I happened to glance at the fire extinguisher in my garage today. As shown above, it has lost pressure, and the needle on the gauge is no longer in the green zone.
Question 1: This means (choose one):
- It’s time to get it recharged.
- It’s time to throw it away.
- It’s time to fertilize my garden.
Question 2: A standard home general-purpose fire extinguisher is filled with a powder. That powder is:
- Baking soda.
- Garden fertilizer.
Weirdly enough, the answers are 1-c, and 2-b. What I thought was a rechargeable fire extinguisher filled with baking soda is, in fact, a disposable item filled with fertilizer.
1: This Kidde (r) fire extinguisher is not just disposable, it has a fixed expiration date.
That came as a surprise, from the look and feel of it. This model — FX340GW — has a solid aluminum cylinder, heavy-duty hose, metal fittings, and a gauge. It weighs in around eight pounds. It seems like it’s the real deal, not some disposable piece of junk.
I vaguely recall buying the best one they had at the big-box hardware store, figuring that in the long run a rechargeable one was the right choice. In hindsight, I passed right over all those cheap disposable fire extinguishers in order to by an expensive disposable fire extinguisher.
In fact, it says it’s disposable.
Right on the device, in tiny ultra-low-contrast white-on-gray lettering, on shiny plastic material. So, to know that this is a disposable, you just have to blow the image up to read it. And squint.
No ambiguity there. In fact, it’s not merely a disposable, per the second circled section above, it expires 12 years after date of manufacture. Said manufacture date being in 2007. So more-or-less right on time, it’s dead.
2: This model is still for sale
Source: Tractor Supply.
And you’d still have to be some sort of fire-extinguisher savant to know that it’s disposable. Note that “disposable” appears nowhere in the ad.
With some internet sleuthing, I found out that only the Kidde (r) extinguishers fitted with an all-metal head are potentially rechargeable. But this one, with a plastic top piece, is not.
So that checks out. If I’d had that fact in hand when I bought it, I wouldn’t have bought it. But it’s not as if you’re likely to know that at the time of purchase.
3: Some years of this model were recalled.
Source: Kidde
My extinguisher is not merely a stealth disposable, but a dud stealth disposable. I have no clue how long that recall notice has been out, but the example they show is literally from 2007. The same year mine was manufactured.
4: Nobody recharges these anyway.
In the end, it doesn’t matter anyway, because, as far as I can tell, the entire fire extinguisher recharging service market is oriented toward large commercial establishments. If there is a firm in Northern Virginia that recharges home fire extinguishers, I couldn’t find it with a simple Google search. And if I did, based on the advertising, I’m willing to bet that recharging one of these costs about as much as buying a new one.
In short, it now looks like the very idea of a rechargeable home fire extinguisher is more-or-less imaginary. In a practical sense. I see that I can, in fact, buy a different brand of powder-filled extinguisher that advertises itself as rechargeable. Where or how I could get that recharged, I have yet to figure.
I’ve seen a couple of YouTube videos of people who D-I-Y’ed it using an air compressor, and maybe some special fittings. I’m not sure I’d do that, and it’s not worth the investment to do just one extinguisher.
5: Not filled with baking soda.
The principal ingredient of the fire-suppressant powder is monoammonium phosphate, a chemical which is mainly used as fertilizer (source).
The final set of numbers(1-0-0 above) says that there’s nothing toxic about any of the ingredients, but that the powder is an irritant (e.g., if you breath it in).
After a quick detour to the website gardenmyths.com , to find out what the N-P-K numbers on fertilizer mean*, this means that my fire extinguisher is filled with about three pounds of harmless 10-50-0 fertilizer. With a touch of sulfur on the side.
* Contrary to 99.9% of what you read, they are not the percent, by weight, of nitrogen, phosphorus, and potassium. Under U.S. labeling (which differs from that of other countries): “The N value is the % nitrogen. The P and K values are the % P2O5 and % K2O. … Using this information you can see that a fertilizer NPK number of 10-10-10 contains 10% nitrogen, 4.36% phosphorus, and 8.3% potassium.” The reason is rooted in the history of the chemical tests for those substances. Thanks to gardenmyths.com for that. If nothing else, I learned something new because of my stupid disposable fire extinguisher.
Conclusion
I’ve lost count of how many ways I was confused. I thought this was a reliable, rechargeable top-end fire extinguisher, filled with baking soda. It was in fact a disposable fire extinguisher that had been recalled years ago. Filled with fertilizer.
And nobody in this area appears to recharge these anyway. So the very idea of a rechargeable powder-filled home fire extinguisher is just a non-starter. For example, if you go on the Kidde website, you get exactly zero advice on where to go to get one of their units recharged.
A good way to empty one of these is to discharge it into a loosely-held plastic trash bag (per this YouTube reference). At which point, the bag of fertilizer goes in with my gardening stuff. I can then unscrew the valve on top, and chuck the aluminum cylinder in with metal to be recycled.
I don’t think I’ll be replacing this any time soon.
