Tankerman · Safety — H2S
Hydrogen sulfide (H2S) encountered in some crude oil cargoes is dangerous because it is:
- ALighter than air and harmless
- BHighly toxic and can deaden the sense of smell at hazardous concentrations✓ Correct
- CNon-flammable and inert
- DOnly a problem when frozen
Explanation
H2S is highly toxic; at higher concentrations it quickly paralyzes the sense of smell, so a worker cannot rely on odor to detect it. Atmosphere testing and respiratory protection are required where it may be present.
Authority: Tank Vessel Operations — Toxic Hazards
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