Inside IAQ, Fall/Winter 1998 Page 1

United States Environmental Office of Research and Development

Protection Agency Research Triangle Park, NC 27711

EPA/600/N-98/003 Fall/Winter 1998

 EPA Inside IAQ

EPA's Indoor Air Quality Research Update

In This Issue Page

Evaluation of Low-VOC Latex Paints ...... 1

A Compilation of Data on Emissions

 from Indoor Sources .................. 2

Volatile Organic Emissions from Printed

 Circuit Board Laminates ............... 6

Factors Influencing IAQ, Immunity,

 and Health ......................... 9

Modeling Emissions From Water-Based

 Cleaning Supplies ................... 10

Antimicrobial Agents Used in HVAC Systems 12

Summaries of Recent Publications ........ 12

Glossary ........................... 15

Inside IAQ is distributed twice a year and

highlights indoor air quality (IAQ) research

conducted by EPA’s National Risk Management

Research Laboratory’s (NRMRL’s) Indoor

Environment Management Branch (IEMB) and

other parts of EPA’s Office of Research and

Development.

If you would like to be added to or removed from

the mailing list, please mail, fax, or e-mail your

name and address to;

Inside IAQ, Attn. Kelly Leovic

U.S. EPA - MD-54

Research Triangle Park, NC 27711

Fax: 919-541-2157

E-Mail: kleovic@engineer.aeerl.epa.gov

Also, check our home page on the Internet at:

http//www.epa.gov/docs/crb/iemb/iembhp.htm

EVALUATION OF LOW-VOC LATEX PAINTS

Low-volatile organic compound (VOC) latex paints are advertised as the

"perfect choice" for application in occupied buildings (e.g., hospitals,

nursing homes, schools, hotels, offices, and homes) during normal

business hours. IEMB recently evaluated four commercially available

low-VOC interior latex paints. Formaldehyde emissions were detected

in two of the paints, and detailed analyses were performed on the one

paint with the highest formaldehyde emissions. This paint is promoted

by its manufacturer as "no solvent" and "VOC free" based on EPA

Reference Method 24. The sales brochure claims "virtually no harmful

emissions into the air" and "no unfriendly or irritable odors."

A bulk analysis was performed by extracting the paint with methanol

and then analyzing the extract by gas chromatography/mass

spectrometry (GC/MS). While Method 24 measures only the total

volatile organic compound (TVOC) content, bulk analysis provides more

accurate and precise data for the content of individual VOCs. It was

found that most of the individual VOC concentrations in the paint were

below or near the quantification limit of the analytical techniques used.

The TVOC content (less than 0.1 wt.%) was well below that (about 5

wt.%) of an ordinary latex paint.

Small chamber tests were also performed on the paint. The flow-through,

dynamic chambers have a volume of 53 liters and are constructed with

electropolished stainless steel interior surfaces to minimize adsorption of

VOCs. Small fans were used to enhance mixing and provide a velocity

near the test surface of 5–10 cm/s, which is typical of indoor

environments. Emissions testing was conducted by placing freshly

painted (2–3 minutes) gypsumboard (16.3 x 16.3 cm) in the chamber,

painted side up. The chamber was closed, and clean air (< 5μg/m3

TVOCs) flow was started through the chamber. A flow rate of 0.44

L/min, equivalent to 0.5 air change per hour, was used. Testing was

conducted at 23EC with an inlet relative humidity (RH) of 50%.

Small chamber tests also showed very low VOC emissions for this paint;

however, the peak concentration of formaldehyde in the chamber air

reached as high as 2.0 mg/m3about 30 minutes after painting. The

chamber air formaldehyde concentration decreased by about 85% in the

(Continued on Page 2)
Inside IAQ, Fall/Winter 1998 Page 2

first 24 hours, and the concentration decrease slowed down

considerably in the second 24 hour period. After 120 hours,

the formaldehyde concentration was 0.16 mg/m3.

Formaldehyde is a primary upper respiratory tract irritant,

and its odor is characterized as "pungent." The lowest listed

odor detection threshold is 0.04 mg/m3. Symptoms of eye,

nose, and throat irritation, such as tearing, running nose, and

a burning sensation in these areas, are relatively common with

formaldehyde exposure. Formaldehyde is also classified as a

probable carcinogen based on sufficient evidence in animal

studies. The World Health Organization guideline for indoor

air formaldehyde concentrations is 0.1 mg/m3. The U.S.

Department of Housing and Urban Development recommends

that indoor formaldehyde concentrations from all sources not

exceed 0.5 mg/m3. The California Air Resources Board

recommends for homes an "action level" of 0.12 mg/m3 and

a "target level” of 0.06 mg/m3 or lower.

It was suspected and later confirmed that the biocide used in the

paint was a source of the formaldehyde (up to 50%). (Biocide is

used as an additive to prevent paint degradation by microbial

growth.) However, the source of the remainder of the

formaldehyde is not certain, though it is possible that it is from

the paint formulation, side reactions, or other additives. 

The results illustrate that “no-VOC” does not necessarily

mean no-emissions. The common indoor air definition of

VOC only includes those organic compounds with boiling

points between 50 and 260oC. A number of hazardous air

pollutants (e.g., formaldehyde with a boiling point of -21oC)

are not accounted for by this definition. Also, the VOC

contained in the bulk paint may not be the VOC emitted since

VOCs can be formed as byproducts of chemical reactions

after the paint is applied.

The results also indicate that EPA Reference Method 24 is

probably not an adequate method for measuring the VOC

content of low-VOC latex paints. Since it is a gravimetric

method relying on the difference between weight loss upon

heating and water content of the sample paint, the analytical

precision is 1.5 and 4.7% for within- and between-laboratory

data, respectively. Current bulk analysis and emission test

results showed that the VOC contents of low-VOC latex

paints (e.g., less than 0.1%) are well within the uncertainty

range of Method 24, and the method is apparently not precise

enough to accurately define the VOC content of those paints.

IEMB has shared the results from this study with the paint

manufacturer who was willing to reformulate the paint. To

determine the extent of formaldehyde emissions from interior

paints on the market, a major effort involving the testing of a

number of interior paints would be needed. (EPA Contact:

John Chang, 919-541-3747, jchang@engineer.aeerl.epa.gov)

A COMPILATION OF DATA ON EMISSIONS FROM

INDOOR SOURCES

There is a growing amount of data in the scientific and technical

literature on pollutant emissions from indoor sources. Most of

the data have been reported by researchers interested in

developing testing methods, understanding mechanisms of mass

transfer from source to air, or studying a particular class of

indoor sources. IEMB has been compiling such data primarily to

support its in-house source characterization studies by seeing

where the data gaps are, and to develop descriptive statistics that

might be useful in designing new products, buildings, or

ventilation systems. This article summarizes the approach being

taken by IEMB and the current status of the compilation.

An Excel spreadsheet is used as the structure of the compilation.

Twenty fields (columns in the spreadsheet) have been

established; they are listed and described in Table 1. Note that

data are included only from references that report emission

factors (pollutant emission rate per unit of source), or

experimental data from which emission factors can be

calculated.

Table 2 summarizes the source categorization scheme used.

Source categories and examples of source “types” are shown.

IEMB is trying to use a nomenclature that is compatible with

industrial and commercial terminology, which can be variable. 

While care is taken in selecting references, there are no detailed

acceptability criteria. Articles and reports from peer-reviewed

scientific and technical literature are preferred; these are labeled

“primary” references in the bibliography listed in Table 3.

References that may not have been through peer review but

appear to have been based on good measurement practices are

labeled “secondary” references in the bibliography. References

that summarize results from studies by other authors are used

very little in this database; those that have been are labeled

“tertiary” references in the bibliography.

The database currently has about 5000 records covering

about 60 source types, extracted from about 60 references.

Emphasis to date has been on development of the structure

and data entry guidelines. One round of quality assurance

(QA) has been completed, and a second QA review is

planned. Over the next year, the emphasis will shift to

additional data entry and analysis. IEMB has started to look

at the data with an eye toward developing representative

emission factors for product, building, and heating,

ventilating, and air-conditioning (HVAC) system design.

