Chloroform is an organic compound with chemical formula CHCl3, which is a colorless and sweet viscous liquid. Chloroform can be used as the precursor of PTFE and various refrigerants. It also belongs to methyl chloride and trihalomethane. After inhalation or ingestion, chloroform can be used as a powerful anesthetic, stimulant, anti-anxiety agent and sedative.

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The global total flow of chloroform in the environment is about 660,000 tons/year, of which about 90% is natural. Many seaweeds can produce chloroform, and some researchers think that fungi can produce chloroform in soil. Although the mechanism is not clear, abiotic processes also contribute to the production of natural chloroform in soil. Chloroform is easily volatilized from soil and surface water and degraded in air to produce phosgene, dichloromethane, formyl chloride, carbon monoxide, carbon dioxide and hydrogen chloride. The half-life of chloroform in air is 55 days to 620 days, but its biodegradation in water and soil is slow. Chloroform will not accumulate in large quantities in aquatic organisms.

Chloroform may also be unintentionally produced in the family environment. Bleaching with hypochlorite will produce halogenated compounds in side reactions; Chloroform is the main byproduct. [2 1] When sodium hypochlorite solution (chlorine bleach) is mixed with common household liquids such as acetone, butanone, methyl ethyl ketone, ethanol or isopropanol, in addition to other compounds such as chloroacetone or dichloroacetone, some chloroform will be produced.

In a paper of 1842, Robert Mortimer Glover first proposed the anesthetic characteristics of chloroform. Glover also conducted experiments on dogs to prove his theory. After further perfecting his theory, Glover elaborated his theory in his doctoral thesis in the summer of 1847. James young Young Simpson, a Scottish obstetrician, was one of the reviewers of the paper, but later claimed that he had never read the paper, but came to the conclusion independently.

As we all know, chloroform is a by-product of water chlorination and a series of other disinfection by-products, so it usually exists in tap water and swimming pools. The range of reports varies greatly, but generally speaking, the concentration of trihalomethane in the current health standards needs to be lower than 100 μ g/L [37]. However, there is controversy about the reasonable concentration of chloroform in drinking water. Historically, human exposure to chloroform may be higher because chloroform is used as an anesthetic, a component of cough syrup and a component of tobacco smoke.