Electrical apparatus Fire extinguishers with a Class C rating are appropriate for "live" electrical equipment fires. Because of their nonconductive qualities, both monoammonium phosphate and sodium bicarbonate are widely employed to combat this sort of fire. The presence of electricity should not prevent you from using a fire extinguisher, but you should also avoid putting the pin into the discharge unit while trying to put out the fire with a conductive fluid.
Fluids and gasses Electrical equipment Fires are best extinguished by using a stream of water through a nozzle attached to your fire extinguisher. The water flows outward from the nozzle in all directions, putting out the fire quickly and effectively without leaving any residue. You should never use a pressurized gas such as CO2 or halon 1301 to put out an electrical fire, because the gas will continue to burn even after the source of heat is removed.
Tools and instruments Fires involving wood, paper, and cloth can be difficult to extinguish without some type of fluid. Most hydraulic fluids are effective at soaking up the burning material until the fire is no longer a threat. Some types of oil may cause more problems than they solve since they contain ingredients that provide fuel for the fire when they dry out. Silicone and other non-hydraulic oils should never be used on fires involving flammable materials.
Class C: a fire caused by electrified electrical equipment, such as a power transmission line short circuit. Many homes and businesses may utilize general-purpose or kitchen extinguishers, but other situations, like as labs or warehouses, may require more specialized extinguishers. Class C fires are dangerous because they can cause smoke damage or even carbon monoxide poisoning if not extinguished quickly.
Class C extinguishers are available at home improvement stores and some hardware stores for $10-$20. They hold about 1 gallon of water and are effective against small combustible materials such as paper and cloth.
Class D: a fire resulting from an explosion or combustion with heat and flame. This type of fire is usually caused by an ignition source such as burning material, clothing, or flesh. Fire departments often respond to class D fires because they can be difficult to contain using only water. These fires require special equipment to extinguish because they cannot be put out with a water hose alone. A professional extinguisher operator is needed to put out class D fires.
Class K: a fire that results when hydraulic fluids, lubricants, or other liquids used in machinery break down or leak. These fires are very dangerous because the flames can spread through any building where the damaged machinery was located. Class K fires need to be put out immediately because they can grow large if not taken care of quickly.
An ABC-rated extinguisher is appropriate for use on fires involving common combustibles, flammable liquids, and powered electrical equipment. It may also be used to put out heavy smoke produced by forest fires or industrial accidents.
These extinguishers are rated by the amount of water they can deliver into a 2-foot-diameter cylinder. They are labeled A, B, C, D, E, and G. An "A" model can deliver up to 3 gallons of water per minute for sustained use. A "B" model can deliver 1 to 3 gallons of water per minute for shorter periods. A "C" model can deliver up to 2 gallons of water per minute for shorter periods. A "D" model can deliver 1 gallon of water per minute for shorter periods. An "E" model can deliver 0.5 gallon of water per minute for shorter periods. A "G" model has a manual discharge valve that can be pressed to release the pressure inside the tank without spraying water.
To determine which type of extinguisher you need, measure the diameter of the room where the fire will be located with your hand near the center. If the room is smaller than 30 inches in diameter, then you should have at least one ABC-rated extinguisher on hand at all times.
Class A fire extinguishers are efficient against flames involving paper, wood, fabrics, and polymers. Because of its propensity to smother flames in these sorts of materials, monoammonium phosphate is the principal chemical utilized to battle these fires. The acidity of water can also be used to combat flames in material that does not put out naturally when sprayed with plain water; for example, acids can be used to remove paint from metal surfaces.
The main advantage of using a class A extinguisher is that the risk of damage or destruction to non-combustible objects is reduced because other types of fire extinguishers aren't as effective at putting out flames under those conditions. The secondary advantage is that class A extinguishers use less water than some other types of fire extinguishers; this can be beneficial if you need to conserve resources such as time or energy.
Class A extinguishers contain about 5 gallons of water at 60 degrees Fahrenheit. They should only be used on fires where the temperature cannot be lowered significantly below 100 degrees F otherwise the fire may not be extinguished. Fires that involve electrical wiring should never be fought with a class A extinguisher because it will only cause more damage by exposing live wires to air which increases the risk of them being shorted out.
Class B fire extinguishers are suitable for destroying most small fires such as those caused by smoking materials or spilled gasoline.
Carbon dioxide fire extinguishers are appropriate for use in areas where electrical equipment (Class E) are at risk, as well as fires involving flammable liquids (Class B). They can be used on any electrical appliance or material that may conduct electricity if the connection between the two objects is broken. This includes but is not limited to: appliances with plug-ins (such as lamps), appliances with built-in battery packs (such as cell phones), and materials used in building wiring (such as cable boxes).
Halon gas extinguishers are recommended for use on large commercial equipment (Class D), such as data centers and power plants. These extinguishers can also be used to put out small fires on upholstered furniture or carpet. Note that these extinguishers require regular maintenance to remain effective.
Systems using CO2 or halon gas can also be protected by a fire barrier method. In this case, an extension cord with two plugs is used - one for connecting to a CO2 or halon gas extinguisher, and the other for connecting to the equipment being protected. If the extenstion cord gets too hot to touch, then it needs to be replaced.