This ninety-seventh volume contains evaluations by a group of 25 scientists from eight countries of the carcinogenic hazard to humans of 1,3-butadiene, ethylene oxide and some vinyl halides (vinyl fluoride, vinyl chloride and vinyl bromide). These industrial gases or their epoxide metabolites are direct-acting mutagens that induce malignant tumours at many sites in rodents. The Working Group classified 1,3-butadiene as "carcinogenic to humans"...