The document provides an evaluation of the mutagenic potential of five alternative fumigants to ethylene dibromide(EDB). These include carbon disulfide(CS2), carbon tetrachloride(CCl4), dichloromethane(DCM), ethylene dichloride(EDC), and methyl bromide (MB). Of the five proposed alternatives, DCM, EDC and MB caused gene mutations in lower and higher eucaryotes. These three agents have not been well studied for their potential to cause chromosome damage. There are no available data on the ability of these agents to cause gene mutations in whole mammals, except for EDC, for which the evidence is suggestive. The potential of the alternatives to reach whole mammal germcell DNA has not been studied. But DCM, EDC, and MB do cause heritable effects in Drosophila. CS2 and CCl4 have been predominately negative in mutagenicity tests. Additional studies are needed before a final judgment is reached with respect to their mutagenic potential, however. The mutagenic potencies of each agent were compared within and among various assay systems. Regarding the strength of mutagenicity, EDB is clearly a stronger mutagen than any of the proposed alternative fumigants. Differences in mutagenicity potency among the alternatives cannot be delineated because of limited data usually derived from different laboratories. When final judgments could not be reached because of gaps in current knowledge, recommendations were made on additional studies that could be conducted to better define the potential mutagenic risk.