Guillaume Capon, CREPIM (fire research and testing, France), presented the initial review of published scientific data on whether PIN flame retardants impact the toxicity of smoke emissions, prepared for pinfa (see pinfa Newsletter n°85). 135 relevant scientific articles were identified after a thorough search of scientific publications from the last 30 years, with 22 being identified as containing evidence or data.
The conclusion is that smoke is always toxic, that the nature of the material burning can impact toxicity by a factor of up to 10, but that this is considerably less important than the fire conditions (ventilation = oxygen available) = factor of up to 100. Acute smoke toxicity is caused mainly by carbon monoxide, emitted by any material burning in under-ventilated conditions (as is almost always the case in accidental fires), whereas chronic toxicity (long term, concern for fire fighters) is mainly caused by small particles of soot, related to PAHs and dioxins/furans. Non flame retarded materials will generally burn more, so causing more toxic emissions. PIN flame retardants may in some case act in the gas phase, but they do not contribute to the generation of highly toxic polyhalogenated dioxin/furan emissions. The action of PIN flame retardants in the solid phase will help to trap gases and soot, and so reduce toxic emissions. The positive effect of PIN FRs is conditional on using the right FR, adapted specifically to the polymer. However, the main conclusion of this initial science review is that data is lacking, particularly concerning soot emissions, and particularly as regards data from large scale fires or testing.