Half a million welders are exposed to hazardous hexavalent chromium
Hexavalent chromium [Cr(VI)] is usually produced by an industrial process. Cr(VI) is known to cause cancer. In addition, it targets the respiratory system, kidneys, liver, skin and eyes. Chromium metal is added to alloy steel to increase hardenability and corrosion resistance.
A major source of worker exposure to Cr(VI) occurs during "hot work" such as welding on stainless steel and other alloy steels containing chromium metal. Cr(VI) compounds may be used as pigments in dyes, paints, inks, and plastics. It also may be used as an anticorrosive agent added to paints, primers, and other surface coatings. The Cr(VI) compound chromic acid is used to electroplate chromium onto metal parts to provide a decorative or protective coating.
It is estimated that 558,000 workers are potentially exposed to Cr(VI) in the United States. Workers in a variety of occupations are potentially exposed to Cr(VI). Workplace exposures occur mainly in the following areas:
- Welding and other types of "hot work" on stainless steel and other metals that contain chromium
- Use of pigments, spray paints and coatings
- Operating chrome plating baths
Industrial processes that involve chromium can result in worker exposure to toxic hexavalent chromium. OSHA provides a publicly available Chemical Exposure Health Database which includes industrial hygiene sample results from OSHA inspections. This database does not include worksite inspection sample results from many of the 26 States that operated OSHA-approved State Plans or OSHA consultation visits. This data provides a snapshot of industry sectors and business subcategories where levels of airborne Cr(VI) have been found. Industry profile tables on OSHA’s website are based on Cr(VI) air samples taken during OSHA inspections from 2006 to 2009. While the tables represent only a small fraction of the total number of companies in their respective industries, the results provide insight into where workplace Cr(VI) exposure is occurring in the United States.