Halogenated flame retardants
Bromine, chlorine, fluorine and iodine, are the elements in the chemical group known as halogens. Halogen is derived from Greek, meaning ‘salt-former’, referring to elements which produce a salt in union with a metal. For example, sodium chloride, or table salt, is the most common example of a halogen salt.
Halogenated (those containing bromine and chlorine)flame retardants interfere with the chemistry of the flame.
Halogenated flame retardants function primarily by removing the H and OH radicals during the ignition phase of a fire; acting directly on the flame. When heated, halogenated flame retardants release bromine or chlorine radicals; these react with the hydrocarbon molecules in the flammable gas mixture (smoke) to create hydrogen bromide (HBr) or hydrogen chloride (HCl). These gases then react with the high-energy H and OH radicals, releasing water vapor and the lower-energy Br and Cl radicals—which may remain available to repeat the cycle.
To summarize, the halogen radicals released as the material heats up interfere with gas-phase combustion, slowing or blocking ignition.
Flame retardant chemicals are associated with a variety of serious health and environmental concerns
Halogenated flame retardants have been associated with a variety of serious health concerns, including disruption of hormones, developmental and reproductive problems; create toxic, carcinogenic byproducts if burned, which may be associated with higher rates of cancer in firefighters; halogenated flame retardants build up in wildlife and are found throughout freshwater, marine, and terrestrial ecosystems globally, with the highest levels in top of the food chain predators like birds of prey and marine mammals and are associated with altered behaviors and decreased reproductive success in some species.