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
Under OSHA definitions, 'engulfment' in a confined space refers to:
Answer: The surrounding and effective capture of a person by finely divided solids or liquid
OSHA defines engulfment as the surrounding and effective capture of a person by a liquid or finely divided flowable solid, which can cause asphyxiation, strangulation, constriction, or crushing.
When a non-permit confined space must be reclassified as permit-required, which condition most commonly triggers this change?
Answer: Work activities inside the space create additional hazards such as welding fumes or oxygen displacement
When work performed inside a non-permit confined space introduces new hazards—such as welding that generates toxic fumes or displaces oxygen—the space must be reclassified as permit-required.
Which type of forced ventilation is most effective for purging a confined space of vapors heavier than air?
Answer: Forced air supply directed near the bottom of the space
Vapors heavier than air settle at the lowest points of confined spaces; directing forced air supply near the bottom effectively displaces and purges these vapors upward and out.
What information is NOT required on an OSHA-compliant confined space entry permit?
Answer: The employer's general liability insurance policy number
Entry permits must contain safety and operational information including space identification, hazards, atmospheric test results, authorized personnel, and emergency procedures—not financial or insurance data.
A hydrogen sulfide (H₂S) concentration of 300 ppm inside a confined space represents what condition?
Answer: An IDLH (Immediately Dangerous to Life or Health) condition
NIOSH establishes the IDLH for hydrogen sulfide at 100 ppm; a concentration of 300 ppm far exceeds this threshold and represents an immediately life-threatening condition requiring immediate evacuation.
In confined space operations involving multiple employers on a construction site, what does OSHA require?
Answer: Employers must coordinate entry operations and share information about space hazards with each other
Under 29 CFR 1926 Subpart AA, when multiple employers are involved, they must coordinate entry operations and exchange relevant information about space hazards and entry procedures to protect all workers.
What is the purpose of 'isolation' as a hazard control step in confined space entry?
Answer: To physically disconnect energy sources and block introduction of hazardous materials into the space
Isolation involves locking out/tagging out energy sources, blanking or blinding pipe connections, and otherwise physically preventing hazardous energy or substances from entering or affecting the space.