THERMAL BEHAVIOR AND TOXIC EMISSIONS OF FLAME RETARDED TIMBER IN CONE CALORIMETER TESTS
Free (open access)
Volume 1 (2011), Issue 1
45 - 64
The thermal behavior and toxic emissions of timber products common in industrial buildings in Northern Greece treated or not with ﬂame retardants are investigated. Eight species of wood treated or not with three typical intumescent ﬂame retardants were subjected to constant incident heat ﬂuxes of 35, 50, 65 and 80 kW/m2 in a cone calorimeter linked to the FTIR analyzer. The test results presented in this paper cover the following characteristics: (i) time to ignition, (ii) heat release rate (HRR), (iii) average (300 s) HRR, (iv) effective heat of combustion (MJ/kg), (v) smoke production and (vi) toxic species emissions. The main ﬁndings of the experimental analysis are that under the inﬂuence of the ﬂame retardants: there was either ‘no ignition’ of the samples or a considerable ignition delay (at lower irradiances) compared with untreated samples. Thermal emissions signiﬁcantly decrease in terms of the values of ‘peak HRR’ and ‘First 300 s Mean HRR’ (by a factor varied from 2 to 5 up to type ﬂame retardant used). In the cases of ﬂame retarded samples, where there was ‘no ignition’ or a considerable ignition delay of the samples there were similar or less toxic emissions compared with the bare samples. NH3 was an exception, since both ﬂame retardants contained ammonium in their chemical composition, which was released during the intumescent action of the samples. Based on the results of this study, the application of intumescent ﬂame retardants on wooden surfaces is proposed for the cases where ‘no ignition’ or considerable ignition delay occurred. This could be a safe and cost effective approach in reducing ﬁre losses in industrial buildings.
cone calorimeter, emissions, flame retardant, heat release rate, ignition, intumescent, wood