Occupational exposure to perchloroethylene in the dry cleaning industry

Field surveys were conducted of 67 dry cleaning establishments to assess working conditions and potential for exposure to perchloroethylene, a solvent of choice in this industry. Evaluation of ventilation controls showed that 28% of cleaning machines (transfer type) did not have functioning local exhaust systems, and an additional 32% had inadequately maintained systems providing less than the recommended face velocity at the door opening. Personal sampling was performed in 20 firms to relate operator exposure levels to the process used and degree of local exhaust ventilation. Utilization of the dry-to-dry (closed system) process resulted in a lower mean TWA exposure, 28.3 ppm, as compared to 86.6 ppm for transfer operations. Five-minute peak samples taken during clothing transfer demonstrated significant exposure levels ranging from 11.3 to 533.8 ppm. A lower mean peak exposure (25.3 ppm) was found for firms with local exhaust ventilation at the recommended rate than for facilities with poorly or unventilated cleaning machines (159.7 ppm). The study points out the manner in which available control measures can be used optimally to reduce employee exposure. Increased involvement of trade associations and local health authorities is also recommended to promote the safe use of perchloroethylene in the dry cleaning industry.