Portable Fire Extinguisher Guidelines

January 28, 2019 Roy Williams

Portable fire extinguishers are typically a key element of any business’s fire safety plan.  Understanding the fundamental principles of firefighting, the different types of fires that might occur within a business or building, the proper use of portable fire extinguishers and the different types of portable fire extinguishers and the fires they are effective against are critical to ensuring your fire safety plan is adequate.

Fundamental principles of firefighting

There are four elements that must be present for a fire to exist. There must be oxygen to sustain combustion, heat to raise the material to its ignition temperature, fuel to support the combustion and a chemical reaction between the other three elements. Remove any one of the four elements to extinguish the fire. The concept of Fire Protection is based upon keeping these four elements separate.

A key but very basic element of all fire safety training should always be “Only Fight A Fire If”:

  • The fire is small and contained
  • You are safe from toxic smoke
  • You have a means of escape
  • Your instincts tell you it’s OK

The different types of fires that might occur within a business or building

Not all fires are the same. Per NFPA 10, a fire event may be classified into one or more of the following fire classes.

Class A – Class A fires are fires in ordinary combustibles such as wood, paper, cloth, rubber, and many plastics

Class B – Class B fires are fires in flammable liquids such as gasoline, petroleum greases, tars, oils, oil-based paints, solvents, alcohols. Class B fires also include flammable gases such as propane and butane. Class B fires do not include fires involving cooking oils and grease.

Class C – Class C fires are fires involving energized electrical equipment such as computers, servers, motors, transformers, and appliances. Remove the power and the Class C fire becomes one of the other classes of fire.

Class D – Class D fires are fires in combustible metals such as magnesium, titanium, zirconium, sodium, lithium, and potassium.

Class K – Class K fires are fires in cooking oils and greases such as animal and vegetable fats.

The proper use of portable fire extinguishers

It is important to know the locations and the types of extinguishers in your workplace prior to actually using one. Portable fire extinguishers can be heavy, so it’s a good idea to practice picking up and holding a portable fire extinguisher to get an idea of the weight and feel. Take time to read the operating instructions and warnings found on the portable fire extinguisher label. Not all portable fire extinguishers look alike. Practice releasing the discharge hose or horn and aiming it at the base of an imagined fire. Do not pull the pin or squeeze the lever. This will break the portable fire extinguisher seal and cause it to lose pressure. When it is time to use the extinguisher on a fire, just remember PASS!

  • Pull the pin.
  • Aim the nozzle or hose at the base of the fire from the recommended safe distance.
  • Squeeze the operating lever to discharge the fire extinguishing agent.
  • Starting at the recommended distance, Sweep the nozzle or hose from side to side until the fire is out. Move forward or around the fire area as the fire diminishes. Watch the area in case of re-ignition.

The different types of portable fire extinguishers and the fires they are effective against

When selecting portable fire extinguishers for your business, be sure to first have a solid understanding of what your fire threats are and then make sure you purchase the right portable fire extinguishers that will provide you with the the fire protection you need.

Water and Foam – Water and Foam portable fire extinguishers extinguish the fire by taking away the heat element of the fire triangle. Foam agents also separate the oxygen element from the other elements.

Water portable fire extinguishers are for Class A fires only – they should not be used on Class B or C fires. The discharge stream could spread the flammable liquid in a Class B fire or could create a shock hazard on a Class C fire.

Carbon Dioxide – Carbon Dioxide portable fire extinguishers extinguish fire by taking away the oxygen element of the fire triangle and also be removing the heat with a very cold discharge.

Carbon dioxide portable fire extinguishers can be used on Class B & C fires. They are usually ineffective on Class A fires.

Dry Chemical – Dry Chemical portable fire extinguishers extinguish the fire primarily by interrupting the chemical reaction of the fire triangle. Today’s most widely used type of portable fire extinguishers is the multipurpose dry chemical portable fire extinguishers that is effective on Class A, B, and C fires. This agent also works by creating a barrier between the oxygen element and the fuel element on Class A fires.

Ordinary dry chemical portable fire extinguishers is for Class B & C fires only. It is important to use the correct portable fire extinguishers for the type of fuel! Using the incorrect agent can allow the fire to reignite after apparently being extinguished successfully.

Wet Chemical – Wet Chemical is a new agent that extinguishes the fire by removing the heat of the fire triangle and prevents re-ignition by creating a barrier between the oxygen and fuel elements.

Wet chemical or Class K portable fire extinguishers were developed for modern, high efficiency deep fat fryers in commercial cooking operations. Some may also be used on Class A fires in commercial kitchens.

Clean Agent – Halogenated or Clean Agent portable fire extinguishers include the halon agents as well as the newer and less ozone depleting halocarbon agents. They extinguish the fire by interrupting the chemical reaction and/or removing heat from the fire triangle.

Clean agent portable fire extinguishers are effective on Class A, B and C fires. Smaller sized handheld extinguishers are not large enough to obtain a 1A rating and may carry only a Class B and C rating.

Dry Powder – Dry Powder portable fire extinguishers are similar to dry chemical except that they extinguish the fire by separating the fuel from the oxygen element or by removing the heat element of the fire triangle.

However, dry powder portable fire extinguishers are for Class D or combustible metal fires, only. They are ineffective on all other classes of fires.

Water Mist – Water Mist portable fire extinguishers are a recent development that extinguish the fire by taking away the heat element of the fire triangle. They are an alternative to the clean agent portable fire extinguishers where contamination is a concern.

Water mist portable fire extinguishers are primarily for Class A fires, although they are safe for use on Class C fires as well.

Cartridge Operated Dry Chemical – Cartridge Operated Dry Chemical portable fire extinguishers extinguish the fire primarily by interrupting the chemical reaction of the fire triangle.

Like the stored pressure dry chemical extinguishers, the multipurpose dry chemical is effective on Class A, B, and C fires. This agent also works by creating a barrier between the oxygen element and the fuel element on Class A fires.

Ordinary dry chemical portable fire extinguishers are for Class B & C fires only. It is important to use the correct portable fire extinguishers for the type of fuel! Using the incorrect agent can allow the fire to re-ignite after apparently being extinguished successfully.

The Jay L Harman Fire Equipment team understands your firefighting needs and is ready to help

The team at Jay L Harman Fire Equipment understands that you will have many burning questions on your mind when it comes to choosing the right fire extinguishers and fire suppression systems for your business.

Jay L Harman Fire Equipment is your go-to distributor for OVAL low-profile fire extinguishers in West Texas and New Mexico.

Jay L Harman is the best and one of the biggest firefighting equipment suppliers and service providers in the region, specializing in fire suppression systems, fire extinguishers, emergency lighting, fire fighting protective gear, fire hoses and more. Serving El Paso TX, Las Cruces NM and the surrounding areas, we pride ourselves on buying local and hiring local whenever possible.

Contact Jay L. Harman Fire Equipment in El Paso TX at 915-533-7021 or Las Cruces NM at 575-523-8880.

Since 1925, we have protected businesses throughout the area from the harms and hazards of fires. Every Jay L Harman technician is licensed and regulated by the Texas Department of Insurance State Fire Marshal’s Office.  Each of these technicians continually receives the most up-to-date factory training and certifications by our manufacturers. Contact Jay L Harman Fire Equipment today. Let our friendly and knowledgeable staff tell you more about our fire suppression systems and help you find the ideal fire suppression system for your needs. Learn more about our full offering of fire extinguisher trainingfirefighting servicesfirefighting productsrequest a quote, ask a question or request additional information.