We are familiar with hazards such as cave-ins and underground utilities with excavation and trench work. Recently though a worker died due to Hydrogen Sulfide (H2S) exposure while replacing a sewer line in a trench. Let’s answer a few important questions.

What is Hydrogen Sulfide?

H2S is a colorless, highly toxic, flammable gas. H2S occurs naturally in sewers, manure pits, well water, and oil and gas wells. It is heavier than air and can collect in low-lying and enclosed spaces, such as manholes, sewers, underground telephone vaults and excavation work. Work in confined spaces can be very dangerous when H2S is present.

What are companies required to do?

According to OSHA, employers are required to test the air to detect the presence of the gas, use exhaust systems to reduce hydrogen sulfide levels, train workers on hazards and control methods, and provide personal protective equipment if control methods used are not sufficient to reduce Hydrogen Sulfide levels.

 What went wrong?

 The company failed to protect its workers. The employer was cited for exposing workers to contaminants above safe levels, not providing the necessary training to prepare workers for the hazards, not testing the atmosphere for hazardous gases prior to entry into the space and not having the emergency rescue equipment readily available for workers.

Could death have been prevented?

 Potentially yes. With just a few steps and adhering to the regulations, most deaths can be prevented.

Many H2S trainings cover where it is likely to be present. Furthermore, trainings are likely to review the signs and symptoms of exposure. With adequate training, the worker would have known, that by working on a sewer line, especially within an excavation, he could be exposed to H2S. Perhaps the worker could have also recognized some of the symptoms and evacuated the area.

Additionally, emergency rescue equipment was not “readily available”. When hazardous atmospheric conditions exist, this is a requirement. Due to the low oxygen concentrations and H2S, the employer was required to have the necessary emergency equipment to rescue the worker.

The employer failed to protect the worker due to the lack of training, atmospheric testing equipment, and rescue equipment. Unfortunately, their failure cost a man his life. During excavation and trenching, workers are at risk from more hazards than just cave-ins and underground utility lines.

Contact us if you have any regulatory or compliance questions concerning about Hydrogen Sulfide exposure, the hazards of excavation and trenching, or have any safety needs. We want you to remain compliant and keep your workers safe.


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