These two ingredients are used in cosmetics as thickeners, helping to keep ingredients blended together, and for their foaming abilities. They can be both synthetic or naturally derived (e.g. from coconut oil), and are considered safe for use in cosmetics in concentrations of up to 10%. Cocamide DEA can react with other ingredients to create harmful substance known as nitrosamines. For that reason, it is advised against its use by the Cosmetic Ingredient Review Board.