Guide on Fire extinguishers selection
Fire extinguishers are fire protection devices which control or extinguish fire in situations of emergency, thus saving lives and property. These are necessary devices in homes or offices but equally necessary are the usage of right fire extinguishers and thus this resource guides you on fire ratings, types of fire extinguishers, cautions, maintenance & places for purchase. The resource also briefs about the history and accompanying fire fighting tools of fire extinguishers.
Life is precious and uncertain. The way we insure our property and lives, possibilities of a fire at workplace or even home should not be overlooked and be taken care of. Other than the commercial kitchens or cafeteria, possibility of fire at workplace is also high due to high use of electrical wires and systems. A short circuit or a burning cigarette is enough to ignite the complex electrical systems used in offices. Thus, fire extinguishers must be installed in every office.
Fire extinguishers are used to extinguish small fires. For flames out of control or of ceiling height, fire department must be contacted immediately.History & evolution of fire extinguishers
First fire extinguisher in the records of history dates back to 1723. It was patented by Ambrose Godfrey in England. Godfrey was a famous chemist and his extinguisher consisting of a cask of flame smothering liquid was connected with fuses which scattered the liquid on ignition and resulting explosion of gunpowder. After this model, a modern fire extinguisher was invented in 1818 by Captain George William Manby of Britain. The extinguisher had around 13.6 liters of potassium carbonate solution in a copper vessel within compressed air. The well-known soda acid extinguisher came later. It was patented in the year 1866 by Francais Carlier. The idea was that carbon dioxide gas expelled out of reaction between sulphuric acid and sodium bicarbonate pressurized water through nozzle of extinguisher. Cartridges based extinguishers used water and were invented in 1881 by Read & Campbell. The duo also invented 'petrolex' or carbon tetrachloride model. The Pyrene Manufacturing Company of Delaware even filed its patent in 1910 but these were later withdrawn for use in 1950s due to hazard implications of toxic chemicals. In 1924, Walter Kidde Company had invented carbon dioxide fire extinguisher when Bell Telephone wanted an extinguisher suitable for electrical wires and switchboards equipped place. Refined versions of these extinguishers are still widely used. Halon 1301 was made in 1954 by U.S. Army and Dupont but this also was discontinued and is even restricted in many nations due to ill effects on environment.
Before we understand the types of fire extinguishers now available in today's market, it is important to understand the fire ratings or the types of fire. Categorization may vary internationally. Extinguishers used for each category of fire are different.Fire Ratings & Categorization :
These fire ratings are often depicted with pictograms on the fire extinguishers.Types of fire extinguishers :
Carbon Dioxide fire extinguisher- These extinguishers hold carbon dioxide in highly compressed and pressurized form due to which dry ice forms around the nozzle many times. The chemical is stored in liquid form but expelled in gaseous form. These extinguishers are effective on class B & class C fires. These are good for fighting fires involving electrical equipment. They can cause corrosion and leaves no residue which may harm circuitry. They cause minimum damage to electrical devices. They also work well on class B liquid fires. They should not be used on class 'A' fire as they do not displace enough oxygen and may even cause reigniting. Similarly these should not be used on class 'D' fire as the gas may react with flaming metals. These are commonly used in film industry where action-performing burning stuntmen are later extinguished. However, it should be noted that carbon dioxide gas can be dangerous in the way that it can cause frostbite and suffocation on displacement of oxygen. Thus these extinguishers should be used only in open and not confined spaces.
Dry chemical extinguisher- These fire extinguishers are also known as dry extinguishers and are broadly of two types. One contains sodium or potassium bicarbonate & puts on class B and C fires while the other contains ammonium phosphate & puts on class A, B and C fires. These highly effective extinguishers leave residue that discourages fire rekindling. This residue is a non-flammable blanket of foam. However, these extinguishers are messy on use and leave corrosive effects on certain metals.
Dry chemical extinguishing agents- The powder based dry agents used to discourage fire kindling are discussed below:
Wet chemical extinguisher- Meant for commercial kitchens or class K fire, these fire extinguishers release chemical mist to put out the fire.
