United States National Bureau of Department of Standards

Commerce Washington DC 20234

United States Environmental Protection Agency

Office of Monitoring and Technical Support

Washington DC 20460

EPA 600/4 80 042

August 1 980

Research and Development

Survey on Research

Needs on Personal

Samplers for Toxic

Organic Compounds
RESEARCH REPORTING SERIES

Research reports of the Office of Research and Development, U.S. Environmental

Protection Agency, have been grouped into nine series. These nine broad cate- gories were established to facilitate further development and application of en- vironmental technology. Elimination of traditional grouping was consciously

planned to foster technology transfer and a maximum interface in related fields. The nine series are:

1. Environmental Health Effects Research

2. Environmental Protection Technology

3. Ecological Research

4. Environmental Monitoring

5. Socioeconomic Environmental Studies

6. Scientific and Technical Assessment Reports (STAR)

7. Interagency Energy-Environment Research and Development

8. “Special’’ Reports

9. Miscellaneous Reports

This report has been assigned to the ENVIRONMENTAL MONITORING series.

This series describes research conducted to develop new or improved methods

and instrumentation for the identification and quantification of environmental

pollutants at the lowest conceivably significant concentrations. It also includes

studies to determine the ambient concentrations of pollutants in the environment

and/or the variance of pollutants as a function of time or meteorological factors.

This document is available to the public through the National Technical Information Service, Springfield, Virginia 22161.
A SURVEY ON RESEARCH NEEDS ON PERSONAL SAMPLERS FOR

TOXIC ORGANIC COMPOUNDS

by

Jimmie A. Hodgeson and Alexander J. Fatiadi

Center for Analytical Chemistry

National Bureau of Standards

Washington, D.C. 20234

Interagency Agreement No. AD-13-F-0-034-0

EPA Project Officers

Lance Wallace

Office of Monitoring Systems and Quality Assurance

Environmental Protection Agency

Washington, D.C. 20460

and

Eugene P. Meier

Quality Assurance Division

Environmental Monitoring Systems Laboratory

Environmental Protection Agency

Las Vegas, Nevada 89114

Prepared For:

OFFICE OF MONITORING SYSTEMS AND QUALITY ASSURANCE

OFFICE OF RESEARCH AND DEVELOPMENT

ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

i
DISCLAIMER

This report has been reviewed by the Office of Monitoring and

Technical Support, U. S. Environmental Protection Agency, and approved for

publication. Approval does not signify that the contents necessarily reflect

the views and policies of the U. S. Environmental Protection Agency, nor

does mention of trade names or commercial products constitute or recommendation for use.

ii
FOREWORD

This report is one of a series of reports designed to provide

information on the development of Standard Reference Materials and

measurement methods in support of quality assurance for environmental

monitoring. The National Bureau of Standards and the Environmental

Protection Agency have entered into an interagency agreement to

coordinate the standards and measurement services activities of NBS

with the quality assurance programs of EPA. Reports of work carried

out under this agreement will appear in the EPA Environmental

Monitoring Research Report Series.

Under this agreement, NBS will develop and provide, as directed

by EPA,

as well as other services deemed necessary for assuring the accuracy

and reliability of environmental monitoring data. Standard Reference

Materials developed under this agreement will be available for

purchase from the NBS Office of Standard Reference Materials. Work

under this agreement is coordinated by the Office of Monitoring

Systems and Quality Assurance in EPA and by the Office of

Environmental Measurements in NBS and questions concerning this

program should be addressed to the Office of Environmental Measurements, National Bureau of Standards, Washington, DC 20234.

Standard Reference Materials

Improved or new measurement methods

Standard measurement instruments

Calibration standards and protocols

WILLIAM H. KIRCHHOFF, Chief

Office of Environmental Measurements

iii
ABSTRACT

A survey is presented on the research and development needs for personal

monitoring devices for toxic organic compounds in the ambient atmosphere.

This survey includes a description of organic compounds and their ambient

concentrations in the atmosphere, individual compounds of high priority, a summary of a literature survey, a description of commercially available

workplace samplers, a summary of recent developments in ambient personal

monitoring and recommendations on major research needs. The high priority

compounds identified were predominately volatile chlorinated organics and

consist of the following compounds: methyl chloride, dichloromethane

,

benzene, carbon tetrachloride, chloroform, dichlorobenzenes, 1 , 2-dichloroethane, methyl chloroform, trichloroethylene and perchloroethylene. The

literature survey covers the period, 1974-79, and describes sorbent materials

for organic sampling, analytical procedures, and developments on personal

monitoring devices. The literature is predominately concerned with personal

sampling in the workplace environment. Commercially available personal

samplers described are Dupont’s Pro-Tek organic vapor badge, Abcor’s gasbadge

3-M's organic vapor monitor and the Minimonitor (P. W. West, Louisiana State

University) . Recent activities include a description of an EPA sponsored

program at Monsanto Research Corporation on development of personal samplers

for organics in the ambient atmosphere. Monsanto has developed an active

sampler consisting of a miniature pump with three sorbents in series - Tenax

GC, Poropak-R and Ambersorb XE-349. A description is also given of several

recent field studies on sampling and analysis for benzene and chlorinated

hydrocarbons in the ambient atmosphere. The survey concludes with recommenda

tions for research and development activities in the following areas: evalua

tion of sorbent materials, development of analytical techniques based on electron capture-gas chromatography, evaluation of available active and

passive samplers on the high priority compounds, development of passive

samplers and development of standard mixtures for evaluation and calibration

of personal exposure devices.

iv
CONTENTS

Foreword ill

Abstract iv

Tables vi

1. Introduction 1

2. Organic Compounds in the Atmosphere 2

3. Monitoring Needs 4

4. Survey of Organic Personal Exposure Devices 11

Summary of the Literature 11

Commercially Available Samplers 14

Conclusions 16

5. Summary of Recent Activities 17

6. Recommendations for Research and Development Activities . . 20

References 23

v
TABLES

Number Page

1 Organic Compounds in the Atmosphere 3

2 General Sorption-desorption Systems for Organic Compounds ... 8

3 TSCA Priority List 10

4 Volatile Organic Compounds of Atmospheric Concern 13
SECTION 1

INTRODUCTION

Regulatory decisions on air pollution control, which involve direct and

indirect costs of billions of dollars, should be based on an adequate knowledge of the health impacts of air pollution. A weak link in health effects

studies is our knowledge of individual exposures. The importance of population exposure estimates in air pollution health effects studies makes it

imperative that future studies include estimates more representative of what

people breathe. Studies of air pollution health effects have usually relied

on one or several fixed monitoring stations to provide data for an estimate

of the exposure received by an entire neighborhood. Epidemiologists have

begun to call for something better. Several recent meetings of specialists

in the field of air pollution health effects have led to recommendations

urging the prompt development of small, portable individual air pollution

monitors (1)

In response to this need and under a EPA-NBS Interagency Agreement, the

NBS program is to develop principles and concepts and actual devices for

determining personal exposure to critical air pollutants. Both passive and

active monitors will be developed to provide long-term integrated exposures

(> 24 hours) and data on short-term exposure events (< 1 hour) . During the

first year of the program the pollutants EPA has identified as having the

highest priority are fine particulates, nitrogen dioxide and toxic organics.

Because limited information for personal exposure devices for toxic

organics was available at the beginning of this program, the work reported

here is a survey of the research needs and promising approaches for developmental activities.

In the following discussion we will present a description of the classes

of organic compounds present in ambient air and typical concentration levels,

monitoring needs as perceived from regulations and agency programs, a summary

of a literature survey, a description of commercially available workplace

devices, a summary of some recent activities on personal exposure devices for

ambient organics and recommendations of major research needs in this field.

1
SECTION 2

ORGANIC COMPOUNDS IN THE ATMOSPHERE

Organic compounds are emitted into the atmosphere as a result of biogenic and anthropogenic activities. The most abundant single organic

compound in the atmosphere, methane (CH4 ) , results predominantly from microbiological processes, e.g., dead plant decay, and has a natural tropospheric

background concentration of ca. 1.4 ppm. Another major natural class of

organic component is the terpenes, which are emitted by many living plant

species. Other known natural gaseous organic compounds in the atmosphere

include organic mercaptans and sulfides and methyl iodide (2)

Many of the

other organic compound emissions into the atmosphere are a result of anthropogenic activities. A major source is motor vehicle emissions with other

significant contributions from stationary fuel combustion, solvent evaporation,

solid waste disposal, gasoline marketing and forest fires (2). Thus the

major urban anthropogenic organic class is hydrocarbons, of which the total

concentration may range from background (ca. 1.4 ppm) up to a few parts per

million by volume.

