What is hydrogen sulfide and how toxic is this gas?

What is hydrogen sulfide?
A flammable acidic gas, colorless, can form an explosive mixture when mixed with air, and can cause combustion and explosion when exposed to open flames and high heat energy. At low concentrations, there is a foul egg odor, and at extremely low concentrations, there is a sulfur odor, which is highly toxic.

Why is hydrogen sulfide a notorious and deadly killer?
Hydrogen sulfide is a highly lethal gas, and what's even more deadly is that even low concentrations of hydrogen sulfide can damage a person's sense of smell. When the concentration is high, there is no odor (because high concentrations of hydrogen sulfide can paralyze the olfactory nerve). So, using the nose as a means of detecting hydrogen sulfide is deadly. Hydrogen sulfide can directly act on the brain and has an excitatory effect at low concentrations; High concentrations have inhibitory effects, causing coma, paralysis of the respiratory and vascular motor centers. Inhaling high concentrations of hydrogen sulfide can cause respiratory arrest within 10 seconds, resulting in electrocution like death.

According to incomplete statistics, since 2012, there have been 18 accidents caused by hydrogen sulfide poisoning among major and above accidents, resulting in 62 deaths; There were a total of 33 poisoning accidents, with hydrogen sulfide poisoning accounting for 48.6%.

Where does hydrogen sulfide come from?
Hydrogen sulfide has a wide range of sources and is commonly found in oil and gas well drilling sites, natural gas processing plants, petroleum refineries, sulfur recovery plants, fine chemical enterprises, and mines. In addition, hydrogen sulfide can also be found in pulp mills, sewers, industrial laboratories, etc. Hydrogen sulfide is mainly generated during waste liquid treatment, process production, acid reaction of sulfides, and self heating reaction of ferrous sulfide. When enterprise personnel carry out unconventional operations such as confined space, blind flange pumping, pipeline dredging, and cleaning, inadequate risk analysis and protective measures can lead to poisoning.

How to prevent hydrogen sulfide poisoning?
Install hydrogen sulfide gas detection alarms in areas where hydrogen sulfide is easily generated in the factory or workshop to monitor the concentration of hydrogen sulfide leakage in real time. When the leakage concentration reaches the preset value, the instrument will immediately emit sound and light alarm signals to remind staff to evacuate urgently or take emergency measures. At the same time, the gas detection alarm can also upload the alarm information to the computer terminal through the gas alarm controller, and notify the staff of the alarm situation through telephone, SMS, and APP. It can be remotely operated to avoid the occurrence of disasters and accidents.

When working in confined spaces such as storage tanks and manholes, workers can wear a composite gas detector to monitor the concentration of hydrogen sulfide gas in real time. The composite gas detector can simultaneously detect the concentrations of oxygen, carbon monoxide, hydrogen sulfide, and combustible gases, effectively preventing explosions and poisoning accidents.

Production safety cannot be ignored! Especially when facing toxic and harmful gases such as hydrogen sulfide, installing gas detection alarms, actively warning, and making timely judgments can improve production safety factors and ensure the safety of employees' lives is not violated!

(The image is sourced from the internet)