This standard covers monosodium phosphate, anhydrous, for water supply service. The product described is an orthophosphate used as formulated and in blends to inhibit corrosion of potable water conveyance systems. The product described by this standard is also known as sodium phosphate, monobasic, anhydrous. The main purpose of this standard is to provide purchasers, manufacturers, and suppliers with the minimum requirements for monosodium phosphate, anhydrous, including physical, chemical, packaging, shipping, and testing requirements. The major revisions in this edition of ANSI/AWWA B504 include the following: The format has been changed to reflect current AWWA standard style; The acceptance clause (Sec. I.C) and definitions (Sec. 3) have been revised to approved wording; and Editorial revisions have been included throughout the standard.