The draft appears on the EPA’s Integrated Risk Information System (IRIS), an on-line database of summary health risk assessments and regulatory information on specific chemicals, developed to provide consistent risk information for EPA decisions.
Representing the manufacturers of perc, HSIA has sponsored a number of studies on the solvent. This included an epidemiology study of drycleaning workers in the Nordic countries, which found no evidence of an increased cancer risk related to perc exposure.
Perc is currently used by an estimated 70% of drycleaners in the USA. The EPA’s draft assessment was released for public comment in late June 2008 and will be reviewed by a special panel of the National Academy of Sciences this autumn. It is the first such IRIS assessment to incorporate a comprehensive analysis of associated uncertainties.
The International Agency for Research on Cancer (IARC) convened a panel of internationally regarded experts which concluded in 1995 that perc is "probably carcinogenic to humans," based on limited evidence of carcinogenicity in humans and sufficient evidence in animals.
Although a number of studies of workers exposed to perc have been conducted, the HSIA-sponsored epidemiology study of drycleaning workers in the Nordic countries was the first to compare cancer incidence among exposed workers with those in a similar socioeconomic group (i.e., laundry workers). The study also included all drycleaning workers in the four Nordic countries and represents the largest group of drycleaning workers ever studied. In addition, HSIA has sponsored several toxicology studies as part of voluntary agreements with EPA and the Agency for Toxic Substances and Disease Registry, including studies of the potential developmental, neurotoxic, and immunotoxic effects of perc.