Developers of other emission data bases will also be contacted

to compare compilation and analysis approaches. Comments

are welcome, as are recommendations for additional

references. (EPA Contact: W. Gene Tucker, 919-541-2746,

tucker.gene@epa.gov)
Inside IAQ, Fall/Winter 1998 Page 3

Table 1. Names of fields in indoor emissions database

Name of Field Description Data Entry Guidelines

Record

Number

Number assigned to first field of each record.

Records (rows) generally represent emissions data

for a single pollutant or pollutant class from a single

sample, or set of samples, of a source type.

Occasionally, a record will represent two or more

pollutants.

Source Information

Category Source category of the sample that was tested. (See

Table 2 for listing of source categories.)

Type Source type of the sample that was tested. (See

Table 2 for listing of some source types.) Use

judgement creating new source types; consider

author’s descriptions.

NAICS North American Industrial Classification System

code number. (NAICS replaced the Standard

Industrial Classification, or SIC, system in 1997.)

Enter the code of the source category–or, if

possible–the source type. See

http://www.theodora.com/sic_index.html or

www.census.gov/epcd/naicscod.txt for listing of

NAICS codes and titles, and www/naics4.html.

Emission Testing Information

Reference Code for the reference from which the emissions

data were obtained. Use first three letters of first

author’s last name followed by the last two digits of

year the data were published. If same author (or

more than one author with the same three first letters

of last name) published more than once during same

year, add lower-case a, b, etc. to distinguish them.

Specific

Identification

Specific information about the source sample that

expands on the “source type” entry (such as

composition data, condition or history of the product

from which the sample was taken). If the author’s

description differs from the description used in the

Category and Type fields, enter it here.

Age of Tested

Sample

Time that elapsed between when the source sample

was first put into use and when emission sampling

occurred. If sample was purchased at a store, that

should be noted in the “specific identification” field.

If the reference presents both an empirical model

and tabulated emission factors, enter the tabulated

values and describe the model in the “comment”

field. If an empirical emission model is presented

and measured emission factors are not clearly

tabulated, records should be created for the

following preselected ages, limited to the time period

for which the model is applicable: 1 hour, 24 h, 168

h (1 week), 730 h (1 month), and 8760 h (1 year). In

these cases, note that a specific age has been

selected: e.g., enter “24 h (modeled age).”

Pollution Information

Name Chemical name of the pollutant (or other name, if is

not a single chemical substance).

CASN Chemical Abstract Service (CAS) Number for the

pollutant. For a listing of CAS numbers, see

http://webbook.nist.gov/chemistry/name–ser.htm.

Test Methods/

Conditions

Enter information such as chamber size, material of

construction, air change rate or flow, temperature

and relative humidity during testing, and air

sampling rate or volume.

Analytical

Method

Enter the method(s) used to chemically or physically

characterize the pollutant in the air sample.

Name of Field Description Data Entry Guidelines

Emission Factors

Units Emission factors should be reported in units of

emission rate per unit of source. (Units for emission

rate are general by mass per time; units of source are

area for surface materials, or a single product for

sources like machines or pieces of furniture).

Emission factors for physical or chemical pollutants

should therefore be entered in units of μg/h per m2

for surface materials, or μg/h per unit of product for

other source types. If other units are used in the

reference, convert to the units and note in the

“comments” field that the conversion has been made.

Units for biological pollutants such as fungi should

be entered as reported; colony-forming units (CFUs)

are often used instead of mass.

Number of

Measurements, N

The number of measurements that were made to

establish the values entered into the next four fields.

Where N=1, the emission factor value should be

entered into the “mean” field. When it is not clear

from the reference how many measurements were

made, enter “?.”

Minimum Minimum value, where multiple emission

measurements of a single same sample, or set of

similar samples) are reported in the reference.

Median Median value, where multiple emission

measurements (of a single same sample, or set of

similar samples) are reported in the reference.

Mean (SD) Mean and standard deviation values, where reported.

If a single measurement is reported in the reference,

enter it in this field.

Maximum Maximum value, where multiple measurements (of a

single sample, or set of similar samples) are reported

in the reference.

Emissions Modeling

Yes/No Enter Y or N, depending on whether the reference

includes a mathematical model that represents

measurements taken. Note that references dealing

only with purely theoretical models or discussion of

emission models (i.e., references that do not report

new data) are not to be covered in this data base.

Half-Time Time, in hours, for the emission factor to go from its

maximum value to half the maximum, as estimated

by the model. Also enter standard deviation for the

half-time, if reported.

Comments

Use this field to note special information on the

reference that might be useful to users of the data

base. If emissions modeling was reported, enter the

mathematical form of the model and values for

coefficients; also note range of applicability (e.g., for

time or temperature). Note any adjustments made to

reported data (e.g., change of emission factor units

or conversion of chamber concentration data to

emission factors). If the value entered in the

emission factor field was calculated from the model,

note that in this field. When emission factor data

were not obtained directly from the reference, but

through contact with an author, note by a statement

such as “The value for this emission factor, which is

difficult to estimate from Figure x of the reference,

was obtained directly from the author.”
Inside IAQ, Fall/Winter 1998 Page 4

Table 2. Source categories and types

Category Type (Examples)

Adhesives Carpet adhesive

Flooring adhesive

General adhesive

Cabinetry Kitchen cabinets

Caulks &

Seals

Caulk, general

Sealant, general

Cleaning Agents

(see also pesticides)

Detergent

Disinfectant

Misc. cleaning agents

Solvent-based cleaner

Floor Materials Carpet–synthetic fiber

Carpet–wool fiber

Carpet cushion

Carpet system

Cork flooring

Linoleum

Sheet vinyl flooring

Tile vinyl flooring

Wood flooring

Other flooring

Furnishings Drapery

Drapery lining

Office furniture–metal

Office furniture–upholstered

Office furniture–wood

Residential furniture–metal

Residential furniture–upholstered

Residential furniture–wood

Other furnishings

HVAC Systems and

Components

(see also space heating and

cooking equipment)

Air cleaning device

Air moving equipment

Cooling coils

Ductwork

Heating coils

Humidification equipment

Insulation

Products

Fibrous insulation

Foam insulation

Machines Air cleaner, in-room

Air conditioner, room

Electronic circuit board

Humidifier, in-room

Photocopier, dry-process

Photocopier, wet-process

Printer, laser

Spirit duplicator

Digital duplicator

Vacuum cleaner (see also

occupant activities)

Other machines

Category Type (Examples)

Miscellaneous

Materials

Brick

Ceramic tile

Clothing

Concrete

Glass

Metal

Microbial culture

Misc. stored material

Mortar

Paper-based material

Stone

Occupants and

Occupant Activities

Animals (pets)

Cleaning

Cooking

Human occupants- bioeffluents

Smoking

Human occupants- other activities

Paints and Coatings Oil-based finish

Solvent-based paint

Stain

Varnish

Water-based finish

Water-based paint

Wax

Personal Care Items Hair spray

Other PCIs

Pesticides

(see also cleaning agents)

Moth repellent

Other pesticides

Space Heating and Cooking

(See also HVAC systems and

components)

Electric

Gas fueled

Oil fueled

Solid fuel

Wall and Ceiling Materials

(other than paints and

coatings)

Ceiling tile

Gypsum board

Plaster

Wall paneling

Wallpaper/wall covering

Other wall and ceiling materials

Wood Products Fiber panel material (e.g., 

insulation board, hardboard)

Particleboard

Plywood

Solid natural wood product

Veneer

Waferboard/chipboard

Other wood products
Inside IAQ, Fall/Winter 1998 Page 5

Table 3. References cited to date

ALE96 Alevantis, L. E. (1996). California Department of Health Services, Berkeley, California. (3E) 

ALL78 Allen, Wadden, and Ross (1978).

Am. Ind. Hyg. Assoc. Jour.

39(6):466-471. (1E)

ANT97 Anttonen et al. (1997).

Proceedings of IAQ'97, Healthy

Buildings (ASHRAE). 3:

575-579. (2E) 

BAT91 Batterman, Bartoletta, and Burge

(1991). Presented at 84th Annual

Meeting of AWMA. (2E)

BAY90 Bayer and Papanicolopoulos

(1990). Proceedings of Indoor Air

‘90, 3:725-730. (2E)

BER97 Bernheim and Levin (1997). Proc.

of IAQ '97, Healthy Buildings

(ASHRAE). 3:599-604. (2E)

BLA91 Black, Pearson, and Work (1991).

