Toxicological Evaluations are critically assessed data and recommendations for occupational safety officers, industrial hygienists, and human and animal toxicologists. They are compiled and constantly reviewed under internationally coordinated programs for establishing the risk potential of existing chemicals to rpevent health hazards at the working place. In Volume 12, data for the following chemicals are published: Ethylenthiourea, N,N'-Di-sec-butyl-p-phenylenediamine, p-Nitrosophenol, Dichlorotoluene, 2,4-Dichlorotoluene, 3,4-Dichlorotoluene, Glyoxal, Chloracetyl chloride, Copper phthalocyanine, Dimethylol dihydroxyethylene urea, Acetoacetanilide, Thiourea, 3,4-Dichlorobutene-1
