Description

Sodium Sulfite is an essential inorganic chemical compound widely used as a versatile reducing agent and preservative. Its ability to scavenge oxygen and inhibit oxidation makes it a critical component for maintaining product stability and quality across numerous industries. Key industrial users include manufacturers in the pulp & paper, water treatment, photographic, and food processing sectors, where it ensures process efficiency and product longevity.

Application

• Pulp & Paper Industry: Used as a delignifying agent and bleach in the Kraft process to produce high-quality paper pulp.
• Water Treatment: Acts as an effective oxygen scavenger and dechlorination agent in boiler feed water and wastewater treatment systems.
• Food & Beverage Preservation: Employed as an antioxidant and preservative (E221) to prevent spoilage and maintain color in dried fruits, wines, and other food products.
• Photographic Industry: Serves as a developing agent in photographic solutions to reduce silver halides.
• Chemical Manufacturing: Functions as a reducing agent and sulfonation intermediate in the synthesis of various chemicals, including dyes and pharmaceuticals.
• Textile Processing: Used as a bleaching, desulfurizing, and dechlorinating agent for fabrics.
• Mining & Metallurgy: Applied in ore flotation and as a precipitant for heavy metals from waste streams.

Basic Information

Product Name	Sodium Sulfite
CAS No.	7757-83-7
Molecular Formula	Na2SO3
Molecular Weight	126.04 g/mol
Synonyms	Disodium sulfite; Sulfurous acid, disodium salt; Sodium sulfite anhydrous; Exsiccated sodium sulfite; Natrii sulfis; E221
EINECS	231-821-4

Quality Control

Our Sodium Sulfite is manufactured under strict quality management systems to ensure batch-to-batch consistency and reliability. We offer various grades, including Technical, Food (FCC), and Photo grades, each meeting stringent specifications. Comprehensive testing is performed, and a Certificate of Analysis (COA) is provided with every shipment to guarantee compliance with relevant industry standards.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, well-ventilated area away from incompatible materials. Due to its hygroscopic and easily oxidized nature, the container should be kept tightly sealed under an inert atmosphere for long-term storage to prevent moisture absorption and oxidation. Recommended storage temperature is 15-25°C.

Specification

Item	Specification
Appearance	White crystalline powder
Identification (IR)	Conforms
Assay (as Na2SO3)	≥ 98.0 %
Iron (Fe)	≤ 10 ppm
Heavy Metals (as Pb)	≤ 5 ppm
Water Insolubles	≤ 0.01 %
pH (5% solution)	9.0 - 10.5

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.