Proc. of IAQ'91, Healthy

Buildings (ASHRAE). 267-272.

(2E)

BRO97 Brockmann et al. (1997).

Engineering Solutions to IAQ

Problems, pp. 403-420 (1E)

CHA92 Chang and Guo (1992). Indoor

Air. 2:146-153. (1E)

CHA94 Chang and Guo (1994). Indoor

Air. 4:35-39. (1E)

CHA97 Chang et al. (1997). Indoor Air.

7:241-247. (1E)

COL93 Colombo, De Bortoli, and

Tichenor (1993). Proceedings of

Indoor Air ‘93, 2:573-578. (2E)

DAV91 Davidson et al. (1991).

Proceedings of IAQ'91, Healthy

Buildings (ASHRAE). 299-303.

(2E)

FIS95 Classification of Indoor Climate,

Construction, and Finishing

Materials. FiSIAQ Publication

5E. Finnish Society of Indoor Air

Quality and Climate, Espoo,

Finland, 1995. (2E)

FOR97 Fortmann et al. (1997).

Engineering Solutions to IAQ

Problems, pp. 117-127. (1E)

FUN97 Funch, Winther, and Larsen

(1997). Proc. IAQ'97, Healthy

Buildings (ASHRAE). 3:617-622.

(2E)

HAN86 Hansen and Anderson (1986). 

Am. Ind. Hyg. Assoc. Jour.

47(10):659-665. (1E)

HAW92 Hawkins et al. (1992). American

Industrial Hygiene Association

Journal. 53(5):275-282. (1E)

HET95 Hetes, Moore, and Northeim

(1995). EPA/600/R-95-045. (3E)

HOD93 Hodgson, Wooley, and Daisy

(1993). Jour. of Air and Waste

Manag. Assoc. 43:316-324. (1E)

HOR97 Horn, Ullrich, and Seifert (1997).

 Proc. of IAQ'97, Healthy

Buildings (ASHRAE). 3:

533-538. (2E)

HOW97 Howard, McCrillis, and Krebs

(1997). Engineering Solutions to

IAQ Problems. pp 3-15. (2E)

KER90 Kerr and Sauer (1990).

Proceedings of Indoor Air ‘90,

3:759-763. (2E)

LAR97 Larsen and Funch (1997).

Proceedings of IAQ'97, Healthy

Buildings (ASHRAE) .

3:611-616. (2E)

LEO96 Leovic et al. (1996). Jour. of Air

and Waste Management

Association. 46:821-829. (1E)

LEO97 Leovic et al. (1997). Proceedings

of IAQ'97, Healthy Buildings

(ASHRAE). 3:623-628. (2E)

LUN97 Lundgren, Jonsson, and

Ek-Olausson (1997). IAQ'97,

Healthy Bldgs (ASHRAE).

1:287-292. (2E)

MAY96 Mayo, Figley, and Robinson

(1996). Presented at Clean Air '96,

Orlando, Florida. (3E)

MOR96 Morrison and Hodgson (1996).

Proceedings of Indoor Air ‘96,

3:585-590. (2E)

MUL94 Muller and Black (1994).

Presented at the American

Industrial Hygiene Conf., May

1994. (2E)

NAG95 Nagda, Koontz, and Kennedy

(1995). Indoor Air. 5:189-195.

(1E)

NEL87 Nelms, Mason, and Tichenor

(1987). EPA/600/D-87/165. (1E)

NIU97 Niu et al. (1997). Engineering

Solutions to IAQ Problems. pp.

547-554. (2E)

NOR97 Northeim et al. (1997).

Engineering Solutions to IAQ

Problems. pp 71-81. (2E) 

ROA96 Roache et al. (1996). Proceedings

of Indoor Air '96, 2:657-662. (2E)

SAA92 Saarela (1992). Proceedings of

IAQ <92, Environments for People

(ASHRAE). 349-354. (2E)

SAA97 Saarela, Tirkkonen, and

Suomi-Lindberg (1997). IAQ'97,

Hlthy Bldgs (ASHRAE).

3:545-550. (2E)

SEL80 Selway, Allen, and Wadden

(1980). Am. Ind. Hyg. Assoc.

Journal. 41:455-459. (1E)

SMI90 Smith, Donovan, and Ensor

(1990). Proceedings of Indoor Air

‘90, 3:647-652. (2E)

STR91 Strobridge and Black (1991).

Proceedings of IAQ <91, Healthy

Buildings (ASHRAE). 292-298.

(2E)

TEP95 Tepper et al. (1995). American

Industrial Hygiene Association

Journal. 56:158-170. (1E)

TIC86 Tichenor and Mason (1986).

EPA/600/D-86/088. (1E)

TIC88a Tichenor et al. (1988).

EPA/600/D-88/086. (2E)

TIC88b Tichenor, Sparks, and Jackson

(1988). EPA/600/2-88/061. (1E)

TIC88c Tichenor and Mason (1988).

Jour. APCA. 38(3):264-268. (1E)

TIC89 Tichenor (1989). Environment

International. 15:389-396. (1E)

TIC91 Tichenor and Guo (1991).

EPA/600/D-91/155. (1E)

TUC88 Tucker (1988). Proceedings of

Healthy Buildings <88, 1:149-157.

(3E)

VAN90 Van der Wal, Steenlage, and

Hoogeveen (1990). Proc. Indoor

Air <90, 3:611-616. (2E)

VAN97 Van der Wal, Hoogeveen, and

Wouda (1997). Indoor Air.

7:215-221. (1E)

WAL87 Wallace (1987). Atmospheric

Environment. 21(2):385-393.

(1E)

WOL93 Wolkoff et al. (1993). Indoor Air.

3:113-123. (1E)

WOL96 Wolkoff and Nielsen (1995).

Atmospheric Environment.

30: (15): 2679-2689. (1E)

WOR94 Worthan (1994). Presented at

National Coalition on IAQ

conference, Tampa. (2E)

ZHA97 Zhang et al. (1997). Proceedings of

IAQ'97, Healthy Buildings

(ASHRAE). 3:521-526. (2E)

1E = primary

2E = secondary

3E = tertiary
Inside IAQ, Fall/Winter 1998 Page 6

VOLATILE ORGANIC EMISSIONS FROM PRINTED

CIRCUIT BOARD LAMINATES

The printed circuit board is a vital operating component in

many electronic products; e.g., personal computers (PCs),

telephones, fax machines, and photocopiers. Offgassing from

printed circuit boards is most prominent during the initial use

period when electrical heating occurs in the product. This is

especially true in the case of PC monitors, where internal

operating temperatures can range from 60 to 70EC. 

In this evaluation, IEMB worked cooperatively with Research

Triangle Institute (RTI) to measure emissions from printed

circuit board laminates (without circuitry) to determine if an

alternative laminate would be less emitting than conventional

laminates. The complete study can be found in the EPA

Report, Personal Computer Monitors: A Screening

Evaluation of Volatile Organic Emissions from Existing

Printed Circuit Board Laminates and Potential Pollution

Prevention Alternatives, April 1998 (EPA-600/R-98-034,

NTIS PB98-137102).

Methodology

Because laminates used in PC monitors are subjected to high

operating temperatures, they were selected as test laminates

for this project. As shown in the test matrix in Table 4, eight

samples of the following types of base/resin printed circuit

board laminates were evaluated: Glass/lignin-containing

epoxy (G/L), Glass/epoxy (G/E), Paper/phenol (P/P), and

Paper/ reformulated phenolic (P/RP).

The screening evaluation was conducted to determine if the

glass/lignin-containing epoxy resin and the reformulated phenolic

laminates would be less emitting than conventional laminates

which are made primarily from paper/phenol. Glass/epoxy

laminates were included in the evaluation because they exist

primarily in central processing units (CPUs).

The glass/lignin-containing epoxy and glass/epoxy laminates

were acquired from U.S. manufacturers. The paper/phenol

laminate was acquired from an overseas manufacturer because

almost all phenol-based laminates are produced overseas.

The reformulated phenolic laminate is also produced overseas

and has been in use in Europe within the past 5 years.

