Traditional dry-cleaning operations use a solvent called perchloroethylene, which is toxic enough to be treated as hazardous waste by the EPA. Millions of pounds of this chemical are used every year. It can cause minor allergic reactions among customers and far more serious health problems for workers who are constantly exposed to it. Small amounts of perchloroethylene can seriously contaminate groundwater.
The best alternative is not to purchase clothes that require dry cleaning. Know that you can often hand wash silk, wool, and linen clothes that are tagged “dry clean only.”. Otherwise look for operations that offer either “wet cleaning” or a system that uses liquid carbon dioxide, both of which are safer treatments.
-Abrams, “365 Ways To Save The Earth”, 2008