraformaldehyde because the paraformaldehyde 

, tubes are unstable and lack reproducibility. 

This instrument has a range of 0-5ppm in the 

standard range and 0-250 ppm in the low level 

range. The accuracy is ±3% referenced to the 

chromotropic acid procedure; the reproducibility is 

1 %; and the minimum detection limit is 0.003 

ppm at 0 to 0.25 ppm full scale. It has an optimum 

temperature range of 60°F to 80°F and a relative 

humidity range of 5% to 95%. 
Section 8 

Advantages of this instrument are that it is portable, provides real time measurements, and has a 

practical detection limit of about 0.02 ppm. 

Disadvantages include cost (about $6000), and the 

need for personnel with the expertise to operate the 

instrument and conduct the required calibrations. 

.Modified NIOSH Method P&CAM 125 (Chromotropic Acid .Method): The chromotropic acid 

procedure (NIOSH, 1977) utilizes midget 

impingers to collect HCHO into an absorbing 

solution. Modification of the method to use 1% 

sodium bisulfite rather than distilled water as the 

absorbing solution increases the collection 

efficidency to 98% and eliminates the need for a 

second impinger for sample collection (Meadows 

and Rusch, 1983). 

HCHO reacts with chromotropic acid-sulfuric acid 

solution to form a purple-colored complex which is 

read in a spectrophotometer at 580 nm. Samples are 

typically collected at a flow rate of 1 lpm for 30 

minutes to 1 hour. This method has a sensitivity of 

0.16 ppm for 15 minute samples and 0.04 ppm for 

1 hour or longer samples. 

A relatively simple, portable active sampling system 

can be built using readily available equipment 

(sampling pump, critical orifice, sampling 

impinger, trap impinger, tubing) for about $150. 

Commercially available sampling systems cost $500 

to $800. 

This method has been widely used in both residential and nonresidential sampling. Advantages are 

that it is a relatively simple technique which utilizes 

equipment that is readily available. A moderate 

degree of training is needed for the sampling and 

analytical techniques. Disadvanges are that confidence decreases significantly below 0.10-ppm and 

that: concentrated sulfuric acid is used in the 

analysis. It should not be used in situations where 

phenol may be present. 

Modified Pararosaniline .Method: One of the most 

sensitive methods available is the Lawrence Berkeley 

IAQ Reference Manual 

Laboratory (LBL) pararosaniline method (Miksch et 

al., 1981). This method utilizes midget impingers 

for sample collection and spectrophotometry for 

analysis. HCHO reacts with pararosaniline in the 

presence of sodium sulfite to produce a colored 

product which is read at 570 nm. The method has a 

sensitivity of 0.01 ppm and is not subject to 

interferences from nitrate, nitrite, phenol, ethanol, 

or higher molecular weight alcohols. Other 

advantages of the methqd are that toxic mercury 

compounds are not required, and it is more sensitive 

and more reproducible than the chromorropic acid 

procedure. A disadvantage is that refrigeration is 

required during collection and storage. 

Passive Methods 

Passive personal collectors are available in which 

HCHO diffuses through a tube onto a treated filter, 

onto an impregnated media, or into a liquid sorbent. Sample collection is relatively easy in all of 

these methods, but the analytical methods require 

moderate to high skill levels. Exhibit 8-20 summarizes some of the available methods. If monitors are 

returned to the manufacturer for analysis, the cost is 

typically $15 to $30 for the monitor plus analysis. 

Lower detectable limits range from 0.005 ppm to 

0.01 ppm for a 1 week exposure; shorter sampling 

times result in decreased sensitivity (typically, 0.1 

ppm to 0.3 ppm for 8 hours and 0.7 ppm to 8 ppm 

for 15 minute samples).· 

Care must be taken to ensure proper detection 

limits for the proposed application and proper 

placement of the samplers. Another problem with 

these monitors is lack ofxeliability and cost for 

routine monitoring programs. 

EPA's Method IP-6C (Passive DNPH HPLC 

Method): This method utilizes a passive sampler 

which consists of DNPH-impregnated glass fiber 

filters which ate placed behind diffusion screens and 

sandwiched between two protective caps (U.S. EPA, 

1989). The size of the completeq sampler is 1.5 

inches in diameter and 0.5 inches in depth. HCHO 

and other aldehdyes diffuse to the sampler and react 
IAQ Reference Manual 

with the DNPH treated filters to form a stable 

DNPH derivative. 

Precision for field replicates should be better than 

±20%, and HPLC replicates should have a precision of± 10% or better. Advantages of this method 

include the small size of the sampler, no noise, low 

unit cost, and the ability of unskilled personnel to 

place and retrieve the samplers. The major disadvantage of this method is the sophistication of the 

analysis which requires highly trained personnel. 

MBTH Bubbler Method: The MBTH passive 

bubbler method has been designated as a standard 

test method for HCHO by the American Society of 

Testing and Materials (ASTM, 1990). This method 

utilizes the Passive BubblerTM which consists of a 

glass vial with a septum cap that retains a Knudsen 

disk. The vial, which contains an aqueous solution 

of 3-methyl-2-benzothiazolinone hydrazone 

hydrochloride (MBTH), is inverted for sampling. 

HCHO diffuses through the Knudsen disk at a 

constant rate. After collection, a solution of ferric 

chloride-sulfamic acid is added to form a derivative 

which is measured in a spectrophotometer at 628 

nm. This method allows HCHO to be measured in 

the range of 0.025 ppm to 14 ppm for sampling 

times between 15 minutes and 8 hours. A fourhour sampling time is recommended to measure 

HCHO concentrations in the range of 0.05 to 1 ppm. 

A major advantage of this method is that laboratory 

support is not needed. Kits can be purchased which 

contain a mini-spectrophotometer and all needed 

reagents. 

Interpretation of Formaldehyde Data 

Both workplace and residential standards and 

guidelines have been recommended and promulgated for HCHO. These standards and guidelines 

are based primarily on the irritant effects of HCHO. 

In 1984 the WHO Working Group on Indoor Air 

Quality Research (WHO, 1986) identified <0.06 

ppm as a consensus concentration of limited or no 

Section 8 

concern and >0.12 ppm as a consensus concentration of concern for both long-term and short-term 

exposures. 

The Canadian exposure guidelines identify 0.05 

ppm as the long-term target level and 0.10 ppm as 

action level for long-term exposure (Environmental 

Health Directorate, 1987). 

The U.S. Department of Housing and Urban 

Development established a product standard for 

HCHO emissions from particleboard and hardwood 

plywood paneling used in manufactured housing 

(U.S. HUD, 1984). This standard limits the 

emissions of HCHO as measured by a specific air 

chamber test to no more than 0.3 ppm from 

particleboard floor decking and no more than 0.2 

ppm from interior plywood. Although HUD did 

not establish an ambient standard, the intent of the 

emissions standards is to limit ambient HCHO 

concentrations to less than 0.4 ppm. HUD recognized that sensitive subgroups of the population 

would react to lower levels, and the regulations 

require posting of health notices in the home and in 

consumer manuals to alert potential buyers to this 

risk. 

Exhibit 8-21 shows a dose-effect relationship 

between HCHO concentration and reports of 

irritation effects in a study of nearly 2000 residents 

living in 397 mobile homes and 494 conventional 

homes (Ritchie and Lehnen, 1987). The results of 

this larger-scale study support the conclusions of the 

WHO Working Group that concentrations greater 

than 0.1 ppm may cause adverse reactions in some 

people and may require corrective action. 

Standards or guidelines should not be the sole basis 

for determining whether a given low-level concentration might result in irritant health effects for two 

reasons. First, there is considerable variability in 

response to exposure to HCHO. Although it 

appears that 0.1 ppm is a concentration of concern, 

some individuals may be affected at lower HCHO 

concentrations. Second, existing standards are not 

based on the carcinogenic potential of HCHO. 
Section 8 

Each case must be considered individually based on 

the symptoms that are presented. Even though 

occupants report no symptoms, they should be 

should be encourage~ to reduce their exposures, if 

possible, because ofHCHO's potential role as a 

carcinogen. 

Mitigation Advice for Formaldehyde 

Manufacturers' Strategies 

Manufacturers can reduce HCHO emissions by 

improving quality control during the manufacture 

of pressed wood products or the installation of 

UFFI. In addition, the use of alternative resins 

(phenol-HCHO, methyl diisocyanates, lignosulfonates), resin modifications, processing changes to 

condition the product (increasing temperature or 

curing time) (Fisk et al., 1987). The substitution of 

alternative resins, however, for urea-HCHO resins 

may pose other health problems. For example, 

interior grade products which are made of 

diisocyanate resins pose a potential health risk 

because diisocyanate is a potent sensitizing agent. 

Another problem with products using diisocyanate 

resins is the potential formation of hydrogen 

cyanide under fire conditions. 

Consumers' Strategies 

Consumers can minimize their exposures to HCHO 

by not purchasing potential HCHO-emitting 

products such as UFFI and those made of ureaHCHO resins and urea-HCHO wood finishes. 

Although the use ofUFFI has diminished in the 

U.S., it is still available. It is also used to insulate 

concrete blocks and panels which are used to 

construct nonresidential structures. There is some 

concern that as UFFI ages and deteriorates, HCHO 

and particulates with irritant properties could be 

released into the indoor air (Fisk, et al., 1987). 

Fiberglass batts and cellulose are possible substitutes for UFFI. Cellulose, however, settles in 

sidewall applications which reduces its effectiveness. 

IAQ Reference Manual 

Products made of particleboard, hardwood plywood, 

and MDF should be avoided unless they have a 

barrier which covers any exposed surfaces. Acceptable substitutes are products made of solid wood, 

metal, plastic, or other material that does not emit 

HCHO. Another strategy is to limit HCHOemitting products to small areas. 

Because HCHO is released from its sources over a 

period of time, time itself, is a way of reducing 

HCHO concentrations. Additional storage of 

HCHO-emitting materials such as particleboard 

prior to use could decrease initial HCHO indoor 

concentrations, but this is not generally practical 

once consumers have purchased products. HCHO 

decay rates (and half-life) will vary depending on the 

product and its environment. If occupants are 

experiencing symptoms, allowing additional time 

for decay is not an effective strategy. 

Coatings and Barriers 

Both manufacturers and consumers can apply 

coatings and barriers to pressed wood products (or 

to MDF or hardwood plywood) to reduce emissions. 

These act in one of three ways: 1) by preventing the 

release of HCHO, 2) by preventing the transport of 

moisture into the board, or 3) by the reaction of 

scavenger chemicals with HCHO. 

Coatings are most effective on products such as 

particleboard shelving, subflooring and decking, 

and unfinished surfaces such as joints, edges, and 

undersides of cabinets or countertops. Coatings 

which have been reported to be moderately effective 

include polyurethane and lacquer (Fisk et al., 1987). 

Standard latex paints are not reported to be effective, but some other paints may be effective. For 

maximum effectiveness, several coats should be 

applied and all exposed edges should be coated. 

Other barriers which are reported to have varying 

effectiveness include melamine-impregnated paper, 

acid curing lacquers, decorative laminates, veneers, 
IAQ Referen~e Manual 

polyacrylamide, vinyl wallpaper, vinyl carpet, vinyl 

flooring, and a paint with HCHO-reactive chemicals (Fisk et al., 1987). When consumers apply any 

of these barriers, care should be taken to cover all 

exposed edges. It should be noted that many of 

these materials can release other volatile organic 

compounds. 

Environmental Strategies 

Using environmental factors to control HCHO (and 

other volatile organic compounds) has been reported 

by several investigators (Andersen et al., 1975; 

Godish and Rouch, 1986). Exhibit 8-22 shows 

measured decreases in HCHO concentrations as a 

function of temperature and relative humidity. A 

disadvantage of reducing temperature and relative 

humidity to control HCHO might be energy 

penalties of about 20-30% depending on the season. 

Also, even if dehumidification were used to slow the 

rate of HCHO emission, the total amount of 

HCHO released over time might remain the same 

(Fisk et al., 1987). 

Residential dehumidifiers, increased ventilation 

with less humid outdoor air, and local ventilation 

near humidity sources (bathroom, kitchen) are 

dehumidification methods which might reduce 

HCHO concentrations. Fisk et al. report that 

dehumidification alone or in combination with 

other methods may be effective in reducing small 

increases in HCHO concentrations caused by 

infiltration from house tightening. 

