L5: Fire Hazards

• FIRE

  ● These start when a flammable and/or a combustible material with an adequate supply of oxygen or another oxidizer is subjected to enough heat.

  ● Chemically, this is called combustion wherein substances react rapidly with oxygen to create heat.

  ● If not properly managed, it can cause terrible destruction.

  ● In the Philippines, fire accidents are common due to our different weather conditions like El Niño and heat waves, causing electrical transformers or lines to be altered and cause fire accidents.
• FIRE TRIANGLE

  ● Also known as the Triangle of Combustion.

  ● The fire triangle diagram contains the key elements that start and prolong a fire: oxygen, heat, fuel

  ● According to the fire safety advice center, there is another element that may contribute or aggravate the fire, and that is the chemical chain reactions that take place.

  ○ Basically becoming a fire “tetrahedron”.

  ○ Take away any one of the elements, and the fire expires.
• COMBUSTION PROCESS

  ● Fire is a chemical reaction in which energy in the form of heat is produced.

  ● Fire begins with ignition, most commonly ignited by a match, wherein the friction creates sufficient heat to ignite the phosphorus on the match to combust and make a flame.

  ● Heat is necessary to begin the combustion process. Once started, fire produces its own heat.
• COMBUSTION PROCESS

  ● Wildland fires originate from such sources of heat as:

  ○ Matches

  ○ Cigarette embers

  ○ Cigars or pipes

  ○ Campfires

  ○ Trash fires

  ○ Railroad locomotive exhaust sparks

  ○ Sparks from brake shoes

  ○ Hot-box on railroad cars

  ○ Lightning

  ○ Spontaneous combustion

  ○ Hot ashes

  ○ Arson
• 6 TYPES OF FIRE

  1. Class A Fire (Combustible Materials)
  2. Class B Fire (Flammable Liquids)
  3. Class C Fire (Flammable Gases)
  4. Class D Fire (Burning Materials)
  5. Class E Fire (Electricity)
  6. Class F Fire (Cooking Oils & Fats)
• Class A Fire (Combustible Materials)

  ● Fires involving solids.

  ● Caused by a naked flame or items of high temperatures coming into contact with combustible, carbonaceous materials.

  ■ Could be paper and cardboard, common in offices and manufacturing.

  ■ Could be furniture, or fixtures and fittings.

  ■ Could be the structure of a building.
• Class B Fire (Flammable Liquids)

  ● Fires involving liquids.

  ● Occurs when flammable liquids, such as petrol and spirits, are exposed to a source of ignition. These types of liquid are flammable by design and

  extremely volatile, if not stored safely.

  ■ Cleaning fluids, solvents, fuels, inks, adhesives and paints.

  ■ Areas with flammable or explosive fluids, liquids or chemicals present.

  ○ Restaurant

  ○ Bars

  ○ Laboratories

  ○ Hospitals

  ○ Gas Stations
• Class C Fire (Flammable Gases)

  ● Fires involving gases.

  ● Flammable gases must be stored correctly in sealed containers and only operated by a competent person.

  ■ Manufacturing and industrial warehouses

  ■ Chemical plants

  ■ LPG

  ■ Propane and Butane
• Class D Fire (Burning Metals)

  ● Fires involving the chemical reaction of metals.

  ● Occurs when combustible metals, such as magnesium, lithium and sodium, ignite and are more prevalent in laboratories, warehouses and metal fabricators.

  ● Not often thought of as combustible, some types can be, like mentioned earlier, sodium.

  ● Metals are good conductors of heat, helping spread one of the elements of fire, heat, to spread around, thereby also increasing fire spread.

  ● All metals soften and melt at high temperature, which is a big problem

  when metal joists and columns of structures are present in a fire.
• Class E Fire (Electricity)

  ● Not strictly a class of fire because electricity is more of a source of

  ignition than fuel.

  ● Fires that are a possibility to all premises that use electricity.

  ● Fires in live electrical equipment are an additional hazard, and using water or any other conductors would be fatal.
• Class F Fire (Cooking Oils & Fats)

  ● Deep fat frying and spillages of flammable oils near heat sources like in

  kitchens result in this fire.

  ● Extremely risky in restaurants and kitchens.

