Everyone has heard the line, “What they don’t know won’t hurt them.” It is a lie that people frequently use as an excuse to keep something secret. However, the truth of the matter is that what a person does not know is usually what hurts them in the end, particularly in confined spaces. The atmosphere in those areas can make breathing dangerous if not fatal due to the types of gases that can potentially fill the air, such as hydrogen sulfide (H2S).

Hydrogen Sulfide (H2S)

This highly toxic gas is commonly produced by different industrial processes, such as petroleum extraction, agricultural silos, and even food processing. However, it is also frequently found in nature, particularly wherever decomposition is prevalent—such as in marshy landscapes, hot springs and manure pits.

Should a worker be exposed to hydrogen sulfide (H2S), the side-effects depend on the duration of exposure and the amount of gas present. For example, at 0.01 – 1.5 ppm, the gas smells like rotten eggs; and as long as everyone leaves the area as soon as it is detected, no permanent harm is done. If the amount of gas is higher or the exposure longer, then over time the employees could experience eye irritation, headache, stomach upset, loss of smell and other symptoms of varying degrees. Unfortunately, if the amount of hydrogen sulfide (H2S) hovers around 1000-2000 ppm, death is almost instantaneous.

Read more: Three Dangerous Gases in Confined Spaces