Fire & Explosion

What is the 'fire triangle'?

• AThe three elements required for fire: fuel, oxygen and ignition source (heat)✓
• BTypes of fire extinguishers
• CFire safety zones
• DFire alarm components

Answer: Fire requires three elements: a fuel source, oxygen and an ignition source (heat). Remove any one to prevent or extinguish fire.

What is the 'fire tetrahedron'?

• AAn extension of the fire triangle adding a fourth element: chemical chain reaction✓
• BA building containing fire safety equipment
• CTypes of fire
• DFire prevention methods

Answer: The tetrahedron adds a chemical chain reaction to fuel, oxygen and heat; some fires require all four elements.

What is 'DSEAR'?

• ADangerous Substances and Explosive Atmospheres Regulations✓
• BDesign Safety and Emergency Response
• CDust Safety Equipment Assessment
• DDesign Standards for Emergency Alarms

Answer: DSEAR requires employers to manage risks from explosive atmospheres and implement safety measures.

What is an 'explosive atmosphere'?

• AA mixture of air and flammable vapours, gases or dusts that could ignite if exposed to ignition source✓
• BAny room with fire hazards
• CA confined space
• DStressful working conditions

Answer: An explosive atmosphere is a concentration of flammable materials and air that could detonate or burn rapidly.

Where can explosive atmospheres occur?

• AIn fuel storage, chemical processing, grain storage, painting/coating and firefighting operations✓
• BOnly in chemical factories
• COnly during emergencies
• DRandomly anywhere

Answer: Explosive atmospheres occur in various workplaces: fuel storage, solvent use, grain/flour handling, spray painting and quarrying.

What is 'flash point' of a liquid?

• AThe lowest temperature at which vapours from a liquid can ignite✓
• BThe boiling point
• CThe freezing point
• DThe evaporation rate

Answer: Flash point indicates the flammability hazard of a liquid; lower flash point means greater fire hazard.

What is the 'Lower Explosive Limit' (LEL)?

• AThe lowest concentration of a flammable gas/vapour in air that can ignite✓
• BThe highest concentration
• CThe safe concentration for work
• DThe legal limit

Answer: LEL is the minimum concentration of flammable vapour/gas in air that can cause an explosion if ignited.

What does 'fire risk assessment' involve?

• AIdentifying fire hazards, fire risks, who is at risk, and planning fire safety controls✓
• BOnly checking fire extinguishers
• COnly testing alarms
• DOnly documenting exits

Answer: Fire risk assessment identifies hazards, evaluates risks, determines who is at risk and plans control measures.

Who is responsible for fire safety in a workplace?

• AThe employer and those in control of the premises; H&S staff provide support✓
• BOnly the H&S manager
• COnly the fire brigade
• DOnly senior management

Answer: Employers and those in control have primary responsibility for fire safety; this is a line management responsibility.

What is a 'means of escape' in fire safety?

• AA route that provides a continuous safe passage from any point to a place of safety outside✓
• BEmergency windows only
• CEvacuation routes inside the building
• DRefuge areas only

Answer: A means of escape must provide a safe, continuous route from any location to safety outside the building.

What is the purpose of a fire detection and alarm system?

• ATo detect fire and alert occupants immediately to allow safe evacuation✓
• BTo extinguish fires
• CTo prevent fire starting
• DTo call the fire brigade automatically

Answer: Detection systems identify fire early; alarms alert occupants to evacuate before dangerous smoke/heat develop.

What should a fire evacuation procedure include?

• AAssembly point, roll call procedures, evacuation routes, designated persons, training and drills✓
• BOnly the assembly point
• COnly emergency contact numbers
• DOnly exit routes

Answer: Procedures must include routes, assembly points, roles of staff, responsible persons and regular drills.