Mutagenicity of poultry chiller water treated with either chlorine dioxide or chlorine

U.S. Department of Agriculture regulation of poultry processing requires the eviscerated warm carcasses to be quickly chilled to ensure microbiological safety and wholesomeness of the products. This is achieved by immersing carcasses in icy water for about 1 h. In addition, chlorine is widely used to control the microbial population in poultry chiller water (PCW), and until 1996 it was the only approved disinfectant. Recently, chlorine dixoide has also been approved the U.S. Food and Drug Administration and the U.S. Department of Agriculture as a disinfectant in PCW. Its potential mutagenicity was investigated using the Ames mutagenesis assay with Salmonella typhimurium strain TA 100 without S-9 mix, the protocol formerly demonstrated to be senstive to chlorine-treated PCW. Chlorine dioxide was found to impart negligible mutagenicity to PCW when tested at 4 times the level required for disinfection.