The presence of anthropogenic hydrocarbons in the atmosphere may contribute to adverse environmental consequences. The non-methane hydrocarbons

(NMHC) are reactive in the presence of solar radiation and oxides of nitrogen

(from combustion in mobile and stationary sources) and promote elevated

levels of tropospheric ozone (O3 ) and photochemical smog (3,4). Halogenated

hydrocarbons, in particular the freons, are so stable in the lower atmosphere

that they accumulate and diffuse into the stratosphere. Their photodegradation products destroy O 3 and these compounds thus may pose a long-term threat

to the protective stratospheric O 3 layer (5-8)Other organic compounds are

of concern because they pose a direct toxic threat when inhaled. For example,

emissions of vinyl chloride (9) and benzene (10) are controlled by federal

regulation because of the demonstrated health effects of these compounds ( 11- 13).

A detailed compilation of organic compounds, with ranges of concentration known to be present in the polluted troposphere, has been given in the

excellent monograph by Graedel (14). The classes of compounds compiled

include hydrocarbons, carbonyl compounds, oxygenated organic compounds,

nitrogen-containing organic compounds, sulfur-containing organic compounds,

organic halogenated compounds and organometallic compounds. Table 1 shows

some of these classes and their more prominent members with ranges of con- centration.

2
TABLE 1. CHEMICAL COMPOUNDS IN THE ATMOSPHERE AND AMBIENT CONCENTRATIONS.

Name Concentration Name Concentration

Alkanes (total) 1400 - 6000 ppb Acrolein 1 - 13 ppb

Methane 1300 - 4000 ppb Acetone 0.08 - 6.8 ppb

Ethene 0.7 - 700 ppb Formic Acid 4 -72 ppb

Terpenes (total) 0.1 - 1 ppb Esters (total) 1 - 100 ppb

Cyclic Hydrocarbons (total)2 - 50 ppb Quinones <0.001 - 0.02 ppb

Cyclohexane 3 - 6 ppb Methanol 8 - 100 ppb

Toluene 0.005 - 129 ppb Phenol 2 . 8 ppb

Benzene 0.025 - 57 ppb Halogen Compounds 0.8 - 3.0 ppb

m-Xylene 1 - 61 ppb Methyl Chloride 0.8 - 2.2 ppb

Naphthalene <0.001 - 0.06 ppb Chloroform 0.004 - 0.25 ppb

Pyrene <0.001 - 0.02 ppb Carbon Tetrachloride 0.001 - 0.26 ppb

Benzo[ a] pyrene <0.001 - 0.008 ppb Trichloroethylene 0.01 - 0.35 ppb

Aldehydes +

Ketones (total

oxygen compound)

1 — 200 ppb Vinyl Chloride .005 ppb

Formaldehyde 1 - 160 ppb Halogenated Aromatics ^ 0. 08 ppb

Cyanogen 1C1 - 20 ppb

Sulfur Compounds 4 ppb
SECTION 3

MONITORING NEEDS

It is obvious from the discussion in Section 2 above that there is a wide variety of classes of organic compounds with many individual members

present in a polluted atmosphere. These compounds represent a wide range of

volatilities, polarities, and f unctionalities-properties which will surely

determine the choice of the sampling medium for a given compound or class of

compounds. In addition, the analytical work-up will vary for different

classes of compounds with different chemical and physical properties.

Finally, the most important factor to consider in determining monitoring

needs is the potential health threat, a factor which may range from none to

acute over the range of compounds found in the atmosphere. The potential

health threat of an organic compound is in turn determined by its degree of

toxicity, carcinogenicity or mutagenicity, production rate, emission rate

into the atmosphere, and its atmospheric persistence or lifetime.

In order to begin a program on development of personal exposure devices,

the identification of a finite set of organic compounds (classes) of high

priority based on potential health threat is required. Once this set of com- pounds is identified, candidate sampling methods and analytical work-ups can

be chosen for development and evaluation. Our approach in identifying high

priority monitoring needs has been to a) examine federal regulations relative

to toxic organics in the atmosphere; b) survey documented information on high

priority toxic organics and c) consult with EPA personnel on high priority

agency programs on toxic organics.

The EPA is the federal agency with responsibility for the control of

emissions of toxic organics into the atmosphere. The EPA has several regulatory options available to carry out congressionally mandated emission control.

The Clean Air Act (15) as amended by the Clean Air Amendments (CAA) of 1970

and 1977 provides several options for control. Those options which have

resulted in regulations on organic compounds include 1) National Ambient Air

Quality Standards (NAAOS) /State Implementation Plans; 2) National Emission

Standards for Hazardous Air Pollutants, 3) New Source Standards of Performance

and 4) National Emission Standards for Mobil Sources.

Another major piece of legislation relative to control of organic com- pounds in the environment is the Toxic Substances Control Act (TSCA) of 1976

(16) . The TSCA enables EPA to gather from industry the required information

on any organic chemical produced as needed to determine its potential for

damaging human health and the environment, and to control them where necessary

to protect the public.

4
THE CLEAN AIR ACT

Section 109 of the Clean Air Act requires that the Administrator set

national primary and secondary ambient air quality standards. Primary standard indicates those levels of air quality, including an adequate margin of

safety, which are necessary to protect public health. Secondary standards

indicate those levels which are necessary to protect public welfare from any

known or anticipated adverse effects. Public welfare includes effects on vegetation, wildlife, physical properties of the atmosphere, materials, etc.

NAAQS have been set for particulate matter, sulfur oxides, nitrogen oxides,

photochemical oxidants, non-methane hydrocarbons (NMHC) , and carbon monoxide

(17).

Standards are based on information from air quality criteria documents

prepared in accordance with section 108 of the Act. In addition, for each

criteria pollutant (a pollutant for which NAAQS are established) , EPA must

prepare a document relating control techniques and costs of control. A pollutant is considered a likely candidate for NAAQS if:

1 . there is an adverse effect on public health or welfare

caused by the presence of the pollutant in the ambient

air, and

2 . the presence of the pollutant in the air is the result

of numerous and diverse mobile and stationary sources.

To insure that levels indicated by NAAQS are attained, section 110 of the

Act requires States to submit Implementation Plans which demonstrate procedures for attaining these standards. State plans must provide for attaining

primary standards within three years (a two-year extension may be requested)

,

and secondary standards within a reasonable time after approval of such a plan.

The only regulation for organics under the NAAQS is on NMHC, i.e., total

hydrocarbon minus methane. It should be noted that although a standard exists

for NMHC, routine monitoring for NMHC is done in practice infrequently because

such a measurement is difficult to do accurately at ambient levels and because

the NMHC, as a class, is not directly associated with adverse health effects.

Rather the NMHC promotes the formation of O3 and other toxic components of

photochemical smog.

A potentially more important section of the Clean Air Act for the

regulation of organics is section 111, in particular 111(d). This section

requires EPA to set standards of performance on new or modified stationary

sources for any non-criteria air pollutant "which may reasonably be anticipated to endanger health or welfare".

Section 112 of the Act requires EPA to identify pollutants which cause an increase in mortality or an increase in serious irreversible, or incapacitating reversible illness. These pollutants are generally considered to be less

ubiquitous pollutants covered by the NAAQS.

5
“or anv pollutant which is considered hazardous, EPA must establish

emission standards which provide an ample margin of safety to protect public

health. In general, standards will be established by defining ambient guideline concentrations of a pollutant which provide an ample margin of safety to

orctect health. Dispersion models are then used to determine the allowable

emissions that will ensure that the ambient guideline concentrations are not

exceeded. As presently written, the Act does not permit consideration of cost

or availability of demonstrated control technology in determining allowable

emissions. Hazardous emission standards have presently been promulgated for

the inorganics-mercury, asbestos, arsenic and beryllium and for the organicsvinyl chloride (9) and benzene (10).

