Trichloroethylene (TCE) is a good solvent and is used in manufacturing to clean grease from machinery. It is one of the most abundant environmental pollutants of groundwater in the United States. In some groundwater, TCE undergoes reductive dechlorination catalyzed by anaerobic bacteria that yields vinyl chloride, a potent human carcinogen. TCE removal by dumping or air stripping is now largely disallowed and this has focused efforts on biological methods of TCE remediation in soil and water. The enzyme that starts one branch of this pathway, toluene 1,2-dioxygenase, has many other catalytic abilities, which are documented in a table of the Reactions of Toluene 1,2-Dioxygenase. The spontaneous degradation of trichloroethylene epoxide can produce as many as four products: dichloroacetate, carbon monoxide, glyoxylate, and formate. The number, type, and proportion of products seen depends on the local environment.