TOPIC USE OF PORTABLE FIRE EXTINGUISHERS IN FIRE

TOPIC: USE OF PORTABLE FIRE EXTINGUISHERS IN FIRE FIGHTING. PRESENTOR: - ISAIAH K. KIBUGE BIO MEDICAL ENGINEER KAPSABET COUTY REFFERRAL HOSPITAL NANDI COUNTY.

OBJECTIVES: After this presentation you should have refreshed your mind on: • basic chemistry of fire • identify 5 common classes of fires • select the proper type of extinguisher • apply the “P. A. S. S. method to operate a portable extinguisher.

INTRODUCTION • What is fire? • Is the Rapid oxidization of materials in the exothermic chemical process of combustion realizing Heat, Light and various reaction products. • Positive aspect: - It is an important process that affect ecological system across the globe. E. g. stimulating growth, used by human for generating heat for various purposes (cooking, steam generation) • Negative Aspect: -Atmospheric pollution, Hazard to life and property. v. FIRE IS A GOOD SERVANT AND BAD MASTER

Chemistry of Fire. • Three components Oxygen Heat Fuel • All the three must be present in sufficient proportions for a fire to start

Extinction of Fire • Combustion will continue as long as oxygen, ignition and temperature are present. • Removal of any one of them leads to collapse of the triangle of combustion. • To suppress fire just remove any one of the 3 components

Methods Of Extinguishing Fire Heat Oxygen Cooling (water) Smothering Fuel Starvation (physical removal) Fire prevention at its most basic is keeping fuel away from heat sources

Starvation is achieved by removal of the fuel burning in the fire. Sometimes combustible material can be removed by shutting off gas valves or fuel flows. SMOTHERING By excluding the oxygen in the surrounding atmosphere the fire will be extinguished. COOLING The most commonly used fire fighting medium is water. Water absorbs heat from the fire and cools the fuel to a temperature where it no longer produces flammable vapors.

Classes of Fire • Class A – Fire involving ordinary combustible materials e. g. Wood, paper, textiles , grass • Class B - Fire involving flammable liquids e. g. oil, grease, petrol, spirits, kerosene and paints • Class C- Fires involving flammable gases e. g. L. P. G, propane, butane, acetylene, methane, etc.

Classes of fire continued • Class D – Fire involving Flammable and inflammable metals • Class E – Fires involving electrical equipment e. g. computers, photocopiers, electricity mains etc

Portable Fire Extinguishers. i). Water type-in pressurised cylinders and Hose reel. ( class Awood, paper, trash) ii}). Carbon Dioxide- (class E-Electrical equipment) iii). Dry Chemical Powder (ABC)- Multi-Purpose iv). Air foam (AFFF)- class B-flammable liquids v). Fire Blanket vi). Sand

Distribution and location of portable fire extinguishers Maximum distance of travel- 30 m Along the line of exit Near but not too near the risk area Near doors in or out according to occupancy In multi storey buildings, uniform throughout the building at stair landings, corners or corridors In groups forming fire points in shallow recesses where possible On wall brackets- about 1 m from the floor level o o away from extreme temperatures(4 C – 43 C)

Advantages of Portable Fire Extinguishers • Can be CARRIED to a fire • Jet goes far and can be controlled • Some shield the operator from danger

Limitations of Portable Fire Extinguishers LIMITED IN: • Capacity - 1 to 9 kg. of extinguishing agent • Range - Typically 1 m to 5 m • Duration - Discharge their contents in only 5 to 30 seconds! • They are costly • Their operation requires training • They require regular maintenance

Common Features of portable fire extinguishers Locking pin Carrying handle / operating lever Pressure gauge Label : – – Type (Water, C 02, Dry Chemical) Classification (A, B, C) Capacity Rating Instructions Discharge nozzle or horn

Extinguishers cont. Most fire extinguishers will have a pictograph label showing which types of fire the extinguisher is designed to fight. For example, a simple water extinguisher might have a label like this… …which means it should only be used on Class A fires.

i). Water type Fire Extinguishers • Large red fire extinguishers that stand about 60 cm tall and weigh about 9 kg when full. • It can be either pressurized or cartridge type • Used for fighting class A fires • Its cooling, soaking, absorption and emulsifying qualities make it the most commonly used extinguisher

Water cont. Water extinguishes fire by taking away the “heat” element of the Fire Triangle. • Water Extinguishers are designed for Class A fires only: Wood, paper, cloth. Using water on a flammable liquid fire could cause the fire to spread. Using water on an electrical fire increases the risk of electrocution. If you have no choice but to use the extinguisher on an electrical fire, make sure the electrical equipment is un-plugged or de-energized

Water cont. §Also found in hose reels, suitable for multi storey buildings. §Their water supply is continuous and ensures that the jet goes far. §W/co 2 will be found in office buildings, particularly in public hallways, as well as in Residence Halls. • They may also be found in computer laboratories. • It is important to remember, however, that computer equipment must be disconnected from its electrical source before using a water extinguisher on it.

ii). Carbon Dioxide Fire Extinguishers • CO 2’s are designed for Class B , C and E • (Flammable Liquids, Gases and Electrical Sources) fires only! • Modern CO 2 cylinders are red. They range in size from 1 kg to 20 kg or larger. On larger sizes, the horn will be at the end of a long, flexible hose.

Carbon Dioxide cont. Physical properties of CO 2 Clean , dry, non-toxic but suffocating, non corrosive, poor conductor of electricity and has good expansion ratio and penetration. The pressure in a CO 2 extinguisher is so great, bits of dry ice may shoot out of the horn!

