The U.S. Environmental Protection Agency (EPA) classified formaldehyde as a probable human carcinogen as far back as 1987. In 2011, the Department of Health and Human Services (HHS) determined that formaldehyde is a known human carcinogen based on sufficient human and animal inhalation studies. The International Agency for Research on Cancer (IARC) also classifies formaldehyde as a human carcinogen., , , , Formaldehyde is a chemical that is widely used by industry to manufacture buildin.