At recommended occupational exposure levels, it is unlikely that methylene chloride, perchloroethylene, or trichloroethylene would produce adverse effects, even from repeated exposure. Used properly by trained personnel and stored in accordance with accepted practices, chlorinated solvents can be used safely. 

When considering the toxicity of chlorinated solvents, the route of exposure is important. The likely routes of exposure are inhalation, ingestion or direct contact with the skin or eyes. It is also important to distinguish between short-term exposure (acute effects) and long-term exposure (chronic effects). 

These issues are covered in Dow's chlorinated solvents Product Stewardship Manual. You may request a printed copy of the entire manual or download a PDF file of the section on Human and Environmental Health Considerations (80KB PDF).

For additional information, visit the Halogenated Solvents Industry Alliance (HSIA) web site.