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 ------- |