CFI Portable Fire Extinguishers & Suppression Equipment 2 — Questions and Answers
Question 1: A carbon dioxide (CO2) fire extinguisher is being inspected. Which condition would require it to be removed from service?
- A full charge reading on the gauge
- Loss of more than 10% of its listed weight (Correct answer)
- A plastic horn showing minor surface scuffs
- A tag showing inspection within the last 11 months
Correct answer: Loss of more than 10% of its listed weight
NFPA 10 requires CO2 extinguishers to be removed from service and recharged if they have lost more than 10% of the net agent weight listed on the nameplate.
Question 2: What does the term 'hydrostatic testing' refer to in the context of portable fire extinguishers?
- Testing the extinguishing agent's chemical composition
- Pressure testing the extinguisher cylinder with water to verify structural integrity (Correct answer)
- Measuring water content in dry chemical agents
- Testing the nozzle flow rate with water
Correct answer: Pressure testing the extinguisher cylinder with water to verify structural integrity
Hydrostatic testing involves filling the cylinder with water and pressurizing it beyond operating pressure to verify the shell has no cracks, flaws, or leaks.
Question 3: Under NFPA 10, stored-pressure dry chemical extinguishers require hydrostatic testing at what interval?
- Every 3 years
- Every 6 years
- Every 12 years (Correct answer)
- Every 15 years
Correct answer: Every 12 years
NFPA 10 requires stored-pressure dry chemical extinguishers to undergo hydrostatic testing every 12 years.
Question 4: A fire inspector observes that the inspection tag on an extinguisher shows the last inspection was 13 months ago. What is the correct action?
- No action required since it is less than 2 years
- Document the finding and require immediate annual maintenance (Correct answer)
- Immediately discharge and replace the extinguisher
- Only take action if the pressure gauge reads low
Correct answer: Document the finding and require immediate annual maintenance
NFPA 10 requires annual maintenance; an extinguisher with a tag showing over 12 months since the last inspection is overdue and must receive immediate maintenance.
Question 5: Which fire extinguisher class is rated for fires involving energized electrical equipment?
- Class A
- Class B
- Class C (Correct answer)
- Class D
Correct answer: Class C
Class C extinguishers use non-conductive agents suitable for use on energized electrical equipment, preventing electrical shock to the operator.
Question 6: According to NFPA 10, what is the maximum travel distance to a Class A fire extinguisher in a light-hazard occupancy?
- 50 feet
- 75 feet (Correct answer)
- 100 feet
- 150 feet
Correct answer: 75 feet
NFPA 10 allows a maximum travel distance of 75 feet to a Class A extinguisher in light-hazard occupancies.
Question 7: When inspecting a multipurpose dry chemical extinguisher, the inspector finds the pull pin is missing but the pressure gauge reads in the green zone. What is the correct action?
- No action needed if the gauge reads normal
- Tag it out of service; missing safety devices require immediate correction (Correct answer)
- Note in the report and re-inspect in 30 days
- Replace the agent and recharge immediately
Correct answer: Tag it out of service; missing safety devices require immediate correction
A missing pull pin is a safety device deficiency that renders the extinguisher out of service under NFPA 10 until corrected.
CFI Portable Fire Extinguishers & Suppression Equipment 2
A carbon dioxide (CO2) fire extinguisher is being inspected.
Which condition would require it to be removed from service?