Sterigmatocystin is a carcinogenic mycotoxin produced by Aspergillus versicolor etc., and has
been discussed as an aflatoxin-related substance as an intermediate of aflatoxin B1
biosynthesis. Its structure is similar to that of aflatoxin, while its toxicity is much lower than
aflatoxin.
Monitoring of feeds and feed materials has hardly been conducted, although there is a report
that sterigmatocystin at 16.3 mg/kg was detected in brown rice stored in Japan.