Halon 1301, R13B1, Halon 13B1 or BTM (Bromotrifluoromethane), is an organic halide with the chemical formula CBrF3 that is used for fire suppression. It is far less toxic than other fire suppressing agents, such as bromochloromethane.
Halon 1301 was developed in 1954 in a joint venture between DuPont and the U.S. Army. It was introduced in the 60’s as a gaseous fire suppression fixed systems agent that was effectively used in total flooding systems, aircraft, telecommunication switching centers, and mainframe computers and other valuable materials. The maritime industry also used it widely as a third level of protection, in the event that main and emergency fire pumps become ineffective or inoperable.
Due to its limited range and invisible discharge, Halon 1301 was never widely used in portables outside of military and spacecraft applications. Unlike CO2, Halon 1301 does not produce the characteristic white cloud, and when fighting large fires, it is challenging to direct. It produces fewer toxic byproducts than Halon 1211, which is critical for combat or space conditions where a compartment may not have the ability to be immediately ventilated, so Halon 1301 is ideally suited for spacecraft and armored vehicles. Contained in 2.75 pound portable extinguishers with sealed, disposable cylinders for quick recharging, Halon 1301 is widely used by the U.S. Military and NASA.
Due to environmental concerns, Halon 1301 is widely being replaced by other agents such as CO2 and E-36 Cryotech wet chemical. Other sizes such as 2.75, 3, and 4 pounds were also made as civilian models.
Avoiding all unnecessary exposure to Halon 1301 is best practice, as is limiting exposures to concentrations of 7% and below to 15 minutes. Little to no effects are noticed when exposure to Halon 1301 is in the 5% to 7% range, however at levels between 7% and 10% central nervous system effects such as tingling in the extremities and dizziness have been documented. Evacuation is common practice for the operators of many Halon 1301 total flooding systems, upon the impending discharge of the agent.
Being the primary agent used in commercial aviation engine, auxiliary power unit fire zones, and cargo compartments, Halon 1301 systems are among the most commonly used and effective fire protection systems used on commercial aircraft. Efforts to find a suitable and widely accepted replacement for Halon 1301 have not been successful.