This November 2005 memo and appendices describe the methods by which EPA conducted its refined risk assessment of the Major Source and Area Source facilities within the perchloroethylene (perc) dry cleaners source category; EPA performed this assessment to inform a potential residual risk rule for these sources. The assessment evaluated chronic cancer, chronic non-cancer and acute inhalation risk for a single hazardous air pollutant (HAP), perchloroethylene (perc).

For more information on the rule, visit the regulation page for Dry Cleaning Facilities: National Perchloroethylene Air Emission Standards.

• Perchloroethylene Dry Cleaners Refined Human Health Risk Characterization (PDF)(69 pp, 2 MB, November 14, 2005)