Sciencemadness Discussion Board

Solid fueled gas generator fire extinguishers?

Bert - 19-11-2021 at 17:47

Maus and Element 50 are two trade names I've recently run into.

Apparently these are pyrotechnic gas generators, their output gasses being used as fire extinguishers. If the sales materials are truthful, they're the best thing since the invention of water... Supposedly these leave zero residue, don't dammage/corrode metal, harm electronics or motors, have non toxic output products, safe for use indoors & effective for A, B and C type fires. I do find a disclaimer the Element 50 shouldn't be used on metal fires.

The Maus appears to have a percussion (or perhaps electrical?) push button igniter. The Element 50 appears to have the good old "remove cap and strike" red phosphorous/chlorate/ground glass friction ignition as used on road flares.

I have not yet personally seen any of these devices.

The distributor of the "Element 50" device in USA are QUITE evasive about answering simple questions such as "what's it made of?" and "What are the output gasses?". Additionally, the description of how it works in their FAQ seems like meaningless word salad to me.

I've found a claim that the Maus system is:

"potassium nitrate, formaldehyde and melamine. The potassium nitrate allows the melamine and formaldehyde to combust. The combustion byproduct of the melamine and formaldehyde are what extinguish the fire (by both oxygen starvation and chemical interruption".

Can't believe THAT mixture would produce only non toxic gasses.

Elsewhere I've found a claim that the Element 50 system is:

"Potassium nitrate, organic oxidizer and plasticizers resin"

I'd like to see the stoichiometry for either system. And their SDS/MSDS, google hasn't turned such up for me yet.

[Edited on 11-20-2021 by Bert]

Deathunter88 - 20-11-2021 at 03:34

It's pretty dumb in my opinion, doesn't work with even a bit of wind.

Bert - 20-11-2021 at 09:58

Quote: Originally posted by Deathunter88  
It's pretty dumb in my opinion, doesn't work with even a bit of wind.

More conventional CO2/Halon/dry powder fire extinguishers are also interfered with by outdoor wind.

I COULD see this technology having applications in a vehicle engine compartment. Especially if it didn't require the equipment to be radically cleaned/decontaminated before return to service.

The Maus company is now are selling a fire extinguisher STICKER for use in electrical device cabinets, essentially comprising a self stick layer carrying another thin layer of a micro encapsulated (funcional, not chemical) Halon analogue. Overheating allows the extinguishant to escape its encapsulation-

Stuff works, if it can't be blown away.

Not going to replace water in many applications.

SWIM - 20-11-2021 at 11:42

I'm mighty curious about just how this thing works as well, and what it actually emits.

It reminds me of Phillips' fire annihilator.

A basic extinguisher that was developed in the early 19th century.

It just used a pyrotechnic mixture mixed with a hydrated salt to generate steam, but was possibly the first solid fueled gas generator fire extinguisher.

Phillips later used this technology to make what may have been the first successful steam powered model helicopter. Certainly much earlier and greater in range than the Forlani steam reservoir helicopter, but smaller too.

Bert - 20-11-2021 at 14:04

Could you post links to information on Mr. Phillip's devices?

I find a reference to P. T. Barnum backing a USA product launch demo for the "fire anihilator" which failed spectacularly, no technical description given.

I also find a reference to a steam helicopter with rotor tip jet propulsion and flown off of a ground based boiler, alleged to have lifted so well it tore the hose loose and was lost from sight.

SWIM - 20-11-2021 at 15:39

My information on the Phillip's fire annihilator is limited.

Read about it in Octave Chanute's Progress in Flying Machines (1893) on page 50. This is available in googlebooks for free reading.

It says his helicopter used charcoal nitre and gypsum to generate steam as did the original fire annihilator.

This may mean he improved the formula since 1842, or possibly he insisted on calling it "the original fire annihilator" for marketing purposes.

Here's a diagram of the fire annihilator from Look and Learn.
Came up on an image search.
There seems to be very little information about it on the internet but I'll add anything I do find.

Here is the FAQ for the element 50 extinguisher which says the gas emitted contains largely 'free radicals of potassium and nitrogen'.

And apparently these gasses come from the saltpeter.

They'd get more of both i think if they loaded it with potassium azide, but that might be a tad more dangerous.

Attachment: ElementOperationDescription.pdf (82kB)
This file has been downloaded 67 times

U243447_Phillipss-Fire-Annihilator-Section.jpg - 64kB

[Edited on 20-11-2021 by SWIM]

Edit: Looks like 'fire annihilator' became a generic term for extinguishers using chemical reactions for power in the years after the Phillips was invented.

