NEBOSH CC Fire Prevention in Construction 3 — Questions and Answers
Question 1: What type of fire is associated with flammable liquids and gases on a construction site?
- Class B (flammable liquids) and Class C (flammable gases) (Correct answer)
- Class A only
- Class D only
- Class F only
Correct answer: Class B (flammable liquids) and Class C (flammable gases)
Class B fires involve flammable liquids such as petrol, diesel, solvents and adhesives. Class C fires involve flammable gases such as LPG, acetylene and natural gas. Both are common on construction sites due to the use of fuels and bottled gases.
Question 2: Which type of fire extinguisher must NOT be used on electrical fires?
- Water extinguisher (Correct answer)
- CO2 extinguisher
- Dry powder extinguisher
- None of the above
Correct answer: Water extinguisher
Water extinguishers conduct electricity and must never be used on live electrical equipment. Using a water extinguisher on an electrical fire risks electrocuting the person operating the extinguisher.
Question 3: What is the meaning of a continuous fire alarm signal on a construction site?
- Evacuate immediately via the designated escape routes to the fire assembly point (Correct answer)
- Investigate the source of the alarm before evacuating
- Report to the site office for instructions
- Continue working until a second alarm is activated
Correct answer: Evacuate immediately via the designated escape routes to the fire assembly point
A continuous fire alarm signal means evacuate immediately. Workers must leave the site using designated escape routes and go directly to the fire assembly point. No work should continue until the all-clear is given by the responsible person.
Question 4: What precautions should be taken when storing flammable liquids on a construction site?
- Store in a dedicated, ventilated, fire-resisting store away from ignition sources and in quantities no more than necessary (Correct answer)
- Store in the site office for convenience
- Store in open containers to allow vapour to dissipate
- Store as many containers as possible to avoid frequent deliveries
Correct answer: Store in a dedicated, ventilated, fire-resisting store away from ignition sources and in quantities no more than necessary
Flammable liquids must be stored in a designated fire-resisting store (or metal cabinet), kept well ventilated to prevent vapour build-up, away from ignition sources, and in the minimum quantity needed. Containers must be kept closed when not in use.
Question 5: What is the fire risk associated with polyurethane foam insulation boards on a construction site?
- They are highly combustible and produce toxic smoke when burning, spreading fire rapidly (Correct answer)
- They are naturally fire resistant and require no precautions
- They only pose a risk when cut
- They present no significant fire risk if kept dry
Correct answer: They are highly combustible and produce toxic smoke when burning, spreading fire rapidly
Polyurethane foam insulation boards are highly combustible and produce large quantities of dense, toxic smoke when burning. They can contribute to rapid fire spread and have been involved in serious construction site fires. Storage and use must be carefully managed.
Question 6: What measures should be implemented to protect a construction site against arson?
- Perimeter fencing, access control, removal of combustible waste, CCTV and security patrols (Correct answer)
- Only installing fire extinguishers
- Relying on neighbouring properties to report suspicious activity
- Painting warning signs on the hoarding
Correct answer: Perimeter fencing, access control, removal of combustible waste, CCTV and security patrols
Arson prevention requires: secure perimeter fencing, controlled access, removal of combustible materials and waste from the site at the end of each day, CCTV surveillance, security lighting and out-of-hours patrols to deter and detect intruders.
NEBOSH CC Fire Prevention in Construction 3
What type of fire is associated with flammable liquids and gases on a construction site?