S 1312 (OTTO) Selenic acid, 98% Cas 7783-08-6 - used as a specialized oxidizing agent. S 1312 (OTTO) Selenic acid, 98% Cas 7783-08-6 - used as an oxidizing agent. Its derivative sodium selenate is used in the preparation of glass and animal feeds. It acts as an analytical reagent and also used for the preparation of other selenium salts such as gold(III) selenate.