NEBOSH Fire Safety Management 2 — Questions and Answers
Question 1: A CO2 fire extinguisher is identified by which colour band on a red body?
- Blue
- Cream
- Black (Correct answer)
- Yellow
Correct answer: Black
A CO2 (carbon dioxide) extinguisher has a black colour band on a red body under BS EN 3. CO2 extinguishers work by displacing oxygen and are suitable for Class B (flammable liquid) and electrical fires. They leave no residue, making them ideal for use on sensitive equipment.
Question 2: Which class of fire involves flammable gases such as propane or butane?
- Class A
- Class B
- Class C (Correct answer)
- Class D
Correct answer: Class C
Class C fires involve flammable gases including propane, butane, methane, and natural gas. The primary method of dealing with a Class C fire is to shut off the gas supply if safe to do so. Dry powder extinguishers can be used to control the flames, but the gas supply must be isolated to prevent re-ignition.
Question 3: How often should fire drills typically be conducted in a workplace under UK fire safety guidance?
- Every month
- At least once per year, with more frequent drills for high-risk premises (Correct answer)
- Every five years
- Only when new employees start
Correct answer: At least once per year, with more frequent drills for high-risk premises
UK fire safety guidance recommends fire drills at least once per year in most workplaces, with higher-risk premises such as care homes, hospitals, and HMOs conducting them more frequently (e.g., every 6 months). Drills should be recorded and evaluated to identify weaknesses in the evacuation procedure.
Question 4: What is the main mechanism by which a foam extinguisher suppresses a Class B (liquid) fire?
- Cooling the liquid below its flash point
- Forming a film or blanket over the liquid surface to seal vapours from the oxygen supply (Correct answer)
- Chemically reacting with the liquid to neutralise it
- Absorbing the liquid into the foam
Correct answer: Forming a film or blanket over the liquid surface to seal vapours from the oxygen supply
Foam extinguishers work primarily by forming a cohesive blanket or film over the surface of the burning liquid. This seals the flammable vapours from the oxygen in the atmosphere, smothering the fire. The aqueous component also provides some cooling effect on the fuel surface.
Question 5: What measures can be taken to prevent arson in the workplace?
- Store all combustible materials inside the building only
- Control access to the site, secure waste storage areas, improve lighting, remove external combustible materials, and install CCTV (Correct answer)
- Lock all fire exits permanently
- Remove all fire extinguishers to prevent misuse
Correct answer: Control access to the site, secure waste storage areas, improve lighting, remove external combustible materials, and install CCTV
Arson prevention measures include: controlling site access with fencing and gates, securing waste bins and skips away from buildings, installing external lighting and CCTV, removing combustible materials from building perimeters, securing letterboxes, and ensuring vacant areas are properly secured. Arson is the single largest cause of fires in non-domestic premises in the UK.
Question 6: What is the purpose of fire-resisting doors in a building's means of escape?
- To prevent theft during evacuation
- To compartmentalise the building and protect escape routes from fire and smoke for a specified period (Correct answer)
- To improve the building's thermal insulation
- To reduce noise between rooms
Correct answer: To compartmentalise the building and protect escape routes from fire and smoke for a specified period
Fire-resisting doors (fire doors) compartmentalise the building by containing fire and smoke within defined areas for a rated period (typically 30 or 60 minutes — FD30 or FD60). They protect escape routes such as corridors and stairways, giving occupants time to evacuate safely and limiting fire spread to aid firefighting operations.
NEBOSH Fire Safety Management 2
A CO2 fire extinguisher is identified by which colour band on a red body?