Sodium sulfite is a white, granular or powdered solid. It is used in the pulp and paper industry, in the photographic industry to keep developer solutions from oxidizing and to wash fixer from film and photo-paper, in the textile industry as a bleach, desulfurizer or dechlorinator and in the tanning of leather.Sodium sulfite (CAS 7757-83-7) is an odorless, solid white powder with a salty sulfurous taste that is soluble in water. It is primarily used as a food preservative (e.g., to prevent dried fruit from discoloring) and as an antioxidant. In the past, sodium sulfite was used to make pulp in the paper industry, but its use now accounts for less than 10% of the total pulp production, and the number of sulfite mills continues to decrease. Sodium sulfite is also used water treatment and photography