Research studies on hexavalent chromium Cr(VI) on workers involved in chromate production, chromate pigment production and chromium plating have shown that it is a human lung carcinogen. In addition, chronic inhalation of Cr(VI) has effects on the respiratory tract, bronchitis, decreased pulmonary function, pneumonia, and nasal itching and soreness. It can also affect the liver, kidney, gastrointestinal, and immune systems, and possibly the blood. Dermal exposure to hexavalent chromium may cause contact dermatitis, sensitivity, and ulceration of the skin.
Field studies at painting and coating facilities using Cr(VI) containing products exceeded the National Institute of Occupational Safety & Health (NIOSH) Recommended Exposure Limit (REL). Other operations that were studied included welding in construction, metal cutting operations on chromium-containing materials in ship breaking, chromate-paint removal with abrasive blasting, atomized alloy-spray coating, foundry operations, printing, and the manufacture of refractory brick, colored glass, prefabricated concrete products, and treated wood products have also exceeded this limit.
In 2008 OSHA enacted specific standards for Cr(VI), 1910.1026 for general industry and 1926-1126 for construction. It lowered the Permissible Exposure Limit for Cr(VI) to 5 micrograms per cubic meter (ug/m3) and the Action Level to 2.5 ug/m3. It also made it a National Emphasis Program in 2010. The standards offer specific steps that employers can take to lessen employee exposures to Cr(VI) including substitution (using a less toxic material or process that results in lower exposures), isolation (such as enclosing the source of exposure), and ventilation (such as using a local exhaust system that captures airborne Cr(VI) near its source).
Changes in the way a task is performed can reduce exposure to Cr(VI). Workers must know the proper way to perform a task in order to minimize their exposure and to maximize the effectiveness of existing controls. For example, a welder who uses a fume extractor should be trained to place the duct as close to the part as feasible. Hexavalent Chromium continues to be recognized by OSHA as one of the most hazardous chemicals in the workplace. It is important that employers using Cr(VI) containing materials follow the standards and implement all available controls to lessen the hazard.
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