Humidity Requirements for Mold Growth

In the warm, humid areas of the United States and of the world, mold or mildew prevention ranks as a major pest-control problem.Leather goods, clothing, foods, mattresses, painted walls, and even glass camera lenses are subject to the unsightly appearance, stain, damage, or musty odor associated with the growth of the lowerorder plants belonging to the fungi and known popu- larly as mildew or mold.As has been mentioned previously in a discussion of the mildew problem (Block, 1946), mold requires for growth and proliferation certain essential physical and chemical conditions.These include satisfactory tem- perature, adequate moisture, sufficient oxygen, proper pH, and essential nutrients.Prevention of mold growth may be effected by restricting any of the above require- ments.Mildew may be controlled also by physical agents that destroy the organism, such as ultraviolet radiation and heat sterilization, and by chemical poi- sons called fungicides.The specific conditions best de- termine the method to be employed to prevent mold growth.In certain applications the control of moisture through regulation of humidity has proved to be most satisfactory (Block, 1951).This applies to the preven- tionof mildew in home closets, rooms, storage spaces and shipping units.