Exposure, perchloroethylene, control

Eamest GS, Spencer AB. 1995. In-depth survey report Perchloroethylene exposures in commercial dry cleaners at Brown s Cleaners, Santa Monica, California. U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health. Report No. ECTB 201-16a. 47 pages. 

WeissNS. 1995. Cancer in relation to occupational exposure to perchloroethylene. Cancer Causes Control 6 257-266. 

Perchloroethylene also faces tightening usage controls as a result of toxicity concerns. The industry is responding to this challenge by engineering hardware solutions modern closed circuit units are designed to minimise solvent losses (thus reducing potential worker exposure). 

The figure above shows the calculated effect of freeboard upon emission control after the cooling coil using CTW has produced its effect. That effect was to reduce perchloroethylene concentration from 1,000,000 ppm (pure solvent in the vapor rinse zone) to 25,000 to 50,000 ppm depending upon the assumed temperature of the CTW The effect of freeboard is to reduce the perchloroethylene concentration from those levels to a few hundred ppm The latter level of emission is easily diluted with only a modest level of room ventilation to produce concentrations of perchloroethylene in the work area well below the exposure limit (25 ppm per ACGIFI and 100 ppm per OSHA)... 

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