The Fire Extinguisher Thread


Senior Staff
This is one piece of gear that ALL of us should carry no matter where we go. The types and sizes of extinguishers vary by brand and intended use, we can discuss them here.

Using the wrong type of extinguisher can be ineffective and dangerous. Water is suitable for class A (paper, wood, grass etc.) fires, but not for class B, C and D or K such as burning liquids, petroleum, electrical fires, or even reactive metal fires. In these cases the use of the wrong type of extinguisher can result failure to suppress, spreading the flames, or the hazard made far worse.

Type ABC fire extinguishers are filled with a mono ammonium phosphate. I do not recommend ABC extinguishers for vehicle fires.

Mono ammonium phosphate is highly corrosive to wiring and other electrical components, and when used to extinguish an engine compartment fire you may succeed in extinguishing a minor fire with an ABC extinguisher, but you will almost certainly destroy any capability to rebuild or repair anything electrical inside the engine bay.

Type BC fire extinguishers contain non-corrosive sodium or potassium bicarbonate. I recommend you equip your vehicle with a BC type extinguisher for potential engine compartment fires.

KIDDE makes an inexpensive 2 and 5 pound BC extinguisher that can be found in the big box hardware or boating stores for around $25-$40 and are good for about 6 years.

That said, technology is evolving in this genre. Currently my go to fire extinguisher in the Jeep is the Element E100. Not cheap, but with a 100 second discharge it has almost 10x longer life than an old school 5lb fire extinguisher.

Weighing less than 1 lb, it also never expires or requires recharging. Can safely be stored in damp and wet environments, provided that the yellow cap covering the tip stays present allowing the tip to remain dry. It has also been tested to work effectively in temperatures from -140F to +320F so extreme weather use is possible. Comes in two sizes (E50 and E100) and fits in a glove box or almost anywhere.
  • Clean and Eco-friendly: No mess, non-toxic, non-corrosive, environmentally friendly
  • Zero thrust discharge: Will not spread oil & liquid fires
  • Safe and maintenance free: No moving parts or compressed gas to ever service
  • Made in Italy (not China!)
  • Fights all major fire classes: A,B,C, & K (cooking oils and grease) fires
  • Compact and easy to use: 13" tall, 1.6" diameter & 0.79 lbs weight

In North America, Underwriters Laboratories (UL) is responsible for the certification of fire extinguishers. UL does their testing to a standard that contains a form (physical shape) component followed by a performance component. Because Element's form does not fit inside of UL's guidelines of what a traditional fire extinguisher looks like (i.e. compressed gas cylinder with a hose and measurement gauge) it is immediately passed over for performance testing. At present UL is being campaigned to update its standards to recognize the different form offered by Element and allow it an opportunity to be tested and certified.

Until the standards are updated Element cannot be used to substitute extinguishers in regulated environments that require a UL (or UL endorsed) certification. Element can however be freely used as an supplement to the extinguishers used where regulation exists.
Here's how it works:

Element is a manual, portable aerosol fire extinguisher. It uses a Potassium powder jet that employs the vaporization of the powder in the environment followed by the condensation of its extinguishing substance. Element works by interrupting a fire’s chain of reaction (the “auto-catalyst” of the fire).

Element is composed of stable, solid minerals; it does not contain gas and is not pressurized. The aerosol-like jet is only produced when the charger is struck with its base. The produced aerosol jet is free of thrust and is essentially an inert salt that emits gas already present in the atmosphere.
This process allows Element to extinguish all types of fires through saturation, while its slow bio-degradation in the environment, furthers the prevention of subsequent fires.

The extinguishing process involves two different reactions: one is physical and the other, chemical.

The physical reaction relates to potassium’s tendency to oxidize rapidly in air. When in contact with air, alkaline salts consume great quantities of oxygen, thus depriving fires of oxygen.

The chemical reaction is created through the stable link between potassium particles and the fire’s combustion particles.

Through the two reactions, a quick oxidation process takes place, immediately transforming the jet from a solid state into a gaseous state freeing the potassium particles. These atoms are able to intercept and interrupt any other free particles produced by the fire’s natural chain reaction combustion process.

