On April 22, 2016, the National Toxicology Program (NTP) issued a monograph concluding that cobalt and cobalt compounds that release cobalt ions in vivo are expected to cause human cancer. Specifically, NTP stated that “[t]here is sufficient evidence for the carcinogenicity of cobalt and cobalt compounds that release cobalt ions in vivo (collectively referred to as cobalt) in experimental animals based on increased incidence of malignant and/or a combination of malignant and benign neoplasms at several tissue sites in rats and mice by different routes of exposure.” NTP’s final monograph and related materials are available online.
