[{"from": "human", "value": "Provide a brief overview of this molecule. [C][=Branch1][=Branch1][=C][Branch1][C][Cl][Cl][Branch1][C][Cl][Cl]"}, {"from": "gpt", "value": "The molecule is a chlorocarbon with the formula Cl2C=CCl2. It is a colorless liquid widely used for dry cleaning of fabrics, hence it is sometimes called 'dry-cleaning fluid.' It has a sweet odor detectable by most people at a concentration of 1 part per million (1 ppm). Worldwide production was about one million metric tons in 1985. Animal studies and a study of 99 twins by Dr. Samuel Goldman and researchers at the Parkinson's Institute in Sunnyvale, California determined there is a 'lot of circumstantial evidence' that exposure to tetrachloroethene increases the risk of developing Parkinson's disease ninefold. The International Agency for Research on Cancer has classified tetrachloroethene as a Group 2A carcinogen, which means that it is probably carcinogenic to humans. Like many chlorinated hydrocarbons, tetrachloroethene is a central nervous system depressant and can enter the body through respiratory or dermal exposure. Tetrachloroethene dissolves fats from the skin, potentially resulting in skin irritation. This reaction can be catalyzed by a mixture of potassium chloride and aluminium chloride or by activated carbon."}]