Welding in the workplace? Be Aware of What’s New Regarding Manganese Exposure

Healthy employees = productive employees

Written by Andy Haymart, CHST
Industrial Hygiene Technician

A new OR-OSHA rule for airborne exposure to manganese is expected to be published later this year. In the proposed rule, occupational health agencies have been recommending more protective (lower) exposure limits for manganese. Inhaled manganese is of great concern because it bypasses the body’s normal defense mechanisms. It can cause serious harm to the lungs, liver, kidneys, and central nervous system. Welders are frequently exposed to manganese fumes from the wire, rods, flux, and base metal. Confined space can significantly increase that exposure.

Because of the link between welding fumes and manganese exposures, the new proposed rule is based on recommendations from the OR-OSHA Manganese Advisory Committee that met over a period of about three years. The Manganese Advisory Committee was made up of representatives from small and large businesses that routinely perform welding and other hot work, as well as consultants who work with these businesses. The Committee also included representatives from manufacturing, construction, and labor and business associations. The new rule will lower the Permissible Exposure Limit (PEL) to 0.1 milligrams per cubic meter (mg/m3) as an 8-hour time-weighted average (TWA), and it retains the current “ceiling” limit of 5 mg/m3. Some challenges to prepare for include using and/or improving engineering controls such as local exhaust ventilation (LEV); and other provisions in the existing Welding, Cutting, and Brazing rules, confined space, and PPE.

We expect more news pertaining to this in the coming months. Your AGC Oregon-Columbia Chapter Industrial Hygienists, and Safety Management Consultants will keep you posted on the new manganese requirements.

Oregon OSHA’s Proposal to Reduce Manganese Permissible Exposure Limit

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