United States
Environmental Protection
Agency
National Risk Management
Research Laboratory
Research Triangle Park, NC 27711
Research and Development
EPA/600/SR-97/004
March 1997
4>EPA Project Summary
Development and Validation of a
Method for Measuring Exempt
Volatile Organic Compounds and
Carbon Dioxide in Consumer
Products
E. E. Rickman, Jr., G. B. Howe, and R. K. M. Jayanty
Ground-level ozone can cause a va-
riety of adverse health effects as well
as agricultural and ecological damage.
Controlling emissions of volatile or-
ganic compounds (VOCs) is important
to reducing ground-level ozone; how-
ever, not all VOCs are photochemically
reactive and several have been ex-
empted from control regulations. Cur-
rently, there is no standard method for
measuring the exempt VOC content of
consumer products. This report de-
scribes the development of such a
method. The new method involves heat-
ing a sample in an oven at 110°C for 1
hour while purging the sample con-
tainer with nitrogen gas. The resultant
mixture of nitrogen and volatile com-
pounds from the sample is then col-
lected in a Tedlar™ bag and analyzed
by gas chromatography with mass se-
lective detection (GC/MSD). An internal
standard is added to the sample con-
tainer to permit quantitation without
measurement of the purge gas volume.
The method was evaluated by analyz-
ing samples that were spiked with
known amounts of the exempt com-
pounds. Recoveries of spiked com-
pounds were excellent, ranging from
86% to 107% for the compounds and
products tested. This method should
be applicable to other volatile com-
pounds that might be present in con-
sumer products and could be useful in
evaluating the risk that these products
pose to the environment.
This Project Summary was developed
by EPA's National Risk Management
Research Laboratory's Air Pollution
Prevention and Control Division, Re-
search Triangle Park, NC, to announce
key findings of the research project
that is fully documented in a separate
report of the same title (see Project
Report ordering information at back).
Ground-level ozone can cause a variety
of adverse health effects as well as agri-
cultural and ecological damage. To con-
trol the levels of ozone in the environ-
ment, the U.S. Environmental Protection
Agency (EPA) has established National
Ambient Air Quality Standards (NAAQS)
for ozone. In 1990, 98 areas in the coun-
try did not meet the NAAQS for ozone,
with over 150 million Americans living in
these areas. VOCs are important contribu-
tors to the formation of ozone in photo-
chemical smog. Control of VOC emissions
is an important strategy for controlling
ozone levels. The 1990 Amendments to
the Clean Air Act (CAAA) require EPA to
conduct a study of VOC emissions from
consumer products. However, there was
no standard method for measuring the
VOC content of consumer products. Such
measurements are needed to assess the
risk to the environment posed by VOCs in
consumer products. Such a method will
also be needed if EPA determines that
the risk associated with VOCs in con-
sumer products is sufficient to require con-
trol regulations.
To address the need for measurement
of VOCs in consumer products, EPA has
established a research program. This pro-
gram has already produced results in four
previous phases:
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Phase I - Preliminary studies were
performed on two candidate methods
for VOC measurement (EPA Refer-
ence Method 24 and Gravimetric
Purge and Trap Gas Chromatogra-
phy).
Phase II - A Consumer Products Test
Methods Work Group was established
with participation from a number of
state and federal agencies. This Work
Group, after consideration of an initial
list of 10 candidate methods, reached
a consensus that further research
should be concentrated on two meth-
ods: EPA Reference Method 24 and
Gravimetric Purge and Trap Gas
Chromatography.
Phase III - A test method was devel-
oped to determine the total VOC con-
tent of consumer products. This
method was based on EPA Refer-
ence Method 24, with added modifi-
cations for sampling and analysis of
consumer products.
Phase IV - The test method devel-
oped in Phase III was validated in an
interlaboratory study.
The validated total VOC method
(Phase IV) for consumer products gravi-
metrically measures the total volatile con-
tent and determines the amount of water
by gas Chromatography with thermal con-
ductivity detection (GC/TCD). The water
content is then subtracted from the total
volatile content to calculate the total VOC
content; however, many VOCs have been
exempted from the list of regulated VOCs
(40 CFR 51.100) due to their low photo-
chemical reactivity and thus low ozone
formation potential. Measurement of these
exempt VOCs in consumer products would
allow EPA to correct the total VOC mea-
surements to better reflect the total ozone
formation risk that consumer products pose
to the environment.
Upon examination of the exempt VOC
compounds, only 12 compounds are rel-
evant to consumer products. Carbon diox-
ide, which is measured by the total VOC
method, is also exempt and therefore is
added to the target list shown in Table 1.
Since it is anticipated that determining
the exempt compound content will be con-
siderably more expensive and time con-
suming than measurement of total VOC
content, a two-step approach to assess-
ing the ozone formation risk posed by
consumer products is envisioned. The first
step would involve measurement of total
VOC content for the product. Consumer
products that might pose significant risks
for ozone formation based on their total
VOC content would then undergo a sec-
ond step of having their exempt VOCs
measured to provide a better assessment
of their ozone formation risk. This report
describes the development and validation
of an exempt VOC measurement method
that would be used as the second step of
the VOC risk assessment process. The
measurement method involves heating a
sample in an oven at 110°C for 1 hour
while purging the sample container with
nitrogen gas. The resultant mixture of ni-
trogen and volatile compounds from the
sample is then collected in a Tedlar™ bag
and analyzed by gas Chromatography with
mass selective detection (GC/MSD). An
internal standard is added to the sample
container to permit quantitation without
measurement of the purge gas volume.
The method was evaluated by analyzing
samples that were spiked with known
amounts of the exempt compounds. Re-
coveries of spiked compounds were ex-
cellent, ranging from 86% to 107% for the
compounds and products tested.
Table 1. Exempt VOC Method Target List
Compound Name
Class II Ozone Depleting Chemicals0
carbon dioxidea
methylene chloride (dichloromethane)
1,1,1,2-tetrafluoroethane (HFC-134a)
pentafluoroethane (HFC-125)
1,1,2,2-tetrafluoroethane (HFC-134)
1,1,1-trifluoroethane (HFC-143a)
1,1-difluoroethane (HFC-152a)
acetone
tetrachloroethylene (perchloroethylene orperc)b
chlorodifluoromethane (HCFC-22)
1,1,1-trifluoro 2,2-dichloroethane (HCFC-123)
1,1-dichloro 1-fluoroethane (HCFC-141b)
1-chloro 1,1-difluoroethane (HCFC-142b)
'Carbon dioxide is not a VOC, but ismeasured by the total volatilesmethod and hasbeen added to the target list to permit correction of measured total volatiles.
bTetrachloroethylene was added to the exempt list during the course of this work (61 FR 4588, February 7, 1996).
c Use of class II ozone-depleting chemicals (58 FR 65018, December 10, 1993) is currently restricted. These chemicals may be phased out in the future.
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£. E. Rickman, Jr., G. B. Howe, and R. K. M. Jayanty are with Research Triangle
Institute, Research Triangle Park, NC 27709.
J. Kaye Whitfield is the EPA Project Officer (see below).
The complete report, entitled "Development and Validation of a Method for Measur-
ing Exempt Volatile Organic Compounds and Carbon Dioxide in Consumer
Products," (Order No. PB97-143143; Cost: $21.50, subject to change) will be
available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Air Pollution Prevention and Control Division
National Risk Management Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
United States
Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268
Official Business
Penalty for Private Use $300
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EPA
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EPA/600/SR-97/004
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