Various chlorinating agents, e.g., sulphuryl chloride and catalysts such as ferrochloride, have been described as making addition dominant over substitution, but it is believed that only chlorine is used in actual practice (De Bruin, 1979).

The critical-use nomination process had led to a number of successes in the transition away from methyl bromide use, involving the use of alternatives such as sulphuryl fluoride, phosphine fumigation and modified atmosphere.

Other routes which are believed to have been used to some extent are the chlorination of hexachlorocyclohexane isomers with sulphuryl chloride or chlorosulphonic acid in the presence of a ferric chloride or other catalyst, and the distillation of heavy-end residues from perchloroethylene production (Brooks, 1984).

On the post-harvest side, she noted slow but steady progress in the adoption of alternatives for mills and food processing, including: the use of heat, integrated pest management, phosphine (when corrosion concerns were managed) and sulphuryl fluoride (alone or in combination with heat); good progress in the adoption of alternatives for commodities (with phosphine adopted widely and heat, cold and modified atmospheres being used in some areas); and slower adoption for quarantine alternatives.