The operator must know how to use the extinguisher. There is no time to read directions during an emergency. The extinguisher must be within easy reach, in working order, and fully charged. The operator must have a clear escape route that will not be blocked by fire. The extinguisher must match the type of fire being fought.
Extinguishers containing water are unsuitable for use on grease or electrical fires.
The extinguisher must be large enough to put out the fire. Many portable extinguishers discharge completely in as few as eight to ten seconds. Choosing Your Extinguisher Select only fire extinguishers that have been tested by an independent laboratory and labeled for the type and size of fire they can extinguish. Use these labels as a guide to purchase the kind of extinguisher that suits your needs. There are three basic classes of fires.