ACGIH Publishes Reduced Guideline for Manganese Exposure

acgihManganese exposure occurs when manganese is heated and reacts with oxygen and creates manganese oxide fume. Exposure to this fume can lead to central nervous system damage. This is of special concern for metal fabricators as manganese is present in various welding rods and filler metals. Prolonged or excessive inhalation or ingestion of manganese has the potential to lead to a condition called manganism. Manganism can lead to weakness, lethargy, paralysis, tremors, and speech and psychological issues.

 

Last year the American Conference of Governmental Industrial Hygienists (ACGIH) published a new threshold limit value (TLV) for manganese of 0.02 mg/m3. This was updated from the previous ACGIH TLV of 0.2 mg/m3. Although the ACGIH limit has been updated, the Occupational Safety and Health Administration (OSHA) has not changed the permissible exposure limit (PEL) of 5 mg/m3. The OSHA limit is federally enforceable unless a state plan has a stricter limit.

 

In order to comply with the updated guidelines, companies may need to conduct air sampling to verify employee exposure. Based on the air sampling results, companies can determine if additional personal protective equipment (PPE), ventilation, work practices, or a combination of these are required to reduce employee exposure.

 

Please contact Bay Environmental Strategies, Inc. at 800 576-2476 for additional assistance and information.