N-MASS 防腐剂;保护剂 A preservative is a chemical that prevents things from decaying. Some preservatives are added to food, and others are used to treat wood or metal. 防腐剂;保护剂
Nitrates are used as preservatives in food manufacture.
硝酸盐在食品加工业中被用作防腐剂。
Though the panels come pre-treated, they needed a final sealing with two coats of preservative.