Fire Safety and Emergency Response
What the exam tests
Fire chemistry, fire classes, extinguisher selection, evacuation and emergency preparedness.
Fire science
Fire tetrahedron: fuel, oxygen, heat and the chain reaction (a triangle for smouldering fires). Remove one leg and the fire stops.
Classes, in the NFPA/OSHA convention used on most Nigerian sites:
- A: solid combustibles such as wood, paper and cloth
- B: flammable liquids such as petrol, diesel and solvents
- C: flammable gases such as LPG and methane
- D: combustible metals such as magnesium and sodium
- K: cooking oils and fats (Class F in European practice)
Electrical fires are not a separate class here; isolate the power and use CO2 or dry powder. Extinguishers: water for A, foam for A and B, CO2 for B and electrical, dry powder for A, B, C and electrical, wet chemical for K. PASS: Pull, Aim, Squeeze, Sweep. RACE: Rescue, Alarm, Contain, Extinguish or Evacuate.
Emergency preparedness covers alarms, clear escape routes, assembly points, roll call, fire wardens, drills, extinguisher servicing and detection.
Worked example
A canteen chip fryer ignites. Reasoning: this is a Class K fire; water causes a violent steam explosion and spreads burning oil, and CO2 can splash the oil. Use a wet chemical extinguisher, or a fire blanket for a small pan, switch off the heat, raise the alarm and evacuate if it is not immediately controlled.
Traps
- Water on live electrical equipment or burning oil.
- Fighting anything larger than a small incipient fire instead of evacuating.
- Forgetting that smoke inhalation, not flame, kills most fire victims.