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ABC Dry Chemical Fire Extinguisher Powder Corrosive?

adh2000

Titanium
Joined
Dec 21, 2005
Location
Waukesha, WI
I don't work day to day in this plant, but have an ownership interest in the business. About a month ago the bathroom exhaust fan burned up and started a fire in the adjacent janitor's closet. The fire was put out by an employee using an ABC dry type fire extinguisher. Unfortunately there was an air handler return right above this area and a bunch of the extinguisher powder was sucked into the air handler and disbursed over the inventory room. Now everyone is worried about how corrosive this powder might be and ServPro has been brought in and produced an astronomical bid to clean the powder off everything. The insurance company will cover it, but I'd rather not see a claim on the insurance and for whatever its worth I consider this sort of a scam anyway. So the question is: How corrosive is this stuff? Is this a big deal? How about they just mop the floor and get back to work?
 
Also will corrode electrical connections. I'd get an iron clad guarantee from them as I also think they are something of a scam.
How long will this "inventory" be there? Will it get further processing that might include cleaning? What was it and how packaged?
 
I had one go off by accident in the rear compartment of a Fire Truck... The compartment was a very large one that held a generator, extra hoses and the Jaws of Life tools and power pack. We cleaned and washed out that compartment for two hours and we still were seeing yellow powder in the compartment for about 6 months.. That stuff is very fine and went everywhere.

Wires on the generator were starting to show corrosion after 10 days. IF the insurance company knows about the fire you already have it on the record. If your inventory is worth anything you need to at least tell the insurance company, let them figure out what to do, so you don't have to eat it later...
 
The chemical becomes very corrosive when exposed to moisture or liquid water on any metals, so mopping is not the best idea, dry cleaning is best.

Once had an automatic system accidentally discharge in a room where my field tools and supplies were stored at a customer site, removed the stuff to the outdoors to commence cleaning the room. It was a humid day and later began sprinkling a very small amount. Every tool and fitting was permanently etched wherever there was the chemical and the slightest hint of moisture. Made for a lot of discolored supplies and tools, aluminum and die cast zinc were the worst affected, the steel was less affected but was still discolored.

If your inventory is metal, you need a good dry cleaning. If the air-handler is full of the stuff, I would suggest you start there first to prevent re-spread of the powder over time. Your heat exchanger wont like it when the inevitable moisture laden air comes along. I would suggest a duct cleaning as well, to mitigate future problems.

SAF Ω
 
Holy crap really, I didn't know this. I'm glad you shared this experience. i'm going to have to check our plant room extinguishers and vehicles.
 
We had a small fire on one of our race cars when the engine blew, no big deal, but the driver freeked out and grabbed a fire bottle from a track worker and emptied it under the engine cover. What a mess, we cleaned that thing for hours before loading it on the truck for the trip from Long Beach Ca. to Warrington Pa. We did not get it clean enough...by the time it got back to the shop it looked like some sort of science experiment gone haywire. The corrosion was amazing.. aluminum and magnesium had some sort of fuzzy stuff growing on it. any steel bits were all rusty. The powder was still coming out of the tub months later. Let your insurance clean it up, that's why you have it.
 
If I may jump in, in the Navy we were trained to use PKP powder which was purple in color, for class "Bravo" fires which are fuel fires. The stuff works great but highly corrosive to anything it comes in contact with and a bitch to clean up, even the carbon steel bottles it was in would rust. Co2 was for for class "Charlie" fires which is electrical. Portable AFFF works great also but leaves a soapy residue. The electricians would have your ass if you shot PKP into anything electrical, unless the fire was out of control then nothings off the table. In my shop I have only 15 lb Co2 bottles and Halon, Halon for the break-room where there is a stove. Mike
 
Hopefully someone will correct me if I am wrong, but I believe Class B-C extinguishers contain baking soda,sodium bicarbonate NaHCo3, non-corrosive; ABC extinguishers contain monoammonium phosphate (NH4H2PO4), which is corrosive in presence of moisture.

The monoammonium phosphate is more effective on class A fires (wood, paper, etc) because it melts and forms a crust on the fuel
 
Learning a lot here...thanks for bringing the subject up........


I had Co2 cylinders on the boat... and a Automatic Halon sysem in the engine area..
fortunatly NEVER needed it or the Co2 ones
 
Gary E
I don;t know what kind of halon system you had on the boat but on one ship I was on the USS Doyle we were in the yards and one of the yard birds dumped it by mistake. Man it sounded like a freight train rolling through the engine room, louder than hell especially in dry dock. The thing about Halon is it doesn't displace/remove the oxygen, so with all the bottles dumped no one was hurt.
 
I installed it in my 33 ft sporfish in about 1975 or so... dont remember the type,,, just that it was automatic and was a lot better than nothing....

Another fellow I knew had a huge Co2 sylinder and a pipe system to flood his engine area.... he never used it either... but they were allways there...

If it does not displace the Oxygen... how does it work? ...I'll look that up sometime...
 
Can you guys still get halon extinguishers? My understanding is that it is now banned because it damages the ozone layer.

We had a truck fire at place I worked 20+ years ago. We emptied about 5-6 fire extinguishers into the fire including a very large one from the mechanics shop. Finally someone grabbed the small halon one out of the office it put the fire out almost immediately.
 
As far as Halon goes its my understanding that it was developed as a refrigerant gas and then was discovered that this stuff puts fires out. From what I know it disrupts the fire triangle, basically gives the fire a hiccup. I am sure that sounds flimsy but I can tell you that it isn't really dangerous until it decomposes due to fire . On the ships we were trained to dump Halon in a machinery space for instance where the concentration of Halon would be about 5-7% , but in a paint locker for example it was much higher around 21%. You would have to wait at a minimum of 15 minutes "soak time" before reentering the space due to re-flashing since it doesn't remove oxygen but the fire would and there is also no cooling effect. If you are in a machinery space and it gets dumped due to error just stand still till its done discharging and then just walk out of the space. It was pressurized by nitrogen if I remember correctly. Anyway it works. Mike
 
Thanks for all the input on this. Looks like the corrosion concern is valid so I'm going to let the insurance company proceed with the cleanup crew. The costs seem to be insane, oh well.
 
abc dry chemical is noted as being non abrasive but I think it can be corrosive with exposure to moisture I suggest you check out the ansul foray dry chemical powder it is abc dry chemical technical bulliten clean up procedures and see also this link https://youtu.be/MG-xFRf5ppM
 








 
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