What is hydrogen sulphide?

Hydrogen sulphide is a colourless gas with the chemical formula H₂S, known for its characteristic smell of rotten eggs. It is mainly produced by the decomposition of organic matter under oxygen-free conditions. In industry, it is used in the production of sulphur and sulphuric acid. Hydrogen sulphide is highly toxic and flammable, which makes its handling and control particularly important.

Creation

Hydrogen sulphide is produced in numerous industrial processes, including the processing of crude oil and natural gas, the manufacture of chemicals and in sewage treatment plants. It is also released by biological decomposition processes in swamps, fermentation vats and other oxygen-poor environments.

Recognition

Hydrogen sulphide has an unmistakable odour of rotten eggs, which is perceptible even at very low concentrations. It is colourless and heavier than air. It can cause irritation on contact with the skin and inhalation of hydrogen sulphide can cause headaches, nausea and shortness of breath. High concentrations can lead to unconsciousness and death.

Limit values

In Germany, the limit values for hydrogen sulphide are regulated by the Technical Instructions on Air Quality Control (TA-Luft) and the occupational exposure limit values (AGW). The OEL for hydrogen sulphide is 5 ppm (parts per million) or 7 mg/m³. These limit values are intended to ensure that the concentrations in the workplace do not cause any damage to health.

Hazards

Health: Even at low concentrations, hydrogen sulphide can irritate the eyes and respiratory tract. At higher concentrations, inhalation leads to severe respiratory tract irritation, coughing, dizziness and nausea. Extremely high concentrations can paralyse the central nervous system and cause respiratory arrest, which can quickly become life-threatening. Environment: Hydrogen sulphide can damage the environment by being released into the atmosphere and contributing to the formation of acid rain. In aquatic systems, it can be toxic to fish and other aquatic life. Economic damage: Improper handling and release of hydrogen sulphide can cause considerable costs due to necessary safety measures and claims for damages. In addition, production losses and increased employee sickness rates can significantly impair the economic efficiency of a company.