FPE Fire Prevention & Hazard Analysis 3 — Questions and Answers
Question 1: The flash point of a flammable liquid is best defined as the:
- Minimum temperature at which vapor ignites momentarily with an applied ignition source (Correct answer)
- Temperature at which sustained combustion occurs without an external ignition source
- Temperature at which a liquid produces enough vapor to ignite spontaneously
- Minimum temperature for a liquid to produce vapors that support combustion indefinitely
Correct answer: Minimum temperature at which vapor ignites momentarily with an applied ignition source
Flash point is the minimum liquid temperature at which sufficient vapors are produced to form an ignitable mixture that briefly ignites when exposed to an ignition source.
Question 2: Which NFPA document provides the classification system for flammable and combustible liquids (Class I, II, III)?
- NFPA 30 (Correct answer)
- NFPA 58
- NFPA 704
- NFPA 77
Correct answer: NFPA 30
NFPA 30, the Flammable and Combustible Liquids Code, classifies liquids into Class I (flash point < 100°F) and Classes II and III based on flash point thresholds.
Question 3: When conducting a Layer of Protection Analysis (LOPA), the term 'Initiating Event Frequency' refers to:
- The likelihood per year that the hazard scenario begins without any protective layer acting (Correct answer)
- The probability that a safety instrumented system fails on demand
- The frequency at which alarms are triggered during normal operation
- The rate at which combustible material accumulates in a space
Correct answer: The likelihood per year that the hazard scenario begins without any protective layer acting
In LOPA, the initiating event frequency is the unmitigated rate at which the loss event scenario is initiated before any independent protection layers reduce the risk.
Question 4: Which fire hazard analysis method uses inductive logic to trace all possible outcomes from a single initiating failure?
- Event Tree Analysis (ETA) (Correct answer)
- Fault Tree Analysis (FTA)
- HAZOP
- What-If Analysis
Correct answer: Event Tree Analysis (ETA)
Event Tree Analysis is an inductive method that starts from an initiating event and branches forward through success/failure of barriers to determine possible outcomes.
Question 5: Under NFPA 30, an inside liquid storage room for flammable liquids must have a liquid-tight raised sill or ramp at least how high?
- 4 inches (100 mm) (Correct answer)
- 2 inches (51 mm)
- 6 inches (150 mm)
- 8 inches (200 mm)
Correct answer: 4 inches (100 mm)
NFPA 30 requires inside liquid storage rooms to have a liquid-tight raised sill or ramp at least 4 inches (100 mm) high at each door opening to contain spills.
Question 6: Spontaneous ignition of a material is most directly characterized by its:
- Autoignition temperature (AIT) (Correct answer)
- Flash point
- Fire point
- Limiting oxygen concentration (LOC)
Correct answer: Autoignition temperature (AIT)
The autoignition temperature is the minimum temperature at which a substance will self-ignite without an external ignition source.
Question 7: In a bow-tie diagram used for fire hazard analysis, the 'prevention barriers' are located:
- Between the hazard source and the top event (left side) (Correct answer)
- Between the top event and the consequences (right side)
- At the top event only
- Outside the diagram as supporting documentation
Correct answer: Between the hazard source and the top event (left side)
In a bow-tie diagram, prevention barriers on the left side block the threat from escalating to the top event, while mitigation barriers on the right side reduce consequence severity.
FPE Fire Prevention & Hazard Analysis 3
The flash point of a flammable liquid is best defined as the: