This experiment involves the burning of a given mass of 100% folded cotton bath sized towels at a fixed ventilation rate of 5 and 10 air change per hour in a small steel chamber of 0.03762m3 attached to a conical shaped heater of the Cone Calorimeter. The ignition of the cotton was investigated at 25KW/m2. A Temet FTIR was used for the toxic gas measurement for raw and diluted tests. Comparison of the two set of data have shown that cone calorimeter with simulated enclosure is a good method for the evaluation of toxicity from materials under air starved fires, but is unrepresentative of CO yields at very low ventialtion rate (5ACH) due to the non repeatabilty of the measured HRR beteween raw and diluted test but repeatable at 10ACH The cotton fires was also observed to exhibited both flaming and slow smouldering combustion with the low yield of acrolein and formaldehyde in the peak heat release rate region, but very high in the smouldering combustion phase. Carbon monoxide and benzene yields were high in the peak fire heat release, but low in the smouldering phase. Analysis of the results using the standard toxicity limits (COSHH and LC50) have shown a good agreement between these toxic limits interms of time to location of the peak toxicity. COSHH 15 minutes toxicity assessment method gave acrolein as the dominant toxic gas for both intense and smouldering fires, while LC50 put CO as the dominant gas. Acrolein, formaldehyde, CO and benzene were found to be the most dominant gases in this experiment.
