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All preservatives must be listed on the label. In canned foods, preservatives are used to maintain quality. The canning process keeps it safe. If a product is correctly processed, it should remain safe until opened or the seal is broken. The U.S. Army has found that canned meats, vegetables and jam were in "excellent states of preservation" after 46 years. However, long storage is not recommended. For high quality (versus safety), the broadest guideline given by the U.S.D.A. is to use high-acid canned food (fruits, tomatoes and pickled products) in 18 to 24 months, and low-acid (meats and vegetables) in two to five years.

Information developed by Carolyn Rude, Retired WSU Extension Faculty - Family Living
March 1997