Trichloroethylene: A Timeline of Use and Toxicity

Trichloroethylene (TCE) is an inflammable synthetic organic compound created in Germany in 1864 and used chiefly as a soybean defatting agent in Europe until the 1910s. It was subsequently discovered to be an effective cleaning agent for drycleaning. Its use became widespread in the post‐World War I years in the United States, where it ultimately found wide acceptance as a parts degreaser in the manufacturing industry, especially for engine parts and an effective anesthetic. Eventually, these uses were found to be a universal process in electronics manufacturing during the post‐World War II era. Although it was only finally found to be hazardous and banned by an Air Quality Management County ordinance (Rule 66) in Los Angeles, California, in 1965, it has a record of being a toxic product when used in uncontrolled processes. Numerous episodes of cattle death in the 1910s were an early warning of its toxicity, and subsequent human deaths in World War I and later years were gradually attributed to its unprotected use or even ingestion. The earliest human deaths occurred in 1924, in the United States, as reported in the literature. Still, it continued to be in use without protective equipment throughout the 1960s until governmental restrictions were applied by the United States Environmental Protection Agency in 1976. Large‐scale releases and groundwater contamination are still being remediated nationwide and worldwide.