[Edited on 21-11-2021 by SWIM]

Bert - 20-11-2021 at 18:29

Having begun my sojourn into certain classes of energetics with Sodium azide salvaged from an airbag inflator, I can understand.

Quite aside from the toxicity...


I can see some possibilities for the system as described, but I'd rather have more permanent gasses vs. water vapor. (N2?) And gas output as cool as possible so convection might not remove the effluent from the desired area too quickly.

Apparently the mixture was formed into a grain, providing easier reloads, protection against constituents settling/stratifying by density in handling as the old "serpentine" powder did during long wagon trips on bumpy roads- and a longer burn time than might be had from a loose powder. That suggests hydrated plaster of paris as a binder, which is gypsum?

Hmm. Anyone ever try to use a Jetex engine to extinguish a fire, rather than START one?! If doped with some Potassium nitrate and a combustible plastic binder that could use up any excess O2, guanidine nitrate IS "an organic nitrate" as per one of these devices description.


I have once again reinvented the wheel-

FIRE SUPPRESSANT COMPOSITION PATENT- Guanidine nitrate/Potassium nitrate based

[Edited on 11-21-2021 by Bert]

SWIM - 20-11-2021 at 21:13

I've now read a couple of critiques of the old Phillips device, and one of them says that it mainly smothers the fire without cooling the materials much and therefore does not work well against wood fires where there is a decent amount of hot coals.

This may be a weak point for the Element too, but maybe that potassium makes the difference.
I'm guessing it forms carbonate in the high Carbon dioxide atmosphere right around and in the fire.

One source said something about potassium oxide, but that sounds a little strange to me.

[Edited on 21-11-2021 by SWIM]

Bert - 21-11-2021 at 08:45

Re: Phillips system/new aerosol systems being ineffective reignition of wood, cardboard & paper fires?

I deal with paper & wood FREQUENTLY (&#%$ing Chinese "cakes" where manufacturer skipped using any fire proofing in cardboard tube adhesives/on cardboard structural members/wooden end plugs/paper wraps and then also used tons of side spit fusing at base of all tubes).

NOTHING but water is very effective. CO2 and/or dry powder knock down the flames for a moment and then they go right back to burning merrily. Same for any wood fire that's gotten well involved. Bucket of water or get out of town.

In a similar vein, TIRE FIRES caused by over heated locked up air brakes on heavy trucks. Since the burning rubber tire is still stuck to the red hot brake disc which ignited it, the ABC dry powder or CO2 extinguisher required to be carried in a commercial vehicle is USELESS in the long run. You're better off urinating on such a fire than blowing dry extinguisher powder on it..


I've run into numerous citations of Potassium carbonate being responsible for suppressing reignition.

I will need to investigate further as to the mechanism. Frankly, as someone who earns their living off of setting shit on fire, I really ought to spend a bit more time on understanding chemistry of combustion (and the closely related matters of fireproofing, fire SUPPRESSION & etc.). I've been largely ignoring half of the related issues?

All in all, pyrotechnically generated aerosol fire suppression systems looks like an old idea that's getting a good bit of play recently.

Below is a Chinese patent with a very specific mixture description, it DOES mention melamine as a fuel along with Potassium nitrate and nitroguanidine. Also some Potassium perchlorate, which would militate against the claims of zero corrosive residue in my experience!


The invention discloses a kind of hand-held fire extinguisher aerosol extinguishing agent extremely preparation method, the extinguishing chemical by mass percentage, including following component:

Potassium nitrate 44% ~ 62%,

potassium hyperchlorate 5% ~ 10%,

ammonium nitrate 3% ~ 8%,

iron oxide 0.5% ~ 1.5%,

melamine 10% ~ 25%,

phenolic resin 5% ~ 9%,

nitroguanidine 5% ~ 12%.

Its preparation process is as follows:The part phenolic resin is dissolved with alcohol, the potassium nitrate, the potassium hyperchlorate, the ammonium nitrate, the iron oxide, the melamine, the nitroguanidine and the remaining phenolic resin is then added, it is in bulk to be mixed evenly, sieving is granulated, is dry, compression moulding.The extinguishing chemical ingredient is simple, of low cost, and preparation process is easy to implement and safe and reliable, and the compatibility between each component in extinguishing chemical is good, and the combustion heat value of the extinguishing chemical is low, safe to use, extinguishing ability is strong, and residue is few after burning.


Justia  Patents  Dry, Combustion TypeUS Patent for Fire-extinguishing aerosol composition for precision electric appliances Patent (Patent # 8,231,801)

Fire-extinguishing aerosol composition for precision electric appliances

Nov 14, 2007 - Shaanxi J&R Fire Fighting Co., Ltd.

