Exposure to chloroprene is primarily occupational. Symptoms reported from acute (short-term) human exposure to high concentrations of chloroprene include giddiness, headache, irritability, dizziness, insomnia, fatigue, respiratory irritation, cardiac palpitations, chest pains, nausea, gastrointestinal disorders, dermatitis, temporary hair loss, conjunctivitis, and corneal necrosis. Symptoms of chronic (long-term) exposure in workers were fatigue, chest pains, giddiness, irritability, dermatitis, and hair loss. Chronic occupational exposure to chloroprene vapor may contribute to liver function abnormalities, disorders of the cardiovascular system, and depression of the immune system. A National Toxicology Program (NTP) study concluded that chloroprene showed clear evidence of carcinogenic activity in both rats and mice. EPA has classified chloroprene as a Group D, not classifiable as to human carcinogenicity. The International Agency for Research on Cancer (IARC) has classified chloroprene as a Group 2B, possibly carcinogenic to humans.
