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Sodium sulfite

CAS Number
7757-83-7
EC Number
231-821-4
Chemical Formula
H2O3S.2Na
Molecular Weight
126.05 g/mol

Description

thoughtful mini-steps: Sodium sulfite (CAS 7757-83-7 ), also known as sodium sulphite and approved as food additive E221 , is an inorganic reducing agent and antioxidant used across food processing and water treatment. Its oxygen-scavenging capability makes it a practical choice for preserving product quality and controlling oxidative degradation in both aqueous systems and dry formulations for industrial manufacturing. In food and beverage production, E221 functions as a preservative and antioxidant in dried fruits, wines, and starch products, inhibiting browning and microbial growth during the storage process. Water treatment operations use it to dechlorinate process water and boiler feedwater, neutralizing residual chlorine before discharge or reuse to protect sensitive equipment and the environment. Pulp and paper manufacturers apply it in kraft and sulfite pulping processes to delignify wood fiber and control brightness. In textile and leather processing, it acts as a reducing agent. It is also used as a stripping agent to correct uneven dyeing in dyebath preparation. Sodium sulfite is supplied as a white crystalline powder or granules in the anhydrous form for easy handling. Standard grades include food-grade ( FCC , E221), pharmaceutical-grade ( USP , BP ), and technical-grade for industrial applications. Packaging typically ranges from 25 kg bags to bulk quantities. Depending on grade and application requirements, this chemical ensures stability and performance. It remains a critical component for manufacturers seeking reliable antioxidant and dechlorination solutions. Contact us for supply of Sodium sulfite Request Quote

Other Names (Synonyms)

sulfurous acid, disodium salt | sodium sulphite | sodium sulfite anhydrous | Na2SO3 | dried sodium sulfite | anhydrous sodium sulfite | Disodium sulfite | Natrium sulfurosum | E221

Key Technical Features

  • High Purity Grade standard
  • Consistent Batch Quality
  • Full Regulatory & REACH Support
  • Global Logistics Network enabled

Physical Properties

Melting Point500 °C
Density2.63 g/cm³
AppearanceSodium sulfite is a white crystalline solid
ColorWhite to slightly yellow
OdorOdorless
FormSolid
Water Solubility23 g/100 mL (20 ºC)
Refractive Index1,484
pH9.0-10.5 (25℃, 1M in H2O)

Safety & Handling

Danger
GHS05· CorrosiveGHS07· Irritant

Hazard Statements

H302Harmful if swallowed
H314Causes severe skin burns and eye damage
H315Causes skin irritation
H318Causes serious eye damage
H319Causes serious eye irritation

Precautionary Statements

P260Do not breathe dust/fume/gas/mist/vapours/spray.
P264Wash … thoroughly after handling.
P270Do not eat, drink or smoke when using this product.
P280Wear protective gloves/protective clothing/eye protection/face protection.
P316Get emergency medical help immediately.
P317Get emergency medical help.
P321Specific treatment (see … on this label).
P330Rinse mouth.
P363Wash contaminated clothing before reuse.
P405Store locked up.
P501Dispose of contents/container in accordance with local regulations.
P265Wash … thoroughly after handling.
P317Get emergency medical help.
P352IF ON SKIN: Wash with plenty of water.
P340IF INHALED: Remove person to fresh air and keep comfortable for breathing.
P317Get emergency medical help.
P317If eye irritation persists: Get medical advice/attention. Get emergency medical help.
P364Take off contaminated clothing and wash it before reuse.
P331Rinse mouth. Do NOT induce vomiting.
P354IF ON SKIN: Take off immediately all contaminated clothing. Rinse skin with water/shower.
P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.

Trade & Regulatory

HS Code28321000
Storage Class13 - Non Combustible Solids
WGK (Germany)1