Participating manufacturers were sent "sampling kits" with

sampling instructions and steel cans. A designated person at

each manufacturing facility was responsible for:

1) Collecting a laminate sample from the production line;

2) Cutting the laminate sample size to 0.15 by 0.25 m; and

3) Immediately sealing the laminate in a labeled, precleaned,

air-tight, 7.85-L steel can provided.

Each can was shipped overnight to RTI, inspected upon arrival,

and then stored at -10 EC for about 4 months. Immediately prior

to testing, the sealed storage cans containing the laminates were

removed from the freezer, and the laminate samples were

transferred to individual clean steel cans for testing. The cans

were the same type as those used for storage. Inside the can, each

laminate sample was placed on its edge, leaning against the side

of the can, in order to maximize the exposed area. The lid of

each test can was fitted with Teflon inlet and outlet tubes which

were attached to the supply air manifold and sampling ports.

This allowed continuous regulated air flow through the chambers

during testing. 

The test cans were then placed in a temperature-controlled

oven maintained at 65±3EC. Oven temperature and RH of the

supply air (50±5% RH at 23EC) were continuously

monitored. As the air was warmed to 65EC, the RH in the test

cans dropped to approximately 6%.

Total air flow to the system was controlled, monitored, and

recorded using mass flow controllers. Just prior to placing the

test cans containing the laminate samples in the oven, each can

was purged with clean air to flush the cans of laboratory air.

Collection of air samples from the test cans began within 10

minutes of placing the test samples in the cans. Flows were

measured and adjusted immediately after the test cans were

placed in the oven, during the middle, and again at the end of

testing.The flow rate was 131 mL/minute (approximately 1.02

Table 4. Test matrix for circuit board laminate evaluation

Air Samples

Laminate Background b G/L-1Aa G/L-1B G/L-2 G/E-1 G/E-2 P/P P/RP-A P/RP-B

Air sample type;

VOC c

1 1 1 1 1 1 1 1 1

VOC duplicate 1 1 1 1 1 1 1 1 1

Aldehyde/ketone 1 1 1 1 1 1 1 1 1

Number of

sampling intervals 9 9 9 9 9 9 9 9

Number of air

samples taken

3 27 27 27 27 27 27 27 27

a

 Laminates supplied without circuitry; copper coated on one side. Sample G/L-2 was copper coated on both sides. b

 A background air sample was taken from two separate test cans prior to the start of the test.

c

 Includes phenol and cresols.
Inside IAQ, Fall/Winter 1998 Page 7

air changes per hour). Air samples were analyzed for VOCs

(including phenol and cresols) and adehydes/ketones. A list

of target compounds were identified from an initial set of air

samples taken for each laminate sample. Quantitative analysis

of these target compounds was then conducted for all

subsequent air samples taken for each laminate sample.

Results

The data presented in Figures 1 and 2 summarize the results

of the aldehydes/ ketones and VOCs emitted from each of the

eight printed circuit board laminates, respectively. The data

are expressed in terms of concentration (Fg/m3) and illustrate

the sum of measured concentrations for all identified

compounds emitted from each printed circuit board laminate

at t = 0 or 5 hours and t = 336 hours (14 days). Emission

factors over time are presented in the report referenced on

page 6.

Figure 1 shows that, at time t = 0 hours, the sum of measured

aldehydes/ketones emitted from the paper/reformulated

phenolic and the paper/phenol laminates ranged from 3,900 to

6,400 Fg/m3. For the same time point, the sum of measured

aldehydes/ketones emitted from the glass/lignin laminates

ranged from 200 to 270 Fg/m3, and emissions from the

glass/epoxy laminates ranged from 33 to 200 Fg/m3. After

336 hours, the sum of measured aldehydes/ketones emitted

from the paper/reformulated phenolic and the paper/phenol

laminates ranged from 650 to 870 Fg/m

3

. The sum of

measured aldehydes/ketones emitted from the glass/lignin

laminates after 336 hours ranged from 42 to 53 Fg/m3, and

concentrations from the glass/epoxy laminates ranged from

17 to 25 Fg/m3. Other observations from the data in Figure 1

are:

1) In the first hours of simulated on-time operation at 65EC,

the paper/phenolic resin-based laminates emit more

aldehydes/ketones than the glass/lignin or glass/epoxy

laminates. It appears that offgassing of volatile

compounds would continue beyond the 336 hours of this

screening evaluation.

2) Concentrations for the glass/epoxy sample 2 laminate are

greater than those for the glass/epoxy sample 1. This

difference could be due to the fact that the glass/epoxy

sample 2 laminate is manufactured by a different

company than the glass/epoxy sample 1 laminate. 

3) All three glass/lignin laminate samples and the two

glass/epoxy laminates show average concentrations 95%

lower than the paper/reformulated phenolic resin-based

laminates.

Figure 2 shows that, at time t = 0 or 5 hours, the sum of

measured VOC concentrations (excluding aldehydes/ketones)

from the paper/reformulated phenolic and the paper/phenol

laminates ranged from 9,600 to 23,000 Fg/m3. Concentrations

from the glass/lignin laminates ranged from less than 1,300 to

1,700 Fg/m3

, and concentrations from the glass/epoxy

laminates ranged from less than 1 to 15 Fg/m3. After 336

hours, VOC concentrations from the paper/reformulated

phenolic and the paper/phenol laminates ranged from 3,900 to

6,200 Fg/m3. For the same time interval, VOC

concentrations for the glass/lignin and glass/epoxy laminates

ranged from nearly 0 to 100 Fg/m3.

Other observations from the data in Figure 2 are:

1) As was the case for the aldehydes and ketones, all three

glass/lignin laminate samples and the two glass/epoxy

laminates show an average sum of measured

concentrations of VOCs to be 95% lower than the

paper/reformulated phenolic resin-based laminates.

2) VOC concentrations from both glass/epoxy laminates are

virtually negligible. This is a good indication, on a

screening basis only, that VOC concentrations from

glass/epoxy laminates would probably not contribute

significantly to indoor air emissions.

3) VOC concentrations at t =5 hours from the paper/

reformulated phenolic laminates are lower than for the

paper/phenol, whereas aldehyde/ketone concentrations

from the paper/reformulated phenolic laminates (Figure

1) were higher than for the paper/phenol. However, at t

= 336 hours, VOC concentrations from the paper/

reformulated phenolic laminates are higher than for the

paper/phenol.

Conclusions

Conclusions from this screening evaluation are:

• Glass/lignin laminates result in lower concentrations of

volatile compounds than paper/phenolic resin-based

laminates. Although this test was conducted on only

eight laminate samples of four different laminate types,

the results show that, for the samples tested, glass/lignincontaining epoxy resin laminates emit lower

concentrations of volatile compounds than the

paper/phenolic resin-based laminates during simulated PC

monitor on-time operation at 65EC. The data also

suggest that, if these laminates were used as pollution

prevention alternatives for paper/phenol circuit board

laminates in PC monitors, reductions in VOC emissions

from PC monitors could be achieved. Alternatively, an

initial exposure period at an elevated temperature would

be a possible control option to reduce volatile emissions

prior to operation in an indoor environment.

• Volatile emissions from glass/epoxy laminates are

relatively low compared to glass/lignin and

paper/phenol laminates. Although glass/epoxy laminates

appear to be good substitutes for paper/phenol laminates,

they are not predominantly used in PC monitors. This is

because glass/epoxy laminates are designed for highspeed applications and data processing, whereas PC

monitors do not perform the same operating functions or

experience the same operating conditions as CPUs.