Other Strategies 

Laboratory data suggest that adsorbents and 

absorbents have some potential to remove HCHO 

from nonindustrial indoor air, but there is limited 

field data to evaluate these techniques. 

In some instances, HCHO-emitting products will 

require removal. Caution must be used when 

multiple sources are present because there is a 

possibility that removal of only one major source 

might result in only marginal decreases in HCHO 

Se~tion 8 

concentrations. All major sources may require 

removal in order to provide the greatest decrease in 

HCHO concentration. In the case ofUFFI.removal, 

the National Research Council of Canada (Bowen, et 

al., 1981) recommends treating wall cavities with a 

3% solution of sodium bisulfite after removal. This 

treatment prevents HCHO release from urea-HCHO 

resin which might remain in gypsum board, wall 

studs, and other surfaces. 

Ammonia fumigation has been identified as a postinstallation treatment for HCHO in residences (Fisk 

et al., 1987). Application methods have included 

setting out pans of ammonium hydroxide, spraying 

ammonium hydroxide, and releasing gaseous 

ammonia. These methods have not been verified for 

different situations .. The treated house cannot be 

used during treatment and for several weeks after 

treatment, and an irritating ammonia odor can 

remain for as long as several months after treatment 

(Muratzky, 1987). 

Investigation Techniques for Volatile 

Organic Compounds (VOCs) Other Than 

Formaldehyde 

Vocs should be considered as a source of 

health complaints whenever there are sensitization 

reactions or symptoms typical of sick building 

syndrome (typically, irritation of nose, throat, eyes; 

fatigue; nausea; difficulty concentrating; skin 

irritation; headache; and dizziness). 

The investigation of these symptoms should focus 

on the characterization of health effects and identification of potential sources which could contribute 

to those effects. Any recent changes in household or 

workplace environments should be evaluated 

carefully to identifY the potential presence ofVOCs. 

Any new home or office building is a potential 

source of hundreds ofVOCs which are emitted by 

wood products, plastics, solvents, glues and adhesives, fillers, dyed fibers, and floor and wall coverings. If occupants in a new building complain of 

odors or symptoms, the building should be evalu-
Section 8 

ated for sources ofVOCs and adequate ventilation. 

Suspect materials in any home or office include new 

carpeting. paint, furnishings, wallpaper, and vinyl 

flooring. Recently dry-cleaned clothing or upholstery and activities such as smoking tobacco products and the recent use of pesticides, solvents and 

solvent-based cleaners, caulks, glues or adhesives, or 

paints and related supplies are also suspect. In 

addition, any changes in brands of products such as 

personal care products or cleaning products may be 

suspect. In the office environment, the use of 

copiers, spirit duplicators, and other equipment 

which might release VOCs can also be suspect. 

In many instances, the sources can be identified and 

various strategies can be employed in an attempt to 

reduce emissions and eliminate symptoms. For 

example, shortly after the carpeting in a home was 

replaced, the eyes of one of the children in the home 

became irritated and somewhat swollen. When the 

child left the home, the irritation and swelling 

improved, but the symtoms became worse when the 

child returned to the home. This scenario suggests 

that the carpeting (dyes or adhesives) may be 

responsible for the child's condition. This is a 

relatively simple and straightforward example; in 

other instances there may be so many potential 

sources that a health effects or building systems 

questionnaire alone may not be able to identify 

sources. 

Measuring Volatile Organic Compounds 

(Other Than Formaldehyde) 

Extensive sampling and analysis ofVOCs may not 

be possible or practical for most investigations for 

several reasons. There are many potential organic 

compounds in the indoor environment, and these 

compounds are generally present in very low 

concentrations. There is a general lack ofdata that 

relates low level exposures to health effects, and 

there is considerably variabiliry in the response to 

exposure to VOCs and other contaminants. Finally, 

the measurement ofVOCs and other organic 

compounds is complicated and expensive. 

IAQ Reference Manual 

However, sampling may be needed in situations 

where sources cannot be identified easily or in 

situations where a physician recommends identifying specific contaminants. 

If sampling is conducted, portable VOC detectors 

might be useful in determining ifVOCs are present 

or identifying potential sources, but these devices 

may not be sensitive enough to detect very low 

concentrations which might affect some individuals. 

Methods for sampling VOCs must be capable of 

measuring concentrations in the ppb-ppt range. 

These methods include both passive and active 

methods, methods which are direct reading, and 

those which require laboratory analysis. An additional review of analytical methods for VOCs in 

indoor air is given by Sheldon et al. (1985). 

EPA has developed guidelines for two methods 

which are based on either the collection of whole air 

samples in SUMMAR passivated stainless steel 

canisters or collection on solid adsorbent tubes (U.S. 

EPA, 1989). 

Method lP-lA (Collection Using Stainless Steel 

Canisters): This method utilizes passivated 

stainless steel canisters (chemically tre~ted, to form 

an inert chrome-nickel oxid" on the inner surface) 

under subatmospheric pressure or pressurized 

sampling modes to collect the sample. The collected gases must be transported to a laboratory for 

analysis. 

At the laboratory the contents of the canister are 

concentrated, separated by a gas chromatograph 

(GC), and analyzed by one or more detectors. 

Possible detectors for the high resolution gas 

chromatograph include specific detectors such as the 

mass spectrometer (MS) in the selected ion monitoring (SIM) mode or the SCAN mode or ion trap 

detector. Nonspecificdetectors such as the flame 

ionization detector (FID), electron capture detector 

(ECD), nitrogen-phosphorous detector (NPD) and 

the photoionization detector (PID) can also be used. 
IAQ Reference Manual 

Exhibit 8-23 summarizes some of the advantages 

and disadvantages of different systems. The selection of the most appropriate detector depends on 

many variables including the type of compounds to 

be identified, budget, required detection limits, 

potential interferences, project objectives, equipment, and personnel capability. 

The precision, accllnj.Cy, sensitivity, and potential 

interferences will vary depending on the compound 

of interest. EPA will provide at no charge some 

cylinder gas standards which are traceable to NIST. 

Advantages of this method include the ability to 

identify and quantify a variety ofVOCs and SVOCs 

at very low levels (ppb-ppt range). The primary 

disadvantages include the cost of analysis by an 

outside laboratory (about $200/sample) or developing in-house analytical capability, the high level of 

skill required by analytical personnel, and the 

caution needed to prevent accidental contamination 

or loss of samples. 

Method lP-lA also contains operating procedures 

for a portable gas chromatograph equipped with a 

photoionization detector. This method is intended 

to provide qualitative information on the presence 

and intensity of unknown volatile compounds which 

assists in the placement of fixed-site samplers. 

Exhibit 8-24 contains a summary of commercially 

available portable VOC detection instruments. 

Solid Sorbents: Solid sorbents are the most commonly used materials for collecting vapor phase 

organics. Once the samplers are prepared they can 

be deployed and collected easily which makes them 

useful in large-scale surveys. Samplers must be 

returned to the laboratory for analysis by GC/MS or 

GC combined with nonspecific detectors (FID, 

ECD, NPD). The collection of vapor phase organics 

by solid sorbents involves three basic steps: collection on the sorbent, desorption of organics from the 

sorbent, and analysis of the desorbed organics. 

Solid adsorbents have several limitations which 

include: 

Section 8 

• formation of artifacts on some adsorbents, 

especially Tenax:R in the presence of NO"; 

• extensive cleanup and thermal conditioning 

is required to ensure contaminant-free 

cartridges; cartridges must be carefully 

handled, shipped, and stored to prevent 

contamination prior to and after sampling; 

• breakthrough volumes of certain compounds are very small on some resins 

sorbents which prevents quantitative 

results; and 

• irreversible adsorption may occur onto 

charcoal which decreases the recovery of the 

analyte (U.S. EPA, 1989). 

In spite of these limitations, adsorption onto solid 

sorbents has several advantages including fhe small 

size of the samplers, portability of the sampling 

devices, ease of use, and the ability to collect 

integrated samples over periods of 8 hours to 12 

hours. 

Exhibit 8-25 summarizes some of the characteristics 

of different collection methods. Either thermal or 

solvent desorption techniques can be used to desorb 

the organics from the sorbent. The preferred method 

of analysis for polymeric resins which adsorb 

through thermal desorption is GC/MS because it 

provides broad spectrum analysis as well as identification of target compounds. Solvent desorption can 

limit the analysis of low molecular weight organics 

because of interferences from the solvent and the 

overall sensitivity of the analysis compared to 

thermal desorption because only a fraction of the 

sample (111 00 or 11500) is used for the analysis: 

Method lP-lB (Adsorption using TenaxR): 

Method 1P-1B utilizes solid adsorbent tubes 

containing 1-2g ofTenaxR to capture a variety of 

VOCs. The cartridges are stored under refrigeration 

until analysis when the organics are thermally 

desorbed, collected into a cryogenic trap, and 

analyzed by a GC/MS data system. 
Section 8 

The analytical finish is the same as for Method IPlA. The precision and accuracy of the method will 

vary depending on the contaminant of interest and 

factors such as breakthrough volumes, background 

contamination of the cartridges, and factors related 

to the analytical instrument and skill of the analyst. 

Interpretation of Volatile Organic 

Compounds Data 

There are limited standards and guidelines for 

evaluating exposures to VOCs (Exhibit 7-1, Section 

7 contains a summary of some existing standards 

and guidelines; Exhibit 3-3, Section 3 contains a 

summary of EPA risk assessments; and Section 8.3 

contains guidelines for some pesticides). The use 

of OSHA, NIOSH, and ACGIH standards and 

guidelines do not provide adequate protection to 

the general public, and their use in nonindustrial 

environments is not appropriate. 

Because of the inherent variability in response to 

VOCs and other organics, guidelines should not be 

the sole basis of determining whether a given lowlevel concentration might result in irritant health 

effects. Each case should be considered individually 

based on the symptoms that are presented. 

Mitigation Advice for Volatile Organic 

Compounds 

It is difficult to provide mitigation advice for VOCs 

other than HCHO because there is very little 

information on control methods and concentrations 

of concern. In general, the methods suggested for 

the mitigation of HCHO also apply to other VOCs. 

Consumer Strategies 

Clients who are concerned about VOCs should be 

encouraged to use products which do not contain 

VOCs or contain lower levels ofVOCs whenever 

possible. A major problem with this advice is that 

consumers may not be able to identify which 

products contain VOCs; and further, emissions of 

IAQ Reference Manual 

VOCs may vary from product to product. In those 

instances where VOC-containing products must be 

used, adequate ventilation during storage and use 

should be emphasized. 

Consumer practices can also be important in 

minimizing indoor air quality impacts from the use 

ofVOC-containing products. Storage of these 

products outside the living area (perhaps in the 

garage) can reduce indoor air concentrations. In 

addition, minimizing the use ofVOC-containing 

products or using these products with adequate 

ventilation is critical. In general, clients can be 

advised that cross-ventilation should be enough to 

prevent any noticeable odor when VOC-containing 

products are used in the home. 

Caulks, sealants, glazing compounds, and joint 

fillers release VOCs (typically aliphatic hydrocarbons, xylene, toluene, petroleum hydrocarbons, or 

methyl ethyl ketone) at varying rates depending on 

the formulation. Fast-drying products (those 

containing styrenes, for example) emit a significant 

fraction of their total weight, but they do so in a 

relatively short period of time (several to 10 days). 

Slow-drying products can be significant contributors to indoor air contaminants over a longer period 

of time (up to one year). Consumers can reduce 

their exposure to contaminants from these products 

by proper selection and use of the product. 

For example, the release of emissions from the 

installation of carpet or other flooring materials can 

be minimized by selecting a fast drying adhesive 

and using maximum ventilation during the installation. 

There appear to be some instances, however, when 

consumer practices will not appreciably reduce VOC 

concentrations. For example, emissions from 

recently dry cleaned clothing can result in elevated 

levels of perchloroethylene in homes. But airing 

clothes out in a garage for 4 hours did not proved 

effective in reducing indoor perchloroethylene 

concentrations (Tichenor, et al. 1988). In this case, 
IAQ Reference Manual 

other methods such as venting the closet to the 

outside might be effective in reducing these concentrations. 

