How to Use a Fire Extinguisher

If a fire breaks out, you need to act fast to prevent the blaze from spreading. Whether you’re in a business, school or home, having a fire extinguisher nearby can help. But if you don’t know how to use it, you could put yourself and others in even greater danger. That’s why it’s important to understand how a fire extinguisher works and when to use it.

You should only use a fire extinguisher on small, confined, and controllable fires. It’s also essential to ensure that your evacuation path is clear of obstructions and that the fire isn’t spreading before trying to fight it. During an emergency, remember the acronym PASS to recall the correct steps to take when using an extinguisher: Pull the pin – this unlocks the operating lever; Aim low – point the extinguisher hose/nozzle at the base of the fire; Squeeze the lever – this discharges the extinguishing agent and can be used to control the fire.

Water extinguishers cool the burning fire by soaking materials with water and reducing their oxygen content. They are easy to operate and the least hazardous of all hand-held fire extinguishers, but they can’t be used on fires involving fats and oils (Class F), burning metals (Class D) or electrical equipment (Class C).

Dry chemical extinguishers are the most common variety and are typically found in offices, shops, schools, hospitals and warehouses. They contain a powdery extinguishing agent, such as monoammonium phosphate (like yellow talcum powder), and nitrogen gas for propellant. These fire extinguishers are effective on class A, B and C fires, but they can be messy to use.

Carbon Dioxide (CO2) extinguishers contain pressurized CO2 gas and can be used on class B fires as well as electrical fires — making them ideal for computer rooms or other high-tech spaces. They work by suffocating the fire rather than by removing heat or melting materials, and they have a relatively short range of about 3 to 8 feet.

Halon extinguishers were manufactured until 1994 and were useful on classes B:C fires. They contain gaseous agents that inhibit the chemical reaction of a fire and have a long atmospheric lifetime, but they are also toxic to humans.

Before using your fire extinguisher, make sure it’s in good condition with the pin still securely locked in place and that the nozzle is free from dust, oil and rust. Look for a pressure gauge to check that the unit’s pressure is at its recommended level. Also, verify that it is not blocked by anything and that it’s mounted within the NFPA height limit and the Americans with Disabilities Act height limit for placement. It’s also important to know when an extinguisher needs to be recharged or replaced. Generally, it must be serviced and recharged after every 30 days of use or annually. It must also be tagged by the fire department to indicate its annual inspection, service and recharge date. The fire department will place a sticker on the extinguisher that indicates this.