Understanding Fire Extinguisher Classes

There is no single fire extinguisher that can is effective on all kinds of fires. Using the wrong extinguisher type might turn out disastrous. For instance, if you use a water based extinguisher on an electric fire, it is possible to spread the fire further and you will expose yourself to electrocution. Thus, it is vital to understand the type of fires add which extinguisher to use for the specific fire type.

Understanding the types of fires
Class A fires
These are fires fueled by combustible organic matter such as paper, cloth, wood, rubber, and some plastics. Such fires are common in restaurant settings which utilize wood as a source of fuels. They are also known to occur in camp sites and other outdoor venues.

Class B fires
These are the fires that occur as a result of flammable or combustible liquids such as tar, petroleum greases, solvents, oil based paints, alcohol, lacquers as well as flammable gases. They are known to happen in gas stations, chemistry labs, manufacturing industries for flammable liquids and in bars.

Class C fires
These fires involve energized electric equipment. Such as overloaded electrical cables and short-circuiting machinery. They are common in server rooms, breaker rooms and any other place where high volume electrical equipment is.

Class D fires
These are fueled by combustible metals such as titanium and magnesium. They are a danger in chemistry labs, manufacturing companies dealing with such metals and any other place where combustible metals are either stored or used.

Class K fires
Class K fires are as a result of cooking media such as animal or vegetable oils and fats. For this reason, they are a danger in home kitchens and restaurants.

Classes of fire extinguishers explained
Water fire extinguisher
The commonest agent for dealing with fires is water. However, it is most suitable for class A fires and cannot be utilized for class B or C fires considering that it is conductive. Usually, such extinguishers are filled with two thirds of water and a third of pressurized air. In some instances, detergents are included in the mix to produce foam. They are about three feet high and weigh about 25 pounds when full. You are likely to find water extinguishers in offices, stockrooms and schools.

Carbon dioxide fire extinguishers
Carbon dioxide cannot support fire. Thus, it is used to remove oxygen so as to contain the fire. Being a natural substance, it is ECO friendly and doesn’t leave any residues behind. Thus, you won’t have to do a cleanup after the fire incidence. The carbon dioxide gas is usually stored as a compressed liquid in the fire extinguisher. As it is let out of the container, it expands and cools the surrounding air. The cooling usually causes ice formation around the area where the gas is expelled from the container. Considering that the fire might re-ignite, continue applying the agent after the fire seems to be off. Such extinguishers are suitable in contamination sensitive areas like food storage rooms, computer labs and processing plants.

Dry chemical fire extinguishers
Multi-purpose dry chemicals
It is used for class A, B and C fires. The chemical used here is mono ammonium phosphate. The chemical is non-conductive and might be slightly corrosive if the area has moisture. If you want to evade the corrosion, it is advisable to scrub the area thoroughly after the fire is out. Dry chemical fire extinguishers are utilized in general offices, schools, homes, hospitals, among other places.

Regular dry chemical
It can be used on class B and C fires. The chemical used here is sodium bicarbonate. It is non-corrosive, non-toxic and non-conductive. After using it, it can be easily cleaned through flushing with water, sweeping or vacuuming. Such extinguishers are suitable for garages, kitchens and laboratories.

Purple K dry chemical
It utilizes a dry chemical known as potassium bicarbonate. It is non-corrosive and non-conductive. Cleanup after putting off a fire requires flushing using water, sweeping or vacuuming.

Foam fire extinguishers
It is suitable for class A and B. Foam acts by floating on the fire thus prevent reflashes and consequently putting off fires. To clean the area, it should be washed away and allowed to evaporate. Such extinguishers are suitable for workshops, homes, garages and vehicles.

For class A, B and C fires. It contains liquid which is ozone friendly that doesn’t leave any residue. They are appropriate for computer labs, theaters and telecommunication.

Cartridge operated fire extinguishers
They are ideal in hazard areas where fast response is needed. Examples include forestry, mining operations and utilities.

Kitchen fire extinguishers
They are usually common in commercial kitchen settings suitable for curbing fires that involve combustible cooking media such as fats and oils.

Wheeled fire extinguishers
These are appropriate where quick mobility is needed. Applications are such as airports, construction sites, petroleum plants, equipment depots and large storage facilities.

Automatic/ manual system fire extinguishers
These extinguishers are used for flammable or chemical storage places, film storage areas, electrical rooms and other unoccupied places. They usually use nitrogen expellant gas or carbon dioxide gas.