Montmorillonite clay is used in some natural pet foods as a natural anti-caking agent. It allows high-quality pet foods to remain free of man-made and chemical agents for this purpose. In addition, it is a natural source of minerals so it may bring with it added health benefits to pets. Since montmorillonite clay comes from the earth, some customers have asked about contamination by dioxin. Nature’s Logic® purchases its clay from a supplier whose product has been tested and shown to contain no dioxin.