Toxic emissions from pinewood crib fires were determined using heated FTIR gas analysis from a 5m 3 compartment fire with an air opening equivalent to 5% of the compartment cross-sectional area (V 2/3 ) in the floor of the compartment and a vent in the ceiling layer, with the air inlet controlling the flow. A 20mm square pine wood crib size of 400 x 400 x 260 mm was investigated. The crib was ignited using a small ethanol pool fire. The flaming fire had a peak HRR of 40 kW and average ceiling temperature of 400 o C. The fire was lean overall at the peak HRR and the fire self-extinguished through lack of air with subsequent smouldering combustion. In spite of the lean combustion in the fire, very high toxic emissions were determined with an FEC LC 50 of > 6. The peak toxicity occurred just before the fire self-extinguished and the key toxic emissions were CO and formaldehyde for deaths, while formaldehyde and acrolein were the most important for impairment of escape.