Section 202 of the Act requires the Administrator to set emission standards for any air pollutant coming from a motor vehicle if the pollutant is

harmful to public health and welfare. Mandatory emission reductions for CO,

total hvdrocarbon ^HC) , and NO were written into the Act for light dutv

x vehicles. The Act required a 90 percent reduction in NO^ (N0+N0o ) to be

effective in l?"f. These deadlines were subsequently extended to allow

vehicle manufacturers additional time to develop control systems.

In summary under the CAA, the only present regulations on organic

compounds are for NMHC under the XAAQS, for vinyl chloride and benzene as hazardous pollutants, and for total hydrocarbons from vehicular emissions.

Of these only vinyl chloride and benzene are associated with direct health

effects and therefore should be considered with regard to personal monitoring

needs. It should be mentioned at this point that West (18,19) has developed

a permeation type, personal sampler for vinyl chloride.

THZ TOXIC SUBSTANCES CONTROL ACT (TSCA)

The TSCA of 1976 is a comprehensive piece of legislation designed to

provide the information required to assess the potential health or environmental threat from chemical substances. The ISCA also provides EPA with the

means for regulating the production, distribution, use and disposal of chemical substances when deemed necessary. A good summary of TSCA may be found in

reference (20) . We only discuss here that aspect of the law which provides

information on toxic organics, which may be subject to regulation and which

may present needs for personal monitoring.

Section - on the "Testing of Chemical Substances and Mixtures" is pertinent to this discussion. Under this section EPA may require manufacturers or processors to provide the test data required to determine whether chemicals

pose potential threats to health or the environment. Test data may be

required to characterize chemical substances in terms of their environmental

persistence and toxicity and to assess health and environmental effects

including carcimogemic, mutagenic, teratogenic, behavioral and synergestic

e z roots

Section - e establishes an Interagency committee to develop a "Priority

list " of chemicals to which EPA should give priority consideration for promulgating rules for obtaining test data. Among the relevant factors the

committee must consider in recommending this list are the following: 1) the

6
quantity of the chemical substance manufactured; 2 ) the quantity vhich na enter the environment; 3) the extent of human exposure to the chemical substance, and 4) the existence of data on the effects of the substance on health

and the environment.

The third factor is particularly important here in that it implies the

need for personal exposure studies. The Priority list may contain up to 50

chemical substances. The fourth report of this interagency ctmmittee to EPA

lists the latest Priority List of chemicals. This list of 33 individual

compounds or classes of compounds is reproduced in Table 2. It is of interest

to note that of these 33 substances, 30 are organic compounds cr classes of

compounds

While we regard the TSCA Priority list to be the comprehensive source in

identifying monitoring needs for specific organics cr classes, seme other

sources of information were examined. The Monsanto Corporation has recently

conducted a study for P?A which resulted in the icentif icaticn of 20 high

priority atmospheric carcinogens from a list of 125 high volume chemicals

having the potential of becoming airborne pollutants (21 . This prioritization was based on a rating scale which for each compound included the

emission rate, the atmospheric persistence and the potency relative to benze-

( a) pyrene.

The chemicals on the list in a prioritized ranking are: benzo ''a, pyrene

,

tetrachloroethylene, ethylene dichloride, benzene, carbon tetrachloride,

ethylene dibromide, toluene-3, --diamine , diexane, acrylonitrile, ethylenimine

,

benzyl chloride, benzidine, pentachlorophenol , dichloropropene , styrene

,

hexachlorobutadiene, di-(2-ethylhexyl)phthalate, vinyl acetate, ethylene

oxide, and acrolein.

Both the TSCA Priority List and the Monsanto list include toxic compounds

of concern, whether their release into the environment occurs through the

aqueous, terrestrial or atmospheric media. We are concerned here about organic

substances which are released into and may persist in the atmosphere. We are further concerned here for personal monitoring needs for vapor phase organics

in the atmosphere. Many of the toxic organics on the previous lists would

occur in the particulate phase if they persist in the atmosphere e.g..

benzo(a)pyrene. A separate task of this same Interagency Agreement is con- cerned with the personal sampling and analysis of pollutants in the particulate phase. Therefore, these lists were culled to eliminate those compounds

with low vapor pressure or high atmospheric reactivity with the IP radical or O 3

. The upper limit chosen for vapor pressure was the boiling point ca. 15!)

°C) of the dichlorobenzenes, which have actually been observed in field

studies as discussed below.

For atmospheric reactivity, compounds with a half-life less than one week

based on reaction with OE radicals were eliminated. A mean tropospheric CP

concentration of 5 x 10 : molecules, ern was chosen and the rate constants were taken from the recent review of Atkinson (22)

Tne choice of cne week is

somewhat arbitrarv, but it does provide a clean dividing _ine between tne

chlorinated comoounds and the other organics, with the exception or benzene.

For example, toluene and the cresols have halt-lives ot 3.3 anc 3.5 cays,

7
TABLE 2. TSCA PRIORITY LIST

Acetonitrile

Acrylamide

Alkyl epoxides

Alkyl phthalates

Aniline and bromo, chloro and/or nitroanilines

Antimony (metal)

Antimony sulfide

Antimony trioxide

Aryl phosphates

Chlorinated benzenes, mono and diChlorinated benzenes, tri, tetra and pentaChlorinated naphthalenes

Chlorinated paraffins

Chloromethane

Cresols

Dichloromethane

1 , 2-Dichloropropane

Cyclohexanone

Glvcidol and its derivatives

Halogenated alkyl epoxides

Hexachloro-1, 3-butadiene

Hexachlorocyclopentadiene

Isophorone

Mesityl oxide

4 , 4-Methylenedianiline

Methyl ethyl ketone

Methyl isobutyl ketone

Nitrob enzene Polychlorinated terphenvls

Pyridine

Toluene

111-trichloroethane

Xylenes

8
respectively, whereas methyl chloride and carbon tetrachloride have half-lives

of 1.6 years and greater than 65 years, respectively. Benzene is included on this criterion in that its half-life is 16.5 days. If the criterion chosen

had been 1 day instead of 7, a few additional compounds, such as toluene and

methyl isobutyl ketone (x = 1.7 days), would have been included but not many.

Rate data with OH were not available for some of the compounds and most

of these were compounds on the Monsanto list containing the vinvl grouping. A

reaction half-life of 10 days with O3 was estimated for these compounds using

10 " 3 cm3 s

* for the rate constant (23) and a mean urban O3 concentration of

10 12 cm 3 (0.05 ppm). Since it is highly probable that the reaction half-life

with OH is less than that with O3 , these compounds were not included. A few

compounds remained with no OH or O3 rate data (e.g., acetonitrile, pyridine

and ethylene oxide) but these were not included because of their probable

atmospheric reactivity.

The remaining compounds are shown in columns 1 and 2 of Table 3. This

table also lists two other sets of toxic organics which are based on current

EPA programs. Column 3 lists nine organic compounds found at elevated

concentrations during a recent EPA field survey in four different urban areas,

New Orleans, Houston, Niagara Falls, and Newark (24a). These compounds are included in an extensive 3-year study—The Total Exposure Assessment Methodology (TEAM) Study—being mounted by EPA to obtain personal exposure data

(24b) . Column 4 lists the eight toxic organic compounds for which EPA has

requested that NBS provide gas standards under a separate task of this same Interagency Agreement.

There are two obvious conclusions which can be drawn from this Table.

The first is that there is considerable overlap among these lists of high

priority organic compounds. The second is that the Table predominately con- sists of low molecular weight , halogenated organic compounds.

9
TABLE

3.

VOLATILE

ORGANIC

COMPOUNDS

OF

ATMOSPHERIC

INTEREST

a) •a CU iH CU TJ U TJ •H cu CU O rH d d d

cn rH

B

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PC £-iH o CU CU

d }H

C cn a) 4h

dd

O o c d O a) <U rH rH

a) o l-i rH rH HQ HQ N rO O >. P^ CJ a c 1-1 rH HQ HQ IH •rH <u CO 4= 4-* 4-1 CU u

PQu o ww PHH

<u tj CU •H CU T) d •H 0) CU o CO cO d B d d o I—f <u HQ O }H cu (U £3 HQ d 4-J rH o rH rH H CJ 0) CU HQ 4H o cn c0 N o CJ O HQ HQ < d d d iH 1-4 •u 4-1 G Q 4-1 B a) o o o CU (U W G CU HQ rH 1—

O o W H o O HQ CU HQ >H Sh M cu 14-1 d O d CJ o o

Pn

dd o o •H cu

r—rH rH

<u o V4 rH tj rH P»> HQ HQ N G o X 1 pH HQ CJ CJ d n rH u CN HQ 4-J IH •H

a) c0

X •H

— 4-1 CU CU }H PQ O u Q rH w x PH H

a) TJ CU •H CU T3

1-1 TJ •H <u O •H u d

HQ rH

B o cu

O rd o rH rH H o l-i HQ P*> gr c0 X CJ HQ

V4 •H •H 4-1 CO 4-1 Q o CU Z CU o o H CU CU >H S CU d d o d d 0) cu rH

a) o rH HQ N X >. P^ CJ d 1-1 HQ HQ iH

a) cO 4H 4-1 CU PQ u W w Ph .

