SUMMARYRates of carbon dioxide production, in air and in 3 % 02, over a range of temperatures, were measured for over thirty commodities, and rates of evaporation, under known water vapour pressure deficit, measured for most of them. Optimum storage conditions in air for each commodity were determined. Storage life under these optimum conditions, and under the nearest practical approximation to them, was estimated. In most cases the optimum temperature is ooC, examples of exceptions being runner beans, cucumbers, potatoes, green peppers and tomatoes. The humidity should usually be high, 100 % r.h. often being optimal, particularly for leafy vegetables, provided the temperature is low. Commodities resistant to evaporation, however, such as the onion, may with advantage be stored at lower humidities, thus reducing the microbial hazards.