Confined Space Entry and Rescue Flashcards
7 cards from real CHST practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Confined Space Entry and Rescue flashcards as text
Which atmospheric condition in a confined space is MOST immediately life-threatening and requires immediate evacuation without any other assessment?
Answer: LEL reading at 12% of lower explosive limit
An LEL reading of 12% indicates a significant flammable atmosphere; evacuation is required when LEL reaches or exceeds 10% of the lower explosive limit.
A construction worker is performing hot work inside a confined space with documented atmospheric testing. The work is paused for a 30-minute lunch break. Upon return, the worker should:
Answer: Re-test the atmosphere before re-entering the space
Atmospheric conditions can change rapidly during breaks, especially with hot work; retesting before re-entry is required to ensure continued safety.
The primary purpose of continuous forced-air ventilation in a permit-required confined space is to:
Answer: Replace and control hazardous atmospheres during occupancy
Forced-air ventilation continuously dilutes and removes hazardous gases to maintain a safe atmosphere while workers occupy the space.
Which of the following rescue methods is always preferred over all others for confined space rescue per OSHA regulations?
Answer: Non-entry retrieval using mechanical means
OSHA requires that non-entry retrieval be used whenever it is feasible, because it protects rescuers from entering the hazardous space.
A confined space attendant who must temporarily leave their post due to an emergency should:
Answer: Have another authorized attendant replace them before leaving
An attendant may not abandon their post unless relieved by another qualified attendant, as continuous external monitoring is essential to entrant safety.
Which type of confined space hazard is classified as an 'engulfment' hazard under OSHA's confined space standard?
Answer: Being surrounded and captured by liquid or finely divided solid material
Engulfment specifically refers to the surrounding and effective capture of a person by liquid or finely divided solid material such as grain, sand, or slurry.
Under OSHA 29 CFR 1926.1204, which of the following is a required duty of the entry supervisor for a permit-required confined space?
Answer: Verify that all conditions specified by the permit have been met before authorizing entry
The entry supervisor must verify that all permit conditions are met and sign the permit to authorize entry before any worker enters the space.