CHCs (volatile halogenated hydrocarbons) are components of many commercial products and chemical formulations, in solvents and extraction agents. They are a parameter to be determined in soil, air and water analyses. Because of their high volatility, i.e. high vapour pressure, the samples must be stored as cool as possible and should be analysed in the laboratory as soon as possible. The analysis is carried out in a gas chromatograph. It should be noted that CHCs cause damage to the ozone layer and some are also carcinogenic. Vinyl chloride CH2=CHCl, for example, is highly carcinogenic. The most important subgroup of the CHCs are the CFCs.

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