The fire extinguisher has been used. Whenever a fire extinguisher has been used, it needs to be recharged immediately so that it is ready to go in case of another fire. Even if it was only lightly used, the extinguisher pressure may decrease over time. The next person the need to use the extinguisher arises, it may be unable to perform correctly and effectively due to reduced pressure or insufficient agent to extinguish the fire.
According to the NFPA 10 codes, fire extinguishers need to be inspected internally every six and twelve years from the noted manufacture date, to ensure it is properly working and ready to work if needed.
Fire Extinguishers also need to be recharged in the event of damage. Examples include dropping the fire extinguisher, the evidence of rust on the canister, or some other form of damage that could affect its functionality.
Not all fire extinguishers are built the same, and each fire extinguisher classification is designed to extinguish a different type of fire. As such, a specific type of extinguisher agent may be effective against certain types of fires, and yet ineffective, and maybe potentially harmful, if used on a type of fire it is not designed to extinguish.
Listed below are the various types of fire extinguishers and their unique characteristics that make them best suited for combating a certain type or types of fire.
Regular dry chemical fire extinguishers are filled with sodium bicarbonate and are used in combating Class B and C fires. The sodium bicarbonate agent is non-corrosive, non-toxic and easy to clean after it has been deployed. Dry chemical fire extinguishers, both regular and multi-purpose, are commonly found in schools, homes, hospitals and offices.
The multi-purpose dry chemical is filled with ammonium phosphate and is used in fighting Class A, B & C fires. Unlike the regular dry chemical fire extinguishers, the multi-purpose dry chemical ammonium phosphate is corrosive. This requires that its residue be thoroughly scrubbed and cleaned from surfaces to prevent damage.
Carbon dioxide fire extinguishers contain a liquid form of C02. When the fire extinguisher is used, the C02 is deployed in the form of a gas, which is effective in fighting Class B and C fires. Carbon dioxide fire extinguishers are environmentally friendly because they do not leave any harmful residue when used.
Carbon dioxide fire extinguishers are commonly found in computer rooms, laboratories and other areas where sensitive electrical equipment is found. This is because the C02 does not affect the computer or other electronic components whereas other extinguishing agents could.
Water fire extinguishers are effective in fighting class A fires but should never be used to fighting Class “B,” “C” or “D” class fires. The reason for this is because Class B fires involve flammable liquids such as oil, Class D fires involve metals such as magnesium, titanium and other metals. A good example to demonstrate this is oil from a ship that is burning on top of an ocean or lake. If you were to use a water fire extinguisher to fight these types of fires, the force of the extinguisher being discharged could spread the fire, worsening the extent and scope of damage. Class C fires are electrical fires and because water is conductive, the user is at risk of being shocked by the electrical current. Electrical fires are common in computer rooms, locations of faulty wiring, in motors or appliances. Being limited in their use, water fire extinguishers are usually less expensive than other types of fire extinguishers.
Wet chemical fire extinguishers contain potassium acetate as the extinguishing agent and are designed for Class K fires. Wet chemical fire extinguishers are ideal for commercial kitchens and restaurants where the fuel source of the fire may be oil, gas or grease. When the fire extinguisher is discharged, the potassium acetate is disbursed in a mist form which will not cause the grease fire to splash onto surrounding surfaces and cause the fire to spread. Additionally, wet chemical fire extinguishers can extinguish class A fires.