Posted on 15/10/2014 in News 32 2014
Scientists discuss whether fire risks justify using PIN FRs

In the recently published book on “Polymer Green Flame Retardants” (2014, see image), David Purser and Vyto Babrauskas et al. discuss whether or not the use of flame retardants is justified when compared to the chemical risks of toxic and environmental impacts:

David Purser examines how flame retardants can reduce fire dangers by reducing the probability of ignition (start of fire) and by slowing subsequent fire growth and flame spread, so giving more time for occupants to escape or for fire suppression activities. He compares the cases of upholstered furniture & bedding in the UK where fire deaths decreased since the 1988 UK furniture fire safety regulations (combined with other factors such as implementation of smoke alarms) and televisions in the USA where fires increased after a reduction in the use of flame retardants.
Dr. Purser presents in detail fire test data from FR and non FR upholstered furniture, showing that the use of FRs definitely can improve fire performance and tenability time (ASET = the time during which escape is possible from a room), with increases ranging from a few minutes to 20 minutes. He underlines that even just one minute of increased time before rapid fire growth can significantly increase the chance of occupants reaching safety.
He concludes that “FR systems and additives reduce fire losses, fire injuries, and deaths by reducing the probability of serious fires developing …. increasing the time to rapid fire development and the size of the ultimate fire, thereby increasing the time available for escape and the probability of survival for occupants”.

He underlines that, to compare overall advantages and disadvantages of the use of FRs, it is essential that each FR system is examined individually, looking at the extent of release into the environment, bioavailability and possible associated toxic effects. Because FR systems vary enormously for these parameters “it should be possible to choose candidates (FR systems) for all applications which are ‘environmentally friendly’ while still providing a useful fire safety function”.
Vyto Babrauskas, Rebecca Fuoco and Arlene Blum discuss compare the benefits of using flame retardants in polymers with the toxicity risks. They note that “when a number of halogenated FRs received detailed study, they were found to be persistent when introduced into the environment and to have serious adverse health consequences”. No toxicity concerns are expressed about FRs other than halogenated FRs and phosphorus esters, and the authors suggest that less data is available for other types of FR. Concerning benefits of FRs, the authors note that FRs bring a fire safety benefit if they achieve at least one of the following:

  • significantly reduce the severity of fire, once a material is ignited
  • prevent ignition by small flames, for consumer products

They suggest that in furniture foam, FR systems used in the USA do not reduce severity of fire and, in the actual furniture, do not prevent ignition because the flammable covering textile ignites and overcomes the foam’s fire resistance. [note: this is not applicable in the UK, where the furniture fire safety regulations require FRs to achieve reduced heat release from foams and where the covering textile is fire resistant.]
They indicate that in building insulation foam, fire safety treatment could be not necessary on condition that the foam is protected by a fire resistant covering (e.g. plaster board), provided that building regulations ensure rigorously that fires cannot reach insulation material by penetrating cavities and voids, for example.

These authors also consider small flame resistance requirements for TV sets. They show that best estimates for TV set fires are 18.2 fires/million TVs/year in Europe (FRs not used in TV casings) and 13 in the USA (FRs are used) but they consider that this data does not clearly show a fire safety advantage.

They conclude that when assessing flammability standards and fire safety regulations, the long-term environmental and human health impacts of flame retardants should be taken into account, as well as life-cycle impacts associated with production, use and disposal, in particular for standards and regulations concerning consumer products. Their general conclusion is that alternative designs, non-flammable materials, fire barriers and safer chemicals should be considered. “Currently, several halogen-free compounds have been shown to be effective FRs, and almost all production polymers … have halogen-free formulations that will meet current fire safety standards”.

“Fire safety Performance of Flame Retardants Compared with Toxic and Environmental Hazards”, David Purser, Hartford Environmental Research, UK, 36 pages
“Flame Retardant Additives in Polymers: When do the Fire Safety Benefits Outweigh the Toxicity Risks?”, Vytenis Babrauskas, Fire Science & Technology Inc., USA, Rebecca Fuoco and Arlene Blum, Green Science Policy Institute, USA, 36 pages
In: “Polymer Green Flame Retardants”, Ed. C. Papaspyrides and P. Kiliaris, Elsevier ISBN 978-0-444-53808-6, 924 pages, September 2014, 124€ 
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