A fire-extinguishing aerosol for precision electric appliance is disclosed, which includes oxidant, flammable agent, adhesive and additive. The composition of the present invention is characterized in that the oxidant is the mixture of the potassium salt and the strontium salt, in which the content of the potassium salt oxidant is more than or equal to 5 mass % to less than 15 mass % of the total mass of the composition, and the content of the strontium salt oxidant is more than 52 mass % to less than or equal to 60 mass % of the total mass of the composition. In the fire-extinguishing aerosol composition of the present invention, the particle average diameter of all components is less than 50 μm. After quenching the fire in the space in which the precision electric appliance is installed, the fire-extinguishing aerosol composition of the present invention can ensure that the dielectric resistance of the precision electric appliance is more than or equal to 100 MΩ. The fire-extinguishing aerosol composition of the present invention is more reasonable than the prior art, friendly to the environment, and applicable to the precision electric appliance.



This invention belongs to the technical field of fire-extinguishing compositions, and relates to a fire-extinguishing aerosol composition suitable for suppressing fire of types A and B in a relatively confined space, in particular to a fire-extinguishing aerosol composition suitable for precision electric appliances.


The aerosol fire-extinguishing technology, which occurred since the 1990s, is a technology that extinguishes fire by damaging the combustion chain reaction of free radicals in the flame through the chemical reaction of an activity inhibitor produced based on the vigorous oxidation-reduction reaction between oxidant and fuel. Owing to its characteristics such as non-toxicity, non-corrosivity, high capacity efficiency, long storage period, total flooding and all-round fire-suppressing, said technology has attracted much attention. Over ten years since the end of the last century, the aerosol technology has been rapidly developed with continuous emergence of relevant patents. The aerosol fire-extinguishing technology can be mainly divided into the three types: hot aerosol fire-extinguishing technology, cold aerosol fire-extinguishing technology and water mist fire-extinguishing technology. The hot aerosol fire-extinguishing technology includes pyrotechnic composition-based hot aerosol fire-extinguishing technology and water-based hot aerosol fire-extinguishing technology. At present, the pyrotechnic composition-based hot aerosol fire-extinguishing technology, for the most part, refers to pyrotechnic composition-based fire extinguishers that are based on a solid substance composed of an oxidant, a flammable agent, an adhesive and a combustion rate regulating agent. As a substitute for Halon, the pyrotechnic composition-based hot aerosol fire extinguisher displays a high fire-extinguishing efficiency, the fire-extinguishing apparatus is simply structured without the need to use any pressure-proof container, the fire-extinguishing components can be combined modularly, and stored at normal temperature and pressure, the maintenance is convenient, the fire extinguisher can be stored for a long period of time, and has a low cost, with an ozone depletion potential ODP=0, and a relatively low global warming potential GWP, thus is obviously superior than other types of fire extinguishers with respect to the price/performance ratio, which helps to open up the market and advance the implementation of the Halon substitute plan.

In the prior art before the disclosure of the present invention, an alkali metal nitrate, in particular potassium nitrate, is preferably selected by the pyrotechnic composition-based hot aerosol fire-extinguishing technology in most cases as an oxidant for pyrotechnic composition-based hot aerosol fire-extinguishers in consideration of its capability to satisfy most requirements in the principle of component selection. For the prior art using a single component potassium nitrate as oxidant in fire-extinguishing aerosol compositions, the most frequently used is the hot aerosol fire-extinguishing technology 

[Edited on 11-21-2021 by Bert]

SWIM - 21-11-2021 at 10:05

So it looks like those carbon tetrachloride fire extinguishers had at least two advantages over other early water-less fire extinguishers.

1: Evaporative cooling of hot materials.
2: Phosgene generation eliminates witnesses to poor extinguisher performance.

[Edited on 21-11-2021 by SWIM]

Bert - 21-11-2021 at 20:40

Quote: Originally posted by SWIM  
Phosgene generation eliminates witnesses to poor extinguisher performance.[Edited on 21-11-2021 by SWIM]

Everything is a business model...

I've seen enough references to some of the Halon series of extinguishants producing phosgene or other toxic gasses to be a bit worried about employing such in an enclosed area at this point. Certainly, they were the best choice available for aircraft cabin & engine compartment use 30 or more years ago but they are ridiculously expensive now.

I'm seriously thinking about getting a few samples of these pyrotechnic gas generator type extinguishers and doing my own testing.

NFPA ( the USA insurance "industry" group who writes the whole USA's insurance and fire codes in such a way as to guarantee our insurance "industry" comes out ahead on their bets) doesn't recognize this class of extinguishers and isn't interested in developing a rating system to encompass such. That's well into the category of praising with faint damnation, IMHO.

[Edited on 11-22-2021 by Bert]

[Edited on 11-22-2021 by Bert]