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Hydrogen sulphide stinks of rotten eggs, but kills without smell
Hydrogen sulphide is a poisonous gas whose odor in small doses is associated with the stench of rotten eggs. At higher concentrations, the gas paralyzes the sense of smell, which means that we rarely detect the spill before it is too late. The typical cause of death in hydrogen sulfide accidents is respiratory arrest.
Hydrogen sulphide is a toxic gas species with the chemical formula H2S, which typically occurs in sewers, manure and septic tanks, cargo holds with trash fish and other places with oxygen-poor conditions. It is typically formed by the breakdown of sulfur-containing proteins, or by sulfate-reducing bacteria reacting inorganic sulfite or sulfate. It can also be found in crude oil, natural gas and biogas.
In 2014, two fishermen perished on their fishing boats at Strandby in North Jutland as a result of a hydrogen sulfide accident. The accident occurred when the two fishermen were in the cargo hold and were unloading trash fish. Here they were exposed to a high concentration of hydrogen sulfide, which cost them their lives. Along the way, a pump man tried to rescue the two fishermen – he is brain damaged today.
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Few notice the hydrogen sulphide gas in case of accidents
The concentration of hydrogen sulphide is crucial to the impact on the body. At 0.0003 to 100 ppm (parts per trillion / billion parts) we will notice the gas as it sets tracks in the air in form of a heavy stench of rotten eggs. If you exceed 100 ppm, the gas will stun the sense of smell, which means that we can no longer smell the gas, and theoretically do not know that we are in danger. At a concentration of 500 ppm and above, the gas will cause respiratory arrest, which is the typical cause of death in hydrogen sulfide accidents.
Another example of a hydrogen sulfide accident was when a pump on a paper mill broke, causing a hole in the pump housing. As a result, large amounts of a sulphide containing solution ran into the sewer where it reacted with a slightly acidic liquid and even released hydrogen sulphide.
Twelve people were seriously poisoned and two died. Subsequently, it turned out that of the ten survivors, only two had detected the smell of rotten eggs.
Gas detectors remedy numerous accidents
From time to time, we see hydrogen sulfide accidents, such as the incident at the fishing vessel at Strandby and the paper mill. But with the help of from Geopal Systems’ wide range of gas detectors, the vast majority of harmful emissions are detected before things go wrong. The purpose of the gas detectors is that, at too high concentrations of hydrogen sulphide or other toxic gases, they must alarm the personnel, and in this way, rectify accidents.
Geopal Systems’ gas detectors are considered some of the best on the market and therefore help to prevent gas accidents on a daily basis from a wide range of customers. Detecting hydrogen sulphide takes place at Kalundborg Biogas plant, Maarbjerg Energy Center and Dragør Wastewater treatment plant.
