The shelf life of food refers to its best edible period. Article 99 of China's Food Safety Law, which was implemented in 2009, clearly stipulates that the term "shelf life" as mentioned in this law refers to the time limit for prepackaged foods to maintain its quality under the storage conditions specified in the label. The shelf life of a product refers to the best edible period of the product. The shelf life of the product is provided by the manufacturer, and marked on the product to limit the use. During the warranty period, the product manufacturer shall be responsible for the product quality meeting the relevant standards or the quality conditions explicitly guaranteed. Sellers can sell these products with confidence, and consumers can also use them with confidence. Shelf life is not the only criterion to identify whether food and other products have deteriorated. The reason for deterioration may be the premature deterioration of substances with changes in storage methods and environment. Therefore, food should be eaten as soon as possible before the expiration of the shelf life.