4-> CO •H

CO

X

0)d <u p'' CU d 4-1 N CO •H d a B 1h

<u CU CU o l-i o

TJ

Xd i-i o

cd tH o cd CL 4-1

U < l-i u HQ o O PH o O o 4-1 d l-i CO rH rH CU O o < H HQ HQ e 1 1 rH u

IS) CJ o HQ HQ CO

•H }H

a CJH

r-H TJ o •H rH

rH TJ

B

X

C HQ 1 HQ

O

4-1

d CJ CM 4-1

d

a) o •H «. <uG S S Q rH X CO

10

From

Monsanto

Priority

List,

Reference

21.

Ubiquitous

Ambient

Organics

Included

in

two

EPA

Field

Studies,

Reference

24.

Organic

Standards

Being

Prepared

for

EPA

Under

Same

Interagency

Agreement.
SECTION 4

SURVEY OF ORGANIC PERSONAL EXPOSURE MONITORS

SUMMARY OF LITERATURE SURVEY

A literature survey on sampling and analytical methods for detection of

toxic organics at ambient levels is a part of the EPA-NBS project. Little

work has been done to this date on personal exposure devices for toxic or- ganics at ambient levels. The aim of this work is to evaluate the recent

developments on performances of several sorbents as collection media for the

quantitative concentration and analysis of volatile, hazardous vapor-phase

compounds from the ambient atmosphere. A brief summary on commercial monitoring devices is also included.

The literature in this survey covers the five year period (1974 - 1979)

It is appropriate at this point that the open literature and EPA reports on classes and ranges of concentration of hazardous organic compound present in

the urban and non-urban ambient air should be considered first. The survey

below discusses the solid sorbents and analytical techniques which have been

used, as well as developments on sampling devices (dosimeters)

Activated carbon has been selected and used by NIOSH for collecting

organic vapors (26,27). However, the detrimental effects caused by water and

the reactivity of collected samples with charcoal, dictates the evaluation of

alternative solid adsorbents. The criteria for the evaluation of methods for

the collection of organic pollutants in air using solid sorbents is a subject

of several recent papers (28,29,30), a monograph by NIOSH (31) and a recent

EPA monograph (32) ; the analytical methods for organic pollutants have been

recently discussed at length by NIOSH (33)

A recent evaluation (34) of solid sorbent materials for sampling organic

vapors indicated three major classes: 1) porous polymers (e.g., Tenax-GC,

Porapaks, Chromosorbs) ; 2) carbonaceous materials (activated carbons, charcoals, graphitized carbon black, Ambersorbs) ; and 3) others (e.g., molecular

sieves, silica gel, liquid-coated solid supports).

The porous polymers were found (34-37) to have the most desirable properties for air sampling, having low background and low reactivity as well as high capacities for many compounds. However, the porous polymers were found

to have little capacity for the more volatile compounds. The carbonaceous

materials were noted to have much better capacities for volatile compounds,

but are plagued with reactivity problems and susceptibility to water vapor

(hydrophylicity)

11
The additional advantages for sampling of organic pollutants with porous

polymer sorbents are high selectivity, ease of sample handling and ability to

analyze polar materials not recoverable from charcoal (38) ; more on the

subject is reported elsewhere (39-42). After a thorough evaluation of five

major solid sorbents, three were selected for future consideration for use in

a miniature air sampling system (34)

Tenax . The only high-temperature (400 °C) adsorbent available which

allows the quantitative thermal desorption of low-volatility organic compounds.

Porapak R. One of the highest-capacity polymeric adsorbents with an overlap in range of utility with Tenax-GC.

Ambersorb XE-340 . Anticipated for the desorption of compounds of intermediate volatility; more stable than charcoal towards water vapor.

By an independent study (43) , Tenax-GC was found to be superior to other

sorbents as a collection medium for volatile, hazardous, vapor-phase com- pounds from the ambient atmosphere. The effects of humidity, background air

pollution, repeated re-use of sorbent, and transportation and storage of

collected samples were also investigated. The general sorption-desorption

systems for organic compounds in regard to the most used sorbents, desorption

solvents and the types of compounds collected is summarized in Table 4.

Evaluation of a technique for sampling low concentrations of organic vapors

in ambient air is a topic of a recent paper (44)

Many analytical techniques have been applied to the identification and

quantitation of organic compounds in ambient environmental media. In effective measurement of the ambient concentration of a toxic material in air, the

following steps are involved a) collecting the sample (sorbent medium, e.g.

Tenax-GC, carbon, chromosorb, etc.); b) extracting the components of interest

from the sample; c) concentrating the extract, and d) injecting the sample

into a gas chromatograph coupled to a suitable detector. A combined technique of capillary gas chromatography with mass spectrometry has been recently

applied for analysis of air pollutants (45) . A NIOSH Manual of Analytical

Methods has also been published (33) . A recent book (46) discusses in detail

the chemistry sources, sampling and collection of air pollutants, as well as the analysis of pollutants by instrumental methods.

In 1970, the Occupational Safety and Health Administration (OSHA) developed standards to protect employees against the potentially harmful effects

of approximately 400 chemicals (20,26). This set of standards is routinely

reviewed and updated as more and more clinical information on the physiological impact of these chemicals became available. When these occupational

standards were first published, the recommended sampling method for organic

vapors was the charcoal tube method.

The charcoal tube method was originally selected by NIOSH and recommended as the referee sampling method for organic vapors (26,51,61). The

method involves pumping of a known volume of air through a charcoal packed

tube for a measured period of time (the charcoal serves as an adsorbent for

organic vapors) . The charcoal is then extracted with an appropriate solvent

12
TABLE 4. GENERAL SORPTION-DESORPTION SYSTEMS FOR ORGANIC COMPOUNDS.

Sorbent

Activated

carbon

Silica gel

Activated alumina

Porous polymers

Chemically bonded

and other GC

packings

Thermal Desorption

Desorption Solvent Types of Compounds

Carbon disulfide

dichloromethane

ether (1% methanol

or 5% isopropyl

alcohol sometimes

added)

Misc. volatile organics:

methyl chloride, vinyl

chloride, and other chlorinated aliphatics, aliphatic

and aromatic solvents,

acetates, ketones, alcohols,

etc

Methanol , ethanol

diethyl ether,

water

Polar compounds

alcohols, phenols, chlorophenols, chlorobenzenes,

aliphatic and aromatic

amines

Water, diethyl Polar compounds:

ether, methanol alcohols, glycols, ketones,

aldehydes, etc.

Ether, hexane,

carbon disulfide,

alcohols

Wide range of compounds

phenols, acidic and basic

organics, multi-functional

organics, etc.

Ether, hexane,

methanol

Specialized high boiling

compounds, pesticides,

herbicides, polynuclear

aromatics, etc.

None Misc. volatile organics,

halogenated organics,

hydrocarbons, aromatics, etc.

13
(usually carbon disulfide) and the extractant analyzed with a gas chromatograph. The major disadvantage of this method is that it employs personal

sampling pumps, which can weigh up to 2 pounds each.

Recently several industrial companies introduced a new type of air

sampler, the passive organic vapor dosimeter, which can replace the charcoal

tube. This dosimeter also relies on the ability of charcoal to selectively

adsorb organic vapors, but differs in that the vapors enter the sampler by

molecular diffusion or permeation rather than by mechanical means. Consequently, the dosimeter requires no electrical power. Recent emphasis has

also been toward the development of portable personnel dosimeters which could

be used up to eight hours to determine "time-weighted-average" (TWA) exposures.