  ● Fires from cooking oils and fats can be made significantly worse by using a

  liquid-based agent to extinguish it.
• Types of fire extinguisher

  1. Water
  2. Dry Powder
  3. Foam
  4. CO2
  5. Wet Chemical
• Water

  ● Use on:

  i. Wood

  ii. Paper

  iii. Textiles

  ● DO NOT USE on:

  i. Flammable liquid

  ii. Live electrical equipment
• Dry Powder

  ● Use on:

  i. Wood

  ii. Paper

  iii. Textiles

  iv. Flammable liquids

  v. Gaseous fires

  vi. Live electrical equipment
• Foam

  ● Use on:

  i. Wood

  ii. Paper

  iii. Textiles

  iv. Flammable liquids

  ● DO NOT USE on:

  i. Live electrical equipment
• CO2

  ● Use on:

  i. Flammable liquids

  ii. Live electrical equipment

  ● DO NOT USE on:

  i. Wood

  ii. Paper

  iii. Textiles

  iv. Flammable metal fires

  v. Confined spaces
• Wet Chemical

  ● Use on:

  i. Cooking oil ires

  ii. Wood

  iii. Paper

  iv. Textiles
• 4 STAGES OF FIRE

  1. Incipient
  2. Growth
  3. Fully developed
  4. Decay
• Incipient

  ● First stage of fire.

  ● Combination of fire triangle elements and continuous chemical reaction

  result in a fire.

  ● Also known as ignition.

  ● Fire is in the smallest phase, providing a golden opportunity to take action and suppress the fire.
• Growth

  ● Fire not controlled at the ignition stage will convert into the second stage

  (growth stage).

  ● During this stage:

  ■ Fire keeps consuming combustible material as fuel

  ■ Presence of oxygen multiply its growth

  ● The shortest and most dangerous stage, as sometimes within a fraction of

  a second, fire from just ignition turns into a huge fire.

  ● This stage is mostly responsible for the trapping of persons and firefighters.
• Fully developed

  ● After the Growth stage, fire is considered fully developed when:

  ■ All combustible materials have caught fire

  ■ Growth stage has reached maximum potential

  ● Temperature in this stage is the highest (maximum) amongst all

  stages, and is the dangerous stage for fire-fighters or personnels trapped in

  the affected site– as leaving the site is very difficult.
• Decay

  ● Last and longest stage of a fire.

  ● In this stage, the elements that cause the fire are put to their final point.

  ■ All fuel present at site has already burnt.

  ■ Presence of Oxygen has decreased.

  ● Special observation and care should be taken in this stage too since fire is

  stopped/slowed down by reduction of fuel or insufficient oxygen.
• Before a fire – Prevention Measures

  i. Have adequate suitable smoke alarms

  ii. Keep emergency numbers on easy access

  iii. Mke fire escape plan and emergency exit diagrams

  iv. Practice fire exit plan regularly

  v. Consider an insurance company for financial assistance and risk management plans

  vi. Use authorized electrical appliances and machines only

  vii. Keep fire extinguishers and blankets near emergency exit

  viii. Store matches and lighters in secure places

  ix. Don’t overload electrical outlets

  x. Use surge protected multi-outlet power strips and extension cords only

  xi. Get annual maintenance checks for oil, gas and wood heating units

  xii. Install electrical safety switch or circuit
• During a fire – In case of fire

  i. Treat fire as an emergency and exit the building immediately

  ii. Immediately inform nearest fire station

  iii. During evacuation, feel doors for heat before opening

  iv. To escape dense smoke in air, fall and crawl to reduce inhalation exposure

  v. Remain in room if unable to exit

  ■ Keep the door closed and await assistance or notify rescue personnel of location.

  vi. Keep track of colleagues/neighbors and notify personnel if missing

  vii. Avoid collecting personal items before moving out

  viii. Do not use elevators during emergency, walk or run through the stairs
• After a fire – Safety Rules

  i. Once in safe place:

  ■ Call/report about fire outbreak

  ■ Inform about safety/assistance required

  ii. Await further instructions from fire emergency department and stay safe in refuge area

  iii. Don’t panic, nor should you hinder the evacuation and/or fire exhaustion

  process