Triethanolamine and diethanolamine are widely used in cosmetics as emulsifiers and/or foaming agents (giving a creamy texture). They can cause allergic reactions, eye irritation and dryness of hair and skin. DEA and TEA can form cancer-causing nitrosamines when they come in contact with nitrates. They are toxic if absorbed into the body over a long period of time. Triethanolamine is used in the manufacture of a type of mustard gas for chemical warfare.