Conditioning 

The potential effectiveness ofVOC control by 

conditioning is illustrated by VOCs chamber 

studies of caulk. VOC emissions decreased by more 

than 90% from caulk treated for 4 hours at room 

temperature and 1.8 ach. At 0.4 ach the time for 

90% ofVOCs to be emitted increased to about 20 

hours, or five times as long as for 1.8 ach (Tucker, 

1988). This method can be used for individual 

products or larger areas (for example, after installation of new carpeting or after painting). 

HCHO and other VOCs might also be reduced by 

using increasing temperature and ventilation for 

SectionS 

some period of time (several days to 1 to 2 weeks). 

Under these conditions, emissions of volatile 

organic compounds will accelerate and be exhausted 

from the building. Girman et al. (1987) provided 

one of the first reports of the potential effectiveness 

of this procedure in office buildings. 

Removal 

When concentrations cannot be reduced or symptoms persist, avoidance of the product or removal of 

the source may be required. The mitigation of 

VOCs and other organics in the environment of 

hypersensitive individuals is difficult and requires 

an integrated approach including substitution of 

products and materials, removal, mechanical 

ventilation, and control devices. 
Exhibit 8·20. Se,lected passive for•a,Jdebyde ID'easureJDeat •etbods. 

Method 

Air Quality 

Research a 

U.S. EPAb 

Air Technology Labsc 

Sampling 

HCHO reacts with sodium 

bisulfite-treated filter 

paper in a vial 

HCHO reacts with sodium 

bisulfite solution in a badge 

HCHO reacts with sodium 

bisulfite-created filter paper 

in a badge 

HCHO reacts with DNPH 

impregnated filter paper in 

the presence of acid 

HCHO reacts with MBTH 

solution in the Passive 

BubblerTM 

ANALYTICAL TECHNIQUES 

Analysis 

spectrophotometry 

(chromortopic acid 

procedure} 

spectrophotometry 

(chromotropic acid 

procedure) 

spectrophotometry 

(chromotropic acid 

procedure) 

HPLC 

spectrophorometty 

(MBTH} 

Sensitivity, ppm 

1.68 ppm-hr (0.011 ppm 

for 1 week exposure) 

1.6 ppm-hr (0.010 ppm 

for 1 week exposure) 

0.8 ppm-hr (0.005 ppm 

for 1 week exposure) 

0.05 ppm for 4 hr 

exposure 

0.025 ppm for 8 hr 

exposure; 0.05 ppm 

for 4 hr exposure 

SOURCE: aNagda, Rector, and Koontz (1987); bu.S. EPA (1989); cASTM (1990) 

Comments 

recommended minimum exposure of 

1 week; reproducibility of±25%; not 

sensitive for short-term residential 

sampling 

shelf life of sampler is 2 weeks after 

exposure which suggests a maximum 

exposure of 2 weeks; accuracy of 

±13.1% over the range of 1.6 to 54 

ppm-hts; precision of5.9% 

not sensitive enough for short-term 

residential sampling; requires 

sophisticated equipment and 

analytical skills; accuracy ±25% 

overall accuracy of±10% to ±19:8% 

in laboratory and field testing, 

respectively; precision of ±5% 

samples should be stored in the dark; 

overall system accurately in field 

testing of±l9.8% 
IAQ Reference Manual Section 8 

Exhibit 8·21. A dose•effect relationship between formaldehyde (HCHO) exposure and 

selected health effects in mobile and conventional homes. 

Mobile Homes 

100% 

90 

80 

c:: 70 

j 60 

C) 

c:: 50 'E 

0 

a. 40 Q) 

a.= 

::R "' 30 

20 

10 

0 Eye Nose/Throat Headache Skin Rash 

Conventional Homes 

100% 

90 

80 

70 c:: 

0 

·.;::: 

.2 60 ·;::: 

...!:: 

en 

c 50 "t 

0 

a. 40 Q) 

a.= 

::R C> 

30 

20 

10 

0 Eye Nose/Throat Headache Skin Rosh 

~ :S: .1 ppm Ill .1 to .3 ppm ~ ;;:: .3 ppm HCHO Concentration 

SOURCE: Ritchie and Lehnen (1987). 
Section 8 IAQ Reference Manual 

Exhibit 8·22. Effect of temperature and relative humidity on formaldehyde (HCHO) levels In 

a mobile home under controlled conditions . 

. 3 

[ 

c.. 

8 ..... 

2 

c .2 ~ 

8 

0 

::r: 

u 

:I: 

.1 

0 20 

SOURCE: Adapted from Godish and Rouch (1986). 

25 

Temperature °C 

30 35 
IAQ Reference Manual Section 8 

E•hibit 8·23. Advantages and disadvantages of nonspecific and specific detector systems 

for VOC and SVOC analysis. 

NON-SPECIFIC MULTIDETECTOR ANALYTICAL SYSTEM 

ADVANTAGES 

• somewhat lower equipment cost than GC-MS 

• less sample volume required for analysis 

• more sensitive 

DISADVANTAGES 

• cost of calibrating multiple detectors 

• compound identification is not positive 

• lengthy data interpretation (2 hr for analysis 

and data reduction) 

• intetference(s) from similar (co-eluting 

compounds 

• cannot identify unknown compounds 

outside of calibration and without standards 

• does not differentiate targeted compounds 

from interfering compounds 

SPECIFIC DETECTOR ANALYTICAL SYSTEM 

ADVANTAGES 

• positive compound identification (ions) 

• greater sensitivity than GC-MS-SCAN 

• less operator interpretation than for multidetectorGC 

• resolve co-eluting peaks to achieve 

enhancement in sensitivity 

• more specific than the multidetector GC 

ADVANTAGES 

• positive compound identification 

• can identify all compounds 

• less operator interpretation than for 

multidetecror GC 

• can resolve co-eluting peaks 

SOURCE: U.S. EPA (1989) 

GC-MS-SIM 

DISADVANTAGES 

GC-MS-SCAN 

• can't identify nonspecified compounds 

• somewhat greater equipment cost than 

multidecector GC 

• greater sample volume required than 

for multidetector GC 

• universality of detector sacrificed 

DISADVANTAGES 

• lower sensitivity than GC-MS-SIM 

• greater sample volume required than for 

mulridetecror GC 

• somewhat greater equipment costs 
Exhibit 8·24. Commercialy available portable YOC detection instriJments. 

5AMP 

DETECTION RANGE, RESPONSE CAUBRATION SERVlCE LACK OF RATE 

MONI10R PRINCIPLE PPM SENSITIVITY TIME,s ACCESSORIES TECHNIQUES WEAKNESSES RATE RESPONSE cosr,$ LPM 

550,551 PlO 0-200, 0.1 ppmar <s • &g Sampling •Umbili<:alconl 8hrs 4300 l.:i 

555.580 PlO 0·2000, G-200ppm roo short 

(AIO,lnc.) 0-10,000 • Digital readout hard to read 

• Flame out frequently 

OVA 108, 128 FlO 0-10, 0.2ppm 2 •Thermal •Hand Space • Battery failure Shrs 6300 

Century Systems. Inc. 0-100, (Model U8) Oesorbers • Direct Injection • Sample line kinks 

(r"Oxboro) 0-1000, 0.5 ppm 2 avaibble • Bag Sampling •Compounds 

0-10,000 (Model lOS) • Optional GC containing OuN give 

0-100,000 available lowrespon&e 

• Neg. resp. to COjC02 

Pl-101 PID I O.lppm <5 •Three lamps • External Gas Cyl. • Three lamps-may 10brs •Cihydro- 4955 0.5 

(HNu Systems, Inc.) 1-20 Low molecular available • Bag Sampling miss something carbons 

1-200 weights aromatics • 9.5 (aromatics) •CH4 

1·2000 •10.2 (2-4 

compounds) 

•11.7 

(halocarbons) 

TLVSniJfer Cara1ycic 0-500 2.0ppm 5 • Bag Sampling 900 

(Bacharach) combustion 0-5000 oHeadSpace 

0-50,000 

Ecolyser 400 Caralyric D-1001f LFL 19!' LFL 15 • Bag Sampling • Changes in gas temp/ 

(Energetics Science) combustion humidity alkas 

l response 

Miran lA 1R ppm to% !ppm 1.4.10 9500 

(Foxboro) and40 

Miran IB IR ppmto91 U,500 

(Foxboro) 

Seen tor GCfEC, Argon 0.01 ppbO 2 Preconcentraror •Internal gas cyl. 12,950 

(Sentex) Ionization P!D organics Thermal • Preconcenrrator Desorption •GCColumn 

GCColumns 

Auto Cal. from 

Integral Gas 

Cylinder 

Photovac Standard PID 0 0.1 ppbBen=e 2 • Dual Column • Column operates at oH,Q 6995 

Automatic Computer (UV Light) with signal-to- • Manual/ Auto ambient temperature .o; 8995 

AutoComp. noise ratio 4:1, Injection • STD in lab, then ro 10,50() 

Communication Good for • Column Cond field at diflerent 10,955 

aromatics •Pre-flush temperature 12,955 

aAumDial • Can't injeCt liqaid 

Modem sampling 

• Prngrammable • Ligbr fractions 

interfere 

Pho!OV!IC Tip P!D 0-2000ppm 0.05 ppm 3 Benzene 

SOURCE: U.S. EPA (1989) 
Exhibit 8·25. Characteristics of sorption collection methods. 

SORBENT 

organic polymeric resins 

(Tenax GC, XAD) 

inorganics (silica gel, 

alumina, florisil, molecular sieves) 

activated carbon 

carbon molecular 

sieve 

APPLICATION 

sample by 60-300°C, except 

highly polar compounds 

strongly sorb water; not 

generally useful 

sample bp 0-300°C, polar 

and nonpolar compounds 

sample bp 0-70°C, very polar 

and volatile compounds 

SOURCE: U.S. EPA (1989) Method lP-lB. Collection using solid absorbent tubes. 

DESORPTION 

thermal 

solvent 

thermal 

ANALYSIS 

CG/MS 

GC/FID 

GC/ECD 

GC/NPD 

GC/MS 
Section 8 

REFERENCES 

.Andersen, I., G.R. Lindqvist, and L. MS'llhave. 1975. "Indoor 

air pollution due to chipboard used as a construction material." 

Almos. Environ. 9: 1121-1127. 

.American Society for Testing and Materials (.ASTM). 1990. 

"Standard test method fur measurement of formaldehyde in 

indoor air (passive sampler methodology)." Method D 5014-

89 . .ASTM: Pittsburgh, PA. 

Bowen, R.P., C.J. Shirtliffe, and G . .A. Chown. 1981. Ureaformaldehyde fo(.lm insul(,ltion: Problem identification (,lnd remeditll 

mfiJSIIrtS for wood frame conslrnction. Building Practice Note 23. 

ISSN 071-5216. National Research Council of Canada: 

Otrawa, Canada. 

Cohn, M.S., A.G. Ulsarner, and P.W. Preuss. 1984. "Sources 

contributing to formaldehyde indoor air levels." Indoor Air. 

Vol. 3. Sensory and Hyperreactivity Reactions to Sick Buildings. · 

Swedish Council for Building Research: Stockholm, Sweden. 

pp. 133-138. 

Environmental Health Directorate. 1987. Exposure Guidelines 

for Residential Indoor Air Quality. Health Protection Branch, 

Environmental Health Directorate: Ottawa, Canada. 

Fisk, W.J., R.K. Spencer, D.T. Gtimsrud, F.J. Offermann, B. 

Pedersen, and R. Sexcro. 1987. Indoor Air Quality Control 

T«hniques. Radon, Formaldehyde, Combmtion Products. Noyes 

Data Cocp.: Park Ridge, NJ. 

Gammage, R.B. and K.C. Gupta. 1989. "Formaldehyde," 

Chap. 7. Indoor Air Quality. P.]. Walsh, C.S. Dudney, and 

B.D. Copenhaver (eds). CRC Press: Boca Raton, FL. 

Girman,J., L. Alevantis, G. Kulasingam, M. Petreas, and L. 

Webber. 1987. "Bake-out of an office building." Indoor Air 

'87. Vol. 1. Volatile Organic Compounds, Combmfion Gases, 

Particles and Fibers, Microbiological Agents. Oraniendruck 

GmbH: Berlin, Germany. pp: 22-26. 

