IARC Classifies 1-Bromopropane as “Possibly Carcinogenic”
A new monograph released by the International Agency for Research on Cancer classifies the solvent 1-bromopropane as a category 2B carcinogen, IARC’s designation for substances that are possibly carcinogenic to humans. 1-bromopropane, also known as 1-BP and n-propyl-bromide, is a solvent used in the production of pesticides, flavors and fragrances, and pharmaceuticals. It is also used in dry cleaning and vapor degreasing. IARC based its determination on studies of the effects of exposure to 1-BP among mice and rats. Among workers, the monograph notes that “dermal exposure can be a significant source of 1-bromopropane absorption and most common glove and chemical protective materials do not provide adequate skin protection.” In the United States, 1-BP was the focus of a joint OSHA-NIOSH hazard alert in 2013. The U.S. National Toxicology Program added 1-BP to its Report on Carcinogens in 2014, having found that the substance is “reasonably anticipated to be a human carcinogen.”  IARC’s assessment of 1-BP is found in volume 115 (PDF) of the agency’s monographs series. The monograph also discusses six other substances, two of which—3-chloro-2-methylpropene and N,N-dimethyl-p-toluidine—were also classified as category 2B carcinogens. 3-chloro-2-methylpropene is used in the production of pesticides and as a fumigant of vegetable seeds. Occupational exposures to N,N-dimethyl-p-toluidine, which is used in the production of dental materials, dentures, dyes, pesticides, and artificial fingernail preparations, can occur among health professionals, nail salon workers, users of industrial glues, and workers in the chemical industry. Summaries of IARC’s findings appear in The Lancet Oncology.