ICH M7

ICH M7 addresses the assessment and control of DNA-reactive mutagenic impurities in pharmaceuticals to limit potential carcinogenic risk. It focuses on substances that can directly damage DNA at low levels, leading to mutations and potentially cancer, and that are usually detected with the bacterial reverse-mutation, or Ames, test. ⁶³ Because mutagenicity is generally regarded as a non-threshold phenomenon, ICH M7 controls mutagenic impurities without carcinogenicity data using a Threshold of Toxicological Concern of 1.5 micrograms per day, below which cancer risk is considered negligible. ⁶⁴ Its hazard assessment relies on complementary QSAR methods plus expert review, documented in formats such as QPRF.