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New Limits on Hexavalent Chromium- Cr(VI)
Exposure to hexavalent chromium may occur when welding with electrodes that contain chromium. This includes all stainless steel electrodes, and some low alloy steel and hardfacing electrodes (consult the product label or material safety data sheet to determine which products contain chromium). Evidence suggests that workers exposed to hexavalent chromium have an increased risk of developing lung cancer.

On February 28, 2006 the Occupational Safety and Health Administration (OSHA) issued an amended standard, Occupational Exposure to Hexavalent Chromium, that lowered the Permissable Exposure Limit (PEL) to 5 micrograms per cubic meter of air. This was a considerable reduction from the previous PEL of 52 micrograms per cubic meter of air. Employers with 20 or more employees must be in compliance by November 27, 2006 and those with 19 or fewer employees by May 30, 2007.

The first step, which is mandatory, is to determine the 8-hour time-weighted average exposure to Cr(VI) for each employee exposed to Cr(VI). A professional industrial hygienist should be consulted since specialized methods are required.

If overexposure is determined;

• All employees who may be exposed to levels of Cr(VI) above the PEL must be informed and their exposure monitored at least once every three months (rotating employees to different jobs to comply with the standard is specifically prohibited).
• Engineering and work practice controls must be used to reduce and maintain exposure levels at or below the PEL. This can include enclosing the source of exposure, or placing a barrier between employees and the source of exposure, or using ventilation and exhaust systems to reduce the exposure.
• If these fail to sufficiently reduce exposure then respiratory equipment must be used. Respiratory equipment must be worn until effective engineering controls are installed.
• Engineering controls must be implemented by May 31, 2010.

For more detailed information visit www.osha.gov. A comprehensive guide for small business may be found at http://www.osha.gov/Publications/OSHA_small_entity_comp.pdf.

There are several simple steps that you can take to reduce exposure;

• Avoid the fume plume coming off the weld puddle. Arrange work areas so that existing ventilation or natural draft directs the fume plume away from the employee.
• Do not overweld. The more weld metal deposited the more fume produced. A 5/16” fillet requires approximately 50% more weld metal than a 1/4” fillet and will result in 50% more fume.
• Tune in the welding arc. Excessively low or high voltage will increase fume levels.
• Consider alternative materials. Acceptable low alloy steels without chromium may be available to do the job.
• Consider using a welding process that produces less fumes, such as submerged arc, or substitute a gas shielded process for an open arc process.

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