Safety Matters: Portable Fire Extinguishers covers major kinds of extinguishers, from the air-pressurized extinguishers to the dry-chemical and the carbon dioxide based extinguishers. Get a comprehensive overview of fire safety basics with Safety Matters: Portable Fire Extinguishers. In less than ten minutes, the program describes how a fire starts, how it can be prevented and which kind of extinguisher should be used on which type of fire. The program helps employees determine when (not) to use a fire extinguisher, and identifies the five major types of fires, and the appropriate extinguisher for each.