Most fire extinguishers expire after ten to twelve years. And it is suggested to replace them at that time. But all rechargeable fire extinguishers can be serviced at six years and hydro tested at twelve years. This will insure proper working order. I am a fire extinguisher tech and have serviced extinguishers dated back from the early nineties with no issues. Also there is a recall on some Kidde fire extinguishers and they will replace those for free. Look up Kidde recall and follow the link Hope this helps
Most fire extinguishers have a 12 year expiration date from manufacture. On the bottom is a number which should say something like “16” that’s the year of manufacture. After 12 years is when you should replace it. It should still work, but always replace it
I have a family full of fire fighters and have at least 4 in my home and I always check the pressure fist and flip it upside down every so often (the more the better) you should feel some movement or hear the contents shift down if it doesn’t it I don’t trust it
We have a local free medical clinic that has three 5 pound extinguishers dating to 2013. Our most recent inspection revealed that each had a lable specifying a more involved inspection at the 6 year point. So our fire inspection company took the three back to their lab where (I think) they will do a much more involved inspection of the valve, trigger, contents, etc. Perhaps this is overkill .. I dunno .. but maybe just a pressure guage still being in the green (as my three personal small 30 year old extinguishes shows) is not totally reliable of readiness to use.