Fire Prevention and Fire Fighting

• Basic Occupational Safety and Health module 1: Fire Prevention and Fire Fighting is presented.

Course Learning Outcome

• The principles and concepts of Health and Safety and life critical are important.
• Needed is a demonstration of fire prevention methods and information pertaining to firefighting.

Topic Learning Outcomes

• Legislation and identification of government agencies that control OSH regulations are to be discussed.
• A description of the fire tetrahedron elements enhances understanding of fire extinguishment.

Fire Tetrahedron

• It is commonly referred to as the fire tetrahedron.
• Fire cannot exist without all elements in place and in the right proportions.
• A flammable liquid will ignite only if the fuel and oxygen proportions are correct.
• Some fuel-oxygen mixes may require a catalyst.
• A catalyst helps reactants to combust but is not directly involved in chemical reaction during combustion.

Requirements for Combustion

• Fire is heat and light produced from rapid combination of oxygen with other materials.
• A combustible substance must be present for fire to exist.
• Temperature must be high enough for combustion.
• Sufficient oxygen must be present to sustain rapid combustion.
• Fuel is needed for combustion
• Sufficient quantity of oxygen must be available.
• Heat must be applied to start combustion - generates enough heat to sustain the reaction.
• Capable oxidation rate must be capable of sustaining a flaming fire.

Fire Extinguishment

• Removing any element of the fire tetrahedron will extinguish the fire.
• Extinguishment methods include:
  • Turning off the gas supply (fuel source removal).
  • Covering the flame completely with CO2.
  • Applying water (removes heat faster than produced).
  • Using a retardant chemical like Halon to the flame.

Fire/Life Safety - Fire Protection

• Class A Fires involve ordinary combustibles like wood and paper.
• Class B Fires involve flammable and combustible liquids and gases.
• Class C Fires involve energized electrical equipment.
• Class D Fires involve combustible metals.
• Class K Fires involve cooking oils and fats.

Portable Fire Extinguishers: General Requirements

• Extinguishers must be mounted, located, and identified, allowing accessibility.
• Only approved extinguishers should be used.
• Extinguishers should be kept with full charge and function.

Exits

• At least two exits are required on every floor and basement to clear the work area in 5 minutes.
• Additional exits are needed when travel distance from any occupied space in high-hazard occupancy is more than 23 meters.
  • Travel distance must not exceed 31 meters for industrial, 61 meters for business, and 30.5 meters for commercial establishments in moderate/low-hazard occupancy.

Stairways

• Stairs, platforms, stairways, and landings should be comprised of incomustible materials in buildings over three stories.
• In buildings over three stories of non-fire resistant construction with roof slopes less than 1 in 4, at least one stairway must extend through the roof.
• Stairways for fire exits must lead to the street or through fire-resistant passages of equal width to all exits.
• All approaches to fire exits must remain clear and properly marked.

Fire Doors

• Stairway enclosures, fire exits, and partitions require self-closing fire doors that open easily from either side towards the line of travel, except for the last floor.
• Doors to stairways should open on landings with path equal to door width.
• Doors swinging on both sides, vertical-sliding doors, rolling shutters, and revolving doors can't be used as exits.

Fire-Fighting Facilities: Water Supply

• If there is no public water supply system connection, a private water supply reservoir for fire fighting systems for 8 hours must be present.
• The supply system with tanks or reservoirs and pumps must be located to prevent impedance.

Fire-Fighting Facilities: Hydrants and Hose

• Hydrants must match the type/size used by the local fire department.
• They must be located/protected from mechanical damage.
• Hose couplings/nipples should match the local public fire department type/size.

Selection of Extinguishers

• Extinguishers must be chose for the specific class or classes or hazards
  • Class A fires (wood, cloth, paper, rubber etc.) = foam, dry chemicals and water
  • Class B (flammable liquids, graese, greases) = Carbon dioxide (CO2), dry chemical, foam
  • Class C (energized electrical equipment) = carbon dioxide, dry chemicals, multi-purpose dry chemicals
  • Class D (combustible metals) = types approved for combustable metal hazards only
  • Class K for cooking oils/fat fires should use a “wet chemical” agent, potassium acetate which saponifies fats into a soapy foam suppressing oxygen and preventing re-ignition by cooling.

Alarm Systems and Fire Drills: Sounding Devices

• Buildings two stories or more in height must be equipped with a fire alarm system.
• Alarm quality and pitch must be distinct and audible to all persons in the building.
• Hand-operated fire alarm boxes are needed on every floor.
• The meters to reach a station must not exceed 30 meters for industrial and commercial establishments (moderate/low hazard).
• With same hazard occupancy, distance between alarm boxes should not exceed 61 meters for business establishments.
• Fire-alarm stations need to be conspicuous, accessible, and in the path of escape from fire.
• Every place of employment depending on potential fire magnitude organize fire brigade to deal with emergencies.

Fire-fighting Drills

• Fire brigade members need to be physically qualified and trained in firefighting.
• They need training in hose use, ventilation, salvage, rescue, first aid and related activities.
• Employees in buildings with changing occupants need training to direct others to safety.
• Occupants of each area of a building should assemble outside in a place away from firefighting activity.
• Fire exit drills in buildings with two or more establishments needs to be planned as one establishment
• The fire-exit drill committee organization and composition needs to be in accordance the requirements of the local fire department
• The Fire Code and the Local Department determine when a fire brigade should be organized.