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 and in working order, 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 on electrical fires.
The extinguisher must be large enough to put out the fire. Many portable extinguishers discharge completely in as few as 8-10 seconds. Use these labels as a guide to purchase the kind of extinguisher that suits your needs. There are three basic classes of fires. All fire extinguishers are labeled using standard symbols for the classes of fires they can put out.