Potassium has strong inhibitor qualities due to its weak ionization energies. The extinguishing agent being used is composed of Potassium Nitrate, organic oxidizer, and plasticizer resin.

When Potassium Nitrate (KNO3) discharges from the extinguisher it vaporizes in the environment followed by the condensation of its extinguishing substance. When it reacts (inside the body of the extinguisher) it breaks down and the aerosol that is formed is made up primarily of free radicals of Potassium K+, of Nitrogen N (an inert gas), and water vapor.

The aerosol that comes out of the unit reacts with the fire. Potassium radicals (K+) capture the Oxygen of the combustion thereby extinguishing it.
At the end of the extinguishing process the following is discharged to the atmosphere:

As a solid: particles of Potassium (that have reacted with the Oxygen of the fire) having a size between 3-4 microns. These particles are invisible at sight and heavier than air. They disperse in the atmosphere and tend to deposit on the ground in no appreciable amounts.

As a gas: As Nitrogen; an inert gas already present in the air we breathe at more or less 78%.

As water vapor (and lastly) extremely minimal toxic by-products that are a result of the combustion process.
The chemical reaction is best illustrated by the following image:

fire stages.png
Stage 1: Fire is initiated by the flame chain carriers: O, H and OH
Stage 2: The Element aerosol introduces Potassium radicals (K) into the flame chain reaction
Stage 3: K radicals attach themselves to O, H and OH and remove them from the flame reaction without depleting surrounding Oxygen.


Great article, great info, and wonderful refresher of the various types of fires and to carry the right type of extinguisher for vehicle travel.

These Element Extinguishers have been getting a lot of traction in the outdoor and adventure fields and I'm further encouraged to get one after reading your piece on them.

As for fires and types of extinguishers, we're just going over this very thing at my kid's place this week with her and the grandkid. Scares me to death to think of them having a fire in this old 1860's Maine house with no one around who knows what to do. Using older, almost out-of-date fire extinguishers for real-life practice, replacing them with new ones I just bought.

When I had a studio the local FD would inspect all commercial buildings and tag the extinguishers, making everyone get new extinguishers every year, even if the existing ones still read 'in the green.' I ended up with a bunch of still-good extinguishers, though it instilled in me to be more vigilant and practiced in their use than I had been in the past.



Founding Member
I bought one of these a while back.

When I first read about them I didn't see a real need for it. Bought one to try it anyway, decided I liked having it after using it. It may not be for everyone, just another option. I do a lot of work chasing/pitting for desert racing/rock crawling. I like the idea that I can throw it on top of an engine fire if needed. It works well for it's intended purpose of snuffing a camp fire as well.

Back to fire extinguishers...carry the biggest one you can...those little 2 pound chrome ones look cute, will effectively put out a cigarette.
Just waiting on my favorite equipment supplier to start stocking the Elements. Need a new one anyway and not messing with another RV jobber.

A side benefit to these is ease of mounting or storage. A flashlight mount will help keep one anywhere and far more convenient to access if needed if you think through placement. I see the occasional extinguisher mounted in a cool yet unreachable area. At least they have one but it will take a while to use if you can get to it at all.
Very interesting and thanks for posting it.

I have moved beyond the usual powder type extinguishers to an AFFF type. Unfortunately, they do need to be protected from freezing in cold weather. I'll have to take a look at these.
I would also like to emphasize how effective a simple shovel & some dirt can be at suppressing multiple types of fires. NOT saying that it’s an acceptable replacement for a proper fire extinguisher!!! But, it can be an effective option that is often forgotten about. Not to mention it can have many other uses around camp or on the trail.


Senior Staff
I would also like to emphasize how effective a simple shovel & some dirt can be at suppressing multiple types of fires. NOT saying that it’s an acceptable replacement for a proper fire extinguisher!!! But, it can be an effective option that is often forgotten about. Not to mention it can have many other uses around camp or on the trail.
This is an absolute, time honored FACT. I fought forest fires long ago in WA and our primary tools were the shovel and pulaski.

These days, my primary concern is being prepared for a vehicle fire or an issue with my camp fire getting out of hand, everything else is tertiary to me.

But if my extinguisher is kaput, a shovel full of dirt or two certainly can't hurt if the engine bay is ablaze ;)
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