Mono Ammonium Phosphate Powder ( i.e. ABC Powder) Features This product is made ammonium dihydrogen phosphate (different specifications available depending on different content to meet user?s varied requirements) and treated by complete silication damp-proof and caking-proof processing. It can be used in multiple fire-fighing to extinguish fires of class A, classs B and Class C and is therefore also called ABC general powder extinguishing agent.