Tankerman · Inert Gas — Tank Entry
Before personnel may enter a cargo tank that has been inerted, the atmosphere must be:
- AGas-freed and ventilated to about 20.9% oxygen with toxic gases below safe limits✓ Correct
- BLeft inert to protect them
- CReduced to 8% oxygen
- DFilled with pure nitrogen
Explanation
An inert atmosphere is fatal to enter. The tank must be ventilated/gas-freed to a normal oxygen level (about 20.9%), with hydrocarbon and toxic gases (e.g., H2S, benzene) below their exposure limits, tested, and a permit issued before entry.
Authority: SOLAS II-2; 29 CFR 1915 (enclosed space)
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