This standard covers sodium chlorite, in either solid (granular, flake, or powdered) or aqueous-solution form, for use in making chlorine dioxide for use in water supply service. Sodium chlorite must be packaged and labeled according to the Federal Insecticide, Fungicide, and Rodenticide Act, as administered by the US Environmental Protection Agency (USEPA). The main purpose of this standard is to provide purchasers, manufacturers, and suppliers with the minimum requirements for sodium chlorite, including physical, chemical, packaging, shipping and testing requirements. The major revisions in this edition of ANSI/AWWA B303-95 include the following: the format has been changed to AWWA standard style; and, the acceptance clause (Sec. I.C) and the definitions of parties (Sec.3) have been revised to approved wording.