試題詳解

20. You want to enter a gas-free cargo tank on oil tanker and atmospheric condition of cargo tank was checked prior to entering. What hydrocarbon vapor concentration you should get to ensure safety?
(A) Less than 35% LFL (Lower Flammable Limit).
(B) Less than 10% LFL (Lower Flammable Limit).
(C) Less than 5% LFL (Lower Flammable Limit).
(D) Less than 1% LFL (Lower Flammable Limit).