SafetyQuestion 334 of 360
The atmosphere in a sewer vault tests as oxygen-deficient. Before any worker enters, what is the required corrective action?
a.Mechanically ventilate the space and retest until the atmosphere is within acceptable limits
b.Have the worker hold their breath and work quickly
c.Light a candle to burn off the bad air
d.Enter anyway since low oxygen is not dangerous for short tasks
Explanation
Under Title 8 §5157, a hazardous atmosphere must be controlled by continuous mechanical (forced-air) ventilation, and the space must be retested to confirm it is within acceptable limits before and during entry. Ventilation dilutes and removes toxic or flammable gases and restores oxygen. Entering an oxygen-deficient space without ventilating is a frequent cause of confined-space fatalities.
Law Reference: Cal/OSHA Title 8 §5157Practice all 360 questions free — no signup required.
Related questions on this topic
- Testing a sewer manhole, the meter shows the flammable gas reading as a percentage of the Lower Explosive Limit (LEL). Below what LEL reading does Cal/OSHA generally consider the flammable atmosphere acceptable for entry?
- During a permit-required confined space entry into a sewer, Cal/OSHA requires an attendant. What is the attendant's primary role?
- A plumber notices a rotten-egg smell while opening a sewer cleanout, then the smell fades. What toxic gas is this most likely, and why is the fading smell dangerous?
- A worker will descend into a deep sewer manhole. What retrieval equipment does Cal/OSHA generally require to aid non-entry rescue?
- Cal/OSHA sets a Permissible Exposure Limit (PEL) for hydrogen sulfide, a gas plumbers meet in sewers. Approximately what is the 8-hour PEL for H2S under Title 8?
- A supervisor wants to skip the full permit process for a sewer entry by claiming the space is 'reclassified' as non-permit. Under Cal/OSHA, when is such reclassification allowed?
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