Preservatives refer to a class of additives that can prevent the deterioration of goods, including food preservatives as well as chemical preservatives. For food preservatives, a small amount of consumption or exposure usually has no significant effect on the human body, but if a large amount is ingested, it may be harmful to the human body. Exposure to or accidental ingestion of chemical preservatives can produce relatively more serious harm to the human body. Preservatives include more types, such as sorbic acid and potassium sorbate in food preservatives, which are internationally recognized as safer preservatives and usually do not affect the body’s intestinal flora and can be degraded by the digestive tract, but a large intake can also affect the metabolic balance of the body. It is not recommended to consume too much food containing preservatives, especially for special groups such as children and pregnant women. Preservatives such as benzoic acid are corrosive and may be harmful to the liver and kidneys when consumed in excessive amounts and should be avoided. Chemical preservatives, such as formalin, are aqueous solutions of formaldehyde, which have the effect of antiseptic and sterilization, are corrosive and have an irritating odor and are toxic, and are mainly used for soaking animal specimens. If the skin contact formalin, may cause allergic reactions, should avoid direct skin contact, if inadvertently touched should use water to rinse. In addition, due to the strong volatility of formalin, it can also cause irritation to the eyes as well as the mouth and nose, which may lead to tearing eyes and coughing. Therefore, the state prohibits the use of such additives in food.