Chantrelle Johanson

Project title: Characterizing the Health and Safety Needs of the Dry Cleaning Industry in King County

Degree: MS | Program: Occupational & Environmental Exposure Sciences (OEES) - no longer offered | Project type: Thesis/Dissertation
Completed in: 2011 | Faculty advisor: Michael G. Yost


The process of dry cleaning uses non-aqueous solvents to clean fabrics, rather than water. Dry cleaning has existed as an industry since the mid 19th century. Historically, solvents such as kerosene, benzene and gasoline were commonly used as cleaning agents. Today, the most common solvent is perchloroethylene (PERC), a colorless, odorless liquid with toxic properties that has been classified as a probable human carcinogen by the U.S. Environmental Protection Agency (EPA). Although alternative solvents are available, adoption of these new technologies has been slow. The alternative solvents are often expensive, they generally do not clean as well as PERC, and there is large data gap in the information about their potential adverse effects on human health.

There are approximately 375 dry cleaners in King County. The majority of these are using PERC machines but the exact percentage is unknown. Most of what we know about dry cleaning in King County is from field investigation efforts led by the Local Hazardous Waste Management Program in King County (LHWMP).