Protecting Construction Workers from the Dangers of Hydrogen Sulfide

Construction is one of the most dangerous professions, with one in five worker fatalities in 2018 occurring within the industry. The dangers of a construction site extend beyond the fatal four dangers reported by OSHA (falls, electrocution, struck-by-objects and caught-in-between) to those that cannot be easily spotted. Known as the silent killer, Hydrogen Sulfide, commonly referred to as H2S or sour gas, is the second most common cause of workplace gas inhalation fatalities following carbon monoxide. The colorless, flammable gas is naturally produced by the decomposition of organic material and is also emitted as a by-product of many industrial processes.

Often collecting in low-lying and enclosed, poorly ventilated spaces, construction workers surveying and performing tasks within basements, caves, tunnels, manholes, landfills, underground utility vaults, marshy areas and sewer lines, as well as those working with asphalt, can easily and quickly be overpowered by exposure to the gas. Symptoms vary according to exposure—at lower exposure rates (0.001 – 1.5 ppm), H2S is often first detected as a rotten egg smell, while at higher rates (3 – 5 ppm), the odor is more offensive.