Bromotrifluoromethane
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Image:Bromotrifluoromethane-chemical.png Halon 1301 is a trade name for bromotrifluoromethane, it is also known as BTM, Halon 1301 BTM, or Freon 13BI. The chemical formula is CF3Br. Its CAS number is Template:CASREF.
It was introduced as an effective gaseous fire suppression agent in the 1960s, and was used around highly valuable materials such as in aircraft, mainframe rooms, and telecommunication switching centers, usually in total flooding systems.
This is a volatile extinguishant that should be used only with a breathing apparatus (when volume exceeds 5%). In higher concentrations it causes giddiness and mildly impaired perception. There is also a risk of toxic and irritant pyrolysis products, hydrogen bromide and hydrogen fluoride.
After some lessons were learned in the Vietnam War, Halon 1301 started being used in the F-16 fighter aircraft to prevent the fuel vapors in the fuel tanks from becoming explosive; when the aircraft enters area with the possibility of unfriendly fire, Halon 1301 is injected into the fuel tanks for one-time use. Due to environmental concerns, trifluoromethyl iodide (CF3I) is being considered as an alternative. [1]
Alternatives to Halon 1301 in fire extinguishing systems are being deployed. Most of installations can be converted to fire sprinklers. In other cases, different total flooding agents can be used. The alternatives for normally occupied areas include C4F10 (PFC-410 or CEA-410), C3F8 (PFC-218 or CEA-308), HCFC Blend A (NAF S-III), HFC-23 (FE 13), HFC-227ea (FM 200), IG-01 (argon), IG-55 (argonite), HFC-125, or HFC-134a. For normally unoccupied areas, the alternatives include carbon dioxide, powdered Aerosol C, CF3I, HCFC-22, HCFC-124, HFC-125, HFC-134a, gelled halocarbon/dry chemical suspension (PGA), blend of inert gas and powdered aerosol (FS 0140), and IG-541 (Inergen). [2]