Godish, T. 1985. "Residential formaldehyde samplingCurrent and recommended practices." Am. Ind. Hyg. Assor.J. 

46{3): 105-110. 

Godish, T. and]. Rouch. 1985. "An assessment of the Berge 

equation applied to formaldehyde measurements under 

controlled conditions of temperature and relative humidity in a 

mobile home."]. Air Poll. Cont. Assoc. 35: 1186-1187. 

Godish, T. and]. Rouch. 1986. "Mitigation of residential 

formaldehyde contamination of indoor climate control." A mer. 

Indust. Hyg. Assoc.}. 47:792-797. 

IAQ Reference Manual 

Kennedy, E.R., D.L. Smith, and C.L. Geraci, Jr. 1985a. "Field 

evaluations of sampling and analytical methods for formaldehyde." Advances in Chemistry Series. No. 210. Formaldehyde: 

Analytical Chemistry and Toxicology. V. Turoski (ed). American 

Chemical Society. pp. 151-159 . 

Kennedy, E.R., A.W. Teass; and Y.T. Gagnon. 1985b. 

"Industrial hygiene sampling and analytical methods for 

formaldehyde. Past apd present." Advances in Chemistry Series. 

No. 210. Formaldehyde: Analytical Chemistry and Toxicology. 

V. Turoski (ed). American Chemical Society. pp. 1-12. 

Meadows, G.W. and G.M. Rusch. 1983. "The measuring and 

monitoring of formaldehyde in inhalation test atmospheres." 

Am. Ind. Hyg. Assoc.}. 44: 71-78. 

Miksch, R.R., D.W. Anthon, L.Z. Fanning, C.D. Hollowell, K. 

Revzan, and J. Glanville. 1981. "Modified pararosaniline 

method for the determinacion of formaldehyde in air." Anal. 

Chem. 53: 2118-2123. 

Muratzky, R. 1987. "Formaldehyde injuries in prefabricated 

houses: causes, prevention, and reduction." Indoor Air '87. 

Vol. 2. Environmental Tobacco Smoke, Multicomponent Studies, 

Radon, Sick Buildings, Odors and Irritants, Hyperreactivities and 

Allergies. Oraniendruck GmbH: Berlin, Germany. pp: 690-

694. 

Nagda, N.L., H.E. Rector, and M.D. Koontz. 1987. Guidelines 

for Monitoring Indoor Air Quality. Hemisphere Publishing Corp.: 

Washington, DC. 

National Institute of Occupational Safety and Health (NIOSH). 

1977. "NIOSH 77-l57A Method No. P & CAM 125." 

Manual of Analytical Methods. Vol. II. 2nd edition. U.S. 

Department of Health, Education and Welfare: Cincinnati, 

OH. 

Ritchie, l.M. and R. G. Lehnen. 1987. "Formaldehyde-related 

health complaints of residents'living in mobile and conventional homes." Am.}. Pub. Health. 77(3): 323-328. 

Sheldon, L.S., C.M. Sparacino, and E. D. Pellizzari. 1985. 

"Review of analytical methods for volatile organic compounds 

in the indoor environment." Indoor Air and Human Health. 

Gammage, R.B. and S.V. Kage (eds). Lewis Publishers: 

Chelsea, MI. 

Tichenor, B.A., L.E. Sparks, M.D. Jackson. 1988. Evaluation of 

Perchloroethylene Emissions From Dry Cleaned Fabrics. EPA-600/2-

88..()61. U.S. Environmental Protection Agency: Research 

Triangle Park, NC. 
IAQ Reference Manua? 

Tucker, W.G. 1988. "Emissions of air pollutants from indoor 

materials: An emerging design consideration." 5th Canadian 

Building and Construction Congress. Montreal, Canada. 

November 27-29. 

U.S. Consumer Product Safety Commission (CPSC). 1986. 

Briefing Package on Formaldehyde Emissions from Urea-Formaldehyde 

Pressed Wood Products. CPSC: Washington, D.C. 

U.S. Department of Housing and Urban Development (HUD). 

1984. "Manufactured home construction and safety standards; 

final rule." Federal Register. 49(155): 31995-32013. 

U.S. Environmental Protection Agency (EPA). 1989. Compendium of methods for the determination of air pollutants in indoor air. 

Draft. Atmospheric Research and Exposure Assessment 

Laboratory: Research Triangle Park, NC. 

World Health Organization (WHO). 1986. Indoor Air Quality 

Research. Euro Reports and Studies 103. WHO, Regional Office 

for E.urope: Copenhagen, Denmark. 

Wallace, L.A. and Ott, W.R. 1982. "Personal monitors: A 

state-of-the-art survey."]. Air Poll. Cont. Assoc. 32(6): 602-610. 

8.5. INVESTIGATION TECHNIQUES FOR 

BIOLOGICAL CONTAMINANTS 

Many investigations of biological contaminants, particularly those involving fungi, can be 

handled by obtaining a detailed symptom history 

and performing a careful inspection of the building. 

Discussions with the physician or other health care 

provider (if one has been consulted) may be helpful. 

It is important to i~entify the presence of activities 

which may precipitate or aggravate symptoms and 

any changes in lifestyle and/or building characteristics which could contribute to symptoms. 

A useful reference to assist in the investigation 

of bioaerosols is a document developed by the 

Bioaerosols Committee of the ACGIH (1989). The 

focus of this document is on the office environment, 

but the principles also apply to residential environments. Areas which are covered in the guidance' 

document include medical preassessment, on-site 

investigations, air sampling, and remedial actions 

for viruses, bacteria, endotoxin, fungi, protozoa, and 

antigens. Biocides are also discussed. 

Section 8 

Walk· Through 

A telephone interview can be used to obtain pre-

"fim~nary information, but a walk-through is 

generally needed to identify potential sources of 

contamination. A survey form that can be used for 

potential sources of allergens is given in Exhibit 

8-26. 

Both indoor and outdoor environments must be 

, evaluated to identify materials or situations which 

can foster the growth and amplification of biological 

agents. It should be remembered during these 

investigations that some problems depend on season 

or climatic changes, and these may not be detected 

during the inspection. 

An important area of emphasis during investigations related to fungi and some bacterial contaminants is identifying moisture problems; Section 5 of 

the Reference Manual provides a foundation for 

understanding the moisture balance in the. home. 

Other useful references that can help the investigator to detect and solve moisture problems are 

published by the National Center for Appropriate 

Technology (NCAT, 1983) and ASHRAE (1988, 

1989). 

Outdoor Environment 

Any barriers to air movement around the house, 

such as heavy vegetation or firewood, can result in 

the accumulation of moisture and promote mold 

growth. The outdoor environment should be 

evaluated for landscaping close to the house which 

might result in shade and moisture levels which 

favor the growth of microorganisms. The grounds 

should be evaluated for proper drainage; any 

standing water should be noted. If a sump pump is 

used, the outlet for the drainage pipe should be 

evaluated for adequate distance from the house, and 

the slope of the ground should be checked to be sure 

that drainage occurs away from the house. 

The presence of accumulated bird droppings around 

the grounds or in air intakes should be noted. The 
Section 8 

grounds should be evaluated for trash and food 

sources, harborage, and fecal material from pets. 

Exterior of the House 

The soffits, fascias, gables, bottom edges of siding, 

areas below windows, exterior siding at bathrooms, 

flashing, and remaining exterior should be examined for signs of physical and moisture damage. 

The presence of blistering paint or black/dark 

streaks or lines which border a discoloration may 

indicate problems. Uneven, warping, or sloping 

surfaces should be noted. Wood can be tapped to 

detect wet or decaying wood (characterized by a 

dull, dead, muted sound in contrast to dry wood 

which has a sharp, clear sound when tapped). 

The foundation should be examined for signs of 

"efflorescence" (a white powdery substance or line of 

minerals that is left after moisture has moved 

through it) which may indicate the presence of 

microbial contamination. Ctumbling concrete may 

also indicate problems. 

Some moisture problems are weather or seasonally 

dependent. For example, some roof drainage 

problems can only be observed if it is raining. Also, 

roof designs with valleys are more likely to have ice 

dams during the winter which can damage roofing 

materials and promote moisture problems through 

constant freeze/thaw cycles. 

The exterior of mobile homes should be checked for 

unusual water stains which may appear along the 

outside corner where the wall meets the ceiling. 

The foundation area of all homes should also be 

evaluated for signs of rodent entry. Downspouts 

and the slope of the ground around the foundation 

should be checked to determine if water drains 

properly away from the foundation. 

The House and Its Interior 

A major emphasis of the interior inspection should 

be to identify evidence of situations or conditions ' 

IAQ Reference Manual 

which foster or could lead to moisture problems. 

There are many visual and sensory clues that suggest 

moisture problems, but some problems may be 

hidden and require additional investigation. 

Although microbes will not typically be sampled, 

temperature and relative humidity should be 

measured. A relative humidity between 30% and 

50% promotes comfort and reduces the likelihood 

of problems with microorganisms. A relative 

humidity below 30% can cause problems with 

dryness and irritation of the mucous membranes; 

humidities greater than 50% are more likely to 

cause problems with mold and mildew. If someone 

in the household has respiratory problems which 

require a more humid environment, a potential 

solution is to humidify only one area of the house, 

rather than the entire house. 

Visible mold and mildew: The interior should be 

examined for evidence of visible mold and mildew. 

Special attention should be given to wall-ceiling 

joints and wall-floor joints, areas behind furniture, 

plants, poorly ventilated closets, and window 

coverings. Greenhouses (all areas, including plants), 

bathrooms (showers, bathtubs, behind and at the 

base of the toilet, windows, underneath sinks), and 

kitchens (underneath sinks) should be carefully 

checked for signs of mold, mildew, and rotting 

wood. 

Indoor swimming pools and hot tubs should be 

checked for visible mold and mildew problems, and 

the method and adequacy of moisture control 

should be noted. The interior should also be 

evaluated for the presence of organic substrates. If 

carpeting or other flooring materials are damp or 

have been water damaged, the floor underlayment 

and any pads must be examined for evidence of 

microbial growth. If water leaks have occurred, it 

may be necessary to examine insulation inside of 

walls for damage. 

Presence of organic substrates: Other sources of 

microbes and biological agents such as carpeting, 

wicker and straw items, pets, and plants should be 

noted. The presence and condition of pets should be 
IAQ Reference Manual 

evaluated. (For example, do dogs have fleas? Are 

bird cages cleaned regularly?) General dust levels 

should be noted along with the presence of pests 

such as cockroaches. 

Dampness, standing water, and condensation on 

surfaces: A history of water damage (flooding, 

broken pipes, overflowing toilets, sinks, or bathtubs) should be obtained. The interior should be 

examined carefully for evidence of water damage or 

moisture. Smaller houses (under 800 ft2

) tend to be 

more prone to moisture problems because of the 

ratio of sources to total living area. Musty odors or 

a sensation of dampness in the air are indicative of 

mold, mildew, or rot. Also, lingering odors from 

normal household activities may indicate inadequate 

ventilation, which in turn, could be related to 

moisture problems. 

Condensation problems can occur during the winter 

or summer. The presence of condensation on 

windows or other smooth surfaces such as concrete 

or masonry walls is a sign of excessive moisture (or 

the need to insulate or warm the surface). Based on 

average window glazing and 7 4 °F interior temperature, the maximum relative humidity within a space 

for no condensation on single glazed (ASHRAE, 

1988) and for double glazed windows (ASHRAE, 

1989) is: 

Maximum Relative Humidity 

Temperature Single Double 

Glazing Glazing 

40°F 39% 59% 

30°F 29% 50% 

20°F 21% 43% 

wop 15% 36% 

oop 10% 30% 

-10°F 07% 26% 

-20°F 05% 21% 

-30°F 03% 17% 

Moisture problems with double-hung windows 

might not be as readily visible because condensation 

can occur inside the wall caviry as a result of warm 

Section 8 

moist air condensing on the cold weights inside the 

wall cavity. 

Sweating pipes and water leaks are potential causes 

of microbial growth. If plumbing tuns underneath 

a crawl space, it should be checked for leaks (after 

running the water for 10 to 15 minutes); exterior 

faucets should also be checked. Standing water in 

the crawl space or basement should be noted. 

