Several epoxides were evaluated for cutagenic activity by the following test systems: (a) microbial mutagenic assay system, (b) body fluid analysis, (c) host mediated assay, (d) induction of DMA repair, (e) micronucleus test and (f) the dominant Tethal test. DGEBPA (diglycidyl ether bisphenoT A), DGEBPA (distiTled) and DCPDGE (dicyclopentadiene glycidyl ether) were mutagenic in the microbial assay but inactive in the remainder of the test systems. In view of the in- activity in the intact animal systems, it is felt that these compounds pose the Teast mutagenic hazard to man of the chemicals evaluated. DGEMPG (diglycidy1 ether of neopenty1 glycol) and CGE (o-cresy1 glycidy1 ether) were mutagenic in bacteria and induced DNA repair. In addition, mutagenicity was discovered in the urine of DGEMPG and CGE treated mice. These results plus a possibility of preimplantation Toss in the dominant lethal test suggest that DGENPG and CGE are weak mutagens. BGE (buty1 glycidyT ether) was determined to be mutagenic as evidenced by an induction of increased dominant lethality, DMA repair and bacterial mutation. These data also support the conclusion that BGE poses a hazard by skin exposure. The 012-014 alky1 glycidy1 ether was only active in the microbial assay with very minimal activity. This data leads to the determination of the C12-CI4 alkyl glycidyl ether as nounutagenic.