At what minimum concentration of hydrogen sulfide (H2S) in the air does an immediate threat to human life occur?

Chemical Environmental Engineering MCQs for PPSC, FPSC, NTS, and Pakistan government job tests. Select an option below, then read the explanation.

PPSCFPSCNTSPakistan govt jobs
Subject
Chemical Environmental Engineeringchemical-engineering › chemical-environmental-engineering-chemical-engineering
Published
11 Mar 2019
Last updated
28 May 2026

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Explanation

Exposure to hydrogen sulfide at or above 700 ppm poses an acute risk to human life, making it a critical safety threshold. Lower concentrations such as 50, 100, or 300 ppm are hazardous but do not typically cause immediate life-threatening effects.

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