The 20-400 White Metal Aluminum Cap has a gold food-grade interior coating. The Pulp & aluminum liner provides a very good barrier to moisture and oxygen and is compatible with a wide range of products. The liner features aluminum foil as the product contact surface with a pulp backing. Should not be used with any acids, bases, corrosives or aqueous products. Please test with your product to determine the suitability of this cap for a specific application.