Non-flame retarded 8.1 5.5 x 10-7 0
Phosphorus based treatment 0.35 55.7 x 10-7 1.2 x 10-7
Bromine based treatment 0.45 234 x 10 2.88 x 10
0.57 7.7 x 10-7 0 0.57
0.024 78 x 10-7 1.68 x 10-7 0.024
0.031 328 x 10-7 4030 x 10-7 0.032
On the basis of these results, overall cancer risks (due to TCDD, TBDD and PAH emissions) were estimated for each type of furniture. This suggests that the differences in TCDD+TBDD emissions (order of g/million sofas/year) are considerably less significant than the differences in PAH emissions (order of kg/year), leading to an overall cancer risk factor for the non-FR furniture an order of magnitude higher than for the flame retarded furniture. One should keep in mind, however, that total cancer risk described above is very small compared to the risk from background emission levels from all sources of PAH and TCDD + TBDD.
Cancer risk due to PAH and PCDD/F emissions.
BaP equivalent (kg)1 TCDD equivalent (kg) TBDD equivalent (kg)
Cancer risk BaP2 Cancer risk TCDD Cancer risk TBDD Sum Cancer Risk 2 2 3
For one million sofas over their 10 year life time. Unit risk factor x equivalent (BaP-equiv. emissions×URFBaP) + (TCDD-equiv.×URFTCDD
) + (TBDD-equiv.×URFTCDD
Unit Risk Factor (URF)
1.4 µg/m3 Assume equivalent to
The major conclusions from the study are:
The addition of flame retardants to meet the UK furniture fire safety requirements resulted in a sofa with significantly improved resistance to ignition and flame spread
The major part of the NOx, CO and CO2 emissions was due to the furniture production while the fires were responsible for the major part of the HCN, PAH, PCDD/F and PBDD/F emissions.
The non-FR treated case gave higher HCN and PAH emissions due to the larger number of fires that these sofas are involved in. The HCN emission for the non-FR furniture life cycle was 4-80 times those from the FR cases. The PAH emissions from the non-FR furniture were 10-25 times those from the FR cases.
The TCDD and TBDD equivalents, and HCl, were higher for the FR furniture, than for the non-FR case.
A true estimate of the environmental impact of the adoption of high fire performance material cannot be made without the inclusion of the emissions associated with a fire. In the case of certain key species (e.g. PAH, dioxins) fire emissions are a significant part of the total environmental impact.
Ideally, when evaluating the environmental and societal impact of the choices made to adopt a high level of fire safety one should include all the emissions presented in this report. Currently no agreed evaluation method to take into account and compare all the different emissions using the Fire-LCA Model exists. However, the following general observations can be made:
Controlling the ignitibility and growth of fires in furniture has a major effect on reducing certain toxic environmental pollutants such as PAH.
Since the non-FR sofa did not contain significant amounts of halogen additives much lower amounts of halogenated species (TCDD and TBDD equivalents) were calculated for this sofa during its life cycle. However, in contrast, the non-FR sofa emitted far greater amounts of PAHs than either of the FR treated sofas.
Applying the ‘Unit Risk Model’ enables an indication of the relative importance of these two classes of toxic environmental pollutants to be obtained. This model compares the potential cancer risks due to dioxins and furans to that from PAHs. Using this model one can see that:
8 HCN is not significant from an LCA perspective as emissions are low compared to other sources but is included in the analysis since it is a very toxic substance that is considered to cause a lot of deaths in fire situations.