If you’ve never seen a carbon dioxide (CO2) extinguisher before, then you’ll realize that not all fire extinguishers are going to look alike or function the same. CO2 extinguishers certainly look and operate differently from standard multipurpose ABC extinguishers you’ve likely seen your whole life. But businesses that work with potentially flammable liquids or electrical equipment may need a CO2 extinguisher and need to learn how to use and inspect it properly.
Take a look at these specialized extinguishers, what sizes they come in and how to inspect one. They fall under Class B and C for dealing specifically with liquid and electrical fires.
How a CO2 Extinguisher Works
The body of these extinguishers is generally smaller and slightly wider than the taller and slender body of the all-purpose extinguishers. These also come with a hard horn on the front that can spew the carbon dioxide gas contained inside. There’s no pressure gauge as you’d find on the all-purpose models.
By using the nozzle, the non-flammable CO2 can easily be sprayed instantly on flammable liquids and burning electrical equipment. The CO2 is very cold and essentially removes the oxygen of the fire when sprayed on contact. You’ll see how cold it is when you occasionally see dry ice emanate from the horn.
Keep in mind these won’t work well on Class A fires because the chemistry of such a fire is different. With oxygen being more challenging to remove from a Class A fire, it could reignite.
The Different Sizes
You can buy anywhere from a five to 20-pound size CO2 extinguisher, depending on how much you work with flammable equipment. A 20-pound CO2 extinguisher will be considerably heavier to handle, and that might also make it more challenging to hang up on a wall as you can with other extinguishers. They can weigh up to as much as 100 pounds.
Inspecting a CO2 Extinguisher for Safety
If you’ve had a CO2 extinguisher sitting around for a while, you should give it a quick inspection to make sure that it’s still operable when you need it. First, check to see if the plastic seal pin is still in place. A broken seal can mean that it’s ineffective and should be taken to your local fire department for inspection.
You can also weigh your extinguisher to see if it still has carbon dioxide gas inside. The weight should be labeled somewhere on the body, and if it weighs considerably less than what it says, you should replace the extinguisher.
Also check for tampering to the pin and nozzle. Any signs of tampering means it likely won’t operate correctly during an emergency.
References:
http://www.sc.edu/ehs/modules/Fire/05_co2.htm