United States
Environmental Protection
Agency
Air and Energy Engineering
Research Laboratory
Research Triangle Park NC 27711
Research and Development
EPA/600/S2-88/061 Jan. 1989
&EPA Project Summary
Evaluation of Perchloroethylene
Emissions from Dry Cleaned
Fabrics
Bruce A. Tichenor, Leslie E. Sparks, and Merrill D. Jackson
A study was conducted to
evaluate the emissions of
perchloroethylene (perc) from dry
cleaned fabrics to determine: a) how
the introduction of fresh dry cleaning
Into a home affects the indoor
concentration of perc, and b) the
effectiveness of "airing out" for
reducing perc emissions. Small
chamber tests were conducted to
determine perc emission charac-
teristics for three fabrics at several
temperatures and air exchange rates.
Test house studies were conducted
to determine the indoor concen-
tration of perc due to the placement
of dry cleaned clothing in the house.
Based on the study results, and
assuming the test conditions were
representative of normal dry cleaning
and consumer practices, it is con-
cluded that
1) Emissions from freshly dry
cleaned clothing cause elevated
levels of perchloroethylene in
residences, and
2) For the three fabrics tested,
"airing out" of dry cleaned
clothing by consumers will not
be effective In reducing
perchloroethylene emissions.
Significant variations in dry cleaning
practices and/or in the mix of fabrics
and clothing being cleaned could
provide different results and
conclusions.
This Project Summary was
developed by EPA's Air and Energy
Engineering Research Laboratory,
Research 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).
Introduction
The EPA's Air and Energy Engin-
eering Research Laboratory (EPA/
AEERL) conducted a short term study to
evaluate the emissions of perchloro-
ethylene (perc) from dry cleaned fabrics.
Specifically, the study was designed to
answer two questions:
•To what extent does the residual perc
in dry cleaned fabric increase the
concentration of perc in residential
environments?
•How effective is "airing out" in
reducing indoor perc concentrations?
A study consisting of five components
was conducted: 1) Fabric/Clothing Se-
lection; 2) Emission Factor Determination
(Small Chamber Testing); 3) Evaluation
of Perc Residuals (Solvent Extraction); 4)
Indoor Air Quality (IAQ) Model Analysis;
and 5) Evaluation of Indoor Concen-
trations (Test House).
Results
Emission Factors
Emission factors for perchloroethylene
from dry cleaned fabrics were
determined by testing in small
environmental test chambers under
controlled conditions. Evaluation of the
data from these tests provided several
conclusions:
- A preliminary screening evaluation
showed that wide variations in initial
emission factor, Ro, and emission
factor half-lives, t(1/2), occurred
between different fabrics. Thus, the
-------
type of fabric is important in
determining indoor emissions of perc
from dry cleaned clothes.
Based on the screening study and on
the prevalence of fabrics used in dry
cleaned clothing, three fabrics were
selected for investigation: 55%
polyester/45% wool; 100% wool; and
50%polyester/50% rayon.
The air exchange rate showed no
effect on the emission factor or decay
rate for the three fabrics investigated.
This suggests that the emissions are
limited by the diffusion of perc within
the fabric and are not controlled by
evaporative processes. This also
suggests that increasing the ventila-
tion by airing out the clothes will not
speed up the emission of perc.
Since the three fabrics tested had
emission factor half-lives of about a
day, airing the clothes out for a few
hours before hanging them in the
home will do little to reduce the indoor
perc concentrations. For fabrics with
faster perc decay rates, airing out
may be more practical.
- Temperature had a major impact on
the emission factors and decay rates.
Increases in temperature caused
higher initial emission factors and
lower half-lives. Thus, exposing the
clothing to higher temperatures prior
to bringing them home shows promise
as a means of reducing in-home
exposure to perc.
Residuals
No acceptable data were developed
on the perc residuals within the fabric.
The solvent extraction procedure, using
methylene chloride, failed to produce
reliable results. A fully tested "standard
method" is needed.
Indoor Concentrations
All the test house experiments
showed that the introduction of dry
cleaned clothing caused elevated levels
of perc in the house. Differences in
concentration between the tests were
probably due to differences in the
amount of perc retained at the dry
cleaner.
Bruce A. Tichenor, Leslie E. Sparks, and Merrill D. Jackson are with EPA's Air
and Energy Engineering Research Laboratory, Research Triangle Park,
NC 27711.
Bruce A. Tichenor is the EPA Project Officer (see below).
The complete report, entitled "Evaluation of Perchloroethylene Emissions from
Dry Cleaned Fabrics," (Order No. PB 89-118 681/AS; Cost: $15.95,
sub/'ect to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Air and Energy Engineering Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
Model Results
The IAQ model, using emissions d
developed in the small chambe
predicted indoor perc concentratio
which compared favorably with the
measured in the test house. The effi
of perc "sinks" in the test house was al
demonstrated.
Conclusions
Based on the study results, a
assuming the test conditions a
representative of normal dry cleaning a
consumer practices, it is concluded tha
1) Emissions from freshly d
cleaned clothing cause elevated levels
perchloroethylene in residences.
2) For the three fabrics teste
"airing out of dry cleaned clothing
consumers is not effective in reduci
perchloroethylene emissions."
It is emphasized that the
conclusions are based on the results
the study reported herein. Signifies
variations in dry cleaning practices and<
in the mix of fabrics and clothing bei
cleaned could provide different resu
and conclusions.
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
riff is o .2 s; •
Official Business
Penalty for Private Use $300
EPA/600/S2-88/061
0000329 PS
1 * "
60604
------- |