SafetyQuestion 329 of 360
Before entering a sewer vault, a plumber lowers a multi-gas meter to test the atmosphere. In what order must the atmosphere be tested?
a.Toxic gases, then flammable, then oxygen
b.Flammable, then oxygen, then toxic
c.Order does not matter as long as all three are tested
d.Oxygen first, then flammable gases/vapors, then toxic gases
Explanation
Under Title 8 §5157, atmospheric testing must follow the sequence oxygen first, then flammable gases and vapors, then toxic gases and vapors. Oxygen is tested first because most combustible-gas sensors need adequate oxygen to read accurately. Testing in this order ensures each reading is valid before entry, and testing must continue or be monitored during occupancy.
Law Reference: Cal/OSHA Title 8 §5157Practice all 360 questions free — no signup required.
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