Areas where insulation is easily accessible (attic, 

crawl space, basement) should always be checked for 

dampness and adequacy of air spaces. 

It may be necessary to examine the building 

materials on the cold side of the building envelope 

to determine if a vapor retarder is present or has 

been improperly installed. Tightly built and wellinsulated homes require a properly installed vapor 

retarder to prevent moisture transfer through 

building materials. If a vapor retarder is absent or if 

it has been improperly installed, every point subject 

to air leakage could be a potential cause of condensation within the walls. Common problems include: 1) the installation of vapor retarder on the 

cold side of the wall surface resulting in condensation in the walls, 2) installation of low-perm 

retarders on both sides of a wall designed to prevent 

moisture intrusion can also prevent moisture from 

escaping; 3) breaks in the vapor barrier; and 4) the 

lack of a ground-cover vapor retarder in the crawl 

space. 

The building materials on the cold side of the home 

should be inspected to determine whether sheathing 

or siding may be acting as an unwanted vapor 

retarder, and the building should be evaluated to 

determine if there are areas where the vapor retarder 

was not installed (rim joists, between floors, and so 

forth). 

Heating, ventilating, and air-conditioning 

systems: The heating, ventilating, and air-conditioning systems should be checked for condition and 

obvious problems. Special attention should be 

given to the condition, operation, and maintenance 
Section 8 

of humidifiers and dehumidifiers (in-line and 

portable), water or swamp coolers, heat recovery 

ventilators; these should be examined for the 

presence of moisture, stagnant water, and slime 

growth. Filters and air clean'ing devices should be 

evaluated for the presence of dust buildup and 

moisture. 

It is important to determine if there have been any 

changes in the energy efficiency of the home or 

other factors which could affect the efficiency of the 

heating and cooling system. If the house has been 

weatherized and tightened, but the heating and 

cooling systems have not been upgraded, problems 

can result. The temperature settings that are 

typically maintained during the different seasons 

should be noted. 

Humidifiers which are commonly used include 

ultrasonic, steam, evaporative, warm-mist, and coolmist units. All humidifiers can be a source of 

microbial contamination, and they must be cleaned 

frequently. Portable and console humidifiers should 

be examined for the presence of film or scum on the 

water surface, on the sides or bottom of the tank, or 

on exposed motor parts. The presence of any of 

these conditions may indicate the presence of 

bacteria or fungi. A crusty deposit or scale within 

the tank, or on parts of the tank, or a white deposit 

in the surrounding area is minerals which have 

settled out of the water or become aerosolized, 

creating a surface where bacteria or fungi can grow. 

Ducting in crawl spaces should be examined for 

obvious openings. Fiberboard plenums should be 

evaluated, particularly in the absence of vapor 

barriers in the crawl space. Interior registers should 

be removed and ducts should be checked for signs of 

microbial growth and a buildup of dust. 

Crawl space, basement, and attic: The crawl 

space, basement and attic should be examined for 

moisture damage and/or standing water. Floor and 

ceiling joists and exposed sheathing should be 

checked for signs of rot, mildew, or mold. Rotting 

wood can be detected easily by tapping the wood as 

IAQ Reference Manual 

described previously or by using a sharp implement 

(ice pick, small chisel, screwdriver) to test the 

toughness of the wood. To perform this test, the 

implement is jabbed into the wood and pried up. 

Decayed or rotting wood breaks out with little 

resistance and in relatively short lengths; wood in 

good condition is hard to pry up, and it breaks into 

long slivers. 

Decayed wood can be affected by white rot (wood 

appears whiter than normal with dark lines bordering the discoloration), brown rot (brown or black 

discoloration), soft rot (wood is soft and cracked), 

and blue stain (a blue, brownish black, or steel-gray 

colored stain). White rot and brown rot are the 

most serious forms of damage, and removal of wood 

is indicated if these forms are present. 

Sumps and drains should be checked for proper 

capping and drainage (run water for 5 minutes and 

observe for water backup). The crawl space floor 

should be checked for the presence of a vapor 

retarder. Any standing water, loose insulation, 

wood, and paper products must be removed. Vents 

should be evaluated for condition, total number and 

size, and obstructions. 

The basement should be checked for additional 

signs of moisture-damp air, damp walls, seepage 

of water, efflorescence, and visible mold or mildew. 

Any insulation in the basement or attic should be 

checked for dampness. 

Measuring Biological Contaminants 

House Dust Mites 

House dust mites can be identified directly through 

air sampling or indirectly by analyzing dust 

samples. Air sampling is complicated by the fact 

that the allergen is associated with larger particles 

(> 10 microns) which may be removed rapidly from 

the air and are subject to reentrainment through 

routine activity. Dust mites can be reliably counted 

microscopically, but counting mites is not a direct 

measurement of allergen and it is subject to large 
IAQ Reference Manual 

sampling errors. Allergen assays are more rapid, 

direct measurements that are easily standardized and 

have accuracies of 620% (Platt Mills et al., 1990). 

A simple test is available in the U.S. for testing dust 

mite allergen levels indirectly by a semiquantitative 

analysis of guanine levels (ACAREX test kit) in 

house dust. Guanine is contained in the excreta of 

dust mites and other arachnids, but the dust mite 

appears to be the primary source of guanine in 

indoor dust. In this method, guanine is first 

dissolved out of the dust sample. The solution is 

then tested with a strip containing an azo reagent. 

A positive test is indicated by a red color which 

varies in intensity depending on the guanine 

concentration. Test kits can be purchased for about 

$15 for ten tests and $7.50 for four tests. Bischoff 

(1987) reports on evaluations of house dust mites 

using this test in European homes. 

Airborne Microorganisms 

In many instances the symptom history, combined 

with the walk-through inspection will be sufficient 

to determine if microbial contamination exists and 

is a likely cause of problems. At this stage of the 

investigation if no apparent microbial sources are 

found, it is unlikely that air sampling will provide 

additional, useful information (ACGIH, 1989). 

However, sampling may be required in some 

instances. If so, it is important to have adequate 

information and knowledge. The investigator must 

work closely with the laboratory to ensure the use 

of proper sampling techniques, correct enumeration 

of organisms, correct interpretation of data, and 

the development and use of a quality assurance 

program. 

The ACGIH Committee on Bioaerosols stresses that 

careful thought and planning must precede any 

sampling program. The investigator should be 

aware that there is no single sampling method 

which will recover all potential bioaerosol components, and air sampling rarely provides proof of 

inappropriate exposures to bioaerosols. It is especially important to utilize a laboratory that has 

Section 8 

mycologists and bacteriologists who are experienced 

in the assessment of environmental microbial problems. 

Some guidelines for sampling and analyzing fungi 

are provided below. These methods are appropriate 

for organisms that result in hypersensitivity diseases, but not for infectious disease-causing organisms such as bacteria and viruses. The reader should 

consult the ACGIH's guidelines and Chatigny 

(1983), Chatigny et al. (1983, 1989) for further 

information on sampling bioaerosols. 

Surface Sampling: A relatively simple technique 

that can be used in residential investigations is to 

collect surface samples using sterile cotton swabs 

that are premoistened with water to maintain 

viability of the collected organisms. An area that is 

about 25 cm2 (about 4 in2

) is swabbed and the 

collected material is innoculated directly onto the 

surface of culture plates. Also, bulk samples can be 

collected into sterile sample containers and then 

processed onto culture media; dilution may be 

required. Both of these methods can prove useful in 

identifying "hot spots." Used in conjunction with a 

symptom questionnaire, further sampling may not 

be required to make an informed judgment. Another relatively simple technique, cellophane-tape 

imprinting, can be used for the rapid identification 

of mold colonies growing on organic materials 

(Kozak et at., 1980). 

The ACGIH Committee on Bioaerosols does not 

recommend taking surface swabs and "bulk" 

samples unless these are taken in conjunction with a 

well-controlled indoor/outdoor sampling program. 

However, the Committee acknowledges that 

collecting these samples during the walk-through 

may prove useful if indoor air sampling is subsequently needed. (Burge and Solomon, 1987; 

ACGIH, 1989; Kozak et at., 1985). 

Air Sampling: The sampling of bioaerosols is 

similar to sampling for particulates. Biologicallyderived particles that can become airborne indoors 

range in size from less than 1 micron for viruses to 
SectionS 

over 200 microns for fungal spores. This large 

range in particle size and the variety of particles that 

can be present in the airstream combine to make 

sampling and characterization of bioaerosols a 

~hallenging task. The collection of qi.tantitative 

data requires special expertise and is expensive; 

several different sampling devices and analytical 

schemes may be required. For this reason, most 

investigators report qualitative results and these 

may be sufficient in many investigations. 

Sampling location should include both outdoors 

and indoors. The outdoor sample (from a site that is 

removed from obvious sources) serves as a reference 

point to determine whether or not amplification is 

occurring indoors. During nonresidential investigations outdoor samples should also be collected from 

the air intake ofbuildings. 

Indoors, samples should be collected in areas near 

occupants who complain of symptoms and those 

who do not. Samples should be collected from or 

near potential sources such as humidifiers and air 

inlet and exhaust diffusers at different times during 

the day. 

For example, in an office building samples can be 

collected before the HV AC is turned on and before 

workers arrive. During work hours, samples can be 

collected at the beginning of the day, when maximum occupancy occurs, and before and after 

operational changes are made in the HV AC system. 

Samples can also be collected at the end of the day, 

after occupants leave and with the HV AC off. 

Kozak eta/. (1985) recommend at least one outdoor 

sampling site to evaluate taxonomic groups and 

concentrations, multiple indoor studies with 

emphasis on areas with water damage, and at least 

one volumetric survey in the area suspected of 

having a problem. 

Sampling equipment for bioaerosol sampling 

includes gravity samplers, inertial impactors, and 

filtration samplers. Gravity samplers such as 

culture plates and adhesive-coated glass are the 

IAQ Reference Manual 

most widely used samplers, but these are not 

recommended by the Committee on Bioaerosols. 

The efficiency of sampling depends both on particle 

size and the movement of air over the sampling 

device. Gravity samplers tend to overestimate the 

concentration of large-sized particles, and underestimate smaller-sized particles which may be more 

important biologically. Another weakness of these 

devices is that they do not provide volumetric data. 

Exhibit 8-27 summarizes the samplers that have 

been recommended by the Committee on 

Bioaerosols. Of these samplers, the slit to agar 

samplers and the glass impingers are the most 

efficient and accurate. But this level of accuracy is 

not always needed and other samplers such as filter 

cassettes may be used. Filter cassettes underestimate viable aerosol concentrations, but they can be 

used in situations when high concentrations are 

suspected. Filter cassette samplers are not recommended for bacteria because of potentially low 

viability which results from drying; however, 

impingers with appropriate media can be used. 

In situations where the investigator does not know 

what agents to expect, a combination of samplers is 

recommended. A broad range of agents can be 

identified using a combination of slit sampler and 

visual identification, culture plate cascade samplers 

with several culture media, and either a filter 

sampler or liquid impinger followed by bioassay, 

biochemical, or immunological analysis (Burge and 

Solomon, 1987). Collected samples should be 

transported to the labo~atory within 24 hours, and 

source samples should be processed immediately. 

There may be instances when illness exists, but 

measured spore counts are low using the recommended techniques. In these situations large 

volume air samples can be collected either into a 

liquid or onto a filter. If the air flow rate of the 

sampler is greater than that provided by the ventilation system, samples can still be collected for 

identification of spores, but the data should be not 

be used for quantitative purposes. 
IAQ Reference Manual 

The ACGIH Committee on Bioaerosols recommends the following sampling modalities for 

organisms associated with specific fungal diseases: 

1) Histoplasmosis-sample at the source 

only; cannot culture from air samples; 

2) Aspergillosis-culture plate sieve or slit 

impactor with efficient collection to 1 J.Lm; 

3) Hypersensitivity pneumonitis-culture and 

particulate sieve or slit impactors with 

efficient collection to 1 J.lm or high-volume 

filtration when the antigen is known; 

4) Allergic asthma, rhinitis-culture and 

particulate impactors with known particle 

collection efficiency or high-volume 

filtration when the antigen is known. 

