Comprehensive investigation evaluating the carcinogenic hazard potential of acetaminophen.

In 2019, the California Office of Environmental Health Hazard Assessment initiated a review of the carcinogenic hazard potential of acetaminophen under Proposition 65. In conjunction with this review, a multidisciplinary team of experts with significant experience in the fields of hazard assessment, acetaminophen mechanism of action, epidemiology, and preclinical and clinical safety performed comprehensive weight of evidence reviews. The reviews evaluate multiple sources of data, including results from preclinical carcinogenicity, genotoxicity, human epidemiology, and mechanistic studies examining biochemical pathways of acetaminophen metabolism. This introductory article summarizes the comprehensive weight of evidence reviews that were performed on the carcinogenicity hazard potential of acetaminophen which are contained in 6 separate companion articles in this issue of Regulatory Toxicology & Pharmacology. Collectively, these results confirm that acetaminophen is not a carcinogenic hazard at any dose level, consistent with previous conclusions of key scientific bodies.