Dry chemical fire extinguishers EEK!

[NewportNic]

My employer is a member of the Construction Association of Michigan, and I received a safety alert that should be of interest to all of us Stakers.

A man was killed when the cartridge type dry chemical exploded. When the cartridge was activated the corroded bottom of the extinguisher failed, propelling the extinguisher upwards striking him in the neck and chin.

While we do not have inspectors looking around in our home shops, I hope we do have extinguishers and that they are in "GOOD WORKING CONDITION". Dry chemical extinguishers are great at putting out shop fires but over years the contents can become an unusable lump and as this incident demonstrates corrosion can be deadly.

Please check your extinguishers!
When was the last time they were serviced?

The place you get your Oxy-Acetylene can usually help you with the service that might be required
.

[Craig A]

I can't believe I never read this post before NOW but it honestly scared me.
Enough so that I renamed the thread and am posting so it gets some more attention.
I have never given a thought to that possiblity.
Those extinguishers are cheap enough that replacing them every now and then shouldn't break anyones' bank......

[bobsaunders]

Over the years I have found them for sale in garage sales. I knew they could go bad. Often wonder why you would sell one that reads charged. I was told hitting the bottom with a rubber hammer does not help them or test them.

How do you dispose of old ones?

[Jeff and Maria Smith]

Hey all,
I can only speak for my area, but all the local volunteer fire departments around here check, service, refill, and recharge extinguishers. It may be worth checking into.
Jeff

[Motormowers]

So even if your gage reads OK it could still be junk? How can you tell?

[NewportNic]

So even if your gage reads OK it could still be junk? How can you tell?

With dry chemicals you can't! They must be emptied and recharged.

and then their is the one inside your hot truck...
this was inside a Forest Service Truck back in 2003 they don't know why it failed.
http://www.nmsu.edu/safety/news/news...losion2003.htm

[Beanscoot]

I had a small kitchen fire years ago and had two dry chemical extinguishers. So I deployed the first one, which went pfff and a tiny trickle of powder came out, then it expired. So I quickly grabbed the other one which did the same thing. Negligible pressure in both.

Both of these had gauges that indicated they were charged.

I was also thinking recently about uses for old units, I have one that has a very nice looking aluminum formed vessel of about half a gallon capacity. Maybe a gas tank?

[pegasuspinto]

Fire extinguishers should be inspected, and hydrostated, just like any pressure vessel. In case anyone does not know, the type of extinguisher that failed has a seperate CO2 cartridge that gets pierced to charge the extinguisher, I know in this area the railroad and some industrial users use them, they are probably a lot better for mobile use and in places where they temperature varies a lot, but they are not exempt from inspections-tho if they are in a truck or a remote spot, they often still get forgotten. As for the one in the kitchen and in your shop, they are worth the extra expense to get a real commercal type unit. The typical yearly inspection is just a visual exam to make sure they are still in pressure and not leaking, and they get a teardown, inspection, new valve, hydro, and recharge I think it was every 6 years?

Robert

[KeithW]

I may not be correct but thought that there are two types of dry chemical extinguishers. One holds pressure in the vessel with the chemicals all the time. When you open the valve the pressure and chemical are released. The other holds the chemicals in an unpressurized vessel and has a small cartrige that holds high pressure. When you open the valve the small cartrige pressurizes the large container forcing the chemicals out. The small home units tend to be the first type and the large commercial ones the second. Once again I may be wrong and hopefully someone who knows better will set me straight.

keithw

[spfx_dude]

In my area you only really see the presurized dry chem. Fire extinguishers need yearly checking to be up to NFPA codes this is why the tags are so important. Additionally, if the safety seal is broken you must always consider the extinguisher spent! I tend to travel to engine shows with CO2 and Dry chem because you can put out an engine fire with CO2 and not have all the mess. One just has to be wary of the wind speed and direction. The dry chem is for backup. Yes, every number of years they need to be dumped down, and hydrostatically tested like any other pressure vessle. You also want to treat all extinguishers with care; we wouldnt handle our nitrogen or welding bottles the way some people handle extinguishers, yet some are under the same pressures! I also use pressurized water in my work, but we dump them so regularly that we do our own refils and always carry a certified back up. I sent a number of them in for testing once and the company destroyed them all because there were slight dents in the base... grrrr. I had to point out to them that these were our day to day use ones and not for general certification.

My two cents

[NewportNic]

I too love my refillable water extinguisher. I have it around whenever I'm using my torches, great first line of offense. Cheap and Easy to refill and if pressurized to 100 psi won't freeze right at 32 F (until you release pressure).


Mrs Klaus, Do you smell smoke?

[sparksandslag]

Regarding the dry chemical in the extinguisher becoming a solid lump---in our monthly employee safety meetings this point was brought up, and the solution is very simple. Pick some day that you will remember each month (mine is the day my retirement check comes in), take the extinguisher and turn it upside-down and shake the living dickens out of it. If allowed to sit in one place very long the soda inside the shell will pack tighter than a bankers fist. Then when you really need it, the propellant will just fan the flames. I suspect that the extinguisher that blew the bottom out had been sitting on a damp floor and had rusted through. Put that fella on a bench or mount it in a bracket. Also, while you are shaking the soda loose, check that the dirt daubers haven't stopped the hose end up with mud.