• In general, concentrations decay over time. The results

show that a majority of the compounds decayed to low

levels (-50 Fg/h-m2) after 336 hours at 65EC. However,

the data clearly show that some of the compounds would

likely have continued to emit from the laminates beyond

the 336 hours of the test. (EPA Contact: Kelly Leovic,

919-541-7717, kleovic@ engineer.aeerl.epa.gov)
Inside IAQ, Fall/Winter 1998 Page 8

P/P P/RP - A P/RP-B G/L - 1A G/L - 1B G/L - 2 G/E GE - 2

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

Laminate Sample

Concentration (μg/m3)

t = 0 h t = 336 h

P/P =Paper/phenol

P/RP = Paper/reformulated phenolic 

G/L = Glass/lignin GE = Glass/epoxy

P/P P/RP - A P/RP - B G/L - 1A G/L - 1B G/L - 2 G/E GE - 2

0

5,000

10,000

15,000

20,000

25,000

Laminate Sample

Concentration (μg/m3)

t = 0 or 5 h t = 336 h

P/P =Paper/phenol

P/RP = Paper/reformulated phenolic 

G/L = Glass/lignin GE = Glass/epoxy

Figure 1. Sum of measured concentrations at t = 0 h and t = 336 h for all reported

aldehydes and ketones for each laminate tested

Figure 2. Sum of measured concentrations at t = 0 or 5 h and t = 336 h for all reported

VOCs for each laminate tested, excluding aldehydes and ketones.
Inside IAQ, Fall/Winter 1998 Page 9

FACTORS INFLUENCING IAQ, IMMUNITY, AND

HEALTH

In June 1995, a conference on IAQ, Immunity, and Health

was held at North Carolina State University in Raleigh, NC.

It was cosponsored by the Cornell University Institute for

Comparative and Environmental Toxicology, the Cornell

Center for the Environment, and North Carolina State

University and provided an opportunity to examine a

significant societal inhalation toxicology issue. The program,

which brought together leading national scientists as well as

policy formulators, also included important policy

perspectives for discussion of scientific data application. This

article provides an overview of the proceedings by the

organizing committee.

Discussions focused on how indoor air pollutants, including

both industrially and naturally derived volatile chemicals and

allergens, as well as cofactors (e.g., levels of outside air

pollutants such as ozone), might affect upper respiratory tract

symptoms and immune response. The need to consider the

entire range of outdoor pollution factors (e.g., particulates,

pollen, ozone, NO2) as well as indoor chemical emissions and

the entire range of allergens (e.g., dust mites, mold spores,

rodent and insect allergens) was stressed by several

presenters. In the case of VOC emissions, the relevance of

evaluation methodologies to actual exposure conditions was

emphasized. This was required to avoid potential erroneous

interpretations of results as they relate to actual risk. For

example, carpet emissions were reported to become

significant only at temperatures exceeding 62EC; however,

this was not usually the case under conditions that actually

occur in typical indoor environments.

Exposure scenarios to measure inhalation responses were

discussed by several presenters. In particular, issues

concerned the exposure methodologies (e.g., whole body,

head, nose and mouth, nose only, intratracheal), dose

response, and the type of endpoints that would be important

for determining health implications. Endpoints that were

discussed included sensory irritation, sensitivity to infection,

allergic challenge responses (including asthmatic-type

responses), cellular and biochemical changes in nasal lavage,

hypersensitivity pneumonitis, and pulmonary function

endpoints.

An overall consideration of immune effector functions in the

context of inhalation exposure was presented, and several

presenters described the chemical mediators and/or

biomarkers associated with inflammatory reactions. In

particular, the codependent relationship of the neurological

and immunological systems in controlling inflammatory

reactions was detailed.

Additional sympathetic nervous system neurotransmitters

such as norepinephrine were discussed as regulators of

immune cell activity. This was extended beyond model

neuroimmune interactions for a consideration of the

integrative topics of stress, psychology, and altered immune

capacity. Within this discussion, it was shown that specific

stressors can exert targeted effects over certain portions of the

immune system.

Potential individual genetic (allelic) variation in response to

indoor air was considered and was particularly relevant given

the possible existence of hypersusceptible subpopulations of

humans for certain stimuli-induced symptomologies. In this

case, the investigators reported on a rodent model for

hypersensitive pneumonitis.

The symptomology of multiple chemical sensitivity (MCS)

was delineated, as well as the approaches to enhanced health

of the patients. The unclear etiology of both MCS and sick

building syndrome was discussed, as well as the data and

hypotheses that might link these conditions to immune and/or

inflammatory processes. The potential for psychoneurogenic

associations with MCS was considered, and additional

presentations described the physiological linkages involving

the nervous and other (e.g., immune) systems, and the

opportunity to investigate possible underlying biochemical

involvement in MCS symptomology was enhanced. Therefore,

the determination of cause-effect relationships in MCS

symptomology should be more readily approachable in the

future.

The role of specific biomarkers for detection of differential

sensitization was discussed. Significant progress has been

made in the areas of inflammation and immunomodulation.

This occurred with the development of both functional assays

and biomarkers for the detection of respiratory versus contact

sensitizing potential of environmental factors. Similar

progress has been made relative to nonspecific inflammatory

processes. This research progress pertains not only to the

direct capacity of indoor air factors to serve as potential

sensitizers but also to the possibility that such factors could

alter the host relative to sensitizing potential and/or the

challenge response to allergens. The biomarkers described

here offer a potentially sensitive and economical method for

screening emissions from indoor products for their sensitizing

and/or host-allergy response potential.

The combined presentations point to a research and evaluation

direction for indoor air and immunity issues in which crossdisciplinary expertise should contribute to the effective

resolution of these issues. Two presentations crossed the

science-policy boundary to provide specific examples of the

opportunities for effective outreach to the general public. In

these presentations, the benefits of a consolidated effort for

the translation of specific indoor air and health findings into

cost-effective remedial action within communities were also

discussed. (EPA Contact: Mary Jane Selgrade, 919-541-

2657, selgrade.maryjane@epa.gov)
Inside IAQ, Fall/Winter 1998 Page 10

MODELING EMISSIONS FROM WATER-BASED

CLEANING SUPPLIES

Executive Order 12873, issued Oct.20, 1993, requires federal

agencies to purchase “environmentally preferable” products.

As a pilot project under this executive order, EPA and the

General Services Administration worked together to develop

guidance for federal agencies to select environmentally

preferable cleaning supplies. These cleaners are biodegradable

degreasers. They are generally diluted with water before use,

and are frequently applied using a hand-held pump spray.

Three types of chemical compounds are of primary concern

in these cleaners: terpenes, butyl cellusolve (2-butoxyethanol),

and ethoxylated nonylphenol surfactants. The largest potential

exposure is to the cleaning staff, but there is also exposure to

building occupants.

EPA encountered difficulty evaluating the risk associated with

indoor air exposures because the method used to compare

risks relied on overly simplified indoor air models. The goal

of this research is to improve upon EPA’s indoor emission

models for water-based cleaners. The first phase of work

focuses on improving models for evaporative emissions from

films or pools, and validating them in the laboratory.

Emissions from the aerosol will be examined later.

Products Tested

Two different water-based cleaners have been selected for this

work. The first (Cleaner A) is a 2-butoxyethanol-based

product with an ethoxylated nonylphenol surfactant. The

second (Cleaner B) is a terpene-based cleaner. Both cleaners

will be analyzed by gas chromatography/mass spectrometry

(GC/MS) to identify and quantify VOCs that may be emitted

during and after use.

Headspace Measurements

Headspace measurements are being made over various cleaner

dilutions to determine partition coefficients, and hence

Henry’s Law constants. Headspace measurements will also

be made over various dilutions of a laboratory formulated

cleaner surrogate, containing only 2-butoxyethanol (at the

same concentration as Cleaner A) and water. The data will be

used to:

• Provide input for modeling;

• Compare to Henry’s Law predictions made by a

structure/activity relationship program (HENRYWIN

v3.00, SRC-HENRY for Microsoft Windows, 1994-

1997); and 

• Compare the partition coefficients of the diluted

cleaner to those of the VOCs and water to see whether

the surfactants and minor constituents have any effect

on partitioning. If there is a large effect, it may be

necessary to do additional work before emissions can

be successfully modeled and predicted.

Models

In the past, IEMB has developed and verified mass-transferbased models to predict the evaporative emissions from

solvent-based indoor coating materials based on Raoul’s Law.

However, the emissions from aqueous solutions behave in a

diufferent manner which conforms to Henry’s Law.

The proposed models have the potential to predict the

emissions based on the product formulation. A series of

chamber tests will be conducted to evaluate these candidate

models. For the purposes of modeling the evaporative

emissions, the surfactant (ethoxylated nonylphenols) is

considered to be non-volatile.