Carbon Dioxide cont. • Carbon dioxide is a non-flammable gas that takes away the oxygen element of the fire triangle. • CO 2 is very cold as it comes out of the extinguisher, so it cools the fuel as well. • CO 2 may be ineffective in extinguishing a Class A fire because it may not be able to displace enough oxygen to successfully put the fire out. • Class A materials may also smolder and re-ignite. • CO 2 s will frequently be found in laboratories, mechanical rooms, kitchens, and flammable liquid storage areas.

iii). Dry Chemical (ABC) Fire Extinguishers Modern ABC extinguishers are red. They range in size from 1 kg to 9 kg. They put out fire by coating the fuel with a thin layer of dust. This separates the fuel from the oxygen in the air. • The powder also works to interrupt the chemical reaction of fire.

Dry Chemical cont. ABC” fire extinguishers are filled with a fine yellow/white powder. The greatest portion of this powder is composed of mono-ammonium phosphate, magnesium stereate, sodium bicarbonate etc. . The extinguishers are pressurized with nitrogen or have a gas cartridge. • Physical properties • Non toxic, Non abrasive, non hygroscopic, poor conductor of electricity

Dry Chemical cont. It is extremely important to identify which types of dry chemical extinguishers are located in your area! • An “ABC” extinguisher will have a label like this, indicating it may be used on Class A, B and C fires. • You don’t want to mistakenly use a “BC” extinguisher on a Class A fire thinking that it was an “ABC” extinguisher.

Dry Chemical cont. Dry chemical extinguishers with powder . designed for Class B and C fires (“BC” extinguishers) may be located in places such as commercial kitchens and areas with flammable liquids • You will find ABC’s in public hallways of new buildings, in laboratories, offices, chemical storage areas, mechanical rooms, vehicles, etc.

Air Foam (AFFF) • Suited for class ‘B’ fires, may also be used for class A • Available in 9 litre cylinder to 50 kg trolley type • 99% of its contents is water, 1% air foam solution • Works by eliminating oxygen from the fire • Provides a smothering and cooling effect on the burning liquid • It forms a cohesive and adhesive blanket that effectively puts off the fire and shields the operator from radiated heat

Air Foam (AFFF) Available in three types with either cartridge or stored pressure propellants TRICLASS with AFFF additives enable it to fight class A fires by cooling and B by sealing liquid fires JETSPRAY Foam has no harmful effect on the ozone layer and is a replacement for Halon 1211 which has been withdrawn Both JETSPRAY and TRICLASS extinguishers have a unique nozzle that ensures operator safety if in accidental contact with live electrical equipment ASPIRATED Foam with a smothering effect which deprives fire of oxygen; very effective on flammable liquid fires

Foam cont. . It is suitable for small liquid spill fires or small oil tank fires where it is possible for the foam to blanket over the surface of the liquid involved. Foam extinguishers may not extinguish fire on a vertical plane. Where foam is required for hydrocarbon fires, light water is recommended-preferably by spray applicator. As alcohol is miscible with water, when on fire it will break down ordinary foam and should be considered a special risk.

Others • Sand • Water buckets • Fire blankets- for small spills of oil and frying pan fires

Fire Blankets made of asbestos or fibre glass material. It comes in different sizes from 1200 mmx 1200 mm to 1800 mmx 1800 mm. they are suitable for small kitchen /frying pan fires and as rescue equipment. Care should be taken to avoid the user from burns arising from improper usage

Operation of extinguishers (Remember PASS) • P = Pull the pin. • A = Aim the nozzle at the base of the fire. • S = Squeeze the handle. • S = Sweep from side to side. • The PASS Method will work on all types of extinguishers.

P. A. S. S. Method Pull the pin • This will allow you to squeeze the handle in order to discharge the extinguisher

P. A. S. S. Method Aim at the base of the fire • Aiming at the middle will do no good. • The agent will pass through the flames.

P. A. S. S. Method Squeeze the handle • This will release the pressurized extinguishing agent

P. A. S. S. Method Sweep side to side • Spray the extinguisher at the base of the fire. • Cover the entire area that is on fire. • Continue until fire is extinguished. • Keep an eye on the area for re-ignition

Use a portable extinguisher ONLY if the: • Building is being evacuated (Fire alarm has been actuated) • Fire Brigade has been called (Dial 999!) • Fire is NOT spreading (small and contained) • EXIT IS CLEAR (fight fire with your back to an exit ) • Proper extinguisher is at hand, and. . . – – You have been trained and know how to use it! You use “Buddy System” - have someone back you up! • Get assistance BEFORE trying to fight a fire!

Make sure your extinguisher can be used in an emergency. • The extinguisher should be mounted on the wall. • The area in front of the extinguisher shall be clear of any obstructions • The pressure gauge should be in the green zone • The inspection tag should show that the extinguisher has been inspected within the last 1 year.

Care and Maintenance of Extinguishers At least once a month (more often in severe environments) you should inspect your extinguisher. Ensure that: The extinguisher is not blocked by equipment, coats or other objects that could interfere with access in an emergency. The pressure is at the recommended level. On extinguishers equipped with a gauge (such as that shown above) that means the needle should be in the green zone - not too high and not too low. The nozzle or other parts are not obstructed. The pin and tamper seal (if it has one) are intact. There are no dents, leaks, rust, chemical deposits and other signs of abuse/wear.

Mtce… Wipe off any corrosive chemicals, oil etc. that may have landed on the extinguisher. Some manufacturers recommend shaking your dry chemical extinguishers once a month to prevent the powder from settling/packing. Fire extinguishers should be pressure tested (a process called hydrostatic testing) after a number of years to ensure that the cylinder is safe to use. Consult your owner's manual, extinguisher label or the manufacturer to see when yours may need such testing.

Thank You!!!! Fire Prevention Is Your Responsibility!!!