A preservative is a substance that is added to food or other perishable items to extend their shelf life and prevent spoilage. Formalin, an 8-letter word, is a preservative made from formaldehyde and water, and is used to preserve biological specimens. An 8-letter word for another preservative is ADDITIVE, which is a general term for any substance added to food to enhance its flavor, texture, or shelf life. ICE, a 3-letter word, is also a preservative, as freezing food can slow down the growth of bacteria and other microorganisms. SALT, a 4-letter word, is another preservative, as it draws moisture out of food, making it difficult for bacteria to grow. Finally, BRINE, a 5-letter word, is a preservative solution made from SALT and water, and is used to pickle vegetables and other foods.