21 C.F.R. § 186.1750

(a) Sodium chlorite (NaCLO2, CAS Reg. No. 7758-19-2) exists as slightly hygroscopic white crystals or flakes. It is manufactured by passing chlorine dioxide into a solution of sodium hydroxide and hydrogen peroxide.

(b) the ingredient is used at levels from 125 to 250 parts per million as a slimicide in the manufacture of paper and paperboard that contact food.