For example, current standards for vinyl chloride vapor (9,47) call for an action level of 0.5 ppm TWA exposure, which if exceeded, requires the implementation of an extensive personal monitoring program. This directive (9,47)

permits a maximum allowable 8-hr TWA exposure of 1 ppm to vinyl chloride and

a maximum permissible exposure of 5 ppm for no more than 15 min. A method

for measuring the exposure of personnel to vinyl chloride has been developed

which utilizes the permeation technique for sampling (18)

The abundant literature on the development strategy for pollution

dosimetry is a subject of several papers, monographs, and books (25,32,46,48-

59).

COMMERCIALLY AVAILABLE SAMPLERS

Several types of badge-size devices for monitoring individual exposure

to hazardous organics at ambient concentrations now are being produced by

several industrial companies. These types of samplers are passive and are worn on the clothing as small badges. By definition, a passive personal

monitor is a device worn on an individual for the purpose of measuring - without the use of an active flow device - personal exposure (61) . There are several advantages to passive monitors (badges); they are small, lightweight,

and easily worn by any individual. The badge uses the principle of diffusion

or permeation of the organic vapor through a membrane to a charcoal sorbent.

The badges, however, are not without disadvantages - e.g. high humidity

alters the adsorption of various organic vapors on charcoal. It is not yet

apparent what can be done to correct for high humidity effects in passive

monitors with charcoal sorbent (61) . Commercially available passive organic

samplers include DuPont's Pro-Tek badge, Abcor's gasbadge, 3-M's organic

vapor monitor and the Minimonitor (P. W. West).

Recently DuPont's Applied Technology Division (62-64) introduced an inexpensive and very light (7.7 g) Pro-Tek pollution-monitoring badge for

hazardous organics. The organic vapor monitoring system is designed around a small strip having 300 mg of activated charcoal contained in a rectangular

envelope perrorated with a known number of accurately sized pores. After

activating the badge by removing impervious covers from the pores, the

contaminants diffuse through the pores and are adsorbed on the charcoal. The

badge can be deactivated by replacing the impervious strips. Two sampling

rates, 50 cc per minute and 100 cc per minute, can be selected by using one or both sides of the badge. Each side has an impervious cover over the

porous badge.

14
To analyze for contaminants, the charcoal strip is removed and placed in

a vial containing a set amount of solvent (e.g. carbon disulfide). The

solvent extracts the contaminants from the charcoal strip, and analysis is

performed by conventional gas chromatography. The manufacturer claims this

badge to be virtually independent of pressure effects and that it is only

slightly affected by temperature and ambient air velocity.

Depending on the organic contaminants adsorbed by the charcoal, the

sampling range varies between 0.2 ppm-hour and 2000 ppn-hours. The desorption efficiency for ccramon vapors, such as benzene, toluene, and carbon

tetrachloride, is between 95 and 100 percent. Larger molecules, e.g., more

polar compounds, such as acrylonitrile, show smaller desorption efficiencies,

but they are well within NIOSH requirements and give reproducible results.

The passage of the vapors through the pores is controlled strictly by molecular diffusion, and diffusion coefficients of various vapors duplicate the

accepted literature values for these vapors (62) . The detection limit claimed

for benzene is 0.20 - 0.25 ppm (64).

The Abcor Gasbadge is 6.5 cm long, 5.1 cm wide, and 1.6 cm thick. It

weighs approximately 43 g and consists of seven parts: the sliding cover;

the front plate of the badge, which has a 4.4 cm x 3 cm opening to allow

diffusion of gases; a protective screen; a draft shield; an open grid that

defines the diffusion geometry; the collection element (activated carbon)

and the back plate of the badge. The Gasbadge is reusable by replacing the

collection element. This dosimeter, which comes in two sizes, also relies on the ability of charcoal to selectively adsorb organic vapors and collection

of the vapors by molecular diffusion rather than by mechanical means. The

charcoal is solvent extracted and the extractant analyzed with a gas chromatograph. The Gasbadge specifications claim: sampling time - 8 hr nominal

sampling range - 0.2-160 ppm/8 hr TWA (benzene); accuracy - = 25 percent at

0.2 ppm for benzene (65,66); shelf-life - 2 years.

The 3-M Organic Vapor Monitor is an oblong badge which is 10.2 cm long

(including the clip), 4.4 cm wide at its widest point, and 1.2 cm thick. The

sampling opening is circular with a 3 mm diameter. This badge weighs 13.5 g.

During sampling, the unit consists of six pieces: the outer rim; the draft

shield, which is held in place by the outer rim; an open grid that defines

the diffusion geometry; the collection element; and the solid back piece of

the monitor. The sixth piece is a clip for attachment to the person. The

3-M passive monitor allows for in situ sample elution. The Aldrich Chemical

Company, Inc. (Milwaukee, Wisconsin) is a sale representative for the 3-M

Organic Vapor badge.

The Mini-Monitor, which was developed by Philip West at the Louisiana

State University, is a circular badge. Its diameter is 5.0 cm, it is 0.625 cm thick and weighs 35 g. A feature unique to the MiniMonitor is that the

badge works on the principle of permeation of contaminant gases through a membrane, followed by adsorption of the pollutant (s) onto approximately 1.35

g of PCB activated charcoal. The MiniMonitor case is reusable by introducing

a fresh supply of charcoal.

15
CONCLUSIONS

The minimum detection limits of badges with activated carbon adsorbents

could be reduced into the parts-per-billion range (10-20 ppb) by increasing

sampling rate by a factor of two or more. Also, the sensitivity of charcoal

badges may be improved considerably by eliminating or reducing the background

adsorption, i.e., trace impurities adsorbed prior to sampling.

NIOSH is planning to look further into the use of passive monitors by

testing different solid sorbents as the collection element and perhaps evaluating electrochemical detection techniques. As far as their application to

ambient personal monitoring goes, the available passive monitors have some major drawbacks: 1) the monitors generally lack specificity (a drawback of some other sampling techniques as well) ; and 2) the detection limits of the

monitors--at the low end of the scale—may not meet the needs of ambient

sampling. While it is true that collection on the element is an enrichment

step, it could take a long time to accumulate a detectable sample from

ambient air. With certain new products that are coming out, (e.g., porous

beads or porous polymers) and as the technology (e.g., electrochemical detection) allows us to develop more effective procedures, passive monitoring

should be feasible in the ambient atmosphere.

16
SECTION 5

SUMMARY OF RECENT ACTIVITIES

The literature survey in Section 4 and the discussion on conmercially

available samplers is almost total^r concerned with personal exposure

sampling in the work-place atmosphere. Pollutant concentrations cf concern

are in the part-per-million range (ppm) and the best minimum detectable

limits for the samplers discussed above are a few tenths of a ppm for 3-2-

hour sampling. It is obvious from Section 2 ''see Table 1) that the concen- trations of individual toxic organic compounds in ambient air will be in the

part-per-trillion fpptj range or 2-3 orders of magnitude less than in the

work-place atmosphere. Since the pumping speeds available would be about the

same for ambient personal sampling as work-place sampling, the total amount

of sample collected for the ambient case would be 2-3 orders of magnitude

less than for work-place sampling, ire can expect then that there will be

quite different and 'or more difficult problems associated with ambient

sampling. The published literature yields little information on personal

sampling for toxic organics in the atmosphere. There is some, as yet

unpublished, information on recent activities in personal sampling for

organics which is discussed below.

For the past two years, the Monsanto Corporation has conducted a research

program to develop a portable, miniature, sorbent-based sampler and the

associated analytical technology for the purpose cf assessing individual

exposure to toxic (primarily carcinogenic) compounds (67,68). The program

consists of three phases: 1) evaluation and selection cf sorbent materials

and sampler design; 2) laboratory development of a prototype sampler and

development of analytical methodology, which is capillary gas chromatography

mass spectrometry (GC/MS); and 3; field evaluation cf the system in selected

urban areas. The first two phases of this program are essentially complete.

