Abstract
Food Safety Commission of Japan (FSCJ) conducted a risk assessment of 3-nitrooxypropanol (3-NOP) (CAS No. 100502-66-7), using the evaluation documents for feed additive designation. This feed additive is a nitrate ester of 1,3-propanediol developed to reduce methane generated in the first stomach of cattle (rumen). The data used in the assessment include the fate in animals (mice, rats, cattle), residues (cattle), genotoxicity, acute toxicity (rats), subacute toxicity (mice, rats and dogs), chronic toxicity/carcinogenicity (rats), reproductive/developmental toxicity (rats and rabbits), and others. The lowest no-observed-adverse-effect level (NOAEL) for possible adverse effects of 3-NOP was 100 mg/kg bw per day in 52-chronic toxicity, 104-week chronic toxicity/carcinogenicity, and two-generation reproductive toxicity studies in rats. Given this, FSCJ specified an acceptable daily intake (ADI) of 1 mg/kg bw per day by applying a safety factor of 100 to the NOAEL.