Traditionally, the two(food preservatives) are often distinguished by use rather than chemical structure, because the same substance, such as phenol, is used as a preservative at low concentration and as a disinfectant at high concentration. Most people believe that the term preservative is not applicable to drugs for systemic application. Drugs commonly used as preservatives and disinfectants include various substitutes of phenol, such as biphenols, cresols, xylenols, cationic surfactants, halogens, oxidants such as hydrogen peroxide and permanganates, aniline dyes and acridine dyes, heavy metal salts and alcohols (alcohols) and aldehy DES, etc.
Food preservatives are also used as food additives for the purpose of maintaining the original quality and nutritional value of food. 25 kinds of preservatives are specified, such as benzoic acid, sodium benzoate, sorbic acid, potassium sorbate, calcium propionate, etc.