Chromium is a steel gray, lustrous, hard metal extracted from chromite ores. In 2011, U.S. production of chromium was estimated at 160,000 metric tons, coming almost entirely from recycling stainless steel scraps. In addition, the U.S. imported 430,000 metric tons of chromium, primarily from South Africa, Kazakhstan, Russia and China. Chromium is valued for its high corrosion resistance and hardness. It is most often used as an alloy (ferrochrome) in stainless steel and in chrome plating. In addition, chromium is used in the pigment and dye, tanning, and glassmaking industries, in reflective paints, for wood preservation, to anodize aluminum, to produce synthetic rubies, as a catalyst in chemical manufacturing and as an isotope in medicine. Elemental chromium is seldom found naturally in the environment. The oxidized states of chromium III and chromium VI are the most important forms of the chemical. Chromium III is an essential trace element in humans but chronic exposure may be harmful. Chromium VI (hexavalent chromium) is the oxidized state of principal concern in occupational safety and health and the environment because of its extreme toxicity and designation as a human carcinogen. OSHA's hexavalent chromium safety and health topics page provides comprehensive information on health effects, exposure controls, OSHA standards, and additional resources on this toxic substance.
Who is exposed to the common forms of chromium?
Occupational exposures to chromium occur primarily in the metal and chemical manufacturing industries, although exposures are also possible in other industries where chromium compounds are used.
Occupational exposure to chromium can occur in the following industries and operations:
- Stainless steel welding [Cr(VI)]
- Chromate production [Cr(VI)]
- Chrome plating [Cr(VI)]
- Ferrochrome industry [Cr(III) and Cr(VI)]
- Chrome pigments [Cr(III) and Cr(VI)]
- Leather tanning [mostly Cr(III)]
Occupations that may involve chromium exposures include:
- Painters [Cr(III) and Cr(VI)]
- Abrasive blasting workers [Cr(III) and Cr(VI)]
- Workers involved in the maintenance and servicing of copying machines and the disposal of some toner powders from copying machines [Cr(VI)]
- Battery makers [Cr(VI)]
- Candle makers [Cr(III) and Cr(VI)]
- Dye makers [Cr(III)]
- Printers [Cr(III) and Cr(VI)]
- Rubber makers [Cr(III) and Cr(VI)]
- Cement workers [Cr(III) and Cr(VI)]
- Workers involved in welding, cutting, brazing, soldering, torch and other hot work operations. [Cr(III) and Cr(VI)]
OSHA sets enforceable permissible exposure limits (PELs) to protect workers from the health effects of exposure to chromium metal and various chromium compounds under 1910.1000 Table Z-1 Limits for Air Contaminants. The most toxic form of chromium is hexavalent chromium. OSHA requirements for protecting workers from hexavalent chromium exposure are found in specific OSHA standards covering general industry (Chromium (VI) - 1910.1026), shipyards (Chromium (VI) - 1915.1026), and construction (Chromium (VI) - 1926.1126).