Glacial acetic acid (C2H4O2) is a concentrated form of acetic acid, containing no water. It typically has a purity level of over 99%, making it an essential reagent in laboratories and manufacturing. Its most significant uses include the production of acetate fibers and plastics, a critical component in the synthesis of various chemicals, and as a preservative in the food industry—especially in pickling.
In addition to baking, E920 is sometimes used in processed foods to enhance texture and stability. It can help maintain the quality of certain meat products, where it functions similarly to its role in dough by providing improved structure and moisture retention.