Benzoin was found to be negative when tested for mutagenicity using the Salmonella/microsome preincubation assay, using the standard protocol approved by the National Toxicology Program (NTP). Benzoin was tested in as many as 5 Salmonella typhimurium strains (TA1535, TA1537, TA97, TA98, and TA100) in the presence and absence of rat and hamster liver S-9, at doses of 0.033, 0.0333, 0.100, 0.333, 0.3333, 0.667, 1.000, and 3.3333 mg/plate. The highest ineffective dose tested in any S. typhimurium strain was 3.3333 mg/plate. Precipitate was observed in most cultures at the high dose and also some clearing of the background bacterial lawn was also seen.
Mortelmans K et al; Environ Mutagen 8:1-119 (1986)