An article by materials fire safety expert Marcelo Hirschler in “Fire Protection Engineering” provides an overview of toxicity questions related to different flame retardants and to fire smoke and gases.
As summarised in pinfa Newsletter n°54, Mr. Hirschler first argues that the key to reducing fire injuries and deaths is heat release rate (how fast a fire gets hotter). Inhalation of combustion products is cause of death for 2/3 of fire fatalities, and a study of more than 5 000 fatalities in the USA showed that this is principally related to carbon monoxide (CO) asphyxiation.
CO emissions are linked to the quantities of materials burned, at around 0.2 g CO per g material consumed. Mr. Hirschler writes “The overall smoke toxicity of materials containing flame retardants is not significantly different from that of materials that do not contain flame retardants.” Although FRs inhibit combustion, the level of CO is around 20% of fire gases irrespective of the materials burning in large fires. All fire smokes also contain, at very low concentrations, different chemicals which are potential carcinogens, in particular PAH (polycyclic aromatic hydrocarbons) the most toxic of which is BAP (benzo[a]pyrene). The author considers that the exposure hazard to professionals (e.g. fire fighters) regularly confronted by these known carcinogens in smoke is extremely high compared to relatively minor contributions resulting from halogenated flame retardants. He concludes that flame retardants “are an essential first line of defence in terms of passive fire protection … Published data overwhelmingly shows that flame retardants do not contribute significantly to either acute or chronic fire toxicity in real fires. While some flame retardants have been removed from the market in recent years, the vast majority in commercial use do not present significant toxicological concerns.”
“Flame retardants and the associated toxicity”, M. Hirschler, Fire Protection Engineering, 2015-10-01 http://www.sfpe.org/?page=FPE_2015_Q4_2