Fire Safety Flashcards

What are the three elements required for fire to exist (fire triangle)?

Answer: Fuel, oxygen, and ignition source (heat)

Fire requires three elements simultaneously: fuel (any combustible material), oxygen (typically from air — minimum ~16% concentration), and an ignition source (heat, spark, flame, friction, chemical reaction). Removing any one element extinguishes the fire or prevents ignition.

What type of fire extinguisher is used for class B fires (flammable liquids)?

Answer: Foam or CO₂ extinguisher

Class B fires (flammable liquids: petrol, oils, solvents, paints) are extinguished by foam (which smothers and seals the surface) or CO₂ (which displaces oxygen). Water must never be used on flammable liquid fires as it spreads the burning liquid. Dry powder is also effective but leaves significant residue.

What is a 'hot work' fire watch and what are the responsibilities?

Answer: A designated person who monitors the area during and for 30–60 minutes after hot work to detect and extinguish any fires started by sparks or heat

The fire watch person remains at the work area throughout hot work and for a minimum of 30–60 minutes (or longer per fire safety standards) after work stops, monitoring for smouldering or delayed ignition. This is one of the critical controls on a hot work permit. Fires from hot work often start in hidden voids after work has finished.

What is the recommended sequence of actions when discovering a fire?

Answer: Alert (raise the alarm), Contain (close doors), Evacuate (leave and take others), Call emergency services (999/911/112), Attack only if safe and trained to do so

The fire action sequence: 1) Raise the alarm immediately (warn everyone), 2) Alert the fire service (call emergency number), 3) Evacuate all personnel using designated exits, 4) Only attempt to fight the fire if it is small, you are trained, you have the correct extinguisher, and an escape route is available. Life safety is always the priority.

How does automatic sprinkler system work and what is its purpose?

Answer: Heat-sensitive sprinkler heads activate individually when local temperature exceeds their rated threshold, discharging water to suppress the fire — not set off by smoke

Sprinkler heads contain a heat-sensitive element (glass bulb or fusible link) that activates at a preset temperature (typically 57–68°C). Only heads in the fire area activate. Sprinklers suppress or extinguish over 99% of fires before fire service arrival, significantly reducing both fire and water damage compared to uncontrolled fire.

What is the purpose of fire detection systems in buildings?

Answer: To detect fire at the earliest possible stage, trigger alarms to alert occupants, and enable swift evacuation before conditions become untenable

Early fire detection saves lives by maximizing evacuation time before fire gases and heat render escape routes untenable. Detection systems (smoke detectors, heat detectors, flame detectors, multi-sensor detectors) feed into a fire alarm panel that activates alarms, triggers suppression systems, and may directly alert the fire service.