5 How safe is Halon?
Halons are low-toxicity, chemically stable compounds that have been used for fire and explosion protection from early in the last century. Halon has proven to be an extremely effective fire suppressant. Halon is clean (i.e., leaves no residue) and is remarkably safe for human exposure. Halon is a highly effective agent for firefighting in closed passenger carrying areas. Due to its effectiveness and relatively low toxicity, the FAA continues to recommend or require Halon extinguishers for use on commercial aircraft.
Extensive toxicity evaluations have been compiled by nationally recognized United States medical laboratories and institutions on Halon 1301 and Halon 1211. These evaluations have shown that Halon 1301 is the safest extinguishing agent available, and that Halon 1211 is the second safest. Dual Halon concentrations of about 5% by volume in air are adequate to extinguish fires of most combustible materials. This concentration is equivalent to emptying twelve 2.5 lb. units in a closed room of 1000 cubic feet, which would be highly unlikely.
6 Does Halon remove oxygen from the air?
It is a common misconception that Halon, like CO2, "removes oxygen from the air."
According to the Halon Alternative Research Corporation (www.harc.org): "Three things must come together at the same time to start a fire. The first ingredient is fuel (anything that can burn), the second is oxygen and the last is an ignition source. Traditionally, to stop a fire you need to remove one side of the triangle-the ignition, the fuel or the oxygen. Halon adds a fourth dimension to fire fighting-breaking the chain reaction. It stops the fuel, the ignition and the oxygen from working together by chemically reacting with them.
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