User:Snehakrishna/1,2,3-trichloropropane

1,2,3 Trichloropropane (TCP) is a chemical compound that is commonly used as an industrial solvent. Although it is not currently labeled as a contaminant by the United States federal government, new research shows that it could have severe health effects. Currently, only California has significant regulation on this compound.

Production
1,2,3-Trichloropropane can be produced via the chlorination of propylene. Other reported methods for producing 1,2,3-trichloropropane include the addition of chlorine to allyl chloride, reaction of thionyl chloride with glycerol, and the reaction of phosphorus pentachloride with either 1,3- or 2,3-dichloropropanol. TCP also may be produced as a byproduct of processes primarily used to produce chemicals such as dichloropropene (a soil fumigant), propylene chlorohydrin, propylene oxide, dichlorohydrin, and glycerol.

Uses
Historically, TCP has been used as a paint or varnish remover, a cleaning and degreasing agent, and in the production of pesticides. Currently, it is also being used as a chemical intermediate in the process of making chemicals such as hexafluoropropylene and polysulfides and and an industrial solvent.

Effects of Exposure
Humans can be exposed to TCP by inhaling its fumes or through skin contact and ingestion. TCP is recognized in California as a human carcinogen, and extensive animal studies have shown that it causes cancer. Short term exposure to TCP can cause throat and eye irritation and can affect muscle coordination and concentration. Long term exposure can affect body weight and kidney function.

Existing Regulation
As of now, only the state of California has any regulation on 1,2,3-trichloropropane. Even there, it is only viewed as an unregulated contaminant that should be monitored. Although there is not much regulation on this substance, it has proved that TCP is a carcinogen in laboratory mice, and most likely a human carcinogen as well. On a federal scale, there is no MCL (maximum concentration level) for this contaminant. In California, there is only a notification level of .005 ppb (parts per billion) in groundwater. However, other safety and health departments have created limits on how much exposure a person can have to TCP safely. The Permissible Exposure Limit (PEL) is 50 ppm or 300 mg/m3. The concentration in air at which TCP becomes an Immediate Danger to Life and Health (IDLH) is at 100 ppm. These regulations were reviewed in 2009.

Proposed US Federal Regulation
In a new drinking water project that was proposed by the US Environmental Protection Agency (EPA), TCP is one of sixteen chemicals that are being considered for regulation. These sixteen chemicals are all suspected human carcinogens.

TCP as an Emerging Contaminant
TCP does not contaminate soil. Instead, it leaks down into ground water and settles down at the bottom of the ground water reservoir because TCP is more dense than water. This makes TCP in its pure form a DNAPL (Dense Nonaqueous Phase Liquid)and it is therefore harder to remove it from groundwater. There is no evidence that TCP can naturally decompose, but it might in favorable conditions. Groundwater remediation of TCP can occur through in situ chemical oxidation, permeable reactive barriers, and other remediation techniques. Several TCP remediation strategies have been studied and/or applied with varying degrees of success. These include extraction with granular activated carbon, in situ chemical oxidation, and in situ chemical reduction. Recent studies suggest that reduction with zerovalent metals, particularly zerovalent zinc, may be particularly effective in TCP remediation. Bioremediation may also be a promising clean-up technique.