Confined Spaces in Construction questions for the CHST
CHST5 Domain 1: Hazard and Risk Identification and Control (K1.6 Confined spaces). 2 free questions below. Every answer quotes and links the regulation paragraph it rests on.
Regulations covered
- 29 CFR 1926.1203 General requirements.
- 29 CFR 1926.1204 Permit-required confined space program.
Text pulled from the eCFR, current as of 2026-10-14.
Question 1
A crew is working in a permit space that was reclassified as a non-permit space after hazards were eliminated. Partway through the shift, a worker's monitor shows a new hazard developing inside the space. What must happen first?
Show answer and source
Answer: B. Each employee in the space must exit, and the entry employer then reevaluates and reclassifies the space as a permit space as appropriate
When hazards arise in a space that was reclassified as non-permit, every employee must exit, and the entry employer then reevaluates and reclassifies it as a permit space as appropriate. Letting some workers stay or continuing work under the old classification ignores the exit requirement.
Answer B rests on
29 CFR 1926.1203(g)(4)(opens ecfr.gov in a new tab)“If hazards arise within a permit space that has been reclassified as a non-permit space under paragraph (g) of this section, each employee in the space must exit the space. The entry employer must then reevaluate the space and reclassify it as a permit space as appropriate in accordance with all other applicable provisions of this standard.”
Question 2
Before a crew enters a below-grade vault, a qualified tester completes pre-entry testing and the permit is signed. An authorized entrant at the opening smells a strong solvent odor that the posted readings don't reflect. He asks the supervisor to retest the space while he watches. The supervisor says the permit is already signed, so the space has been evaluated. What does the standard require the employer to do?
Show answer and source
Answer: D. Reevaluate the space with the requesting entrant present, because he has an indication that the original evaluation may have been inadequate
The entrant has a concrete indication, the odor, that the evaluation may have been inadequate. The standard requires the employer to reevaluate the space in his presence when he asks. A signed permit does not excuse the employer from this, and retesting without the entrant or delaying the results would not satisfy it.
Answer D rests on
29 CFR 1926.1204(e)(5)(opens ecfr.gov in a new tab)“Reevaluate the permit space in the presence of any authorized entrant or that employee's authorized representative who requests that the employer conduct such reevaluation because there is some indication that the evaluation of that space may not have been adequate; and”
10 more confined spaces in construction questions in the full CHST bank
Related topics
Original practice questions, not real exam items. PassCited is not affiliated with or endorsed by BCSP.