US and European Rules - US Regulations

OSHA PEL for Cr⁶⁺

The new OSHA Cr⁶⁺ PEL (permissible exposure limit) issued on February 28, 2006 lowers the upper limit for exposure of workers to hexavalent chromium (as Cr) to  5 µg m^-3 from its previous 52 µg m^-3, measured as 8-hour time-weighted averages.  This drastic reduction affects any industrial process that could generate Cr⁶⁺ air emissions, including hard chrome plating, chromic acid anodizing, priming and painting, chromate conversion, welding, and rework of materials containing chromium.  The limit applies to all forms of Cr⁶⁺, including chromium trioxide, chromic acid and chromates.

The OSHA rule, based on the fact that inhaled Cr⁶⁺ is a known human carcinogen, mirrors purely advisory limits for Cr⁶⁺ set by other organizations:

• The ACGIH (American Conference of Governmental Industrial Hygienists) recommends several different TLVs (threshold limit values) for chromium, chromates and other chromium compounds. 

  • For water-soluble Cr⁶⁺ compounds such as CrO₃ the TLV is 50 µg m^-3 (as Cr)

  • For insoluble Cr⁶⁺ compounds the TLV is 10 µg m^-3. 

• The NIOSH (National Institute for Occupational Safety and Health) has recommended a 10-hour time-weighted average for all Cr⁶⁺ compounds of 1 µg m^-3. 

In addition to reducing the PEL for Cr⁶⁺, the new OSHA rule places a number of burdens on employers, who are now required to:

• Monitor employee exposure to Cr⁶⁺

• Establish separate regulated areas when Cr⁶⁺ levels are expected to exceed the PEL

• Provide respirators for workers exposed above the PEL

• Provide other PPE (personal protective equipment) as necessary for eye and skin protection, together with change rooms and wash facilities

• Institute housekeeping activities to control spills and releases of Cr⁶⁺

• Provide medical surveillance for employees who are exposed above the PEL, show signs or symptoms of Cr⁶⁺ exposure, or are exposed in an emergency

• Train workers about Cr⁶⁺ hazards, and use signs and labels to communicate the hazards

• Keep records of exposure, surveillance and training.

The PEL action level, which is the threshold that determines when ongoing monitoring is necessary, is 50% of the PEL or 2.5 µg m^-3.  However, if Cr⁶⁺ concentrations are shown to be <0.5 µg m^-3 under all expected conditions, then the OSHA rule does not apply at all.

Timing:

• The effective date for the standard is 90 days from publication (May 29, 2006).

• Date when provisions become effective (except engineering controls) – 180 days from the effective date (November 27, 2006), or 1 year for companies with <20 employees.

• Date when engineering controls become effective – 4 years after publication (March 1, 2010).

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