The sugar industry is confronted with the problem of safe bagasse storage over extended periods. For long term storage, bagasse is accumulated in large exterior stockpiles of 200-3 000 tonne capacity for periods ranging from six months to three years. The quantity in storage is determined by the specific steam production requirements of an individual mill. Current storage capacity is relatively small. If an alternative paper or chemical feedstock usage for bagasse developed, the quantity in storage at one site could exceed 100 000 tonnes. In all mills the bagasse bin operates a s a buffer fuel storage and is a critical part of the boiler fuel supply system. Spontaneous combustion of bagasse in this situation represents a significant threat to the integrity of capital plant in addition to the loss of a valuable energy source. The paper is concerned primarily with external bagasses storage.