CFPS Fire Hazard Management 3 — Questions and Answers
Question 1: A fire protection specialist is reviewing a chemical plant that stores oxidizers. Which statement BEST describes why oxidizers increase fire hazard?
- Oxidizers lower the autoignition temperature of nearby fuels
- Oxidizers supply additional oxygen, accelerating combustion and potentially enabling burning without atmospheric oxygen (Correct answer)
- Oxidizers are inherently flammable and add to the fuel load
- Oxidizers reduce the flash point of adjacent flammable liquids
Correct answer: Oxidizers supply additional oxygen, accelerating combustion and potentially enabling burning without atmospheric oxygen
Oxidizers release oxygen during decomposition, which can sustain or accelerate combustion even in oxygen-depleted environments, significantly increasing fire severity.
Question 2: According to NFPA 652, which document must be completed for facilities that handle combustible dusts to determine whether a dust hazard exists?
- Process Hazard Analysis (PHA)
- Dust Hazard Analysis (DHA) (Correct answer)
- Fire Hazard Analysis (FHA)
- Quantitative Risk Assessment (QRA)
Correct answer: Dust Hazard Analysis (DHA)
NFPA 652 requires a Dust Hazard Analysis (DHA) to identify, evaluate, and document fire, flash fire, and explosion hazards associated with combustible dust.
Question 3: A fire safety specialist is evaluating a spray paint booth. The MOST appropriate ventilation rate to maintain flammable vapor concentration below hazardous levels is:
- At least 1 air change per hour
- Sufficient to keep vapor concentration below 25% of the LFL (Correct answer)
- Sufficient to keep vapor concentration below 50% of the UFL
- At least 6 air changes per hour regardless of spray rate
Correct answer: Sufficient to keep vapor concentration below 25% of the LFL
NFPA 33 requires spray booth ventilation to maintain flammable vapor concentrations below 25% of the Lower Flammable Limit (LFL) as a safety margin.
Question 4: When assessing fire hazards in a cold storage facility, which factor presents the GREATEST ignition risk unique to these environments?
- Reduced humidity lowering ignition temperatures
- Ammonia refrigerant leaks creating a flammable atmosphere (Correct answer)
- Ice accumulation increasing electrical resistance in lighting circuits
- Sub-zero temperatures causing sprinkler heads to freeze open
Correct answer: Ammonia refrigerant leaks creating a flammable atmosphere
Anhydrous ammonia used in refrigeration systems is both toxic and flammable (flammable range 15-28% in air), making refrigerant leaks a critical fire and explosion hazard.
Question 5: A risk matrix combines two primary variables to prioritize fire hazards. These two variables are:
- Probability of ignition and probability of detection
- Likelihood of occurrence and severity of consequences (Correct answer)
- Number of people exposed and cost of suppression
- Fuel load and heat release rate
Correct answer: Likelihood of occurrence and severity of consequences
A risk matrix evaluates hazards by plotting likelihood (probability) against consequence severity to determine overall risk priority.
Question 6: In the context of fire hazard management, 'inherently safer design' (ISD) is best exemplified by which action?
- Installing automatic sprinklers in a flammable storage room
- Substituting a flammable solvent with a non-flammable alternative (Correct answer)
- Adding secondary containment around a flammable liquid tank
- Increasing inspection frequency for hot work permits
Correct answer: Substituting a flammable solvent with a non-flammable alternative
Inherently safer design eliminates the hazard at its source; substituting a flammable solvent with a non-flammable one removes the fire hazard entirely rather than controlling it.
Question 7: Which NFPA standard specifically governs the storage, use, and handling of liquefied petroleum gases (LPG) to minimize fire and explosion hazards?
- NFPA 30
- NFPA 54
- NFPA 58 (Correct answer)
- NFPA 59A
Correct answer: NFPA 58
NFPA 58, the Liquefied Petroleum Gas Code, governs the storage, handling, transportation, and use of LP-Gas to minimize associated fire and explosion hazards.
CFPS Fire Hazard Management 3
A fire protection specialist is reviewing a chemical plant that stores oxidizers.
Which statement BEST describes why oxidizers increase fire hazard?