Optimising the number of layers in firefighters' hoods

To optimise protection from fire afforded to the head, an investigation into layering of firefighters' hoods was undertaken. Hoods made from 1 to 4 layers of Kermel/FR Viscose (50 per cent blend) were flame challenged for up to 10 seconds (53 kW m⁻² to 85 kW m⁻²) on a manikin head. Protection was increased with more layers. After four seconds of flame it was predicted that 74 per cent of the head suffered 2° or 3° burns with a 1‐ply hood. This fell to 59 per cent and 45 per cent respectively, when a breathing apparatus mask and helmet were also worn. For a 4‐ply hood corresponding predicted burns fell to 13 per cent, 8 per cent and & 8 per cent. Between 50 per cent to 67 per cent of these reductions occurred using a 2‐ply hood, and 80 per cent with 3‐ply. In conclusion, the most appropriate benefit was gained by adopting a 2‐ply hood. Three or more layers interfered with helmet fitting and communications, and offered little increased benefit.