Clean agent fire extinguishers

KC-watts · October 2014

Imagine a component in your installation catches fire. If you're present, you can grab your hardware store ABC extinguisher and hose it with the yellow powder. Result is the fire is out, but all electronics and electrical connections are coated with a corrosive mess. Alternatively, you spray a clean agent, like halon, and only the malfunctioning device is damaged from the original fire. Automatic extinguishers release a gas, so to be effective, the shed should be sealed.

A small automatic halon-replacement extinguisher for a 50sq ft shed costs just over $200 new. Automatic halon-1301 units on the used market are far less and even more effective. Handheld "visible" spray units based on halon-1211 are surprisingly inexpensive, even new.

Buying halon units at swap meets is easy. The weight of the halon is evident by a gentle rocking motion. If the tare weight matches on a gas only agent (halon-1301), there is pressure. If the tare weight matches on a liquid agent (halon-1211), the gauge must be in the green showing the nitrogen charge. This stuff is stable in the atmosphere for 400 years, so the contents are good. If you're concerned your swap meet unit will work, you can always sell it. Unlike freon which has good replacements, halon is still a premium agent.

ramloui · October 2014

Re: Clean agent fire extinguishers

Most MCC rooms have CO2 fire extinguishers now. It is the most cost effective replacement for Halon which has a very high ozone depletion potential. Halon may also be illegal in some jurisdictions.

inetdog · October 2014

Re: Clean agent fire extinguishers

ramloui wrote: »

Most MCC rooms have CO2 fire extinguishers now. It is the most cost effective replacement for Halon which has a very high ozone depletion potential. Halon may also be illegal in some jurisdictions.

The big drawback of CO2 extinguishers, of course, is the need to either rapidly ventilate the room (not a great idea in case of fire) or get all personnel out of the room before the extinguishing system discharges.
Or use very limited strength spot systems whose CO2 contribution is diluted down to a breathable level by the rest of the air in the room.

waynefromnscanada · October 2014

Re: Clean agent fire extinguishers

New halon extinguishers banned in Canada in 1998. Refills of already existing fixed in position systems banned from being refilled 1 Jan, 2010.

KC-watts · October 2014

Re: Clean agent fire extinguishers

I only suggested halon in the context of finding a used device and how they are still the best overall clean agents. Halon alternative FE-241 is toxic, so like CO2, you need to lock out the system if the room is occupied. Another halon alternative, FM-200, is safer for occupied areas, but is quite expensive.

mike95490 · October 2014

Re: Clean agent fire extinguishers

Computer rooms in California can keep the existing systems, but new installs or recharge of old ones, needs new Ozone safe agents.

So we have ozone prohibition at ground level (smog) and preservation at high altitudes (ozone layer that blocks UV) Do the heavy Halon molecules actually migrate to the upper atmosphere and cause ozone depletion ?

KC-watts · October 2014

Re: Clean agent fire extinguishers

mike95490 wrote: »

Do the heavy Halon molecules actually migrate to the upper atmosphere and cause ozone depletion ?

As a gas, they are free to mix in the turbulent atmosphere. Good thought, though. I do have a story about that line of thinking. A lab was doing very sensitive nitrogen-14/nitrogen-15 ratio testing in ice core samples and wondered why their reference gas ratios kept changing. It turned out, the nitrogen gas bottle had not been replaced for some time nor had significant gas draws to cause turbulence inside the bottle. The N-15 actually settled due to gravity. Easy fix was just to lay the gas bottle on it's side.

oil pan 4 · October 2014

Re: Clean agent fire extinguishers

If you use a dry chemical in your kitchen or on electronics once, you wont do it again.

KC-watts · October 2014

Re: Clean agent fire extinguishers

Well, I just got back from a boating swap meet and saw a very nice stainless 1.4 lbs halon 1211 extinguisher. It was never used, but showed no charge. I could not tell if there was any liquid inside. I've read the nitrogen charge is more likely to leak through the seal leaving the larger halon molecules. In this case, the seal was likely compromised enough to let the halon slowly boil off.

oil pan 4 wrote: »

If you use a dry chemical in your kitchen or on electronics once, you wont do it again.

Yup, I did something stupid in the kitchen and let loose the dry chemical nuisance dust all over my kitchen. I wiped up as much as I could, but eventually my blender and George Foreman grill corroded and stopped working.

Dave Angelini · October 2014

Re: Clean agent fire extinguishers

It seems to me depending on a old extinguisher form a marine environment equals whatever you did stupid in your kitchen.
Electronic systems that are installed correctly and maintained should not be catching on fire. Extremely small odds of this happening. Smoke detectors and a decent date coded fire extinguisher should be all you need. A good electrician might help also. Losing the blender would be tough!

KC-watts wrote: »

Well, I just got back from a boating swap meet and saw a very nice stainless 1.4 lbs halon 1211 extinguisher. It was never used, but showed no charge. I could not tell if there was any liquid inside. I've read the nitrogen charge is more likely to leak through the seal leaving the larger halon molecules. In this case, the seal was likely compromised enough to let the halon slowly boil off.

Yup, I did something stupid in the kitchen and let loose the dry chemical nuisance dust all over my kitchen. I wiped up as much as I could, but eventually my blender and George Foreman grill corroded and stopped working.

Cariboocoot · October 2014

Re: Clean agent fire extinguishers

Gosh if my electrical equipment caught fire my only concern would be putting out the fire.

Since it would be burned up, I would not worry about how difficult the clean-up of a pile of fried trash would be. No way would I expect to put it back in service.

oil pan 4 · October 2014

Re: Clean agent fire extinguishers

A toaster caught fire and after the dry chemical settled it went so far as the bed room on the other side of the house. (the house did not have central A/C or heat)
CO2 or water for me from now on.

peakbagger · October 2014

Re: Clean agent fire extinguishers

The prior poster described it well, the powder goes everywhere and is bear to clean up. General with engine fires, the top end of the motor need to be taken off and cleaned out at a minimum.

Clean agent fire extinguishers

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