Chromium is a naturally occurring element found in rocks, animals, plants, soil, and in volcanic dust and gases. Chromium is present in the environment in several different forms or valence states. Metallic chromium (non-valent) is used for making steel. Hexavalent and trivalent chromium are used for chrome plating, dyes and pigments, leather tanning, and wood preserving. Trivalent chromium occurs naturally while hexavalent chromium compounds rarely occur naturally and are typically associated with industrial sources. Exposure to hexavalent chromium occurs from ingesting contaminated food or drinking water, or breathing contaminated air.

Inhalation of hexavalent chromium at high levels can damage the nose and cause lung and nasal cancers. Dermal exposures may cause skin ulcers or allergic reactions.