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Hexavalent Chromium Fumes

Hexavalent Chromium Fumes

The Occupational Health and Safety Administration (OSHA) enforces strict regulations regarding worker exposure to hexavalent chromium [Cr(VI)] in several industries. Hexavalent chromium, a volatized and oxidized form of chromium, has been identified as a carcinogen. OSHA has subsequently established stringent regulations for workers who are potentially exposed to it in the general, construction, shipyard, and marine terminal industries. The health hazards associated with the inhalation or direct contact with hexavalent chromium are well documented and include lung cancer, damage to the respiratory tract and harm or irritation to the eyes and skin, as cited in OSHA’s Hexavalent Chromium Booklet.

Also according to this booklet, common processes that can lead to the inhalation of airborne Hexavalent Chromium (dust, fume, or mist) include:*

  • Performing hot work and welding on stainless steel, high chrome alloys and chrome-coated metal
  • Applying and removing chromate-containing paints and other surface coatings
  • Producing chromate pigments, dyes and powders (i.e. chromic acid and chromium catalysts)

Exposure Limits

All employers whose employees could potentially be exposed to hexavalent chromium should conduct sampling to determine the level of exposure. The Permissible Exposure Limit (PEL) for hexavalent chromium is 5 micrograms per cubic meter of air (5ug/m3).  The “Action Level” is 2.5ug/m3 (calculated as an 8-hour TWA).  Specific requirements are mandatory if exposure limits meet or exceed this level.

Recommended Control Measures for reducing exposure to CR(VI) that exceeds the PEL include*:

Engineering Controls:

  • Use a less toxic material or process
  • Isolation (enclosing the source of emission)
  • Ventilation (i.e. use a local exhaust system at the source of emission)

Work Practice Controls:

  • Proper worker training

At Sentry Air Systems, we have specifically tested our equipment for its effectiveness and efficiency in controlling exposure to hexavalent chromium from welding fume.  Robert F. Adams, an Industrial Hygienist, conducted and published an industrial hygiene report evaluating Sentry Air Systems’ welding fume extractor (Model SS-300-WFE) and its ability to maintain safe levels of hexavalent chromium while using an electric welder.  In these tests it was found that the machine effected a 99.3% reduction in the concentration of airborne hexavalent chromium (from 94ug/m3 to 0.1ug/m3) and a 97.2% reduction in potential worker exposure (from 46ug/m3 to 1.3ug/m3) to the carcinogen.

For the full Industrial Hygiene Report, click here (PDF).

Click here for more general information on the Hazards of Welding Smoke.

The Hazards of Welding Smoke (links to NIOSH)

Additional information from OSHA regarding Hexavalent Chromium:

Hex Chrome Standards for General Industry: 29 CFR 1910.1026 (OSHA)

OSHA Fact Sheet: Health Effects of Hexavalent Chromium

*Source: “Hexavalent Chromium” PDF, Occupational Safety & Health Administration

Sentry Air Systems, Inc. provides this information as a customer service, but cannot be responsible for its accuracy or completeness. It is recommended that competent legal authorities as well as safety and hygiene professionals be consulted.