What is 1,2,3 –TCP?
is an exclusively man-made chlorinated hydrocarbon commonly used as an industrial solvent, cleaner, and degreaser, as well in the production of paint thinners and varnish removers. TCP is also used in the production of other chemicals, which is how it became a contaminant in two commonly used soil fumigants used in California to manage nematodes.
Because TCP containing fumigants were extensively used in California, particularly in Kern, Tulare, and Fresno Counties, contamination of drinking water wells became widespread in those parts of the state.
In 1999, the TCP was added to the list of chemicals known to the State of California to cause cancer
. Exposure can occur from drinking or cooking with TCP-contaminated water and from inhaling its steam (such as while showering or washing dishes). Exposure may possibly occur from dermal contact as well. contact with very high concentrations of TCP may irritate or burn the skin, nose, eyes, or throat, and it may cause drowsiness or liver damage. At this stage, it appears that TCP is unlikely to become concentrated in food, such as plants and fish.
In 2009, the Office of Environmental Health Hazard Assessment adopted a Public Health Goal
for TCP in drinking water of .0007 parts per billion (ppb) — one of the most stringent ever established in the state – because of studies showing it to be extremely toxic at low levels. A Public Health Goal is the level in water at which no significant public health impacts are expected. It is not an enforceable standard.