Fire extinguisher had been developed by DuPont and the US Army in 1954. Both 1211 and 1301 work by inhibiting the chain reaction of the fire, and in the case of Halon 1211, cooling class A fuels as well. Halon is still in use today but is falling out of favor for many uses due to its environmental impact. Europe and Australia have severely restricted its use, since the Montreal Protocol of 1987. Less severe restrictions have been implemented in the United States, the Middle East, and Asia. Internationally there are several accepted classification methods for hand-held fire extinguisher. Each classification is
Carbon tetrachloride to use carbon tetrachloride to extinguish fires. The liquid was vaporized by the heat of combustion and extinguished flames, an early form of gaseous fire suppression. At the time it was believed the gas simply displaced oxygen in the area near the fire, but later research found that the gas actually inhibits the chemical chain reaction of the combustion process. In 1911, Pyrene patented a small, portable extinguisher that used the chemical. The extinguisher consisted of a brass bottle with an integrated handpump that was used to expel a jet of liquid toward the fire. As the container was unpressurized,