# Fire Extinguishers: Recharge or Replace? **URL:** \ **Category:** Factual Questions\ **Created:** [March 9, 2015, 11:30pm UTC](https://boards.straightdope.com/t/fire-extinguishers-recharge-or-replace/714645 "2015-03-09T23:30:09Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![PastTense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pasttense/32/14550_2.png) [@PastTense](https://boards.straightdope.com/u/PastTense)\ **Post date:** [March 9, 2015, 11:30pm UTC](https://boards.straightdope.com/t/fire-extinguishers-recharge-or-replace/714645/1 "2015-03-09T23:30:09Z")
I have a couple fire extinguishers (Kidde, ABC , ingredients Monoammonium Phosphate, Ammonium Sulfate, Mica, Talc, Nuisance Dust) which have mysteriously discharged (I have never used them). Why did they discharge? Is it economical feasible to recharge them (these are the low end extinguishers you get at at Walmart)? What is the usual price? Is this something which can only be done in big cities? How do you find the date on the fire extinguisher? Other thoughts? Thanks. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [March 9, 2015, 11:36pm UTC](https://boards.straightdope.com/t/fire-extinguishers-recharge-or-replace/714645/2 "2015-03-09T23:36:34Z")
if they discharged because of bad or deteriorated valves then it would be a waste to recharge. go to the website and see if that model is rechargeable. ---
**Author:** ![Number](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/number/32/242_2.png) [@Number](https://boards.straightdope.com/u/Number)\ **Post date:** [March 10, 2015, 12:09am UTC](https://boards.straightdope.com/t/fire-extinguishers-recharge-or-replace/714645/3 "2015-03-10T00:09:37Z")
This may not be universally true, but a recharging place told me that only extinguishers with metal tops can be recharged. Ones with plastic tops are pretty much disposable. ---
**Author:** ![Iggy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/iggy/32/3364_2.png) [@Iggy](https://boards.straightdope.com/u/Iggy)\ **Post date:** [March 10, 2015, 2:09pm UTC](https://boards.straightdope.com/t/fire-extinguishers-recharge-or-replace/714645/4 "2015-03-10T14:09:02Z")
> [@PastTense](#): > > … > Is it economical feasible to recharge them (these are the low end extinguishers you get at at Walmart)? What is the usual price?\*\* Is this something which can only be done in big cities?\*\* > … Many businesses are required to have fire extinguishers. So even a relatively small city will likely have at least one company that can recharge fire extinguishers. Our island of 60,000 populations has two such companies. Our office is charged about $15-20 per recharge - much cheaper than buying a new one. ---
**Author:** ![bump](https://avatars.discourse-cdn.com/v4/letter/b/7c8e57/32.png) [@bump](https://boards.straightdope.com/u/bump)\ **Post date:** [March 10, 2015, 3:05pm UTC](https://boards.straightdope.com/t/fire-extinguishers-recharge-or-replace/714645/5 "2015-03-10T15:05:38Z")
I actually ended up with a small discharged extinguisher in college- metal top and all. When I looked into recharging it, it ended up costing more to get it recharged/recertified than it would have to buy a larger one of those inexpensive Kidde/First Alert extinguishers at Home Depot. I imagine (but don’t know for sure) that outfits like school districts and universities contract with fire safety companies, who provide the extinguishers and maintain them. So in that model, it makes sense for those companies to have durable, long lasting ones that can be recharged- they probably can do it for very little money in-house, and reuse the fire extinguisher for a very long time. But for a home user, this doesn’t really come into play. ---
**Author:** ![robert\_columbia](https://avatars.discourse-cdn.com/v4/letter/r/e79b87/32.png) [@robert\_columbia](https://boards.straightdope.com/u/robert_columbia)\ **Post date:** [March 10, 2015, 5:22pm UTC](https://boards.straightdope.com/t/fire-extinguishers-recharge-or-replace/714645/6 "2015-03-10T17:22:27Z")
> [@bump](#): > > I actually ended up with a small discharged extinguisher in college- metal top and all. > > When I looked into recharging it, it ended up costing more to get it recharged/recertified… What’s actually involved in fire extinguisher “certification”? Is this more or less the sticker/receipt that the recharging company puts on your extinguisher when they finish refilling it, or are there actually independent and/or government certification organizations that you can take fire extinguishers to for inspection and where extinguishers deemed to meet the standards will receive certifications? ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [March 10, 2015, 5:49pm UTC](https://boards.straightdope.com/t/fire-extinguishers-recharge-or-replace/714645/7 "2015-03-10T17:49:29Z")
the recharging company can test and certify it. to be recharged the device needs a current certification. ---
