CHST Confined Space Entry and Rescue 4 — Questions and Answers
Question 1: During a confined space rescue, a would-be rescuer enters without proper equipment and is overcome by the same hazard as the original victim. This is known as:
- Secondary exposure incident
- Cascade rescue failure (Correct answer)
- Multi-victim entrapment
- Non-entry rescue failure
Correct answer: Cascade rescue failure
A cascade rescue failure (also called a multiple-casualty incident) occurs when untrained rescuers enter a permit space and become victims themselves.
Question 2: OSHA 29 CFR 1926.1203 requires that before an employee enters any space that may be a permit-required confined space, the employer must:
- Immediately classify it as a permit-required confined space
- Evaluate the space to determine if it is permit-required (Correct answer)
- Post a warning sign and prohibit all entry
- Obtain a written variance from OSHA
Correct answer: Evaluate the space to determine if it is permit-required
Employers must evaluate each potential permit-required confined space before entry to determine whether permit-required conditions exist.
Question 3: Which condition would allow a permit-required confined space to be reclassified as a non-permit confined space for entry?
- All workers complete confined space training
- All hazards within the space are eliminated or isolated before entry (Correct answer)
- A safety officer monitors the space continuously
- The space is ventilated for at least 30 minutes prior to entry
Correct answer: All hazards within the space are eliminated or isolated before entry
A permit space may be reclassified as non-permit only when all actual hazards have been eliminated or isolated and the space is verified safe by testing.
Question 4: When using a tripod and mechanical retrieval system for vertical confined space rescue, the retrieval line must be attached to the entrant's:
- Wrist D-rings
- Chest harness front D-ring
- Full-body harness chest or back D-ring (Correct answer)
- Safety belt waist loop
Correct answer: Full-body harness chest or back D-ring
OSHA requires the retrieval line to be attached to the entrant's full-body harness at the chest or back D-ring to allow safe vertical retrieval.
Question 5: A confined space attendant observes an unauthorized person attempting to enter the permit space. The attendant's FIRST action should be to:
- Physically block the person from entering
- Call 911 immediately
- Warn the unauthorized person to stay out and inform the supervisor (Correct answer)
- Evacuate the authorized entrants first
Correct answer: Warn the unauthorized person to stay out and inform the supervisor
The attendant must warn unauthorized individuals away and notify the entry supervisor; physically restraining someone is not the attendant's role.
Question 6: Hydrogen sulfide (H₂S) is especially dangerous in confined spaces because it:
- Burns clothing on contact
- Desensitizes the sense of smell at high concentrations, masking its presence (Correct answer)
- Settles only at ceiling level making monitoring difficult
- Is heavier than air and undetectable by standard monitors
Correct answer: Desensitizes the sense of smell at high concentrations, masking its presence
H₂S paralyzes the olfactory nerve at elevated concentrations, so workers may no longer smell the 'rotten egg' odor and underestimate the danger.
Question 7: According to OSHA confined space standards, which of the following is NOT a required element of a permit-required confined space entry permit?
- Identity of the space and date of entry
- Name and signature of the entry supervisor
- Equipment to be used by entrants
- Workers' compensation insurance policy number (Correct answer)
Correct answer: Workers' compensation insurance policy number
Entry permits must include space identification, date, authorized entrants, attendants, supervisors, hazards, controls, equipment, and communications—not insurance information.
CHST Confined Space Entry and Rescue 4
During a confined space rescue, a would-be rescuer enters without proper equipment and is overcome by the same hazard as the original victim.
This is known as: