Toxic Emissions from Processed Wood in Cone Calorimeter Tests

Bintu G. Mustafa1*, Miss H. Mat Kiah3, Juma Al-Nahdi2, Gordon E. Andrews2, Herodotos N. Phylaktou2, Hu Li2

1Chemical Engineering, University of Maiduguri, Bama Road, P.M.B 1069, Maiduguri, Nigeria
2Schools of Chemical and Process Engineering, University of Leeds, Leeds, LS2 9JT, UK
3Department of Energy Engineering, Faculty of Chemical and Energy Engineering, Universiti Teknologi, Malaysia

*Corresponding author’s Email: bintgrem@yahoo.co.uk, doi.org/10.55639/607.171615


ABSTRACT

Despite the high number of deaths in fires due to toxic gases, there are no specific toxic gas requirements for materials used in buildings. The only standard for building materials in fire tests is smoke visibility obscuration. As our modern world increasingly uses wooden materials in buildings, a comprehensive understanding of their chemical nature and fire-related properties becomes indispensable Oriented Strand Board (OSB), Medium Density Fiberboard (MDF), and Chipboard faced with white melamine (CFM) were investigated for toxic gas measurements. The tests were conducted using a standard cone calorimeter with raw gas sampling (predilution) via an 80mm diameter chimney mounted atop the cone heater exit. Heated gas sampling and Gasmet FTIR toxic gas analysis were done using a 20 hole mean gas sample probe at the conical heater outlet plane. Each wood sample was exposed to the cone calorimeter radiating at 35 kW/m², with ignition delays of 69 s (OSB), 142s (CFM), and 54 s (MDF). Although the peak heat release rates (HRR) were similar across samples, the time variations differed, with CFM showing slower fire growth to peak HRR. The glued surface and manufacturing process introduced about 5% of organic nitrogen compounds into MDF and CFM, leading to very high levels of HCN immediately after the fire started. OSB contained 1/10th the organic nitrogen of CFM and MDF, leading to much lower HCN levels. However, OSB produced four times more formaldehyde and acrolein than CFM and MDF, dominating early-stage fire toxicity. The critical toxic species for all three wood types were carbon monoxide (CO), acrolein, formaldehyde, and benzene, based on both LC50 and COSHH15min basis, which indicates escape impairment.

Keywords:

Fire,
Toxicity,
Wood,
Smoke