MSHA Warns Miners of Hydrogen Sulfide Exposure Hazards
MSHA urges miners to use gas detection equipment, adequate ventilation and appropriate respiratory protection.
- By Stasia DeMarco
- Aug 18, 2026
The Mine Safety and Health Administration (MSHA) has issued a health alert warning miners about the potentially deadly hazards associated with hydrogen sulfide exposure.
Hydrogen sulfide, or H2S, can be released into the air during mining activities and is also present in some industrial operations, sewers, sulfur springs and volcanic gas. Underground mines, confined spaces and manholes can accumulate the gas, creating particularly hazardous conditions for workers, according to MSHA.
MSHA cautioned workers against relying on smell to detect dangerous concentrations of H2S. Although the gas may initially produce a distinctive rotten-egg odor, exposure can quickly impair the sense of smell, making odor an unreliable method of monitoring conditions.
Exposure can cause eye and respiratory irritation, dizziness, headache, fatigue and disorientation. More serious exposures can result in fluid in the lungs, seizures, coma and death.
To reduce exposure risks, MSHA recommends ensuring adequate ventilation, particularly in enclosed areas. Miners working or traveling in areas where hydrogen sulfide may be present should carry gas detectors and use appropriate respiratory protection when working in such areas.
The agency emphasized that gas detection equipment, rather than a worker's sense of smell, should be used to identify potentially dangerous H2S concentration
About the Author
Stasia DeMarco brings a strong and varied journalism background to her role at Occupational Health & Safety, having previously served as a multimedia editor, broadcast journalist, professor and reviewer across major news organizations. As Content Editor, she writes news and feature articles, hosts sponsor and editorial webinars, co-hosts the SafetyPod worker health and safety podcast, and manages the brand’s digital and social media presence. She is committed to informing and engaging the safety community through compelling reporting and conversations that support safer, healthier workplaces.