**Author:** ![robert\_columbia](https://avatars.discourse-cdn.com/v4/letter/r/e79b87/32.png) [@robert\_columbia](https://boards.straightdope.com/u/robert_columbia)\ **Post date:** [March 10, 2015, 6:10pm UTC](https://boards.straightdope.com/t/fire-extinguishers-recharge-or-replace/714645/8 "2015-03-10T18:10:41Z")
> [@johnpost](#): > > the recharging company can test and certify it. > > to be recharged the device needs a current certification. Can you, in theory, recharge it at home (or in Uncle Bill’s barn, etc.) and then take it for certification, or can it only be certified if it is recharged by a recognized recharging company? After all, Uncle Bill really recharges them well, take a look at his work! That’s some fine rechargin’ there. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [March 10, 2015, 6:18pm UTC](https://boards.straightdope.com/t/fire-extinguishers-recharge-or-replace/714645/9 "2015-03-10T18:18:37Z")
it is tested when it is empty of extinguishing substance. if it pases the test then it is certified and can be refilled. ---
**Author:** ![dstarfire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dstarfire/32/5762_2.png) [@dstarfire](https://boards.straightdope.com/u/dstarfire)\ **Post date:** [March 10, 2015, 7:44pm UTC](https://boards.straightdope.com/t/fire-extinguishers-recharge-or-replace/714645/10 "2015-03-10T19:44:17Z")
> [@robert\_columbia](#): > > Can you, in theory, recharge it at home (or in Uncle Bill’s barn, etc.) and then take it for certification, or can it only be certified if it is recharged by a recognized recharging company? After all, Uncle Bill really recharges them well, take a look at his work! That’s some fine rechargin’ there. Would you really want to pump over 100 psi (to several hundred, depending on the type) of pressure into a metal container (that mysteriously emptied itself) without knowing that it won’t rupture or even explode under that kind of load? Depending on how it breaks, it could send bits of shrapnel flying out at a few hundred mph, or just a good-sized hunk of metal hitting you with the speed of a professional pitchers fastball. ---
**Author:** ![Snnipe\_70E](https://avatars.discourse-cdn.com/v4/letter/s/b5a626/32.png) [@Snnipe\_70E](https://boards.straightdope.com/u/Snnipe_70E)\ **Post date:** [March 11, 2015, 5:43am UTC](https://boards.straightdope.com/t/fire-extinguishers-recharge-or-replace/714645/11 "2015-03-11T05:43:52Z")
If it is old enough it may also need to be hydrostatic tested. Cost more than a new extinguisher. ---
**Author:** ![Gbro](https://avatars.discourse-cdn.com/v4/letter/g/c6cbf5/32.png) [@Gbro](https://boards.straightdope.com/u/Gbro)\ **Post date:** [March 11, 2015, 2:04pm UTC](https://boards.straightdope.com/t/fire-extinguishers-recharge-or-replace/714645/12 "2015-03-11T14:04:48Z")
> [@johnpost](#): > > it is tested when it is empty of extinguishing substance. if it pases the test then it is certified and can be refilled. What I believe you are referring to here is a Hydrostatic recertification. I believe most re-chargeable fire extinguishers need to be hydro-ed every 15 years but also need an annual inspection witch amounts to a visual of the pressure and all seals in place, dates etc and documented. One of the services we used to provide at the Mining Company I worked for is we would re-fill the small household extinguishers for all employees. We had a kit w/ O-rings and fittings for re pressure-ing with nitrogen. Brooks has a kit but I am unable to link to the kit. Most extinguishers that came into the shop were just low on pressure due to a faulty valve. One thing to remember, its the agent inside the extinguisher that puts out the fire. I had a garage fire once and my extinguisher was flat, but I unscrewed the top valve assembly and shook the agent onto the fire and all was well. Kind of like having a large box of baking soda with a small hole in the top. ---
**Author:** ![Gbro](https://avatars.discourse-cdn.com/v4/letter/g/c6cbf5/32.png) [@Gbro](https://boards.straightdope.com/u/Gbro)\ **Post date:** [March 11, 2015, 2:12pm UTC](https://boards.straightdope.com/t/fire-extinguishers-recharge-or-replace/714645/13 "2015-03-11T14:12:00Z")
> [@Snnipe\_70E](#): > > If it is old enough it may also need to be hydrostatic tested. Cost more than a new extinguisher. Recertifying is required for all MSHA-OSHA, DOT, NFPA, USCG, and other governing body’s. At a job I work today (not Mining) we are authorized to take home an expired extinguisher because of the cost of full hydro-re-cert. These quality (Metal) units are much better that a big box store special but keep them at home or cabin. ---
**Author:** ![Snnipe\_70E](https://avatars.discourse-cdn.com/v4/letter/s/b5a626/32.png) [@Snnipe\_70E](https://boards.straightdope.com/u/Snnipe_70E)\ **Post date:** [March 12, 2015, 4:31am UTC](https://boards.straightdope.com/t/fire-extinguishers-recharge-or-replace/714645/14 "2015-03-12T04:31:31Z")
> [@Gbro](#): > > Recertifying is required for all MSHA-OSHA, DOT, NFPA, USCG, and other governing body’s. > At a job I work today (not Mining) we are authorized to take home an expired extinguisher because of the cost of full hydro-re-cert. > These quality (Metal) units are much better that a big box store special but keep them at home or cabin. I worked in retail stores and high rise office buildings. I have several extinguishers that need a hydro to be recertified, I was able to take them home.