From a survey of a wide variety of commercially available sorbent

materials 1) porous polymers, e.g., Tenax-GC, Poropak, Chromosorbs; 2) carbonaceous materials, e.g., activated carbons, Ambersorbs, and 3) others, e.g.,

molecular sieves, silica gel, five were selected by Monsanto for detailed

evaluation. These five were Tenax-GC, Poropak-N, Poropak-R, Ambersorb 7Z340, and SKC activated charcoal. These five were selected because they have

the potential to sample compounds which have a wide range of polarities and

volatilities. These sorbents were evaluated with a matrix of IS organic test

compounds representing a wide range cf volatilities, polarities and functionalities. With these compounds the 5 sorbents were evaluated with respect

to capacity, desorption efficiency 'thermal desorption) , background, decomposition and pressure drop. The three sorbents finally selected were TenaxGC, Poropak-R, and Ambersorb XE-340 for the collection of low volatility,

intermediate volatility and high volatility compounds, respectively.

17
Poropak-R was chosen over Poropak-N because it gave a much better background

in the GC/MS analysis. Ambersorb XE-340 was chosen because of "less difficulty anticipated with desorption and fewer detrimental effects by water and

reactivity with collected samples (68)

The sampler designed by Monsanto consists of three tapered glass tubes,

each containing 1-2 grams of the sorbent, arranged in series, followed by a flow control device and ending with a portable miniature pump.

Considerable progress has also been made in developing the associated

GC/MS analytical technology. The Monsanto personnel have estimated detection

limits of 1-10 ppt for a variety of organic compounds for a 480 liter sample

(1 L/min. for 8 hr.). This is based on an assumed detection limit of 10

nanograms (ng) for capillary column GC/MS (69)

Pellizzari has reported favorable results with the use of Tenax-GC as the sorbent in a glass tube sampler for a wide variety of organic compounds

which may be present in ambient air (43,70, 71). Among the advantages of

Tenax-GC were high collection efficiencies, good thermal desorption efficiencies with low attendant background up to 300 °C, the absence of any effects

from variable atmospheric humidity, and good storage properties. The only

apparent drawback is low capacity or low breakthrough volume (in liters air

per gram of sorbent) for highly volatile organics. Compounds with a vapor

pressure greater than about chloroform (b.p. = 61 °C) can not be collected

efficiently. This would rule out Tenax-GC for the collection of compounds

such as methyl chloride and dichloromethane, which are on the TSCA Priority

List.

Activated carbons should have the efficiency required for the collection

of the highly volatile organics (68). However Pellizzari reports (71),

and the Monsanto report (68) implies, that quantitative thermal desorption

cannot be achieved for ambient samples of organics on activated carbons.

Solvent desorption may work for the activated charcoals, and this is the

technique commonly used in NIOSH procedures. However, the amount of any

individual ambient organic collected in a miniature sampler will be small for

a normal sampling volume, e.g., 1-100 ng. Elution of this amount would

result in a very dilute solution of a very volatile organic and quantitative

concentration of the solution would be difficult. Since only an aliquot of

this dilute solution could be used for the GC analysis, the overall sensitivity of the method would be reduced to the point that may probably be

inadequate for ambient analysis. Brooks and West (72) have recently encountered just this problem in attempting to analyze for a number of volatile

organics adsorbed on Ambersorb XE-340 by solvent extraction.

We are aware of only two field studies utilizing miniature personal

samplers. The first is an unpublished study by Pellizzari, et al. (73).

This study utilized a glass tube cartridge with Tenax-GC as sorbent and a MSA

miniature pump for the personal sampling of benzene in St. Louis and Houston.

The results of this study showed ambient levels of benzene in St. Louis which

could be correlated with source activities and ubiquitous levels of benzene

in the Houston area. The EPA TEAM study mentioned earlier has employed the same personal samplers to measure 8-hour exposures of students at Lamar

18
University in Texas and the University of North Carolina and also of the

general public in Research Triangle Park, N.C., and Elizabeth and Bayonne,

N.J. A dozen or more organic compounds were detected, with concentration

levels ranging from 0.1 to 100 ppb.

There have been several other recent field studies on ambient volatile

organics in which personal samplers were not used, but which are pertinent to

this report. An EPA study in Dallas, Chicago, and Los Angeles (74) utilized

a Tenax-GC sorbent, thermal desorption and GC-flame ionization analysis to

measure ambient concentrations of benzene. Levels observed were 5 yg/m ; (1.6 ppb) for Dallas, 18 yg/m : (5.6 ppb) for Chicago and 19 yg/m : (6.0 ppb)

for Los Angeles.

Another EPA study in New York City, Houston and Detroit utilized an activated carbon sorbent, solvent elution with carbon disulfide and GCelectron capture detection for the measurement of ambient levels of tetrachloroethylene (75). All the measurements in New York City gave values

greater than 0.1 ppb (the minimum detection limit), one-half were greater

than 1 ppb, and the maximum value observed was 10 ppb. In Houston and

Detroit, 90 percent of the measurements gave values less than 1 ppb. If

these results are valid, they would contradict the earlier statements on recovery from charcoal and inadequate sensitivity using solvent extraction.

With regard to sensitivity these results may reflect the much greater sensitivity of electron capture as opposed to flame ionization detection. We have

already alluded to the recent EPA study (24) in Houston, Niagara Falls,

Newark, and New Orleans in which volatile chlorinated organics and benzene

were consistently found. This study utilized 2 1/2 grams Tenax-GC in a glass

tube sampler, collection of ca. 100 liters total sample, thermal desorption

and GC/MS analysis.

19
SECTION 6

RECOMMENDATIONS FOR RESEARCH AND DEVELOPMENT OF ACTIVITIES

We have presented below our concepts of all the major research and

development needs in the field of personal monitoring for toxic organics. We

would recommend top priority for the nine organics from column 3, Table 3 as well as methyl and methylene chloride from the TSCA priority list. With

the exception of benzene, these represent a single class of compounds - volatile chlorinated organics with long atmospheric persistence. This also

presents the possibility of using highly sensitive electron capture (EC)

detection, again with the exception of benzene, in the GC analysis. This

could lead to greatly reduced requirements in terms of amount collected for

many of these compounds.

Research and development activities on personal monitoring for volatile

chlorinated organics are recommended in the following areas:

1. Evaluation of sorbent materials

2. Development of analytical techniques based gas chromatography with

electron capture and photoionization detection.

3. Evaluation of active samplers

4. Development and evaluation of passive samplers

5. Development of standard mixtures for evaluation and calibration of

personal exposure devices.

Tenax-GC has been shown to be an excellent sorbent for a wide variety of

organic compounds and exhibits such desirable properties as good collection

efficiencies, high operating temperature (350 °C) for thermal desorption,

with low background bleeding and a low retentive index for water (43)

However we have seen little documentation on the use of Tenax-GC for the

collection of the particular chlorinated compounds discussed above. Therefore Tenax-GC should be evaluated on these compounds with respect to collection efficiency, breakthrough volume and thermal desorption efficiency.

Brooks (76) reported a low breakthrough volume (< 1 L/g) for CCli+ . As

indicated earlier, Tenax-GC would probably be inefficient for the collection

of the more volatile chlorinated organics such as chloromethanes . Other

sorbents should be evaluated such as Chromosorb 104, as suggested by Pellizzari

(43)

,

or Poropak-R (68)

Another possibility would be to attempt to develop

a porous polymer analogous to Tenax-GC, but with a greater capacity for

highly volatile compounds.

20
Activated carbons and the carbonaceous material Ambersorb XE-340 should

collect the volatile chlorinated compounds, but thermal desorption is not

feasible for activated carbons and more work is required to determine

desorption efficiencies for Ambersorb XE-340. Some effort should be made to

study solvent desorption efficiency and to determine whether EC-GC would have

the required sensitivity with the resulting solutions.

Because of the inherent high sensitivity, EC-GC techniques should be

developed for the analysis of the chlorinated organics. Detection limits in

the range of 10 12 to 10 14

g are possible with EC detection (69). If a chlorinated compound (M.W. = 100) with an atmosperic concentration of 1 ppt

is sampled at a rate of 1 L/min^ for 8 hours (ca. 500 liters) , the amount of

sample collected will be 2 x 10 9 g. If quantitative thermal desorption is

possible, this sample weight is still well above detection limits. On the

other hand, it would be well below the detection limits by flame ionization.

Since many chlorinated compounds are likely to be found in the ambient

atmosphere, the principal problem expected is chromatographic resolution.

