Acrylonitrile is a colourless, volatile, chemically reactive liquid; it does not occur as a natural product. The monomer is used world-wide, on a large scale, in the manufacture of polymers, fibres, and rubbers and as a chemical intermediate. Acrylonitrile-containing polymers have been used in the manufacture of products that come into contact with food; the amounts of acrylonitrile that migrate into foods can be reduced to negligible quantities by the use of good manufacturing practices in the production of the polymers.