Manganese Exposure Risks in Welding: WHS Key Learnings

Welding operations, particularly Flux Core Arc Welding (FCAW), can expose workers to hazardous substances, including manganese, a metal commonly found in welding fumes. Prolonged exposure to manganese can lead to serious health issues, including neurological disorders such as manganism, which affects motor skills and cognitive function. A comprehensive statistical analysis was conducted to assess manganese exposure among workers involved in welding, brazing, grinding, and gouging. This analysis is crucial in applying the ALARA (As Low As Reasonably Achievable) principle to minimize exposure to manganese and protect worker health.

​In this blog post, we will explore the findings from our recent project, focusing on the variability in manganese exposure across different worker groups and the importance of tailored control measures to reduce exposure.
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Manganese Exposure: A Statistical Overview

A total of 32 samples were collected and analyzed to determine the concentration of manganese in the air. The results revealed significant variability in exposure levels across different worker groups, underscoring the need for customized control strategies.
All Samples

• Geometric Mean Manganese Concentration: 0.013 mg/m³
• Geometric Standard Deviation: 4.845
• Confidence Limits: 0.025 to 0.108 mg/m³

These results indicate that while the average manganese concentration is relatively low, the wide range of confidence limits highlights the potential for higher exposure levels in certain work scenarios. This variability emphasizes the need for tailored control measures to ensure worker safety.
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Exposure by Worker Group

Boilermakers

• Geometric Mean Manganese Concentration: 0.017 mg/m³
• Geometric Standard Deviation: 5.178
• Confidence Limits: 0.029 to 0.332 mg/m³

The data for boilermakers shows a higher average exposure compared to the overall sample. The broad confidence limits suggest significant variability in exposure, likely due to different work environments and tasks. This group may require specific attention to exposure control, including enhanced ventilation and respiratory protection.

Millwrights

• Geometric Mean Manganese Concentration: 0.024 mg/m³
• Geometric Standard Deviation: 2.249
• Confidence Limits: 0.015 to 0.329 mg/m³

Although only three samples were collected for millwrights, the results indicate a higher average exposure to manganese. The relatively narrow standard deviation suggests more consistent exposure levels, but the confidence limits still point to the need for consistent protective measures, such as local exhaust ventilation and personal protective equipment (PPE).


Fire Watches - in Confined Spaces

• Geometric Mean Manganese Concentration: 0.011 mg/m³
• Geometric Standard Deviation: 3.049
• Confidence Limits: 0.015 to 0.725 mg/m³

The data for fire watches shows a lower average exposure, but the wide confidence limits (up to 0.725 mg/m³) highlight the potential for high exposure levels in certain situations. This group should be equipped with adequate respiratory protection to mitigate the risk of overexposure.

Confined Space Stand By Workers

• Geometric Mean Manganese Concentration: 0.006 mg/m³
• Geometric Standard Deviation: 6.091
• Confidence Limits: 0.008 to 1.349 mg/m³

Stand By Workers had the lowest average exposure to manganese, but the extremely wide confidence limits (up to 1.349 mg/m³) indicate a significant potential for high variability in exposure levels. This group may benefit from continuous monitoring and adjustments to control measures to ensure that exposure remains within safe limits.
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Implementing the ALARA Principle

The findings from the project underscore the necessity of adhering to the ALARA (As Low As Reasonably Achievable) principle when managing manganese exposure in welding operations. The variability in exposure levels across different worker groups highlights the importance of implementing a comprehensive set of control measures, including:

1. Engineering Controls:
   • Ventilation Systems: Proper ventilation, including local exhaust ventilation, is essential to reduce airborne manganese concentrations in the work area.
   • Fume Extraction: Using fume extraction systems at the source of welding can significantly reduce the amount of manganese and other hazardous substances in the air.
2. Administrative Controls:
   • Worker Rotation: Rotating workers to minimize the duration of exposure can help reduce their overall exposure to manganese.
   • Training: Workers should be trained on the hazards of manganese exposure and the importance of using protective measures.
3. Personal Protective Equipment (PPE):
   • Respiratory Protection: Given the potential for high exposure levels, especially for fire watches and hole watches, providing appropriate respiratory protection is critical.
   • Protective Clothing: Workers should also be equipped with protective clothing to prevent skin contact with welding fumes.

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Continuous Monitoring and Assessment

The variability in manganese exposure levels across different worker groups at the  project highlights the importance of continuous monitoring and assessment. Regular air sampling and exposure assessments are essential to ensure that control measures remain effective and that workers are adequately protected from hazardous substances like manganese.

At Western Health & Safety (WHS), we specialize in conducting comprehensive welding fume exposure assessments, including monitoring for manganese and other hazardous substances. Our team of Certified Industrial Hygienists works closely with clients to develop tailored solutions that meet the specific needs of their workplace, ensuring compliance with safety regulations and protecting worker health.

Conclusion

Manganese exposure during welding, particularly in Flux Core Arc Welding (FCAW), poses significant health risks to workers. The findings from the project demonstrate the variability in exposure levels across different worker groups, emphasizing the need for tailored control measures and adherence to the ALARA principle. By implementing a combination of engineering controls, administrative controls, and PPE, employers can effectively manage and minimize workers' exposure to manganese, ensuring a safer and healthier workplace.

If you are concerned about manganese exposure in your workplace, contact Western Health & Safety today for a comprehensive welding fume exposure assessment. Our team of experts is here to help you protect your workforce and ensure compliance with occupational health standards.

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