A versatile reducing agent serving as oxygen scavenger, dechlorinator, and food preservative with chemical formula Na₂SO₃
Product Overview
Sodium sulfite anhydrous (Na₂SO₃) is a white crystalline powder with slight sulfur dioxide odor, easily oxidized to sodium sulfate in air. This essential industrial chemical provides strong reducing power to scavenge oxygen, neutralize oxidizing substances, and serve as a sulfur dioxide donor.
Core Applications
Photography & Imaging Industry
Key component in fixing bath and developer formulations for traditional darkroom processes
Preserves fixer solutions by preventing oxidation of sodium thiosulfate
Protects developing agents from premature oxidation in developers
Essential for motion picture film and medical X-ray film processing
Water Treatment & Environmental Protection
Oxygen scavenger for boiler feedwater and industrial cooling systems
Protects reverse osmosis membranes from chlorine damage
Removes residual chlorine and chloramines in aquaculture and aquariums
Food Industry (E221)
Preservative and antioxidant for dried fruits, vegetables, juices, wines, and sugars
Inhibits microbial growth and prevents enzymatic browning
Flour treatment agent to improve processing properties
Chemical & Industrial Applications
Reducing agent in organic synthesis for pharmaceuticals and dyes
Textile dyeing and printing as reducing agent and antichlor
Paper industry for dechlorination after pulp bleaching
Leather tanning and mineral flotation processes
Product Grades & Specifications
Available in Industrial Grade, Food Grade (E221), and Reagent Grade (Photographic Grade). Key quality parameters include sodium sulfite content, iron content, water-insoluble matter, and heavy metal limits.
Safety & Handling
Critical Safety Information
Strictly prohibited from mixing with strong acids - releases toxic sulfur dioxide gas
Handle in well-ventilated areas and store separately from acids
Food applications must comply with regulated usage limits and labeling requirements
Exercise caution with strong oxidizing agents due to heat release potential
Quality Assurance
Our anhydrous sodium sulfite features high purity, strong reducing power, excellent solubility, and consistent quality. Food-grade products maintain extremely low impurity levels. We provide detailed MSDS documentation and serve professional clients across multiple industries.