NEBOSH Fire Safety Management 3 — Questions and Answers
Question 1: A wet chemical fire extinguisher is identified by which colour band and is primarily designed for which fire class?
- Blue band, Class C fires
- Yellow band, Class F fires (cooking oils and fats) (Correct answer)
- Cream band, Class A fires
- Black band, Class B fires
Correct answer: Yellow band, Class F fires (cooking oils and fats)
A wet chemical extinguisher has a yellow colour band and is specifically designed for Class F fires involving cooking oils and fats. It works by reacting with the hot oil to form a soapy film (saponification) that seals the surface and cools the oil below its auto-ignition temperature.
Question 2: In the fire triangle, removing the oxygen element is known as which method of fire extinction?
- Cooling
- Smothering (or starving of oxygen) (Correct answer)
- Starvation of fuel
- Chemical inhibition
Correct answer: Smothering (or starving of oxygen)
Smothering removes the oxygen supply from the fire, preventing the combustion reaction from continuing. Methods include using fire blankets, CO2 extinguishers, foam blankets, or closing doors and windows. The oxygen concentration must typically drop below approximately 16% to extinguish most fires.
Question 3: What is the recommended maximum travel distance in a normal-risk area where alternative escape routes are available?
- 18 metres
- 25 metres
- 35 metres
- 45 metres (Correct answer)
Correct answer: 45 metres
Where alternative escape routes are available in a normal-risk area, the maximum recommended travel distance is 45 metres. Alternative routes mean the occupant can travel in more than one direction to reach a final exit, significantly reducing the risk of being trapped by a fire blocking a single route.
Question 4: Which detection system provides both an alarm AND automatic fire suppression?
- Manual call points
- Smoke detectors
- Automatic sprinkler systems (Correct answer)
- Heat detectors
Correct answer: Automatic sprinkler systems
Automatic sprinkler systems provide both detection and suppression. Each sprinkler head contains a heat-sensitive element (glass bulb or fusible link) that activates individually when the local temperature reaches its rated value. Water is then discharged directly onto the fire. The water flow also triggers an alarm signal.
Question 5: Why should a dry powder extinguisher generally NOT be used in a small enclosed space?
- It will damage electronic equipment
- The powder cloud can obscure vision and cause breathing difficulties, making evacuation hazardous (Correct answer)
- It is too heavy to use in small rooms
- It is not effective in enclosed areas
Correct answer: The powder cloud can obscure vision and cause breathing difficulties, making evacuation hazardous
Dry powder extinguishers discharge a large cloud of fine chemical powder that severely reduces visibility and can cause breathing difficulties if inhaled in a confined space. This creates a secondary hazard to the user and others trying to evacuate, potentially trapping them in a disoriented and oxygen-depleted environment.
Question 6: What role does a fire warden (fire marshal) perform during a workplace evacuation?
- They fight the fire using all available equipment
- They ensure their designated area is fully evacuated, assist persons with disabilities, check rooms/toilets, close doors, and report to the assembly point (Correct answer)
- They contact the media about the fire
- They lock all doors to prevent re-entry only
Correct answer: They ensure their designated area is fully evacuated, assist persons with disabilities, check rooms/toilets, close doors, and report to the assembly point
Fire wardens/marshals are trained personnel assigned to specific zones or floors. During evacuation they sweep their area to ensure everyone has left, check enclosed spaces such as toilets and meeting rooms, assist anyone needing help, close doors and windows, and report to the chief fire warden at the assembly point with a status of their area.
NEBOSH Fire Safety Management 3
A wet chemical fire extinguisher is identified by which colour band and is primarily designed for which fire class?