Quality assurance programs that begin with 

sample collection and end with data analysis are 

vital to the success of bioaerosol sampling. A 

quality assurance program includes, but is not 

limited to, proper sampler selection, sampler 

disinfection, routine calibration of flowrates, proper 

choice of media and checks for sterility, quality 

control procedures for analysis, and written protocols. In addition, it is important to use blank 

samples (duplicates or triplicates) for each culture 

medium used at the sampling and control sites. 

Samplers should be sterilized before each use, but 

this may not always be possible. Samplers that use 

culture plates should be swabbedwith alcohol or 

bleach before each use. Plastic culture plates are 

recommended, particularly if samples are to be 

mailed to a laboratory. Fluids for impingers should 

be sterile, and before the impinger is used it should 

be rinsed with sterile fluid. Filter cassettes can be 

presterilized before use, and the Committee suggests that disposable cassettes from major manufacturers are clean enough for most saprophytic 

sampling. 

Section 8 

Samplers should be calibrated according to the 

manufacturer's instructions before and after field 

use. Calibrations should be performed with the 

equipment set up as it will be used in the field; 

sampling pumps should not be calibrated unless 

they are in the sampling train. 

Enumeration of organisms which are collected 

can be determined by a variety of methods including culture assay, bioassay, immunological assay, 

biochemical assay, and direct microscopy. These 

methods which are summarized below are discussed 

further by Burge and Solomon (1987; Platts-Mills 

eta!., 1989). Consultation with the analyst is 

advisable before sampling. The type of analysis 

should be specified to the laboratory before sampling begins. 

Cultural assays involve growing the collected 

organisms and identifying them macroscopically, 

microscopically, or biochemically. These methods 

can be used with culture plate collectors, for 

processing eluates from filters, and for processing 

source samples such as swabs collected from contaminated surfaces. Cultural assays are appropriate 

when only viable organisms are of interest; for 

example, for infectious agents (Legionella, Staphylococcus) and invasive fungal pathogens (Aspergillus f). 

Culture plate assays, however, underestimate actual 

levels and the investigator should be aware of 

limitations of the method. 

Bioassays rely on a living substrate to indicate the 

prevalence of allergenic agents. Allergists use 

bioassays in skin testing. Human skin can react to 

microgram quantities of specific antigens which are 

typically introduced as extracts of dust, pollens, or 

spores, but suitably prepared filter eluates and 

impinger fluids can also be used. 

Immunological assays are newer methods that are 

proving increasingly useful. These tests can be 

useful in studying building-related epidemics such 

as hypersensitivity pneumonitis, humidifier fever, or 
Section 8 

residential problems such mite and cockroach 

antigens, animal-derived sensitizers, and fungalrelated antigens. 

Direct microscopy is useful for the identification and 

counting of morphologically distinctive particles or 

total fimpal spores. Total colony counts (CFU/m3

) 

are calculated l:,y clividing the adjusted number of 

colonies on the plate by t~1e total volume of air 

sampled in cubic meters. In order to facilitate the · 

identification of sources and amplification sites for 

microorganisms, the Committee on Bioaerosols 

recommends identifying the predominant taxonomic groups for fungi at a minimum. In addition, 

viable microorganisms that are present in concentrations greater than 75 CFU/m3 should be identified. 

Interpretation of Biological 

Contaminant Data 

Fungi 

If the walk-through reveals the presence of overt 

mold or mildew contamination (for example, mold 

covering a portion of a wall or floor underlayment), 

sampling is generally not required. Evidence of 

overt contamination is sufficient for recommending 

control measures, and these may be enough to bring 

relief. 

If sampling is conducted, the interpretation of data 

is complicated by the complexity of natural aerosols 

and the large population variances that are encountered. There are no published standards for acceptable exposures to saprophytic aerosols in indoor 

environments. There is no agreement on exact 

levels of fungal bioaerosols which are responsible for 

the onset of disease, nor is there adequate information on dose-effect relationships. 

Some allergists consider fungal levels of 1000 CFU/ 

m3 to be unacceptable to sensitive individuals 

(Tyndall et al., 1987), but levels lower than this 

have been shown to be problematic (Morey, 1988). 

Ohgke et al. (1987) have identified levels of 100 

CFU/m3 to be indicative of fungal colonization. 

IAQ Reference Manual 

Some researchers suggest that levels greater than 

500 CFU/m3 are high enough to warrant a detailed 

environmental survey (Gammage and Kerbel, 

1987). 

Indoor vs outdoor levels: Indoor levels of saprophytic organisms can also be compared to outdoor 

levels to evaluate if a problem exists. During the 

growing season outdoor fungus spore concentrations 

have been reported to range from 1000/m3 to 

100,000/m3 of air (Burge, 1987). If outdoor air is 

the only source, indoor levels of pollen and fungus 

spores are likely to be in the range of 10% to 40% 

of outdoor levels. Levels in mechanically ventilated 

buildings are generally less than 10% of outdoor 

levels depending on the quality of filtration (Burge, 

1988). 

Another method that can be used to compare indoor 

levels to those outdoors is rank order assessment. In 

this method individual taxa are identified and listed 

in descending order of importance for both indoor 

and outdoor locations. A nonparametric statistical 

test such as the Spearman rank order correlation can 

then be used to determine statistical significance of 

differences between the indoor and outdoor ranking. 

Mites 

It is not clear what level of dust mites or dust mite 

allergens should be regarded as a risk level, nor is it 

clear if floor dust levels and exposure are related in 

the same way for different allergens (cat, dust mites, 

and so forth). Proposed values of 2 J.!g/ g Group I 

Dermatophagoides allergen (equivalent to 100 mites/g 

dust or 0.6 mg guanine/g dust) have been suggested 

as a risk factor for sensitization, the development of 

bronchial reactivity, and symptomatic asthma; 

10 J.!g/g Group I allergen (or 500 mites/g dust) 

should be regarded as a risk factor for acute attacks 

of asthma (Platts-Mills et al., 1988). 

Bacteria 

Legionnella can be isolated from a variety of sources 

indoors (humidifiers, shower heads, hot water tanks, 
IAQ Reference Manual 

and so forth). The significance of these findings, 

however, is .not clear. If a known case of disease has 

occured, sources must be cleaned and disinfected. 

In the absence of disease, each case must be evaluated individually. 

Mitigation Advice for Bio'logical 

Contaminants 

Efforts to control microbial growth and the dispersion of allergens in residential and office settings 

should initially focus on removing the offending 

agent or contaminated material. After initial 

control has been achieved, the basic requirements 

for growth (food and water) should be removed and 

goo_d housekeeping activities should be maintained. 

In some cases, the removal of the offending agent or 

source will be direct and simple; for example, 

removing a cat or portable humidifier in a residence. 

In other cases, removal may be difficult or impossible (contaminated floor joists or air ducts in an 

office or residence). In some of these instances, 

cleaning, disinfection, and drying may be effective. 

After remedial actions have been taken, it is important to reevaluate the original complaint both in 

terms of symptoms and sampling. Sensitized 

individuals should be interviewed to determine if 

remedial action has been effective. If sampling is 

conducted, the area may need to be resampled using 

the same protocol. The occupants should be 

encouraged to report any signs of microbial 

regrowth. 

In some office situations personnel may have to be 

reassigned to another area even after remedial action 

because the offending agents have not been eliminated. · Relocation may also be needed in some 

residential problems. The investigator should _ 

consult with the attending physician to verify the 

condition of sensitized individuals and determine if 

further action is needed. 

Section 8 

House Dust Mites/ Animal Danders/ 

Plants 

A variety of measures have been recommended for 

reducing dust mite populations and symptoms in 

mite-sensitive asthmatic children. These include 

replacing feather and down pillows with pillows 

that have synthetic fillings; thoroughly vacuuming 

mattresses, pillows, carpets, and other furn\ture; 

covering the mattress and box springs with plastic; 

and damp wiping the mattress and box springs 

(Sarsfield et al., 1974; Murray and Ferguson, 1983; 

Mathison et al., 1982). However, other studies have 

not found these measures to be effective. 

Of these methods, removal of carpeting and fibrous 

furniture coverings may be effective. High efficiency filtration systems are probably not effective 

because the dust quickly settles after becoming 

airborne. 

Frequent vacuuming using conventional machines is 

probably not effective because dust particles are not 

efficiently collected in the size range which has the 

greatest allergenic potential. Vacuums employing 

steam should be avoided because they may increase 

mite proliferation by increasing warmth and 

moisture levels. Vacuum attachments which 

prevent the release of collected particulates may be 

more effective than conventional vacuums alone. 

HEPA-type vacuums are also more effective. 

Enclosing the mattress and box spring in plastic 

covers can be effective; these can be purchased from 

department stores or purchased from allergy 

specialty supply companies. Even when these are 

used, it is important for all bedding to be removed 

and washed each week in a hot wash and rinse cycle 

(a water temperature of 130°F is needed to kill 

mites). The liners of waterbeds should also be 

washed with hot water on a weekly basis. 

Dust mite populations can also be controlled by 

applying acaricides to mite-infested materials; the 
Section 8 

use of these chemicals should be considered cautiously to avoid potentially dangerous products and 

application methods. Benzyl benzoate (4.6%) can 

be applied as a dry powder to materials such as 

carpets, followed by vacuuming to remove the 

miticide and killed mites. Although this miticide 

is considered to be safe (Morgan, 1989), it is 

important to remove all of the miticide before 

allowing children or pets to reenter the area. If 

residues remain, irritation effects could result from 

contact. Ingestion of toxic amounts can result in 

seizures. 

Since avoidance measures have not been as effective 

as'desired, Korsgaard (1983) has proposed climate 

control as a potentially effective strategy for reducing mite populations. Specifically, mite populations 

can be reduced if indoor humidity levels are maintained below 45%. Anderson and Korsgaard (1986) 

have suggested designing new and remodeled 

buildings so that interior environmental temperature and humidity conditions will control the 

number of house dust mites to less than 100 mites 

per gram of dust. 

Removal of pets from household interiors may be 

required to avoid allergic responses. If an individual 

is sensitive to plant pollens, removal of interior 

plants is not needed, providing that flowering 

plants are not allowed to pollinate. Air-conditioning and air filtration are usually effective in removing outdoor pollen from the circulating air. 

Airborne Microorganisms 

The growth and dispersion of microorganisms can 

be controlled by maintaining the proper moisture 

balance in the home; some specific strategies which 

can be implemented are as follows. 

Outdoor Environment 

Any obstructions to airflow should be removed; for 

example, firewood should be relocated to an area 

away from the house. Problematic trees and shrubs 

IAQ Reference Manual 

should be pruned or removed. If bird droppings are 

a problem, nesting areas and feeders should be 

removed or relocated. Trash, garbage, and other 

food and harborage should be removed. 

Chronic dampness near the structure can be eliminated by ensuring that all surface drainage slopes 

away from the house. Porous borders such as 

washed gravel can be installed around foundations 

to facilitate drainage. Perimeter footing drains can 

be installed, but this is a relatively costly procedure. 

These drains should be installed in new construction 

if drainage is poor. If a high water table is a 

problem, the crawl space can be ventilated and a 

ground water retarder can be installed. Drainage 

problems in the basement and crawl space can be 

solved by sump pumps, drain pipes, or drain tiles. 

Exterior of the House 

The exterior of rhe house should be kept in good 

repair; this includes painting if needed; repairing or 

replacing roofs, flashings, chimneys, vents, soffits, 

fascias, siding, and so forth.' Downspouts should be 

installed, cleaned, or repaired as needed to ensure 

proper drainage. Foundation cracks and any entry 

points for rodents should be repaired. 

The House and Its Interior 

Indications that moisture control is needed indoors 

include humidity greater than 50%; a sensation of 

dampness; lingering odors; or the presence of visible 

contamination, water damaged or rotting surfaces, 

and condensation. 

Excessive humidity indoors can be eliminated by 

four general approaches: 1) eliminate unnecessary 

evaporation and sources; 2) discharge moisture to 

the outdoor air; 3) ventilate the interior; and 4) 

prevent condensation from occuring by providing 

the proper barriers. 

Ventilation and air circztlation: If high outdoor 

humidity is a seasonal or year around problem, 
IAQ Reference Manual 

crawl spaces, attics, and interior spaces should be 

ventilated. Ventilation can also be increased 

through wall vents or window vents. 

