Hydrogen sulphide (H₂S)
Highly toxic, explosive, life-threatening
Hydrogen sulphide (H₂S) is a colorless, extremely toxic and highly flammable gas that can be fatal even in small quantities. At low concentrations, it smells like rotten eggs – but this smell is not a reliable indicator: from around 100 ppm, H₂S numbs the sense of smell, causing a dangerous habituation effect.
H₂S is produced during biological decomposition processes, in sewage treatment plants, during oil and gas extraction, in the paper and pulp industry and in the chemical industry.
Toxic and quickly fatal – H₂S blocks cell respiration
Hydrogen sulphide has a similar effect to hydrogen cyanide – it blocks oxygen transport in the cells. The result: respiratory paralysis and death within a few minutes at high concentrations.
Toxicological guideline values & symptoms:
- 0.01-0.3 ppm: Odor threshold (not reliable)
- 10 ppm: eye irritation, coughing
- 100 ppm: loss of odor (feigns safety)
- 300 ppm: respiratory arrest possible – acute danger to life
- >500 ppm: fatal after a few minutes
- >1,000 ppm: immediately fatal
Caution: The smell of H₂S is not a reliable warning signal – professional detection is vital!
Explosive risk – H₂S forms highly explosive air mixtures
In addition to its high toxicity, H₂S is also highly flammable. Even low concentrations in poorly ventilated rooms can produce an explosive mixture. The explosion limits are between 4.3 and 46% by volume in air.
Typical danger zones:
- Biogas and sewage treatment plants
- Tanks, silos, containers
- Oil and gas systems
- Pumping stations & channels
- Laboratories & petrochemical plants
Gas detectors for H₂S – Early warning saves lives
Because H₂S acts so quickly and cannot be reliably smelled, H₂S gas detectors are an essential part of any safety strategy in hazardous environments. Our warning systems offer:
- Sensitive sensors from a few ppm (partly ppb range)
- 24/7 real-time monitoring with high response speeds
- Visual and audible alarms when limit values are exceeded
- Connection to ventilation or security systems
- Portable devices for maintenance, service & emergency teams
- Stationary systems for industrial plants, laboratories & containers
Areas of application for H₂S gas detection
Our gas detection solutions are used wherever hydrogen sulphide is produced or can escape:
- Oil and gas industry (upstream & downstream)
- Sewage treatment plants & wastewater treatment plants
- Pulp and paper production
- Chemical industry & reactor plants
- Agriculture (biogas plants, slurry tanks)
- Refineries, landfills & tank farms
Safety begins with reliable gas monitoring
Don’t rely on your sense of smell!
Rely on professional H₂S gas detectors that provide early warning, protect employees and ensure plant safety. Our systems can be flexibly integrated and meet the highest standards of reliability and response speed – for a safe working environment with H₂S risk.
The following gas sensors and systems from Bieler+Lang can detect hydrogen sulphide
We will be happy to advise you on the selection of suitable detectors and the corresponding evaluation devices for your individual application.
