Esperase is a proteolytic enzyme preparation that can be used as a processing aid in the food industry. The following studies were performed to establish safety for the consumer: oral toxicity study (13 wk) in the rat; teratogenicity study in the rat; gene mutation assays in Salmonella typhimurium and mammalian cells in vitro, and chromosome aberration assay in vitro. General toxicity was low; the effects seen were attributed to proteolytic activity and the loading with sodium chloride. Neither of these factors will be relevant to consumers of the processed food. There was no evidence of effects on pregnancy outcome or mutagenic potential. When these results are considered together with existing knowledge of the production organism and the chemical and microbiological characterization of the enzyme preparation, they indicate that Esperase will be safe for its intended application in food processing.