Fire Extinguisher Knowledge Base

Fire extinguishers are among the most effective and affordable means for protecting your property from fire damage. Many fires begin small, at a single location, and can often easily be suppressed using the appropriate type of fire extinguisher. This proactive response can save people and property from harm, or contain the fire until emergency response professionals arrive.

But there are many different types of fire extinguishers and Protegis Fire & Safety is here to provide you with information about each of them.

Water Extinguishers: Water is one of the most commonly used extinguishing agents for type A fires. You can recognize a water extinguisher by its large silver container. They are filled about two-thirds of the way with ordinary water, then pressurized with air. In some cases, detergents are added to the water to produce a foam. They stand about two to three feet tall and weigh approximately 25 pounds when full.

Water extinguishers are designed for Class A (wood, paper, cloth, and certain plastics) fires only.

CO2 – Carbon Dioxide Extinguishers: This type of extinguisher is filled with Carbon Dioxide (CO2), a non-flammable gas under extreme pressure. These extinguishers put out fires by displacing oxygen, or taking away the oxygen element of the fire triangle. Because of its high pressure, when you use this extinguisher pieces of dry ice shoot from the horn, which also has a cooling effect on the fire.

Multi-purpose – Dry Chemical Extinguishers: Dry chemical extinguishers put out fires by coating the fuel with a thin layer of fire retardant powder, separating the fuel from the oxygen. The powder also works to interrupt the chemical reaction, which makes these extinguishers extremely effective. They contain an extinguishing agent and use a compressed, non-flammable gas as a propellant.

Dry Chemical extinguishers will have a label indicating they may be used on class A, B, and/or C fires.

Class K – Wet Chemical Extinguishers for Kitchen Fires: Due to the higher heating rates of vegetable oils in commercial cooking appliances NFPA 10, Portable Fire Extinguishers, now includes a Class K rating for kitchen fires extinguishers which are now required to be installed in all applicable restaurant kitchens. Once a fire starts in a deep fryer, it cannot always be extinguished by traditional range hoods or Class B extinguishers.

These extinguishers will be found in commercial cooking operations such as restaurants, cafeterias, and other locations where food would be served.

Regular testing and inspection is the only way to be certain. Our technicians can perform a physical and visual inspection of the extinguisher and update the necessary documentation at the required regular intervals. Let our technicians evaluate your facility, including the type of fire hazards you may face, and recommend the right fire extinguisher solution for your operations.

Annual Fire Extinguisher Service – What Actually Happens?

Today, we are going to take a closer look at each step involved in an annual fire extinguisher inspection. 

Annual Fire Extinguisher Inspection Steps:

1. Look for damage to extinguisher
2. Investigate the gauge
3. Make sure the pull pin works
4. Reseal the pull pin
5. Look for issues with the hose
6. Check for powder in the head
7. Make sure threads aren’t stripped
8. Check for the date (6 year and 12 year)
9. Invert the extinguisher
10. Remove last year’s inspection tag
11. One vast visual inspection
12. Clean with a rag!

Step 1: Look for Damage to Extinguisher

This first step to certify an extinguisher for the next year is to make sure there is no damage to the exterior. You want to thoroughly check it and make sure the instructions and serial number are on it.

Step 2: Investigate the Gauge

You want to make sure the gauge is in the green. If the indicator is off to the left, that means a recharge is needed. Factors that could lead to a recharge are:

• The extinguisher has been leaking
• It could be a factory defect

If the indicator is off to the right, that states the extinguisher has been overcharged.

Step 3: Make Sure the Pull Pin Works

Take off the tamper seal and make sure the pull pin has easy and clear access ‘back and forth’ through the place holder. Sometimes the extinguisher falls, or people knock them off, which can bend the pin.

Step 4: Reseal the Pull Pin

Once you are sure the pull pin is straight, insert the pin back into its proper place and reseal it.

Step 5: Look for Issues with the Hose

Hoses that are outside are exposed to bugs which can clog the hose. Insects like mud wasps can create nests inside of the hose.

The easiest way to clean a fire extinguisher hose is with a metal coat hanger.

To make sure the hose is clear, start by blowing air through it. Then, with your finger, see if you can feel the air come through on the opposite side you blew into.

Step 6: Check for Powder in the Head

Before you insert the hose back on, make sure there is no powder left inside of the head. If powder is visible, it could mean the extinguisher has been discharged before.

Step 7: Make Sure Threads Aren’t Stripped

Make sure the hose easily goes back into place. If not, the threads may be stripped and needing replacement.

Step 8: Check for the Date (6 Year and 12 Year)

This shows when a fire protection company will have to do extensive maintenance on the extinguisher. A 6 and 12 year inspection will need to be done.

Two easy ways to tell that a 6-year inspection has been done:

• There is a collar on the extinguisher
• There is a label, initialed by a service tech, saying inspection complete.

The 12-year test will be done in 2022 (for an extinguisher made in 2010) and this is when the hydrostatic test will need to be performed.

Step 9: Invert the Extinguisher

To avoid the powder from caking (as the result of sitting too long) you need to invert the extinguisher and strike it with a mallet or tap it on the ground.

Powder that has caked will not come out!

Step 10: Remove Last Year’s Inspection Tag

Insert your new tag, make sure it is punched for the correct date/year, and wrap the tag around the gauge.

Step 11: One Last Visual Inspection

Take one last look to make sure everything is in operating order and that there is no corrosion.

Step 12: Clean with a Rag!

Very, very important! Clean the fire extinguisher with a rag to make sure the extinguisher is clearly visible, and all the labels are visible.


The main idea is to get you aware of everything that goes into an annual fire extinguisher inspection. You can see why every step is important to keep the extinguisher in working order.

Three common steps routinely missed are:

• Making sure the pin is completely straight
• Removing the hose and check for clearance
• Make sure the head is clear, indicating no prior use

We hope you never have to use a fire extinguisher, but if you do, it would be devastating if it doesn’t work properly. Make sure you hire a reliable fire safety partner who follows all the necessary steps.