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Bromochlorodifluoromethane (BCF), also referred to by the code numbers Halon 1211 and Freon 12B1, is a haloalkane with the chemical formula C F 2 Cl Br. It is used for fire suppression, especially for expensive equipment or items that could be damaged by the residue from other types of extinguishers. [1]
Exposure to Halon 1301 in the 5% to 7% range produces little, if any, noticeable effect. At levels between 7% and 10%, mild central nervous system effects such as dizziness and tingling in the extremities have been reported. [8] In practice, the operators of many Halon 1301 total flooding systems evacuate the space on impending agent discharge.
In the 1970s, Halon 1211 came over to the United States from Europe where it had been used since the late 1940s or early 1950s. Halon 1301 had been developed by DuPont and the United States 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.
Bromochloromethane or methylene bromochloride and Halon 1011 is a mixed halomethane. It is a heavy low-viscosity liquid with refractive index 1.4808. Halon 1011 was invented for use in fire extinguishers in Germany during the mid-1940s, in an attempt to create a less toxic, more effective alternative to carbon tetrachloride .
[citation needed]) Halon 1211 also has low toxicity, although it is more toxic than Halon 1301, and thus considered unsuitable for flooding systems. However, Halon 1301 fire suppression is not completely non-toxic; very high temperature flame, or contact with red-hot metal, can cause decomposition of Halon 1301 to toxic byproducts.
Halotron I. Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Halotron I is a fire extinguishing agent based on the raw material HCFC-123 (93%) mixed with tetrafluoromethane and argon as propellants.
Systems are as diverse as the many applications. [4] [5] In general, however, automatic fire suppression systems fall into two categories: engineered and pre-engineered systems. [6] Engineered fire suppression systems are design specific and most commonly used for larger installations where the system is designed for a particular application ...
In the 1960s, fluoroalkanes and bromofluoroalkanes became available and were quickly recognized as being highly effective fire-fighting materials. Much early research with Halon 1301 was conducted under the auspices of the US Armed Forces, while Halon 1211 was, initially, mainly developed in the UK. By the late 1960s they were standard in many ...