PBTC is 2-phosphonobutane-1,2,4-tricarboxylic acid, an organophosphonate scale inhibitor, chelating agent and corrosion inhibitor. It is used in cooling water, boiler water treatment and industrial cleaning and bleaching agents. Applications include the food-processing and textile industries. The catalogue describes stability at high pH and elevated temperatures. The material is a clear, colourless to pale yellow aqueous solution. Recorded packaging includes 250 kg plastic drums, 1250 kg IBCs and bulk tankers.