Exactly how long it takes for a specific piece of paper to self-destruct depends on the exact nature of the chemicals used to make the product and the way in which paper is stored. Newsprint is usually the cheapest paper available and tends to be the first to decay. Newspaper clippings can often show a significant amount of aging in ten to twenty-five years. Other paper will decay more slowly, but any paper over fifty years of age may have developed significant problems. Heat speeds chemical reactions and causes phot paper to decay more quickly.
Humidity can also destroy paper.
Humidity does its harm in two ways. Humidity levels above seventy percent promotes mold growth. Rapid changes in humidity can also damage paper. Bright light, particularly sunlight and fluorescent light, can also injure records. Like heat, ultra-violet radiation can speed chemical reactions that harm paper.