Description

Sodium Sulfite Heptahydrate is a white, crystalline inorganic salt widely used as a versatile reducing agent and preservative. Its primary commercial value lies in its ability to scavenge oxygen and inhibit oxidation, protecting products and processes from degradation. This makes it an essential chemical for industries ranging from water treatment and photography to food processing and textile manufacturing. We supply high-purity Sodium Sulfite Heptahydrate CAS NO 10102-15-5 to meet the stringent demands of global industrial applications.

Application

• Water Treatment: Acts as an oxygen scavenger in boiler feed water and dechlorination agent in municipal and industrial wastewater treatment.
• Photographic Industry: Serves as a key component in developing and fixing solutions due to its reducing properties.
• Food & Beverage (FCC Grade): Used as a preservative and antioxidant (E221) to maintain color and shelf-life in dried fruits, wines, and other products.
• Pulp & Paper Manufacturing: Employed in the pulping process as a bleaching agent and to remove residual chlorine.
• Textile Industry: Functions as a bleaching, desulfurizing, and dechlorinating agent for fabrics and yarns.
• Chemical Synthesis: Utilized as a reducing agent and sulfonating agent in various organic synthesis reactions.
• Pharmaceutical Intermediates (USP/EP Grade): Used in the production of certain APIs and as an excipient where high purity is critical.
• Mining & Metallurgy: Applied in ore flotation and as a reducing agent in metal processing.

Basic Information

Product Name	Sodium Sulfite Heptahydrate
CAS No.	10102-15-5
Molecular Formula	Na2SO3 · 7H2O
Molecular Weight	252.15 g/mol
Synonyms	Disodium sulfite heptahydrate; Sulfurous acid, disodium salt, heptahydrate; Sodium sulphite heptahydrate; Exsiccated sodium sulfite; Sodium sulfite (Na2SO3) heptahydrate; E221 (heptahydrate form); 10102-15-5
EINECS	231-821-4

Quality Control

Our Sodium Sulfite Heptahydrate is manufactured under a strict quality management system. Products are available in various grades, including Technical, Food (FCC), and Pharmaceutical (USP/EP) specifications, each undergoing rigorous analytical testing. We ensure compliance with relevant industry standards, and a Certificate of Analysis (COA) is provided with every shipment to guarantee purity, identity, and consistency.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, well-ventilated area at room temperature (15-25°C). This material is hygroscopic (moisture-sensitive) and easily oxidized; prolonged exposure to air will lead to absorption of moisture and carbon dioxide, forming sodium sulfate and sodium carbonate. For long-term storage, consider an inert atmosphere.

Specification

Item	Specification
Appearance	White crystalline powder or granules
Identification (IR)	Conforms
Assay (Na2SO3·7H2O)	≥ 98.0 %
pH (5% Solution)	8.5 - 10.5
Heavy Metals (as Pb)	≤ 10 ppm
Iron (Fe)	≤ 10 ppm
Water Insoluble Matter	≤ 0.05 %
Chloride (Cl)	≤ 50 ppm

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