Formula K4P2O7, MW 330.35, CAS 7320-34-5. White powder or lumps, density 2.534, m.p. 1109 degC, soluble in water giving an alkaline solution (pH 10.2 for 1%). Used in food industry as emulsifier, texture improver and chelating agent; prevents struvite in canned aquatic products and discolouration of canned fruit, improves ice-cream overrun and ham/sausage yield. Packed in 25/50/1000 kg plastic-lined woven bags.