Trichloroethylene (TCE), which is used as a degreasing and cleaning solvent, has played an important role in the industrialization of this country. However, the prevalent use of TCE has also left its fingerprint upon our environment making it a common soil and groundwater contaminant at environmentally impacted properties throughout the United States.

TCE has been a widely used solvent in the past, especially for industrial metal cleaning and vapor degreasing purposes. TCE has also found use as a refrigerant, a dry-cleaning agent, a coffee decaffeination agent, a general anesthetic, a chemical intermediate for production of other chemicals and as an ingredient in products such as shoe polish, paints, varnish, paint removers, pesticides and adhesives, to name a few.

TCE was discovered in Germany in the mid-1800s; however, it was not until the early 1900s before industrial TCE production began in Europe. The early use for TCE was in laundries, as well as for textiles and varnishes.

Manufacturing of TCE did not begin in the United States until the early 1920s, following the end of World War I.  Although production of TCE in the United States began in the early 1920s, significant industrial use of the solvent did not begin until the late 1920s.  The most common uses in the United States for TCE early in its production life was for polishes, degreasing in the metals industry and for fats extraction in the food industry.

In the 1930s, TCE began replacing petroleum distillates in dry-cleaning applications. In the mid-1930s, TCE production in the United States was approximately 15 million pounds per year. TCE use began to significantly increase throughout the metal fabrication industries as improvements were made in vapor, spray and immersion degreasing equipment.

With the outbreak of World War II in the early 1940s, the major use of TCE was as a metal degreaser to support the war effort. Major manufacturers of TCE during the war years included Dow, DuPont and Westvaco chemical companies with production increasing from approximately 50 million pounds per year at the start of the war to approximately 200 million pounds per year at the end of the war in 1945. By the end of the 1940s, total TCE production had reached approximately 225 million pounds per year.

In the 1950s, total TCE production reached approximately 350 million pounds by the end of decade. Reasons for the increase of TCE use in the 1950s were the Korean War and the ever increasing industrialization of the United States. Throughout the 1950s, in excess of 90% of all TCE production in the United States was used for metal degreasing purposes.

During the 1960s, TCE continued to be the most popular vapor degreasing solvent due to both its price and performance. These facts led to an increase in domestic production and its ultimate peak production in the United States by the end of the decade and 1970 at approximately 600 million pounds per year. However, the 1960s also marked the first environmental regulations aimed at TCE for its potential contribution to smog in Los Angeles County.

After reaching peak production in 1970, the use of TCE in the United States began to decline. This decline was due to both environmental and economic factors. The 1970 Clean Air Act put emission limits on TCE due to its contribution to ozone and smog creation. Then in 1975, the National Cancer Institute found that TCE could cause tumors in mice and in 1976 TCE was put on the Hazardous Substance List by the United States Environmental Protection Agency. Finally in 1977, the US Food and Drug Agency banned both direct and indirect use of TCE in food.

Economic pressures also lead to the decline of TCE use in the 1970s. The price of TCE precursor production chemicals increased thus leading to the shutdown of several major production facilities. These plant shutdowns, in turn, lead to a TCE price doubling into the mid-1970s. Other companies were not inclined to get into the TCE production market due to both the economic and environmental conditions. As a result, TCE production fell to approximately 400 million pounds per year by the end of the decade.

TCE production and use continued to fall during the 1980s thru the 2000s as increased environmental regulations took hold. In 1980, TCE was regulated as a hazardous waste material. Additional regulation occurred under the Safe Drinking Water Act in 1985 with an establishment of a maximum contaminant level (MCL) of five (5) parts per billion and the lowering of the Permissible Exposure Level by the Occupational Safety and Health Administration in 1989. Although during the 1990s TCE had been suggested as a replacement for other solvents banned under the 1990 Clean Air Act Amendment, the annual United States’ production of TCE had fallen to approximately 100 million pounds per year in 2000 and continues to fall through present day.

The importance of TCE to the industries of this country cannot be understated since TCE was considered the best degreasing solvent available and, in effect, helped build America. At the same time, its popularity and use has also given the United States a lasting environmental legacy of soil and groundwater impacts. TCE is a common contaminant which has been detected at approximately 60% of all National Priority List sites and countless other properties throughout the United States. The majority of environmental impacts of TCE have occurred from the use of TCE as a metal degreaser, due primarily to the releases of spent TCE prior to the advent of environmental regulations in the 1980s.