The combustion products released by fires in agrochemical warehouses are reviewed and a set of elemental conversion efficiencies for production of gases such as hydrogen chlorine and sulphur dioxide is recommended for fire hazard analysis. In the absence of better data, it is recommended that the toxicity of the resulting smoke plume is calculated as the sum of dangerous dose fractions for each toxic component irrespective of its action on the body. It is argued that the hazard from combustion products released by many warehouse fires is at least as great as that from vaporized parent compounds, but that actual hazard range is a complex function of warehouse inventory, the way it is distributed throughout the warehouse, the location of the seat of the fire and the rate of spread of the fire.