At what concentration is hydrogen sulfide considered fatal?

Hydrogen sulfide (H₂S) is a highly toxic gas, and its effects on human health can vary significantly based on concentration and exposure duration. At 300 ppm, exposure to hydrogen sulfide can result in immediate respiratory paralysis and can be fatal within a matter of minutes without prompt intervention.

It’s crucial to note that lower concentrations can lead to severe health effects, including irritation of the eyes and respiratory system, headaches, and dizziness, but at the level of 300 ppm, the toxicity escalates dramatically. The immediate danger associated with this concentration is why it is classified as fatal, marking a critical threshold for safety in environments where H₂S exposure might occur.

Understanding these concentrations helps inform safety regulations and emergency response measures necessary in work environments that may involve exposure to this dangerous gas.