2‐Butenal (Crotonaldehyd)

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the germ cell mutagenicity and carcinogenicity of crotonaldehyde [4170‐30‐3, 123‐73‐9]. Crotonaldehyde is a highly reactive mutagenic and cytotoxic compound without metabolic activation. An oral carcinogenicity study in male rats, with the liver as the only organ examined, provides at most only an indication of a carcinogenic potential. Crotonaldehyde remains assigned to Carcinogen Category 3 B because of the still limited database. Despite some methodical deficiencies, new in vivo studies with positive results for bone marrow and spermatocyte chromosomal aberrations as well as dominant lethal mutations in mice lead to a reclassification in Category 3 A for Germ Cell Mutagens.