Sodium Metabisulfite (SMBS)

Overview

Product Name	Sodium Metabisulfite
Chemical Category	Inorganic Reducing Agent / Preservative / Antioxidant
Molecular Formula	Na₂S₂O₅
Molecular Weight	190.10 g/mol
CAS Number	7681-57-4
Appearance	White or slightly yellow crystalline powder with pungent sulfur dioxide odor

Description

Sodium Metabisulfite is an inorganic compound widely used as a reducing agent, preservative, and antioxidant in various industrial processes. When dissolved in water, it releases sulfur dioxide (SO₂), which acts as an effective disinfectant and antioxidant. It is commonly used in water treatment, food preservation, chemical synthesis, and in industries such as textiles and pulp & paper.

Specifications

Grade Type	Description	Typical Concentration / Purity
Industrial Grade	General use for water treatment, textiles, and mining	≥96.0% – 97.0%
Food Grade	High-purity, low heavy metal content, used in food preservation	≥97.0% – 98.5%
Photo Grade	Ultra-low impurity content for photographic and film processes	≥98.0%
Customized Grade	Tailored particle size, SO₂ content, or impurity level	As requested

Applications

• Water Treatment: Removes residual chlorine and oxygen; dechlorination agent in RO systems.
• Food Industry: Preserves freshness in dried fruits, wines, and juices.
• Textile Industry: Used in bleaching, dyeing, and finishing processes.
• Mining & Chemical: Reduces cyanide in gold extraction; used in chemical synthesis.
• Photography: Acts as a developer preservative and fixing agent.

Advantages

• Strong reducing and antioxidant capability
• Effective dechlorination agent
• Low impurity and heavy metal content (in food/photo grade)
• Prolongs shelf life of products in food and beverage industry
• Cost-effective alternative to sulfur dioxide gas

Storage

Store in a cool, dry, and well-ventilated place away from moisture and incompatible substances (acids, oxidizers). Keep containers tightly closed. Avoid exposure to air and humidity as it decomposes slowly releasing SO₂.

Packaging

• Powder: 25kg or 50kg PE-lined woven bag
• Custom packaging: Available upon request