In a letter to the assembly opposing the labeling requirement, Grocery Manufactuers of America noted that MPCs are an essential ingredient in a wide variety of products ranging from infant formulas, soups, hot dogs, breakfast foods, protein bars, and beverages. They have more functionally superior attributes than nonfat dry milk, including the removal of milk components that are undesirable in some products.
Simply identifying MPCs as an ingredient provides no health or nutrition information to consumers and may inadvertently discourage consumption of these products by people who need them. COO labeling would be burdensome to food manufacturers because currently there is no domestic supply of casein or MPC. Manufacturers rely on multiple sources from different countries, depending upon availability. GMA noted that USDA has stated it would pre-empt any COO labeling enforcement actions.