The Pool Evaporation Models–Two mass transfer source

models, called P1 and P2, are proposed for estimation of the

VOC emissions from a liquid pool (or bucket). Model P1 was

found in the literature (Little, J.C., 1992, “Applying the tworesistance theory to contaminant volatilization in showers,”

Environ. Sci. Technol., 26, 1341-1349). Both models are

based on Henry’s Law and the following expression for mass

transfer for evaporative emissions:

E = kT ( ) C C s − 

where E = emission factor, mg/m2/h;

kT = the overall gas-phase mass transfer coefficient, m/h;

Cs = VOC concentration at air/liquid interface,

calculated based on Henry’s Law, mg/m3; and

C = VOC concentration in the bulk air, mg/m3.

When the VOC concentration at the interface is considered

constant, there is an explicit solution for the indoor

concentration (model P1). All the parameters can be

estimated from the properties of the source and the

environment, and the model is simple enough to be used in a

spreadsheet. Chamber testing will reveal whether models

using this simplification predict emissions sufficiently well for

water-based cleaners.

However, when the volume of the cleaner liquid is limited, the

pollutant concentration in the liquid may not hold constant.

For instance, water evaporation may concentrate the solute.

On the other hand, fast emission of the solute (with large

Henry’s Law constant) may result in decreased concentration

in the liquid. These factors could be important for small or

shallow pools, such as those used in small chamber testing.

Therefore, model P2 modifies P1 to include the effects of

changes in liquid concentration. Model P2 should be

especially useful in interpreting data from small chamber

tests, where the solvent pool is often small and the VOC

concentration in the liquid may change significantly during the

test period. P2 consists of three differential equations, which

can be solved numerically.

Film Evaporation Models–IEMB is evaluating three new

source models for predicting the VOC emissions from waterbased cleaners applied to hard surfaces (i.e., emissions from

the thin film). For the convenience of discussion, the models

will be called F1, F2, and F3, where F stands for “film.”
Inside IAQ, Fall/Winter 1998 Page 11

Model F1 is a comprehensive mass transfer model that takes

into consideration VOC emissions from both the wet and dry

films. The term “dry film” here means the thin film of organic

liquid left on the surface due to water evaporation. Models F2

and F3 are derived from F1 with different degrees of

simplification. Model F3 does not require the Henry’s Law

constant and is simple enough to be implemented in a

spreadsheet.

Model F1 takes into consideration three mass transfer

processes: 

• The rate of VOC emissions from the wet film, described

by Henry’s Law and gas-phase molecular diffusion; 

• The rate of VOC emissions from the “dry” film,

described by the simplified vapor barrier (VB) model

(Guo, Z, et al., 1997 “Predicting the Emissions of

Individual VOCs from Petroleum-Based Indoor

Coatings,” Atmospheric Environment, Vol. 32, No. 2,

pp. 231-237); and

• The rate of dry film formation due to water evaporation,

described by a model similar to the VB model. This mass

transfer process affects the VOC emission rates from

both the wet and dry films. 

Model F2 is a simplified version of model F1. Since the firstorder decay rate constant, k, is inversely proportional to the

film thickness (Clausen, P. A., 1993, “Emission of volatile

and semivolatile organic compounds from water-borne paints

– the effect of the film thickness,” Indoor Air 3, 269-275) and

the dry film is very thin, k is usually very large. The

simplifying assumption is, therefore, that the VOC emission

from the dry film is an instantaneous process.

Model F3 is derived from model F2 by assuming that:

• The wet emission is insignificant compared to the dry

emission; and

• Water evaporation roughly follows the first-order decay

pattern.

Information about the product and the environment required

by each of the three models is given in Table 5. All the

parameters are easy to come by, except the Henry’s Law

constant. There are three ways to find the Henry’s Law

constant:

• Compiled Henry’s Law constants in the literature;

• Experimental determination; and

• Theoretical calculation based on the molecular structure.

Chamber Testing

Three “bucket” tests will be run. In these tests, an open

cylindrical container of diluted cleaner will be placed in a

small chamber, and emissions measured for about a day. The

purposes of these tests are to:

Table 5. Summary of all parameters included in the three

 film models

Category Parameter Model

F1

Model

F2

Model

F3

Environment

Room volume X X X

Air flow rate X X X

Relative Humidity X X X

Air velocity 1 X X

Pollutant

Molecular formula

of VOC X X

Henry’s Law

constant X X

Vapor pressure 2 X

Diffusivity in air 3 X

Test

Product

VOC content in

liquid X X X

Source area X X X

Amount applied X X X

1

 used to estimate gas-phase mass transfer coefficients for VOC

 and water.

2

 used to estimate the decay rate constant for dry emissions (k). 

3

 used to estimate gas-phase mass transfer coefficient for VOC

• Determine the overall mass transfer coefficient using

Cleaner A;

• Verify whether the P1 and P2 models work for

butoxyethanol in Cleaner A; and

• Verify the model for other compounds/products, using

Cleaner B.

Chamber testing will also be conducted to provide data to

compare to the performance of the film evaporation models.

RH proved difficult to control in initial tests in the small

chamber, because the control systems and geometry of the

small chamber produced an unrealistically high RH. Because

the compounds of interest are somewhat polar and

hydrophillic, humidity may affect the emission behavior.

Therefore, this work will be performed in a large chamber.

(EPA Contact: Betsy Howard, 919-541-7915,

bhoward@engineer.aeerl. epa.gov)
Inside IAQ, Fall/Winter 1998 Page 12

ANTIMICROBIAL AGENTS USED IN HVAC SYSTEMS

Biocides or antimicrobial agents can be used to manage

biological contamination in HVAC systems as an alternative

to HVAC component replacement. All commercial biocides

and antimicrobial products are regulated and must be

registered in compliance with the Federal Insecticide,

Fungicide, and Rodenticide Act (FIFRA). IEMB has begun a

study of biocides and antimicrobial agents used in HVAC

systems. The study, which will take place within the next

year, includes:

1) Determining the efficacy of biocides and antimicrobial

agents used in HVAC systems. This will be

accomplished by surveying commercial biocides and

antimicrobial products used in HVAC systems; surveying

the industry to determine product use and preferences;

and conducting tests on 10 biocides and antimicrobial

agents using cultured samples of fungi, mold, and

bacteria.

2) Investigating the application effectiveness of biocides

and antimicrobial agents used in HVAC systems. This

will be accomplished by testing various concentrations

(manufacturers’ recommended concentration and 50%

recommended) of 10 products for 30 and 60 days using

dynamic chambers and evaluating the effectiveness on

fungi, mold, and bacteria and by testing the impact of

organic load to act as a barrier to chemical reaction.

3) Determining the relationship between RH and microbial

growth. The effectiveness of biocides and antimicrobial

agents will be tested at RH levels of 60, 85, and 100% of

saturation.

4) Determining the impact of biocides and antimicrobial

agents on IAQ. Microbial emissions will be measured from

inoculated and treated surfaces. (EPA Contact: Marc

Menetrez, 919-541-7981, mmenetrez@engineer.aeerl.

epa.gov

SUMMARIES OF RECENT PUBLICATIONS

This section provides summaries of recent

publications on EPA’s indoor air research.

The source of the publication is listed after

each summary.

Cost Analysis of Activated Carbon vs.

Photocatalytic Oxidation for Removing Organic Compounds from Indoor

Air–A cost comparison has been

conducted of 1 m3/s indoor air cleaners

using granular activated carbon (GAC)

vs. photocatalytic oxidation (PCO) for

treating a steady-state inlet VOC

concentration of 0.27 mg/m3. The

commercial GAC unit was costed

assuming that the inlet VOCs had a

reasonable carbon sorption affinity,

representative of compounds having

four or more atoms (exclusive of

hydrogen). A representative model PCO

unit for indoor air application was

designed and costed, using VOC

oxidation rate data reported in the

literature for the low inlet concentration

assumed here, and using a typical

illumination intensity. The analysis

shows that, for the assumptions used

here, the PCO unit would have an

installed cost more than 10 times

greater, and an annual cost almost 7

times greater, than the GAC unit. It

also suggests that PCO costs cannot

likely be reduced by a factor greater

than 2 to 4, solely by improvements in

the PCO system configuration and

reductions in unit component costs.

