High moisture content of bread and other bakery products encourages the growth of molds. Molds are killed during the baking process, but airborne contamination of bakery goods occurs when they leave the oven and mold spores are subsequently picked up from the atmosphere, during and after cooling, and from the equipment. Although strict attention to bakery hygiene can greatly reduce contamination, it is not completely eliminated. The rate of mold growth on bread is affected by the number and type of spores present. It is accelerated by high storage temperatures and humidity and it is also influenced by the recipe employed. Wrapped sliced bread is particularly susceptible to mold. The use of a preservative is therefore beneficial in extending the mold-free shelf life of bakery products.