Preservers are substances or agents used to maintain the quality and extend the shelf life of food, cosmetics, and other products. They work by preventing spoilage caused by bacteria, mold, and oxidation. Common examples of preservatives include sodium benzoate, sorbic acid, and vitamin E. In addition to food preservation, some preservers are used in industrial applications, such as protecting wood from decay or preventing rust on metal surfaces. The use of preservatives is regulated by health authorities to ensure safety and effectiveness, balancing the need for longevity with potential health impacts.