Rather, an improved catalyst having a

higher quantum efficiency would be

needed, increasing reaction rates and

reducing illumination requirements

relative to the catalysts reported in the

literature. GAC costs would increase

significantly if the VOCs to be removed

were lighter and more poorly sorbed

than assumed in this analysis. Source:

Accepted for publication in J. of the Air

& Waste Management Assoc. (EPA

Contact: D. Bruce Henschel, 919-541-

4112, bhenschel@engineer.aeerl.

epa.gov)

Enhanced Allergic Responses to

House Dust Mite by Oral Exposure to

Carbaryl in Rats–Epidemiological

studies have demonstrated an

association between use of carbamate

insecticides, including carbaryl, and

increased incidence of allergic asthma

in farmers. In this study, the effect of

oral carbaryl exposure on the

development of allergic responses to

house dust mites (HDMs) was

examined in female Brown Norway

rats. Rats were gavaged for two weeks

with 0, 2, 10, or 50 mg/kg/day of

carbaryl. They were sensitized with a

subcutaneous injection of HDM in

aluminum hydroxide adjuvant 3 days

after the beginning of carbaryl exposure

and challenged with antigen via the

trachea one day after the final carbaryl

ingestion. In 2 days, antigen specific

cell proliferation in pulmonary lymph

nodes was significantly higher in the 50

mg/kg group than in controls, while

antigen specific splenocyte proliferation

was decreased in groups dosed with 2,

10, and 50 mg/kg carbaryl. Total

protein and lymphocyte numbers in

bronchoalveolar lavage (BAL) fluid

were also increased in the 50 mg/kg

group. In 7 days, immune-mediated

pulmonary inflammation (eosinophils),

antigen specific immunoglobulin (Ig) E

level in serum, and antigen specific IgE

and IgA levels in BAL fluid were

significantly elevated in the 50 mg/kg

group. No apparent change was

observed for lactate dehydrogenase and

eosinophil peroxidase in BAL fluid,

while the number of BAL macrophages

were decreased in groups dosed with 10

and 50 mg/kg carbaryl. This suggests

that carbaryl may cause systemic

immune suppression, while enhancing

pulmonary allergic responses to HDM

antigen. Source: Toxicological

Sciences; In Press, Toxicol Sci. March,

1998 (EPA Contact: Wumin Dong,

919-541-7808, dong.wumin@epa.gov)
Inside IAQ, Fall/Winter 1998 Page 13

Entrainment by Ligament-Controlled

Effervescent Atomizer-Produced

Sprays–An innovative spray nozzle for

use with precharged aerosol containers

was developed and evaluated. The new

design allows for the reformulation of

selected aerosol consumer products

using water and air in place of VOC

solvents and hydrocarbon propellents.

This article discusses the entrainment of

ambient air into sprays produced by

this effervescent atomizer. Entrainment

data were analyzed using a model

together with measured momentum rate

data that were collected as part of this

study. The analysis shows that entrainment by sprays produced using this

type of atomizer is predicted to within

about 35%. Source: International

Journal of Multiphase Flow, vol. 23,

no. 5, pp. 865-884, 1997 (EPA

Contact, Kelly W. Leovic, 919-541-

7717, kleovic@ engineer.aeerl.epa.gov)

Evaluation of a Test Method for

Measuring Indoor Air Emissions

from Dry-Process Photocopiers–A

four-laboratory evaluation of a large

chamber test method for measuring

emissions from office equipment was

conducted. A single dry-process

photocopier was shipped to each of the

four laboratories along with supplies

(i.e., toner and paper). Results

demonstrate that the test method was

used successfully in the different

chambers to measure emissions from

the copier. Differences in chamber

design and construction appeared to

have had minimal effect on the results

for the VOCs. Percent relative standard

deviation (%RSD) was used to provide

a simplistic view of interlaboratory

precision. Excluding problems with

suspected analytical bias observed from

one of the laboratories, the precision

was excellent for the VOCs with RSDs

of less than 10% in most cases. Less

precision was observed among the

laboratories for aldehydes/ketones

(RSD of 23.2% for formaldehyde). The

precision for ozone emission rates

among three of the laboratories was

excellent (RSD of 7.9%). Source:

Accepted for Publication by the J. Air

& Waste Management Association,

May 1998 (EPA Contact: Kelly W.

Leovic, 919-541-7717, kleovic@

engineer. aeerl.epa.gov)

Evaluation of Low-Emitting Products

for Use in the Indoor Environment–IEMB recently completed

cooperative research on the application

of pollution prevention techniques to

reduce indoor air emissions from

aerosol consumer products, engineered

wood products, and office equipment.

For aerosol consumer products, one

project focused on developing

measurement methods and models that

can be used by manufacturers to better

understand aerosol behavior so that

more efficacious and less toxic products

can be developed. A second project

resulted in the development and

evaluation of an innovative spray

nozzle for use with pressurized aerosol

containers. The new design will allow

manufacturers to reformulate selected

aerosol consumer products using water

and air in place of VOC solvents and

hydrocarbon propellants. To evaluate

emissions from engineered wood

products, emissions were screened from

four common types of finished

engineered wood used indoors. Acidcatalyzed alkyd-urea coatings and

particleboard were subsequently

identified as the primary emission

sources. Laboratory testing identified

three types of fiber panels as lowemitting alternative materials: fiber

panels made with medium density

fiberboard and methylene diisocyanate

resin, wheat straw and methylene diisocynate resin, and corrugated cardboard.

Three types of lower-emitting coatings

were identified: a two component waterborne polyurethane, an aliphatic urethane

acrylate, and a water-based acrylic. All

three fiber panels and coatings are

commercially available. A fourth project

resulted in the development of a test

guidance method to measure office

equipment emissions. The method was

evaluated by testing four dry-process

photocopiers in one chamber and then

conducting a round-robin evaluation of

one copier. Another component of this

project evaluated emissions from printed

circuit board laminates. Source:

Proceedings of the Annual Air & Waste

Management Association Meeting, San

Diego, June 1998 (EPA Contact: Kelly

W. Leovic, 919-541-7717, kleovic@

engineer.aeerl.epa.gov)

Evaluation of Sink Effects on VOCs

from a Latex Paint–The sink strength

of two common indoor materials, carpet

and gypsum board, was evaluated by

environmental chamber tests with four

VOCs: propylene glycol, ethylene

glycol, 2-(2-butoxyethoxy)ethanol, and

Texanol. These oxygenated compounds

represent the major VOCs emitted from

a latex paint. Each chamber test

included two phases. Phase 1 was the

dosing/ sorption period during which

sink materials (pieces of carpet and

gypsum board samples) were exposed

to the four VOCs. The sink strength of

each material tested was characterized

by the amount of the VOCs adsorbed or

absorbed. Phase 2 was the purging/

desorption period during which the

chambers with the dosed sink materials

were flushed with purified air. The

remission rates of the adsorbed VOCs

from the sinks were reflected by the

amount of the VOCs being flushed.

Phase 1 results indicated that the sink

strength for the four target compounds

is more than 1 order-of-magnitude

higher than that for other VOCs

previously tested by EPA. The high

sink strength reflected the unusually

high sorption capacity of common

indoor materials for the four VOCs.

Phase 2 results showed that remission

was an extremely slow process. If all

the VOCs adsorbed were remittable, it

would take more than a year to

completely flush out the VOCs from the

sink materials tested. The long

remission process can result in chronic

and low level exposure to the VOCs

after painting the interior walls and

surfaces. Source: Accepted for

Publication in the J. of the Air & Waste

Management Association (EPA

Contact: John C. S. Chang, 919-541-

3747, jchang@engineer.aeerl.epa.gov)
Inside IAQ, Fall/Winter 1998 Page 14

Increased Immune and Inflammatory

Responses to Dust Mite Antigen in

Rats Exposed to 5 ppm NO2–Immune

hypersensitivity to HDM is a frequent

cause of respiratory allergy. The

objective of this study was to determine

whether exposure to NO2, a common

indoor air pollutant, modulates immune

responses to HDM and influences

immune-mediated lung disease. Brown

Norway rats were immunized ip with

100 μg semipurified antigen and

Bordetella pertussis adjuvant and

challenged 2 weeks later with an

intratracheal injection of 50 μg of a

crude antigen preparation. Exposure to

5 ppm NO2 for 3 hours after both

immunization and challenge procedures

resulted in significantly higher levels of

antigen-specific serum IgE, local IgA,

IgG, and IgE antibody than air controls,

and increased numbers of inflammatory

cells in the lungs. Lymphocyte responsiveness to antigen in the spleen and

MLN was also significantly higher in

NO2-exposed animals. These data show

that exposure to a common air pollutant

can upregulate specific immune

responses and subsequent immunemediated pulmonary inflammation.

