DPSST Fire Safety 3 — Questions and Answers
Question 1: Under NFPA 1, what is the required minimum aisle width in assembly occupancies for areas with more than 50 seats?
- 28 inches
- 36 inches
- 44 inches (Correct answer)
- 60 inches
Correct answer: 44 inches
NFPA 1 and Life Safety Code require a minimum 44-inch aisle width in assembly occupancies to ensure safe egress.
Question 2: What is the primary hazard associated with a backdraft explosion?
- Toxic gas release only
- Sudden introduction of oxygen to a superheated oxygen-deficient fire environment (Correct answer)
- Structural collapse from water weight
- Carbon monoxide poisoning
Correct answer: Sudden introduction of oxygen to a superheated oxygen-deficient fire environment
A backdraft occurs when oxygen is suddenly introduced into a smoldering, oxygen-deficient fire, causing an explosive ignition.
Question 3: In the Incident Command System (ICS), who is directly responsible for the safety of all personnel on the fireground?
- Operations Section Chief
- Incident Commander
- Safety Officer (Correct answer)
- Division Supervisor
Correct answer: Safety Officer
The Safety Officer has the authority to halt unsafe operations and is responsible for monitoring and ensuring personnel safety.
Question 4: A standpipe system classified as Class II is designed primarily for use by:
- Fire department engine companies
- Trained building occupants using small hose stations (Correct answer)
- Aerial ladder operators
- Hazmat teams
Correct answer: Trained building occupants using small hose stations
Class II standpipes provide 1½-inch hose stations for use by trained building occupants for initial attack before firefighters arrive.
Question 5: Which of the following best describes a 'two-in, two-out' rule under OSHA 29 CFR 1910.134?
- Two firefighters enter and two remain outside for rescue if needed before an interior attack (Correct answer)
- Two hose lines must be charged before entry
- Two escape routes must be identified before entry
- Two incident commanders must approve entry
Correct answer: Two firefighters enter and two remain outside for rescue if needed before an interior attack
The two-in, two-out rule requires that at least two firefighters remain outside in standby rescue mode whenever two or more enter an IDLH atmosphere.
Question 6: What is the purpose of positive pressure ventilation (PPV) in firefighting?
- To increase humidity inside a structure
- To push smoke and heat out of a structure by pressurizing it at the entry point (Correct answer)
- To reduce water pressure in hose lines
- To cool the exterior of a burning building
Correct answer: To push smoke and heat out of a structure by pressurizing it at the entry point
PPV uses a blower at the entry to pressurize the structure and push smoke and heat out through an exhaust opening, improving visibility and conditions.
Question 7: When inspecting a fire extinguisher, which condition requires it to be removed from service immediately?
- The inspection tag is more than 30 days old
- The pressure gauge needle is in the green zone
- The pull pin is missing or broken (Correct answer)
- The label shows Class A rating
Correct answer: The pull pin is missing or broken
A missing or broken pull pin means the extinguisher could discharge accidentally or fail to operate in an emergency.
DPSST Fire Safety 3
Under NFPA 1, what is the required minimum aisle width in assembly occupancies for areas with more than 50 seats?