In commercial use the facility will have a fire prevention service come in and inspect, and certify their extinguishers per a schedule (I think monthly) and yes, they do that for Dry Chem types.. Wet chem types (Contact Mac The Fire Guy) do not need this type of service and may actually do a better job on most fires.
(Mac explains way better than I do). Of course the best place to be in a fire...
ELSEWHERE, but that's not always an option.
I have the 5 pound toy that came with the RV
A 25 pounder I need to get serviced when I get back to MI.
And two Wet Bottles (About a pint each) from Mac the Fire Guy.
And a water bottle.. Compressed air over water, Re-filled and re-compressed when needed,, This is my "Campfire" extinguisher so it gets a lot of use.
Modified garden sprayer (I added an automotive valve stem so I can "pump it up": with my air compressor instead of elbow grease).