Hexavalent chromium (also called chromium-6) is one form of the metallic element chromium, which is listed in the periodic table.
Characteristics of Chromium
Chromium is odorless and tasteless. It occurs naturally in various types of rock, soil, ore and volcanic dust as well as in plants, animals and humans.
Three Common Forms of Chromium
The most common forms of chromium in the environment are trivalent chromium (chromium-3), hexavalent chromium (chromium-6) and the metal form of chromium (chromium-0).
Chromium-3 occurs naturally in many vegetables, fruits, meats and grains, and in yeast. It is an essential nutritional element for humans and is often added to vitamins as a dietary supplement. Chromium-3 has relatively low toxicity.
Uses of Hexavalent Chromium
Hexavalent chromium and chromium-0 are generally produced by industrial processes. Chromium-0 is used primarily for making steel and other alloys. Hexavalent chromium is used for chrome plating and the production of stainless steel as well as leather tanning, wood preservation, textile dyes and pigments. Hexavalent chromium is also used in anti-corrosion and conversion coatings.
Potential Dangers of Hexavalent Chromium
Hexavalent chromium is a known human carcinogen when it is inhaled, and can pose a serious health risk to workers in industries where it is commonly used. Although the potential health risk of hexavalent chromium in drinking water is a growing concern in many communities and at the national level, there is not yet enough scientific evidence to confirm the actual risk or to determine at what level of contamination it occurs.