Defoaming or an Anti-Foaming Agent is a chemical additive that reduces and hinders the formation of foam in industrial process liquids. Defoaming eliminate existing foam and anti-foamers prevent the formation of further foam. Commonly used agents are insoluble oils, polydimethylsiloxanes and other silicones, certain alcohols, stearates and glycols. The additive is used to prevent formation of foam or is added to break a foam already formed.