This is an area which may require the most effort in terms of analytical

technique development. Recent developments in fused silica capillary column

technology should be investigated for improved resolution. The use of flame

ionization detection (FID) is likely the best approach for benzene and some

of the other chlorinated compounds with concentrations of 0.1 ppb or greater.

Photoionization detectors would provide greater sensitivity and applicability

to a broad range of organic compounds and should be evaluated.

Active sampling devices have been developed which may be amenable to

personal exposure studies. Pellizzari (73) has used a personal Tenax-GC

sorbent sampler in the field, and a multiple sorbent sampler has been developed by Monsanto (69). These samplers should be evaluated with volatile,

chlorinated organics with respect to collection efficiency, breakthrough

volumes, desorption efficiencies and tested under realistic field conditions.

The development of passive sampling devices for toxic organics at ambient

levels is a largely unexploited area and should be of considerable interest

in a longer out-put time frame. We are currently investigating some promising passive samplers for inorganic air pollutants at ambient levels (77) and

this technology should be applicable to the toxic organics. The primary

advantage of passive samplers is in their size, and possibly cost, in that no pumps or other moving parts are required. The key to developing an effective ambient passive sampler is in attaining a high equivalent passive

sampling rate. As discussed in the report on passive samplers for NO2 (77)

,

this equivalent sampling rate (F ) is determined by the diffusion rate of

the pollutant to the collection medium and by sampler geometry.

F = D x A/

eq

where D = diffusion coefficient, cm2 /s

A = area of diffusion barrier, cm2

l = length of diffusion barrier,

cm.

21
Since the diffusion rate is constant for a particular diffusion medium and

pollutant, the sampling rate is strongly controlled by the geometry term,

A/2., which can conceivably be made quite large. For a passive membrane NO2 sampler we are evaluating, the diffusion barrier is a thin circular silicone

membrane with an A/£ of ca. 500 (77). Other designs could conceivably further

increase this value. For example, a double sided membrane sampler with

substrate in between would double this value. A multilayered membrane

sampler may increase this rate by the number of layers. There are certainly

other design geometries whereby high area, thin film barriers can be structured within a small personal sampler, and this is an area which should be

explored. Some of the commercially available work place badge samplers have

sampling rates of 30-100 cm' /min. With a more creative design, sampling

rates equivalent to that of available miniature pumps (1 L/min.) should be

feasible.

There remains the question of the feasibility of using commercially

available dosimeter badges (Abcor, 3-M, Dupont) for sampling and analysis of

the volatile chlorinated organics. However, these badges use activated

charcoal as sorbent (the NIOSH method) and thermal desorption and direct

injection into the gas chromatograph apparently cannot be done with any

efficiency (68, 71). The NIOSH work place methods use solvent elution, but

much larger quantities of adsorbed pollutant are available. Nevertheless, we should consider the case of elution of a typical chlorinated organic from

charcoal for EC-GC analysis.

Let us assume a hypothetical case using best estimates. A passive badge

with an equivalent sampling rate of 75 cm' /min. (a high value) would sample

100 liters, of air in a 24 hour period. For a light chlorinated compound

(e.g., mw = 100) at a concentration of 100 ppt (0.1 ppb) , 4 x 10 ' g would be

adsorbed if the efficiency is 100 percent. Let's assume that this compound

can be eluted efficiently with 4 mL of solvent (a typical value) to yield a solution with a concentration of 10 ? g/mL or 10 ~ yg/yL. Injection of 1 uL

(a normal value) of this solution into the chromatograph corresponds to 10 11 g of the chlorinated compound. The detection limits of modern GC instruments

for chlorinated compounds are in the range of 10 - 10 *“ g. Therefore the

compound should be detectable. There were several assumptions made above,

but this simple analysis does demonstrate that the commercial badges should

at least be evaluated for the volatile chlorinated compounds with EC-GC

analysis.

With regard to standard mixtures, NBS is already in the process of

developing standards for some of these chlorinated compounds (see Table 3).

These standards and the generation systems employed should be useful in the

evaluation and calibration of sampling devices considered here. Both cylinder

standards and permeation tube devices are being developed for the compounds

listed in column 4 of Table 3.

22
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23
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24
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29. Melcher, R. G. , R. R. Langner, and R. 0. Kagel . Amer. Ind. Hyg. Assoc.

J. , 39:349, 1978.

30. Bursey, J. T. , D. Smith et. al. American Laboratory (Fairfield, Conn.)

9:35, 1977; Chem. Abstr. 89:168178a.

31. Ballou, E. V. (ed.) Second NIOSH Solid Sorbents Roundtable. NIOSH, HEW

Publication, Cincinnati, Ohio, 1976; Chem. Abstr. 86:194144j.

32. Mage, D. I. and L. A. Wallace (eds.), Proceedings of the Symposium on the Development and Usage of Personal Monitors for Exposure and Health

Effect Studies. EPA-600 . 9-79-032 , June, 1979.

33. National Institute of Occupational Safety and Health: NIOSH Manual of

Analytical Methods. HEW Publication No. (NIOSH) 77-157, Cincinnati,

Ohio, 1977.

34. Brooks, J. J., D. S. West, D. J. David, and J. D. Mulik. A Combination

of Sorbent System for Broad Range Organic Sampling in Air. Ref. 32, p.

383.

35. Melcher, R. G. , R. R. Langer, and R. 0. Kagel. J. Amer. Ind. Hyg.

Assoc., 39:349, 1978.

36. Gallant, R. F. , J. W. King, P. L. Levins, and J. F. Piecewicz. Characterization of Sorbent Resins for Use in Environmental Sampling. EPA600/7-78-054, March, 1978, pp. 79-92.

37. Holzer, G. , H. Shanfield, A. Zlatkis, W. Bertsch, P. Juarez, H. Mayfield,

and H. M. Liebich. Collection and Analysis of Trace Organic Emissions

from Natural Sources. J. Chromatogr. , 142:755-764, 1977.

38. Dietrich, M. W. , L. M. Chapman, and J. P. Mienre. Amer. Ind. Hyg.

Assoc. J. , 39:385, 1978.

39. Ciccioli, P., G. Bertoni, E. Brancaleoni, R. Fratarcangeli , and F. Bruner. J. Chromatogr., 126:757, 1970.

40. Dorigen, J., B. Fuller, and R. Duffy. U.S. NTIS, PB Rep. ISS PB-264446,

1976, p. 312-336; Chem. Abstr. 87:140410e.

25
41. Raymond, A., and G. Guiochon. J. Chromatog. Sci., 13:173-177, 1973.

42. Mieure, J. P., Ref. 31, pp. 121-138.

43. Pellizzari, E. D. , J. E. Bunch, R. E. Berkley, and J. McRae. Analytical

Letters, 9(l):45-63, 1976.

44. Whitmore, F. C., R. L. Durfee, and M. N. Khattak. EPA Contract 68-02-

2618, NTIS-PB 279672. Versar, Inc., Springfield, Virginia, 1977; Chem.

Abstr. 89:220155g.

45. Bursey, J. T. , D. Smith et . al. American Laboratory, 9:35, 1977; Chem.

Abstr. 89:168178a.

46. Butler, J. D. Air Pollution., Academic Press, London, 1979.

47. Federal Register. 39 (194) : 35890 , October 4, 1974.

48. Zlatkis, A., H. A. Lichtenstein, and A. Tishbee. Chromatographia , 6:67,

1973.

49. Bamberger, R. L. , G. G. Esposito, B. W. Jacobs, G. E. Podolak, and J. F.

Mazur. Amer. Ind. Hyg. Assoc. J. , 39:701, 1978.

50. Dravnieks, A., B. K. Krotaszynski, J. Barton, A. O'Donnell, and J.

Burgwald. High Speed Collection of Organic Vapors from the Atmosphere.

In: The 11th Conference on Methods in Air Pollution and Industrial

Hygene Studies, Berkely, California, 1970.

51. Instrumentation for Environmental Monitoring. AIR, Vol . 1, LBL 1.

Environmental Instrumentation Group. Lawrence Berkeley Laboratory,

Berkeley, California, 1973.

52. Instrumentation for Monitoring Air Quality. ASTM Spec. Tech. Publ. 555.

American Society for Testing and Materials, Philadelphia, 1974.

53. Harrison, J. W. , D. E. Gilbert, P. A. Lawless, and J. H. White. Development Strategy for Pollution Dosimetry. Research Triangle Institute.