Bathrooms and kitchens should be vented to the 

exterior, and venting fans should be used. In the 

bathroom ventilation can be provided by windows 

or a fan rated at about 100 cfm. In the kitchen, a 

fan rated at about 100 cfm for conventional stoves is 

adequate, but 400 cfm and greater may be needed 

for draft stoves. A central exhaust fan or attic fan 

may be needed. 

Aquaria should be covered; too many houseplants 

can also pose problems. Clothes dryers should not 

be vented indoors, to the crawl space, or to the attic. 

If there is less than 2 50 ft2 per person or animal, 

increased circulation and ventilation alone may solve 

the problem, but dehumidifiers may also be needed. 

Visible mold and mildew: Smooth surfaces that 

have been contaminated should be washed and 

disinfected. A dilute bleach solution (1:10 to 1:50 

solution) is recommended by the Committee on 

Bioaerosols (ACGIH, 1989). Stronger solutions 

may be needed. Adequate ventilation and proper 

protective equipment should be used during cleaning. 

Other disinfecting agents include phenol compounds (Lysol), ethylene oxide for items that cannot 

be discarded or would be damaged by water, and 

paraformaldehyde. UV light can be used for 

bacteria, but it is not adequate for fungal spores 

(Burge, 1985). 

Porous materials that are contaminated will probably require removal and disposal. These materials 

can include carpets and pads, upholstery, ceiling 

tiles, paper, leather, wicker or straw baskets, wall 

coverings, window frames, baseboards, and others. 

In some instances, particularly aggressive action 

may be needed such as the removal of subflooring or 

even floor joists. 

Mter interior walls, floors, and furniture have been 

cleaned, disinfected, and dried, they can be sealed 

with impermeable finishes such as alkyd paints. 

Section 8 

As a preventive measure in the bathroom, regular 

cleaning of all surfaces is a must. Vinegar, borax, 

and bleach solutions (1 cup to 1 gallon of water} and 

trisodium phosphate solutions ( 4 T to 1 gallon of 

hot water) are inexpensive, but effective cleaning 

solutions. 

Condensation on surfaces, dampness, and standing water: Any condensation or standing water 

must be eliminated. Dripping pipes should be 

identified and repaired. Plants should not be 

overwatered or allowed to stand in water. Increased 

air circulation and ventilation may be needed. 

In the bathroom, dampness can be controlled by 

careful caulking to seal all seams around tubs, 

baseboards, sinks, and shower doors. Tight fitting 

shower doors of glass and metal are preferred to 

plastic shower curtains. Insulation under the tub, 

cold water pipe insulation, and insulated toilet tank 

liners can reduce sweating. 

Floor materials in the bathroom and kitchen should 

be impervious to water; carpeting should be discouraged (it is not allowed in building codes). 

Walls and ceiling paints should be waterproof; 

alkyd oil paints are preferred. An exception to 

waterproofing ceilings is if humidity will be 

removed through attic spaces. Bathroom windows 

with metal or plastic frames are easiest to dean and 

keep dry; wood frames require more maintenance. 

Greenhouses should have floor drains and drainage 

built into beds and planters to prevent standing 

water. To minimize the collection of water on 

expOsed surfaces, all cracks should be sealed and the 

space should be well ventilated (preferably by an 

automatic ventilator): If greenhouse humidity is 

high, air circulation from it into the living space 

may not be advisable. Vapor retarders and insulation should be evaluated and corrected as needed. 

Damp insulation and wood in the attic may require 

replacement of insulation, installation of vapor 

retarders, or the installation of natural or mechanical 

exhaust vents. 
-

lliil 

Section 8 

Vapor retarders that are not installed properly (for 

example joints and penetrations are not sealed) can 

be upgraded by a skilled homeowner or a skilled 

tradesperson. If a double vapor retarder (on both 

sides of a wall surface) is causing problems, or if the 

vapor retarder is on the cold side, the remedy may 

be to place a vapor retarder on the warm side only. 

There are several strategies for waterproofing walls. 

Vapor retarding paints can be applied. Another 

method is to remove the wallboard or plaster, staple 

up sheets of polyethylene (4 to 6 mils), and replace 

the wallboard with new material. Other methods 

can also be used. 

Concrete block homes (1940s and 1950s construction) that have not been renovated may have 

condensation problems because of poor circulation 

of warmed air. These homes often require the 

installation of second wall against the existing wall. 

Insulation can be stapled between the studs, and a 

vapor retarder can be installed over the insulation. 

Wallboard is then nailed to the framing. Door and 

window frames must also be adjusted. 

Heatitzg, ventilating, and air-conditioning 

systems: Improperly sized heating, ventilating, and 

air-conditioning systems should be corrected. Any 

venting systems that introduce potential aerosols 

into the living space should be corrected. Intake 

ducts should be relocated, or sources of contamination should be removed. 

In general, any condensation pans or drainage tubes 

in the heating, ventilating, and air-conditioning 

systems should be checked on a regular basis. 

Drainage tubes that are plugged should be cleaned; 

drain pans should be emptied and slanted toward 

drains. Regular cleaning and maintenance of-all 

system components is a must. 

Condensation in the venting system of mid-efficiency furnaces (or other furnaces) may be solved by 

checking and correcting the size of vents; these 

vents should not be insulated unless specifically 

approved by the manufacturer. 

IAQ Reference Manual 

If disinfection of the heating, ventilating, or airconditioning system components is required, the 

system should be off during cleaning. Disinfecting 

agents should not be sprayed through the system. 

Removal and replacement of entire units or ducts 

may be required if the contamination is heavy or if 

components are not accessible. 

The continuous use of humidifiers particularly in 

new houses (which have a naturally higher moisture 

content from construction materials) and in houses 

without vapor retarders can be a problem. If 

humidifiers are used, water should be changed daily, 

and the tank should be emptied completely before 

filling. If the tank is not removable, it should be 

_cleaned according to the manufacturer's instructions. If instructions are not available, units should 

be free of scale and slime at all times. These units 

should be disinfected (5% bleach or 3% hydrogen 

peroxide solution) every third day (ACGHI, 1989). 

Antifoulant agents that are added to humidifier 

fluid reservoirs to control microbial populations can 

become aerosolized, and they may not be effective 

(Burge eta!., 1980). 

The Consumer Product Safety Commission (1988) 

recommends against the use of tap water in humidifiers' to minimize mineralized aerosols (does not 

appear to be a problem with evaporative humidifiers). Instead, distilled or demineralized water 

should be used to reduce the buildup of scale and 

release of-aerosols. If demineralization cartridges or 

filters are recommended for a particular unit, they 

should be used. Before humidifiers are stored, the 

tank should be drained and cleaned; the units 

should also be cleaned again prior to use. 

Air conditioners are effec;tive in reducing moisture 

levels indoors and indoor concentrations of 

bioaerosols, but they can also act as sources of 

contamination. Filters should be cleaned or replaced regularly (once/month to once/3 months). 

Air conditioner condensation should be drained to 

the outside, not to the crawl space. 
IAQ Reference Manual 

Condensate from the air cooling coil of air conditioners should be collected and diverted to the 

outside of the building or other approved location; 

any other drainage methods such as dischage into a 

· crawl space, under concrete slabs, or through a rigid 

connection into the building sanitary drainage 

system, must be corrected. If drainage is into the 

sewer system, an observable air gap must be installed if it is not present; this prevents sewer gas 

from entering the heating and cooling system. 

If surface condensation is a possibility, all refrigerant ducts, pipes, and fittings installed within a 

structure should be sealed, insulated, and vapor 

retarders should be added as needed. 

If the cooling coil or air-conditioning unit is located 

above a living space or if structural damage could 

result from condensate overflow additional measures 

may be needed. These include installing an additiona! watertight pan of corrosion resistant metal 

beneath the cooling coil or unit to catch overflow 

condensate due to a clogged condensate drain. 

Water or "swamp" coolers are not recommended in 

humid climates because they are a constant source of 

humidity. 

Basement, crawl space; and attic: Standing water 

in the crawl space should be removed by a properly 

working sump pump. Loose wood, paper, and 

insulation should be removed. 

Vent openings should be clear offoundation 

plantings and other obstructions to airflow. An 

adequate number of vents should be installed 

(oriented to take advantage of the prevailing wind) 

and vents should be kept open during the summer 

to provide good airflow in the crawl space. If 

foundation vents are not sufficient to provided the 

required ventilation, an exhaust fan can be installed. 

Uninsulated heating ducts which are located in the 

crawl space should be wrapped at the joints with 

duct tape and insulated. 

SectionS 

Ground moisture can be controlled in the crawl 

space by placing a layer of sheet plastic on leveled 

soil, followed by a 3 inch layer of sand. The foundation should be waterproofed on the outside wall 

(described below) and a drain tile should be installed around the footings to drain away any water. 

An alternadve method of controlling ground 

moisture in the crawl space is to seal the undersides 

of the floor joists with a vapor retarder. Ducts or 

pipes that pass through the retarder are sealed with 

duct tape to the retarder. A moisture-tight surface 

is needed, and this method may not be practical if 

many ducts or pipes are present. 

In the basement, leaks should be sealed; cementbased sealants can be used. The walls and floors can 

be covered with a waterproofing compound. If this 

measure does not work, leakage can be stopped by 

adding a drain tile and waterproofing the foundation. This can be costly because excavation of the 

foundation is required. After the foundation has 

been excavated and the drain tile installed, the 

foundation walls are coated with a thick application 

of asphalt roofing cement (from the footing to grade 

level). A vapor barrier of black 4 mil polyethylene 

film is applied onto the asphalt roofing cement. 

Joints should be overlapped, and the entire barrier 

should be coated with a thin application of the 

roofing cement. The filled area should slope away 

from the house (about 1 in/ft). A knowledgeable 

contractor should be consulted for leakproofing 

operations. 

It may be necessary to install a heater and/or 

dehumidifier in the basement to control moisture. 

Showers in the basement should be discouraged. 

Sumps or other openings to the ground should be 

sealed, and water traps must be properly maintained. If possible a source of light, preferable 

daylight, should be introduced. 

In new construction a vapor retarder should be 

installed in crawl spaces and before pouring concrete 

slab floors and basements. 
Exhillit 8·26. Environ ... nta1l survey for• for evaluating the prenace of poteathrlsources of aller1eas. 

Date. ____ _ 

N~·----------------------- Phone _____________ __ 

Addr~s~------------------------------------

1. OU1DOOR SURVEY (describe each category that applies) 

a. weather conditions at time of survey---------------------

b. cultivated fields----------------------------------

c. number of trees ----------------------------------

d. other landscaping----------------------------------

e. shade level adjacent to structure-----------------------

f. soil drainage-------------------------------------

g. presence of organic debris --------------------------

h. any unusual outdoor activity prior to survey----------------

i. presence of accumulated bird droppings -----------------

2. EXTERIOR OF HOUSE 

a. Evaluate the condition of the exterior shell (warping, blistering 

paint, rot or mildew on wood surfaces). ----------------

b. Evaluate the condition of the exterior foundation (water stains, 

efflorescence, crumbling concrete, rot or mildew on wood surfaces). 

AgeofHome ____________ _ 

Construction Material ________ Number of Occupants __ _ 

c. Exterior footing drains present? If y~, is the point of discharge dear 

or buried? 

d. Evaluate condition of downspouts? Do they hamper drainage away 

from the house? 

e. Evaluate condition of roofing material (peeling or flaking, evidence 

of ice dams). 

f. Are attic vents pr~ent? If y~. d~cribe type and number. ____ __ 

g. Evaluate condition of chimneys (capping, chimney cracks, n~ts). 

3. EVIDENCE OF INTERIOR WATER DAMAGE OR MOISTURE 

a. Relative humidity-----------------------------'--

b. Is there a sensation of dampness or a musty odor? If yes, give locations. 
Exhibit 8·26. Environmental survey form for evaluating the presence of potential sources of allergens ltonflnuedJ. 

c. Is there any visible mold, mildew, or rot? If yes, give locations. 

d. Is condensation present on windows or smooth surfaces? If yes, give 

locations. 

e. Is there evidence of water damage or dampness? (around tub and 

shower, behind and under toilet, behind sinks, at baseboards, around 

splash boards, ceilings, walls, around skylights) If yes, give locations. 

f. Is stadding water present? If yes, give locations. 

g. Has there been any water disaster in the history of the home? (water 

softener/washer/bathtub/toilet overflow, chronic interior water leaks, 

roof leaks, basement leaks, backflushing of sumps) Describe in detail. 

