Oregon OSHA adopts rule to reduce the permissible exposure limit of manganese

Oregon workers across a wide range of industries are exposed to manganese, which can potentially cause health issues.

Oregon Occupational Safety & Health Division (OSHA) recently adopted a rule to reduce the permissible exposure limit of manganese. The rule is set to take effect in September 2022. 

The revised exposure limit is 0.1 milligrams per cubic meter (mg/m3) as an 8-hour time-weighted average. Federal and Oregon OSHA currently allow a manganese “ceiling limit” of 5 mg/m3, but findings from a number of advisory committees led the National Institute of Occupational Safety and Health and the American Conference of Governmental Industrial Hygienists to recommend more protective exposure limits. See the adopted rule for more details. 

Oregon workers across a wide range of industries are exposed to manganese, which can potentially cause health issues. Manganese exposures in Oregon are primarily linked to welding fume. 

“Manganese is a metal often used in the production of steel. Workers may be harmed from exposure to manganese through the breathing of manganese fumes or dusts. Continued exposure can damage the lungs, liver, and kidneys. Exposure to manganese dust or fumes can also lead to a neurological condition called manganism,” according to the Centers for Disease Control and Prevention 

The level of exposure depends on the dose, duration, and work being done. Even more sensitive effects of manganese exposures occur in the central nervous system,” according to the ACGIH threshold limit value (TLV) documentation. This is why the TLV is set at a lower limit of 0.02 mg/m3 as a respirable fraction. 

What this means for your workplace 

Employers should discuss this rule with their SAIF safety consultant or contact safety services at safetyservices@saif.com to find out how this applies to their workplace.