Research Triangle Park, North Carolina, 1975.

54. Strupp, P. E. , P. M. Jones, R. D. Giammar , and T. B. Stanford. Intern.

Confer. Environmental Sensing and Assessment. Las Vegas, Nevada, 1975,

2:22-23; Chem. Abstr. 86:95285k.

55. Morgan, M. G. , and S. C. Morris. Assessment of Research Needs in

Individual Air Pollution Monitors for Ambient Air. Bookhaven National

Laboratory, Upton, New York, 1976.

56. Harrison, J. W. , D. E. Gilbert, P. A. Lawless, J. H. White, and A. E.

O'Keeffe. Development Strategy for Pollutant Dosimetry. EPA-600/2-2-

76-03, February, 1976.

26
57 . Assessment of Benzene as a Potential Air Pollution Problem. Vol. IV,

GCA/Technology Division, Bedford, Massachusetts. Prepared for Environmental Protection Agency, Research Triangle Park, North Carolina 27711.

Publication No. EPA-PB-758 356, January 1976.

58. West, P. W. Toxicology Research Projects Directory. Vol. 4, issue 06

1979; SSIH/IOH 666B.

59. Cralley , L. V., and L. J. Cralley (eds.) Hygiene and Toxicology Vol

III: Theory and Rational of Industrial Hygiene Practice. Wiley-Interscience, New York, N.Y., 1979.

60. a. Collaborative Testing of Activated Charcoal Sampling Tubes for

Seven Organic Solvents. National Institute for Occupational Safety

and Health. HEW Publication No. (NIOSH) 75—184. U.S. Government

Printing Office, Washington, D.C., 1975.

b. Cadoff, B. C. , B. Greifer, P. A. Pella, and J. K. Taylor. Development of Contaminant Generation Systems for Certification of Portable

Air Sampling Instruments. National Bureau of Standards, Washington, D. C. , 1975

61. Woebkenberg, M. L. , in Ref. 32, pp. 7-8.

62. Pro-Tek Organic Vapor G-AA Air Monitoring Badge No. 1. Technical

Bulletin, 1979. E. I. Dupont De Nemours and Company, Inc., Applied

Technology Division, Wilmington, Del. 19898.

63. Chemical and Engineering News. 57(2): 21, July 9, 1979.

64. Frick, R. A., and Graig Schukert. DuPont Applied Technology Division,

Personal Communication, Tel: (302) 774-7458.

65. Gasbadge, Organic Vapor Dosimeter. Technical Bulletin 1979. Abcor

Development Corporation, 850 Main Street, Wilmington, MA 01887.

66. Leah, D. Abcor Development Corporation, 850 Main Street, Wilmington, MA

01887. Personal Communication, Tel: (617) 657-4250.

67. DeAngelio, D. G. , A. G. Desai, and C. R. McMillan. Methods for the

Sampling and Analysis of Organic Materials — State-of-the-Art . Draft

report to the Environmental Protection Agency, Research Triangle Park,

NC. Contract No. 68-02-2773, January, 1979.

68. Brooks, J. J. , and D. S. West. Portable Collection System and Analytical Technology for Atmospheric Carcinogen Assessment. Draft Report to

the Environmental Protection Agency, Research Triangle Park, NC.

Contract No. 68-02-2774, October, 1978.

69. Diard, D. J. Gas Chromatographic Detectors. John Wiley, & Sons, New

York, 1974.

27
70. Pellizzari, E.

9(6): 552 , 1975

D. , J. E. Bunch

,

and B. H. Carpenter. Envir. Sci. Tech.,

rH Pellizzari, E. D. , B. H. Carpenter

,

and J. E. Bunch, ibid . , p . 556

.

72. Brooks , J. J.

,

and D. S. West

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Development of a Portable Miniature

Collection System for the Exposure Assessment within the Microenvironment for Carcinogens, Precarcinogens and Cofactors. 23rd Monthly

Progress Report. Contract No. 68-02-2774. Environmental Protection

Agency, Research Triangle Park, NC, August, 1979.

73. Private communication. Pellizzari, E. D. Research Triangle Institute,

Research Triangle Park, NC.

74. Martin, B. E. , T. Clark and J. Bumgarner. Ambient Air Monitoring for

Benzene - 24 Hour Integrated Sampling in Six Cities. Draft Report.

Environmental Monitoring Systems Laboratory. Environmental Protection

Agency, Research Triangle Park, NC, 1980.

75. Evans, G. F. , R. E. Bumgardner , J. E. Bumgarner, P. L. Finkelstein, J. E. Knoll, and B. E. Martin. Environmental Protection Agency. And G. L.

Sykes, D. E. Wagoner, and C. E. Deckor. Research Triangle Institute.

Measurement of Perchloroethylene in Ambient Air. EPA-600/4-79-047

.

Environmental Monitoring and Support Laboratory. Environmental Protection Agency, Research Triangle Park, NC, August, 1979.

76. See Reference 73. 20th Monthly Progress Report. May, 1979.

77. Cadoff, B. C., S. F. Knox, and J. A. Hodgeson. Personal Exposure

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Agreement No. AD-13-F-0-034-0 . National Bureau of Standards, Washington, D.C., November, 1979.

28
TECHNICAL REPORT DATA

(Please read Instructions on the reverse before completing)

1 REPORT no. 2.

' EPA 600/4-80-042

3. RECIPIENT'S ACCESSION NO.

4 TITLE AND SUBTITLE

Survey on Research Needs on Personal Samples

for Toxic Organic Compounds

5. REPORT DATE

6. PERFORMING ORGANIZATION CODE

7. AUTHOR(S)

Jimmie A. Hodgeson and Alexander J. Fatiadi

8. PERFORMING ORGANIZATION REPORT NO

9. PERFORMING ORGANIZATION NAME AND ADDRESS

National Bureau of Standards

Center for Analytical Chemistry

Washington, D.C. 20234

10. PROGRAM ELEMENT NO.

11. CONTRACT/GRANT NO.

AD-13-F-0-034-0

12. SPONSORING AGENCY NAME AND ADDRESS

Environmental Protection Agency

Office of Research and Development

Office of Monitoring and Technical Support

Washington, D.C. 20460

13. TYPE OF REPORT AND PERIOD COVERED

Final

14. SPONSORING AGENCY CODE

EPA/ORD

15. SUPPLEMENTARY NOTES

16. ABSTRACT . A survey is presented on the research and development needs for personal monitoring

devices for toxic organic compounds in the ambient atmosphere. This survey includes

a description of organic compounds and their ambient concentrations, individual

compounds of high priority, a summary of a literature survey, a description of

commercially available sanplers, a summary of recent developments in ambient personal

monitoring and recommendations on major research needs. The high priority compounds

identified were: methyl choloride, dichloromethane , benzene, carbon tetrachloride,

chloroform, dichlorobenzenes, 1,2-dichloroethane, methyl chloroform, trichloroethylene

and perchloroethylene. The literature survey covers the period, _ 1974-79 Commercially

available personal samplers described are Dupont's Pro-Tek organic vapor badge, Abcor s gasbadge, 3-M's organic vapor monitor and the Minimonitor (P.W. West, Louisiana S L ate

University). Recent activities include a description of an EPA sponsored program at

Monsanto Research Corporation on development of personal samplers for organics. . description is also given of several recent field studies on sampling and analysis

for benzene and chlorinated hydrocarbons. The survey concludes with recommendations

for research and development activities in the following areas: evaluation of sorbent

materials, development of analytical techniques based on electron capture-gas

chromatography, evaluation of available active and passive samplers, eve opmen

passive samplers and development of standard mixtures for evaluation o persona —exposure devices-: ““

17 r key words and document analysis

a. DESCRIPTORS b. IDENTIFIERS/OPEN ENDED TERMS c. COSATl Field/Group

Ambient Atmosphere

Benezene

Cholorinated Hydrocarbons

Air Pollution Methodology 7C

18. DISTRIBUTION STATEMENT

Release to Public

19. SECURITY CLASS (This Report)

Unclassified

21. NO. OF PAGES

. .15

20. SECURITY CLASS (This page)

Unclassified

22. PRICE

$6.50

EPA Form 2220-1 (Rev. 4-77) PREVIOUS EDITION iS OBSOLETE