Source: Fundam. Appl. Toxicol. 31. 65-

70 (EPA Contact: Mary Jane E.

Selgrade, 919-541-2657, selgrade.

maryjane@epa.gov)

Indoor Air Emissions from Office

Equipment: Test Method Development

and Pollution Prevention Opportunities–EPA and RTI conducted

cooperative research to identify pollution

prevention approaches for reducing

emissions from office equipment. The

project included: 1) forming a group of

technical advisors; 2) preparing a

literature review on the operation of, and

emissions from, office equipment as well

as pollution prevention opportunities;

3) developing and evaluating an

Emissions Testing Guidance Document

for Dry-Process Photocopy Machines;

and 4) identifying and evaluating pollution prevention options. Because no

standard test method exists to measure

emissions from office equipment (e.g.,

ozone, VOCs, aldehydes/ ketones,

inorganic gases, and particles), it is

difficult to compare data from different

studies. Thus, the focus of this project

was the development and evaluation of a

large chamber test method for measuring

emissions from dry-process photocopiers.

The goal is to apply the method to better

understand emissions from office

equipment and to develop lower emitting

machines. The test method was evaluated

in two phases. Phase I was a single

laboratory evaluation of the method at

RTI using four mid-range dry-process

photocopiers. Phase I results indicated

that the test method provided acceptable

performance for characterizing emissions,

adequately identified differences in

emissions between machines both in

compounds emitted and their emission

rates, and was capable of measuring both

intra- and inter-machine variability in

emissions. Phase II was a four-laboratory round-robin evaluation of the

method. A single dry-process photocopier

was shipped to each of the four

laboratories along with supplies (i.e.,

toner and paper). Phase II results

demonstrate that the method was used

successfully in the different chambers to

measure emissions and that differences in

chamber design and construction

appeared to have had minimal effect.

Source: EPA Report, “Indoor Air Emissions from Office Equipment: Test

Method Development and Pollution

Prevention Opportunities,” EPA-600/R98-080 (EPA Contact: Kelly W. Leovic,

919-541-7717, kleovic@engineer.aeerl.

epa.gov)

Indoor Emissions from Conversion

Varnishes–Conversion varnishes are

two-component, acid-catalyzed

varnishes that are commonly used to

finish cabinets. They are valued for

their water- and stain-resistance, as

well as their appearance. They have

been found, however, to contribute to

indoor emissions of organic

compounds. For this project, three

commercially available conversion

varnish systems were selected. An EPA

Method 24 analysis was performed to

determine total volatile content, and a

sodium sulfite titration method was

used to determine uncombined (free)

formaldehyde content of the varnish

components. The resin component was

also analyzed by GC/MS (EPA Method

311 with an MS detector) to identify

individual organic compounds.

Dynamic small chamber tests were then

performed to identify and quantify

emissions following application to

coupons of typical kitchen cabinet

wood substrates, during both curing

and ageing. Because conversion

varnishes cure by chemical reaction, the

compounds emitted during curing and

ageing are not necessarily the same as

those in the formulation. Results of

small chamber tests showed that the

amount of formaldehyde emitted from

these coatings was 2.3 to 8.1 times the

amount of free formaldehyde applied in

the coatings. A long-term test showed a

formaldehyde emission rate of 0.17

mg/m2/h after 115 days. Source:

Accepted for Publication in the J. of the

Air & Waste Management Association

(EPA Contact: Elizabeth M. Howard,

919-541-7915, bhoward@engineer.

aeerl.epa.gov)
Inside IAQ, Fall/Winter 1998 Page 15

Ligament-Controlled Effervescent

Atomization–The operating principles

and performance of a new type of spray

nozzle are presented. This nozzle,

termed a “ligament-controlled

effervescent atomizer,” was developed

to allow consumer product

manufacturers to replace VOC solvents

with water and hydrocarbon propellants

with air, while meeting the following

criteria: that the spray mean drop size

remain below 70 μm, that the atomizing

air consumption be less than 0.009, and

that atomizer performance be

uncompromised by the increase in

surface tension or by changes in

viscosity. The current atomizer differs

from previous effervescent designs

through inclusion of a porous disc

located immediately upstream of the

nozzle exit orifice. The purpose of this

disc is to control the diameter of

ligaments formed at the injector exit

place. Atomizer performance is

reported in terms of the spray Sauter

mean diameter, with drop size data

analyzed using a model developed from

first principles. The model describes the

spray formation process as the breakup

of individual cylindrical ligaments

subject to a gas stream. Ligament

diameter is estimated from

manufacturer supplied pore size data

for the porous disc. The model correctly

predicts the experimentally observed

relationship between Sauter mean

diameter and air-to-liquid ratio by

mass, liquid surface tension, and liquid

viscosity. Source: Atomization and

Sprays, vol. 7, pp. 383-406, 1997

(EPA Contact: Kelly W. Leovic, 919-

541-7717, kleovic@ engineer.aeerl.

epa.gov)

Transfer of Allergic Airway

Responses with Serum and

Lymphocytes from Rats Sensitized to

Dust Mite–HDM antigen is one of the

most common allegens associated with

extrinsic asthma. In a model of allergic

lung disease, Brown Norway rats were

sensitized to HDM with alum and

Bordetella pertusis adjuvants to

produce high levels of IgE antibody and

experience bronchoconstriction,

increased airway hyperresponsiveness

(AHR) to acetylcholine , and

pulmonary inflammation after antigen

challenge. The purpose of this study

was to determine whether these

asthmatic symptoms could be

transferred from sensitized animals to

naive recipients via humoral or cellular

factors. Syngenetic recipient rats were

injected with either HDM or bovine

serum albumin from lymph nodes of

sensitized or control rats, respectively.

Other groups received a tail-vein

injection of serum from either HDMsensitized or control rats. Antigen

challenge in rats injected with sensitized

cells caused increases in pulmonary

inflammation and in AHR, but no

changes in immediate bronchoconstriction as compared with control

recipients. Antigen challenge in serum

recipients resulted in immediate

bronchoconstriction but had no effect

on AHR or on pulmonary inflammation. These data show that immunemediated lung inflammation and AHR

are promoted by antigen-specific

lymphocytes, whereas immediate

allergic responses are caused by serum

factors. Source: Respir. Crit. Care

Med. 1998; 157:000-000. (EPA

Contact: Daniel L. Costa, 919-541-

2532, costa.daniel@ epa.gov)

GLOSSARY

AHR - Airway Hyperresponsiveness

BAL - Bronchoalveolar Lavage

CAS - Chemical Abstract Service

CPU - Central Processing Unit

FIFRA - Federal Insecticide, Fungicide,

and Rodenticide Act

GAC - Granular Activated Carbon

GC/MS - Gas Chromatography/Mass

Spectrometry

G/E - Glass/epoxy

G/L - Glass/lignin

HDM - House Dust Mite

HVAC - Heating, Ventilating, and AirConditioning

IAQ - Indoor Air Quality

IEMB - Indoor Environment Management Branch

MCS - Multiple Chemical Sensitivity

NAICS - North American Industrial

Classification System

NRMRL - National Risk Management

Research Laboratory

PC - Personal Computer

PCO - Photocatalytic Oxidation

P/P - Paper/Phenol

P/RP - Paper/Reformulated Phenolic

QA - Quality Assurance

RH- Relative Humidity

RSD - Relative Standard Deviation

RTI - Research Triangle Institute

TVOC - Total Volatile Organic Compound

VB - Vapor Barrier

VOC - Volatile Organic Compound
Inside IAQ, Fall/Winter 1998 Page 16

United States

Environmental Protection Agency

National Risk Management Research Laboratory

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Research Triangle Park, NC 27711

Official Business

Penalty for Private Use

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