FPE Risk Management & Site Safety 3 — Questions and Answers
Question 1: The SFPE Handbook defines 'tenability' in the context of fire egress. Which combination of conditions MOST accurately represents the threshold for untenable conditions?
- Smoke obscuration reducing visibility below 10 m and CO concentration above 200 ppm
- Any visible flame in the egress path and ambient temperature above 35°C
- Heat flux exceeding 2.5 kW/m², CO above 1,400 ppm, or visibility below 3 m in a large space (Correct answer)
- Smoke layer depth greater than 50% of ceiling height and O₂ below 19%
Correct answer: Heat flux exceeding 2.5 kW/m², CO above 1,400 ppm, or visibility below 3 m in a large space
SFPE guidelines identify approximately 2.5 kW/m² radiant heat flux, CO ≥ 1,400 ppm (30-min exposure), and visibility < 3 m (large space) or < 10 m (small space) as tenability thresholds.
Question 2: Which NFPA standard provides the requirements for Fire Risk Assessments for existing buildings, offering a systematic approach to evaluating and documenting fire risk?
- NFPA 551 (Correct answer)
- NFPA 914
- NFPA 805
- NFPA 72
Correct answer: NFPA 551
NFPA 551, Guide for the Evaluation of Fire Risk Assessments, provides methodology for conducting and documenting fire risk assessments in existing buildings.
Question 3: In site safety planning for a large industrial facility, 'exclusion zones' are established primarily to:
- Limit liability for the facility owner during contractor operations
- Prevent unauthorized personnel from entering areas where hazardous conditions may exist during an emergency or hazardous operation (Correct answer)
- Define the boundary of the facility property for insurance purposes
- Restrict access for OSHA inspectors without a warrant
Correct answer: Prevent unauthorized personnel from entering areas where hazardous conditions may exist during an emergency or hazardous operation
Exclusion zones protect unqualified personnel from exposure to fire, explosion, toxic release, or other hazards during emergencies or hazardous work operations.
Question 4: Which index, developed by Dow Chemical, is widely used in the chemical process industry to rank the relative explosion and fire hazard of a process unit?
- Mond Index
- Dow Fire and Explosion Index (F&EI) (Correct answer)
- Chemical Exposure Index (CEI)
- Process Hazard Index (PHI)
Correct answer: Dow Fire and Explosion Index (F&EI)
The Dow Fire and Explosion Index (F&EI) uses a Material Factor and General/Special Process Hazard factors to produce a numerical hazard ranking for process units.
Question 5: Hot work permits are a critical site safety control. Which of the following is the MOST important pre-work verification step before issuing a hot work permit in an area with combustible dust?
- Confirm the worker has a valid welding certification on file
- Verify the area has been cleaned of combustible dust accumulations and that continuous atmospheric monitoring is in place (Correct answer)
- Ensure the supervisor has signed the JSA (Job Safety Analysis)
- Check that the fire extinguisher inspection tag is current
Correct answer: Verify the area has been cleaned of combustible dust accumulations and that continuous atmospheric monitoring is in place
Combustible dust can form explosive atmospheres; removing accumulations and continuous monitoring for dust levels are the highest-priority controls before issuing a hot work permit.
Question 6: In the context of NFPA 921 (Guide for Fire and Explosion Investigations), the 'scientific method' applied to fire investigation requires that the investigator:
- Identify the most probable cause first and then seek evidence to confirm it
- Collect all available data, form hypotheses, test hypotheses against data, and select the cause that is not eliminated by the evidence (Correct answer)
- Defer all cause determinations to the responding fire department
- Rely exclusively on eyewitness testimony to establish origin and cause
Correct answer: Collect all available data, form hypotheses, test hypotheses against data, and select the cause that is not eliminated by the evidence
NFPA 921 mandates that investigators follow the scientific method: data collection, hypothesis formation, and iterative testing, selecting only hypotheses consistent with all evidence.
Question 7: A fire protection engineer is evaluating risk at a facility storing large quantities of flammable liquids. The 'Maximum Credible Event' (MCE) concept is used to:
- Determine the minimum required insurance coverage for the facility
- Define the worst credible accident scenario for emergency planning and consequence modeling (Correct answer)
- Set the design basis for automatic sprinkler flow rates
- Establish the maximum allowable quantity of flammable liquids under the fire code
Correct answer: Define the worst credible accident scenario for emergency planning and consequence modeling
The MCE is the most severe accident scenario considered plausible for a facility and drives emergency response planning, consequence analysis, and protective distance calculations.
FPE Risk Management & Site Safety 3
The SFPE Handbook defines 'tenability' in the context of fire egress.
Which combination of conditions MOST accurately represents the threshold for untenable conditions?