Generally all fire extinguishers are used in a similar fashion: carry the extinguisher to the fire, pull the pin, point the hose, nozzle or horn at the base of the fire, and squeeze the handle. Use a sweeping motion (back and forth) to cover wider areas. When the extinguisher runs out, leave. It is simple, but if you haven’t operated an extinguisher it is easy to get confused, possibly hysterical during an emergency, possibly burned. So you need to be shown how and gain some hands-on experience under controlled conditions.

By law, extinguishers must be conspicuously located and readily accessible for immediate use in the event of fire. Extinguishers must be distributed in such a way that the amount of time needed to travel to their location and back to the fire does not allow the fire to get out of control. OSHA requires that the travel distance for Class A and Class D extinguishers not exceed 75 feet. The maximum travel distance for Class B extinguishers is 50 feet because flammable liquid fires can get out of control faster that Class A fires.

At each sprinkler, the water under pressure in the pipe is held back by a plug held in place either by metal parts or a small glass vial filled with fluid. When sufficient heat hits a sprinkler, the special solder holding the metal parts together melts, or the fluid in the glass vial expands enough to break the glass. In either case, the plug is released and the water begins to flow.