Water extinguisher- These fire extinguishers use water and compressed gas and are meant only for class A fire. These have a numeric rating on them which signifies the amount of water they hold and the size of fire they can handle.
Water agents-The water based agents used in extinguishers are discussed below.
Halon extinguisher- These are short range (4to6 feet) fire extinguishers which release gas that discourage chemical reactions of fire. Halotron II fire extinguishers are used for class A; B & C fires but have some reservations as well. The chemical used is toxic and thus should be used only in open spaces. The chemical leaves no corrosive effects on materials but depletes Earth's ozone layer and thus has severe environmental hazards. Use of this gas is prohibited in some countries.
Metal/Sand extinguisher- These are specially meant for class D fire. These come in various kinds and use different metals to extinguish fire from flammable materials in laboratories. Some extinguishers use sodium chloride, some powdered copper, graphite & other materials.
Class D fire extinguisher agents-The metal & sand based agents used in these extinguishers are discussed below.Fire-fighting equipment :
These are some equipment which must be kept handy at the time of fire in order to fight better.
Axe- The firefighter's axe is usually bright red colored so that it can be easily identified even in smoke. This is basically required to break through doors and windows at the time of fire. It also allows a firefighter to locate support beams. If an area patted by the axe sounds like a thud, there is a probability that it is a support beam. Now this beam should not be hit as it may cause collapse of building.
Attack hose- These are usually connected with a water source and sprays around 175 gallons per minute in order to extinguish fire. The hose is around 2 inches in diameter.
Fireman's keys- These keys are used to control elevators & lifts at the time of fire and are usually at the fire station or inside the glass box close to extinguishers.
Multi-gas detector- The detector detects multiple gases like carbon monoxide, hydrogen cyanide and determines how much amount of oxygen is present in the area so that a safer area can be looked for.Cautions to be exercised :
There are some cautions which must be exercised in the use of fire extinguishers.
-Use of water extinguisher on oil or electrical fires can cause explosion.
- Use of carbon dioxide extinguisher on chemical fire can cause explosion. Maintenance of fire extinguishers :
Maintenance is very necessary for the fire extinguishers to work effectively when required and ensure safety. Following points must be taken care of in order to keep the extinguishers in working condition.Places for purchase of fire extinguishers :
Fire extinguisher agents and services can be found in almost any part of the country. Fire extinguishers can also be easily availed on rent. Some of the shops are mentioned below for your convenience.
Fire Extinguisher Supplier
Phone: 095 55 408611
Address: Action Fire Services,
Mahipalpur, New Delhi
R K Indl Appliances
Phone: 011 2610 6313
Address: 34-C, Arjun Nagar
34-C, Ch. Harsukh Marg, Arjun Nagar,
Safdarjung Enclave, New Delhi
Minimax fire extinguisher delhi
Phone: 098 11 026960
Address: Madhu Vihar
New Delhi
Falcon Fire Services
Phone: 097 11 857094
Address: 140 A Babulal chawk,
Munirka Vilage, New Delhi
Somya Pyrotek Services
Phone: 011 2552 1363
Address: No. 102-A, 1st Floor,
T. C. Jaina Tower-3, A1 Block,
Janak Puri, New Delhi
A good article on fire extinguishers explaining the basics of different types of them as well as the technicalities of the individual systems.
Safety of men and material is the main concern in an industrial unit, office complexes, shopping Mall and housing complexes especially the multi-storeyed towers. The fire extinguishers are to be kept at convenient places so that in an emergency people can use it. It is often seen that people do not show interest in learning how to use these appliances in time of fires. Due to this, many times, we lose the opportunity of controlling the fire in the initial stage when it is not so fierce.
People should cooperate in firefighting drills, attend them and try to learn the basics of these firefighting appliances which are designed and made very easy to be handled and used by even a layman. Men and women both should be trained in the basics of fire fighting in housing towers where a lot of confusion is created during fires as the awareness level is very low.
Another important aspect is the timely refilling of the fire extinguishers. Sometimes due to lethargy, the people are not bothered to refill the fire extinguishers in time and the earlier material in the appliances is expired and will be of no use.
We must give high consideration to safety in our life and should adopt it as a way of life if we want an accident free society.