Fire Safety and Procedures

Key Fire Safety Concepts

• The Fire Triangle illustrates the three elements essential for combustion to occur and sustain itself. Removing any one element will extinguish the fire:

  • Source of Ignition (Heat): Provides the energy needed to start the fire. This can include high temperatures, electrical short circuits, friction, open flames, hot surfaces, static electricity, and exothermic chemical reactions.

  • Source of Fuel (Burnable material): Any substance that can burn. Fuels can exist in solid (wood, paper, textiles, plastics), liquid (petrol, oil, solvents, paints), or gaseous (natural gas, propane, acetylene) states. The physical state and surface area greatly influence how quickly a fuel ignites and burns.

  • Source of Oxygen: Typically present in the air around us (approximately $21\%$ oxygen). Oxygen acts as an oxidizer, reacting with the fuel in a rapid chemical process that produces heat and light. A minimum concentration of oxygen, generally around $16\%$ or less, is required for most materials to burn.

Fire Safety Risk Assessment

• A Fire Safety Risk Assessment is a systematic process of identifying fire hazards and persons at risk, evaluating the risk, and implementing fire safety measures. This is crucial for:

  • Pinpointing potential fire sources and combustible materials.

  • Assessing the likelihood and consequences of a fire.

  • Ensuring appropriate fire safety measures, such as prevention, detection, warning, and escape routes, are in place and effective.

  • Maintaining up-to-date findings and regularly reviewing the assessment (e.g., annually, or after significant changes) to minimize injury, loss of life, and property damage in the event of a fire.

Risks from Heat-Producing Equipment

• Hot Work specifically refers to operations that generate heat, sparks, or flames, posing a significant fire risk. This includes potentially hazardous activities such as:

  • Welding (arc, gas)

  • Flame cutting or oxy-acetylene cutting

  • Soldering

  • Grinding (producing sparks)

  • Brazing

• Sparks and heat generated from hot work can travel considerable distances and ignite nearby combustible materials, leading to serious fires or explosions. Strict controls, such as hot work permits, fire watches, and clear-ups of flammable materials, are essential.

Fire Prevention Measures

• Effective fire prevention involves a combination of identifying risks and implementing proactive strategies:

  • Identify fire risks: Systematically recognize potential sources of ignition, types and quantities of burnable substances, and people who might be especially at risk (e.g., those with mobility issues, young children, or the elderly).

  • Separate ignition sources from flammable materials: Store flammable liquids and gases in designated, well-ventilated areas, away from electrical equipment, heaters, and open flames. Implement strict controls (e.g., 'no smoking' policies).

  • Maintain good housekeeping: Regularly remove waste, store materials neatly, and ensure escape routes are clear and unobstructed. Clutter provides additional fuel for a fire.

  • Install and maintain smoke and fire alarms: Ensure appropriate types of alarms (e.g., optical for smouldering fires, ionization for fast-flaming fires) are installed, regularly tested, and properly maintained in accordance with manufacturer guidelines and local regulations.

  • Provide fire-fighting equipment and training: Ensure suitable fire extinguishers (appropriate for the classes of fire likely to occur), fire blankets, and hose reels are available and regularly serviced. Staff should receive comprehensive training on their correct use and emergency procedures.

  • Regularly update fire risk assessments: Review and revise the assessment whenever there are changes to the premises, processes, or staffing, or at least annually.

Emergency Procedures for Fire Discovery

1. Raise the alarm immediately: As soon as a fire is discovered, activate the nearest fire alarm call point. Shout "Fire!" to alert others in the immediate vicinity.

2. Attempt to fight the fire if trained and safe: Only attempt to extinguish a small fire if you have been trained in using appropriate fire-fighting equipment, if the fire is contained, and if an escape route is readily available behind you. Never put yourself or others at risk.

3. Evacuate if fire-fighting fails or is not attempted: If the fire cannot be controlled, the smoke is too dense, or you are not trained, evacuate the building immediately using the nearest safe exit route.

4. Ensure no one is left behind and close doors on exit: As you evacuate, check designated areas for occupants if safe to do so. Close all doors behind you to help contain the fire and smoke, slowing its spread.

5. Proceed to the designated assembly point: Move directly to the pre-determined safe assembly point and await further instructions from emergency services or fire wardens. Do not re-enter the building until declared safe by authorities.

Classes of Fires

• Fires are classified based on the type of material burning, which dictates the most effective extinguishing agent. Using the wrong type of extinguisher can be dangerous or ineffective. The most commonly recognized classification systems (e.g., European EN2, British Standard BS EN 3) include:

  • Class A Fires: Involve ordinary combustible materials such as wood, paper, textiles, rubber, and plastics. These fires typically leave ash.

    • Recommended Agents: Water, foam, certain dry powder extinguishers.

  • Class B Fires: Involve flammable liquids like petrol, oils, paints, spirits, and flammable gases (though gases are sometimes separately categorized). These materials form flammable vapours.

    • Recommended Agents: Foam, carbon dioxide ($CO_2$), dry powder.

  • Class C Fires: Involve flammable gases such as propane, butane, natural gas, and acetylene. (Note: Under some older or regional classifications, this class might refer to electrical fires, but EN2/BS EN 3 classify gases as Class C).

    • Recommended Agents: Dry powder. The fuel supply should be shut off if safe to do so.

  • Class D Fires: Involve combustible metals like magnesium, titanium, potassium, and sodium, often found in industrial settings.

    • Recommended Agents: Specialized dry powder extinguishers (often labeled 'D type' or 'metal fire extinguishers'), as water or other common agents can react violently with burning metals.

  • Class F Fires: Involve cooking oils and fats (e.g., vegetable oil, animal fat) typically found in kitchens. These fires burn at very high temperatures.

    • Recommended Agents: Wet chemical extinguishers are specifically designed for Class F fires, creating a saponification effect that cools and smothers the fire.

  • Electrical Fires (Not officially recognized as a class in BS EN 3): While not a separate class of fuel, fires involving electrical equipment (e.g., overloaded circuits, faulty appliances) are often referred to as 'electrical fires.' The electricity must be isolated before attempting to extinguish the fire. Once the electrical power is removed, the fire effectively becomes a Class A, B, or C fire depending on the burning material.

    • Recommended Agents (for energized electrical equipment): Carbon dioxide ($CO_2$), dry powder. Water-based extinguishers should NOT be used on live electrical equipment due to the risk of electrocution.