This thirty-ninth volume of IARC Monographs comprises considerations of a number of industrial chemicals used in the production of plastics and elastomers; some of the compounds are also used in paints and adhesives. Two compounds - dichloroacetylene and 4-vinylcyclohexene - can occur as by-products in the production or use of some of these chemicals. New data were available on some of the chemicals evaluated previously: methyl acrylate, ethylacrylate, caprolactam, 4 4'-methylene-dianiline, toluene diisocyanate, vinyl acetate, vinyl bromide, and vinylidene chloride, and these have been summarized and taken into consideration in the re-evaluations. 4 4'Methylenediphenyl diisocyanate, a monomer produced from 4 4'-methylenedianiline (MDA), can hydrolyse to MDA when in contact with moisture; however 4 4'-methylenediphenyl diisocyanate was not re-evaluated in the present volume because no new data on carcinogenicity have become available.