Fire Hazards and Safety

Fire Hazards

• Fire is a chemical reaction between a flammable or combustible material and oxygen, resulting in rapid oxidation, light, and heat.
• Flammable materials have a flashpoint below 1000°F (380°C).
• Combustible materials have a flashpoint at or higher than 1000°F (380°C).
• Examples of flammable liquids include isopropyl alcohol, propane, acetone, MEK, paint thinner, gasoline, kerosene, and aerosol cans.
• Examples of combustible liquids include oil, greases, lubricants, and oil-based paints.
• Fire needs three elements to occur: oxygen, fuel, and heat.
• Fire cannot start if one of these elements is missing.
• Sources of heat include cutting and welding, spontaneous ignition, chemical reactions, the sun, electricity, smoking, and friction.
• Common causes of kitchen fires include unattended stoves, electrical cords, curtains, tea towels, and oven cloths near the stove.
• Faulty wiring, such as improperly installed safety switches or fuses, can cause fires.
• Smoking in bed can cause fires as embers smolder unnoticed and burst into flames later.
• Lightning strikes can ignite objects.
• Poor light fittings, with close-fitting lampshades and light bases, can cause heat buildup that can lead to fires.
• Flammable liquids such as petrol, kerosene, and methylated spirits should be stored away from heat to prevent fire hazards.
• Candles left unattended create a risk, and flammable fabrics near candles pose a fire risk.
• Children are often not well-oriented about fire hazards, and matches, lighters, and candles should be kept away from them.
• Fire extinguishments work by removing one of the three elements: cooling, smothering, or starvation (removing of fuel).
• Different classes of fires have different extinguishing materials — common materials are water, wet cloths/blankets, sand/soil, and dry chemicals.
• Electrical fires (Class C) require specialized extinguishing techniques.
• Combustible metal fires (Class D) are very different and require specialists and specific extinguishing methods.

Fire Stages and Growth

• Ignition Phase:
  • The first stage where heat, oxygen, and fuel combine to initiate a chemical reaction.
  • Types include piloted ignition (external heat) and auto-ignition.
• Growth Phase:
  • The fire expands, oxygen is depleted, and temperature increases.
  • Flashover may occur and is highly dangerous..
  • During this phase, the fire is influenced by environmental factors such as fuel load, fuel type, orientation of fuel relative to the fire, ceiling height, and potential for thermal layering.
• Fully Developed Phase:
  • All fuel has ignited and is burning.
  • The phase is hottest, critically dependent on the oxygen supply.
  • Flammable gases may spread in the area.
  • High levels of carbon monoxide may be present.
• Decay Phase:
  • The fire starts to diminish as fuel and/or oxygen is consumed, potentially leading to a smoldering phase.
  • It is usually the longest stage.
  • Backdrafts could potentially occur.

Fire Response and Drills

• Fire Drill Phases: Alarm, Response, Evacuation, Assembly, Head Count, and Evaluation.
• Rescue: Rescue people from immediate smoke and/or fire areas.
• Alarm: Activate the nearest fire alarm station and contact the appropriate authorities with details of the emergency.
• Contain: Contain smoke or fire by closing windows and doors.
• Extinguish: Extinguish the fire with an appropriate extinguisher if you are comfortable with it.
• Relocate: Relocate to a safe area, away from the main entrance, using stairwells, avoiding elevators.
• Secure: Ensure important documents, money, and heirlooms are safe.

Fire Extinguishers

• Different fire extinguishers are best suited for different types of fires (e.g. water, dry powder, foam, CO2, wet chemical).
• Correct usage is very important – follow instructions.
• There are specific parts of a fire extinguisher (pressure gauge, hose, cylinder, nozzle).
• There is a protocol to correctly use a fire extinguisher (e.g. twist the lock, pull the pin, aim, squeeze, sweep).

This quiz covers the essential concepts surrounding fire hazards, including the chemical reaction that causes fire, the differences between flammable and combustible materials, and the necessary elements for fire to occur. Additionally, it explores common causes of fires and safety measures to prevent them. Test your knowledge about fire safety and its critical components.