4. HEATING SYSTEM: ON or Off during survey (circle one) 

a. forced air b. electric 

c. gravity d. fireplace 

e. space heater (indicate type--------------

f. Heat recovery ventilators. If present, describe condition maintenance 

procedures, and frequency of maintenance. Especially note if condensation removal is needed.----------------

g. Have any renovations, weatherproofing, or other energy efficiency 

measures occurred since the original system was installed? If yes, 

describe:--------------------

h. Has the heating system been changed? If yes, describe: ----

(continued next page) 
Exhibit 8·26. Enviro·nmental swrvey form fo·r evaluating the presence of potential sources of allergens {coatluedJ. 

5. AIR CLEANING DEVICES (circle one) 

ON or OFF during survey (circle) PORTABLE or CENTRAL (circle) 

a. HEPA ___ _ b. electrostatic ____ _ 

c. other ___________________ _ 

d. Evaluate condition, maintenance procedures, and frequency of 

maintenance. _________________ _ 

6. AIR-CONDITIONING SYSTEM ON or OFF during survey 

(circle one) 

a. portable __ _ b. central ___ c. swamp cooler __ _ 

d. Evaluate condition, maintenance procedures, and frequency of 

maintenance. Especially note condensate removal procedures. 

e. Has the cooling system been changed? If so, describe: ___ _ 

7. HUMIDIFICATION OR DEHUMIDIFICATION DEVICE 

ON or OFF during survey (check one) 

a. humidifier b. dehumidifier 

c. in-line __ d. portable __ 

e. How often is the device used?------------

f. If present, evaluate condition and cleaning procedures. 

g. How frequently is the unit cleaned?----------

h. Are slime or scale present? -------------

8. PRESENCE OF ORGANIC SUBSTRATES 

a. Are there wicker or straw items? If yes, check for history of water 

damage. 
Exhibit 8·26. Environmental survey form for evaluating the presence of potential· sources of allergens-(tontinued}. 

b. Are there indoor pets? If yes, which and how many? 

c. What type of bedding is used? Is it cleaned regularly? 

d. Are there house plants? If so, how many, and location. Is there an 

attached greenhouse? Is greenhouse air circulated into the living 

space? 

e. Is there carpeting? If so, what percent of the floor is covered? 

Describe condition (note water stains, dust loading). Note if carpeting is present in bathrooms. 

9. BASEMENT,CRAWLSPACE,ANDATfiC 

a. Is there standing water in the basement or crawl space? If yes, check 

fur length of time present.--------------

b. Check sumps and drains for propet drainage by running water in 

them with a hose for about 5:min.to see if they back up. Are the 

drains dear?-------------------

c. Are there cracks or seepage in the basement?--------

d. Are vapor retardets present in the crawl space, basement (floors or 

walls), or attic? 

e. Are ducts, pipes, and fittings properly insulated in the basement, 

crawl space, or attic?----------------

(continued next page) 
Exhibit 8·26. Envi,ronmental su,rvey for• for evaluating the presence of potential sources of crl1lergens ((onfln,uedJ. 

f. Are there signs of water~damaged wood, damp or wet insulation, or 

visible mold in the basement, crawl space, or attic? ------

g. Do the attic, basement, and crawl space have adequate ventilation? 

Describe vents and exhaust fans. 

h. Do the attic or crawl space act as air plenums? If yes, are there prob~ 

lems associated with this use? 

NOTES: 
Exhibit8·27. Commonly used samplers for collecting indoor bioaerosols. 

PRINCIPLE OF SAMPLING RECOMMENDED MINIMUM 

SAMPLER OPERATION RATE,lpm SAMPLE TIME CFU DETECTED APPLICATIONS/REMARKS 

L Slit to agar impattor impaction onto 30-700 variable; 1-60 min Provides information on 

agar on rotating continuous or 7-day aerosol concentration over 

plate or stationary time; bulky AC operation 

plate 

2. Sieve type impactors 

a. single-stage portable impaction onto 90 or 185 0.5 or 0.3 min 22 or 16 About 40% as efficient as slit 

agar on "rodac" sampler; portable, useful as 

plate probe 

b. single-stage impactor impaction onto 28 1 min 35 Nearly as efficient 

agar, 100 mm as slit, bulky to handle, AC 

plates operation 

c. two-stage impactor impaction onto 28 1-5 min 35 Same as 2b but 

agar, two 100 mm divides samples into 

plates respirable and nonrespirable fractions 

3. Filter cassettes filtration 1-2 15-60 min or 8 hr 8-33 Some dessication loss; 

portable, inexpensive, 

useful as a probe 

4. High-volnrne filtration electrostatic up to 1000 variable 

collection 

into liquid 

5. All glass impingers impingement 12.5 30 min 3 Fungi require wetting agent; 

into liquid useful over wide range of 

panicle concentrations 

6. Centrifugal sampler impaction onto 40 0.5 min 50 Cannot be calibrated; small, 

agar, plastic strips pottable, useful as a probe 

SOURCE: .Adapted from ACGIH (1989) 
Sectiotz. 8 

REFERENCES 

American Conference of Governmental Industrial Hygienists 

(ACGIH). 1989. G11idelines fer the Assessment ofBioaerosols in the 

IndiXIr Environment. ACGIH: Cincinnati, OH. 

Anderson, I. andJ. Korsgaard. 1986. "Asthma and the indoor 

environment: Assessment of the health implications of high 

humidity." Environ. Inti. 12: 121-127. 

American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). 1988. 1988 ASHRAE Handbook. 

Equipment. ASHRAE: Atlanta, GA. 

American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc. (ASHRAE). 1989. 1989 ASHRAE 

F11ndamentals. I-P edition. ASHRAE: Atlanta, GA. 

Bischoff, E. 1987. "Sources of pollution of indoor air by mite 

allergen-containing house dust." Indoor Air '87. Vol. 2. 

Environmental Tobacco Smoke, M11lticomponent St11dies, Radon, Sick 

Buildings, Odors aud Irritants, Hyperreactivities and Allergies. 

Oraniendruck GmbH: Berlin, Germany. pp. 7 42-7 46. 

Burge, H.A. 1985. "Fungus allergens." Clin. Rev. Allergy. 3: 

519-329. 

Burge, H.A. 1987. "Toxogenic potential of indoor microbial 

aerosols." Short-term bioa;says in the analysis of complex environmental mixtures. S.S. Sandhu, D.M. DeMarini, M.J. Mass, M.M. 

Moore andJ.L. Mumford (eds). Plenum Publishing Corp. 

Burge, H.A. 1988. "Environmental Allergy: Definition, 

Causes, Conrrol." IAQ 88 Engineering Solutions to Indoer Air 

Probltrns. ASHRAE: Atlanta, GA. pp. 3-9 

Burge, H.A. and W.R. Solomon. 1987. "Sampling and 

analysis of biological aerosols." Atm. Environ. 21(2): 451-456. 

Burge, H.A., W.R. Solomon, andJ.R. Boise. 1980. "Microbial 

prevalence in domestic humidifiers." Appl. Environ. Microbial. 

39(4): 840-844. 

Burr, M.L., A.S. St. Leger, and E. Neale. 1976. "Anti-mite 

measures in mite-sensitive adult asthma: A controlled trial." 

Lanm. l 0955): 333-355. 

Burr, M.L., B.V. Dean, T.G. Merrett, E. Neale, A.S. St. Leger, 

and E.R. Verrier-Jones. 1980. "Effects of anti-mite measures 

on children with mite-sensitive asthma: A controlled trial. 

Therax. 35: 506-512. 

. IAQ Reference Manual 

Chatigny, M.A. 1983. "Sampling airborne microorganisms." 

Air Sampling lnstroments for Eval11ation of Atmospheric Contaminants. 6th edition. P.J. Lioy {ed). ACGIH: Cincinnati, OH. 

Chatigny, M.A.,J.M. Macher, H. Burge, W.R. Solomon. 

1989. "Sampling airborne microorganisms and aeroallergens." 

Air Sampling Instruments for Evaluation of Atmospheric Contaminants. 7th edition. P.J. Lioy (ed). ACGIH: Cincinnati, OH. 

Chatigny, M.A., H. Wolochow, and D.O. Hinton. 1983. 

"Sampling Aeroallergens." Air Sampling Instruments for 

Evaluation of Atmospheric Contaminants. 6th edition, P.J. Lioy 

(ed). ACGIH: Cincinnati, OH. 

Gammage, R.B. and W.S. Kerbel. 1987. "American Industrial 

Hygiene Association Indoor Environmental Quality Reference 

Manual." Indoor Air '87. Vol. 3. Developing Countries, Guaranteeing Adeqt~ate Indoer Air Quality, Control Measures, Ventilation 

Effectiveness, Thermal Climate and Comfort, Policy and Strategies. 

Oraniendruck GmbH: Berlin, Germany. pp. 567-572. 

Korsgaard,J. 1982. "Preventive measures in house-dust 

allergy." Amer. Rev. Resp. Dis. 125: 80-84. 

Kozak, P.P.,J. Gallup, L.H. Cummins, and S.A. Gillman. 

1980. "Currently available methods for home mold surveys. I. 

Description of techniques." Ann. Allergy. 45: 85-89. 

Kozak, P.P., J. Gallup, L.H. Cummins, and S.A. Gillman. 

1985. "Endogenous mold exposure: Environmental risk co 

atopic and nona topic patients." Indoor Air and Human Health. 

R.B. Gammage and S.V. Kaye (eds). Lewis Publishers: 

Chelsea, MI. 

Mathison, D.A., D.D. Stevenson, and R.A. Simon. 1982. 

"Asthma and the home environment." Ann. Intern. Med. 97(1): 

128-130. 

Murray, A.B. and A.C. Ferguson. 1983. "Dust-free bedrooms 

in the treatment of asthmatic children with house dust or house 

dust mite allergy: A controlled trial." Pediatrics. 71: 418-422. 

National Center for Appropriate Technology (NCAT). 1983. 

Moisture and Home Energy Conservation. How to Detect, Solve, and 

Avoid Related Problems. NCAT: Butte, MT. 

Ohgke. J ., A. Geers, and J. Beckert. 1987. "Fungal load of 

indoor air in historical and newly constructed buildings used by 

public services. Indoor Air '87. Vol. 1. Volatile Organic 

Compounds, Combustion Gases, Particles and Fibers, Microbiological 

Agents. Oraniendruck GmbH: Berlin, Germany. pp. 681-

684. 
IAQ Reference Manual 

Platt-Mills, T.A.E., M.S. Chapman, S.M. Pollart, P.W. 

Heymann, and C.M. Luczynska. 1988. "Establishing health 

standards for indoor levels of foreign proteins." Presented at the 

81st Annual Meeting of the Air PolL Cont. Assoc. Dallas, TX. 

June 19-24. Paper No. 88-110.1. 

Sarsfield,J.K. 1974. "Role of house dust mites in childhood 

asthma." Arch. Dis. Child. 49: 711-716. 

Tyndall, R.L., C.S. Dudney, A.R. Hawthorne, R.Jernigan, K. 

Ironside, and P. Metler. 1987. "Microflora of the typical 

home." Indoor Air '87. Vol. 1. Volatile Organic Compounds, 

Combustion Gases, Particles and Fibers, Microbiological Agents. 

Oraniendruck GmbH: Berlin, Germany. pp. 617-621. 

Section 8 

Additional Information Sources 

Hedden, J. 1982. Heating, Cooling, Ventilation. Solar and 

Conventional. Creative Homeowner Press: Upper Saddle River, 

NJ. 

Kadulski, R. 1988. Residential Ventilation: Achieving Indoor Air 

Quality. The Drawing-Room Graphic Services Ltd.: North 

Vancouver, B.C., Canada. 

Lenchek, T., C. Mattock, and). Raabe. 1987. Superinsulated 

Design and Construction. Van Nostrand Reinhold Co. New 

York, NY. 

Mann, P.A. 1989. Illustrated Residential and Commercial 

Construction. Prentice Hall: Englewood Cliffs, NJ. 

*U.S. GOVERNMENT PRINTING OFFICE:1994-515-003/01048