SODIUM HYDROGEN SULPHITE

Sodium Hydrogen Sulphite is an inorganic bisulfite salt widely used as a reducing agent, antioxidant, oxygen scavenger, and preservative support ingredient in food, beverage, pharmaceutical, and industrial processes.
Sodium Hydrogen Sulphite is also known as Sodium Bisulfite, and Sodium Hydrogen Sulphite is valued because Sodium Hydrogen Sulphite reacts readily with dissolved oxygen and oxidizing species and can also bind carbonyl compounds, helping control browning and oxidative off-flavors in compatible systems.
Sodium Hydrogen Sulphite must be handled with care because Sodium Hydrogen Sulphite can release sulphur dioxide under acidic conditions and sulfites can trigger allergic or asthma-like reactions in sensitive individuals, so Sodium Hydrogen Sulphite use requires appropriate hygiene, ventilation, and regulatory compliance.

CAS Number: 7631-90-5
EC Number: 231-548-0
Molecular Formula: NaHSO3
Molecular Weight: 104.06 g/mol

Synonyms: Sodium Hydrogen Sulphite, Sodium Bisulfite, Sodium Hydrogen Sulfite (US spelling), Sodium Bisulfite Solution, NaHSO3, Sodium Acid Sulfite, Sodium Bisulphite (variant spelling), Sodium Hydrogensulfite, Sodium Hydrogen Sulphite Reducing Agent, Sodium Hydrogen Sulphite Antioxidant, Sodium Bisulfite Dechlorination Agent, Sodium Hydrogen Sulphite Process Chemical, Sodium Hydrogen Sulphite, Sodium Hydrogen Sulfite, Sodium Bisulphite, Sodium Bisulfite, Sodium Acid Sulphite, Sodium Acid Sulfite, Bisulfite of Soda, Bisulphite of Soda, Sodium Pyrosulfite Solution, Sodium Bisulfite Solution, Sodium Bisulphite Solution, Sulfurous Acid Monosodium Salt, Sulphurous Acid Monosodium Salt, Sulfurous Acid Sodium Salt, Sulphurous Acid Sodium Salt, Sodium Hydrogen Sulfite Solution, Sodium Hydrogen Sulphite Solution, Sodium Bisulfite Reagent, Sodium Bisulphite Reagent, Sodium Bisulfite Food Grade, Sodium Bisulphite Food Grade, Sodium Bisulfite Technical Grade, Sodium Bisulphite Technical Grade, Sodium Bisulfite Industrial Grade, Sodium Bisulphite Industrial Grade, Sodium Bisulfite FCC, Sodium Bisulphite FCC, Sodium Bisulfite USP, Sodium Bisulphite USP, Sodium Bisulfite BP, Sodium Bisulphite BP, Sodium Bisulfite Pharmaceutical Grade, Sodium Bisulphite Pharmaceutical Grade, Sodium Bisulfite Antioxidant, Sodium Bisulphite Antioxidant, Sodium Bisulfite Preservative, Sodium Bisulphite Preservative, Sodium Bisulfite Reducing Agent, Sodium Bisulphite Reducing Agent, Sodium Bisulfite Oxygen Scavenger, Sodium Bisulphite Oxygen Scavenger, Sodium Bisulfite Dechlorinating Agent, Sodium Bisulphite Dechlorinating Agent, Sodium Bisulfite Water Treatment Grade, Sodium Bisulphite Water Treatment Grade, Sodium Bisulfite E222, Sodium Bisulphite E222, E222, INS 222, Food Additive E222

APPLICATIONS

Sodium Hydrogen Sulphite is used in water treatment as a dechlorination agent to neutralize chlorine and protect downstream equipment and processes.
Sodium Hydrogen Sulphite is incorporated into wastewater treatment to quench residual chlorine before discharge when permitted and controlled.
Sodium Hydrogen Sulphite is used in membrane and resin protection strategies where chlorine removal prevents damage.

Sodium Hydrogen Sulphite is used in water treatment as a reducing agent to control oxidizing species and support corrosion control strategies in compatible systems.
Sodium Hydrogen Sulphite is incorporated into industrial water loops to reduce oxidative corrosion risk and protect sensitive process steps.
Sodium Hydrogen Sulphite is used in chemical dosing programs where rapid reduction and predictable stoichiometry are required.

Sodium Hydrogen Sulphite is used in pulp and paper processing as a reducing agent and bleaching support chemical in compatible pulping and deinking processes.
Sodium Hydrogen Sulphite is incorporated into paper recycling and deinking operations to improve brightness and reduce ink-related color bodies.
Sodium Hydrogen Sulphite is used in specialty bleaching steps where bisulfite chemistry provides controlled reduction.

Sodium Hydrogen Sulphite is used in textile processing as a reducing agent in dyeing and printing to control color development and remove excess dye.
Sodium Hydrogen Sulphite is incorporated into dye baths to reduce oxidative side reactions and improve shade consistency.
Sodium Hydrogen Sulphite is used in textile finishing to support bleaching and color stripping operations in compatible systems.

Sodium Hydrogen Sulphite is used in food processing as an antioxidant and preservative support agent in applications where sulfites are permitted and labeling is managed.
Sodium Hydrogen Sulphite is incorporated into dried fruit processing and potato processing to reduce browning and oxidative discoloration in compatible operations.
Sodium Hydrogen Sulphite is used in juice and puree processing to protect color and flavor from oxidation when permitted by food rules.

Sodium Hydrogen Sulphite is used in beverage processing as an antioxidant and oxygen scavenger in compatible products and process steps.
Sodium Hydrogen Sulphite is incorporated into winemaking and cider processing to control oxidation and microbial stability through sulfite management.
Sodium Hydrogen Sulphite is used in syrup and concentrate processing to protect flavor and color from oxidation when permitted by food rules.

Sodium Hydrogen Sulphite is used in chemical manufacturing as a bisulfite addition reagent to form bisulfite adducts with aldehydes and ketones for purification.
Sodium Hydrogen Sulphite is incorporated into organic synthesis workflows to isolate and purify carbonyl compounds through reversible adduct formation.
Sodium Hydrogen Sulphite is used in laboratory chemistry as a reducing agent and nucleophile in bisulfite addition reactions.

Sodium Hydrogen Sulphite is used in industrial cleaning and process protection to prevent oxidative discoloration in sensitive raw materials and intermediates.
Sodium Hydrogen Sulphite is incorporated into latex and polymer manufacturing in some cases to control oxidation and stabilize intermediates.
Sodium Hydrogen Sulphite is used in chemical plants as a versatile reducing agent for many controlled reactions.

Sodium Hydrogen Sulphite is valued because Sodium Hydrogen Sulphite provides strong reducing and anti-browning performance, but Sodium Hydrogen Sulphite use requires careful control for SO2 release risk, sensitivity labeling, and compatibility.

DESCRIPTION

Sodium Hydrogen Sulphite is a white crystalline powder commonly supplied as solid or as aqueous solution, and Sodium Hydrogen Sulphite forms bisulfite ions in water.
Sodium Hydrogen Sulphite is more acidic than sodium sulphite, and Sodium Hydrogen Sulphite can release sulphur dioxide in acidic conditions, which is why ventilation and pH control are important in handling.
Sodium Hydrogen Sulphite acts as a reducing agent by consuming dissolved oxygen and oxidizing species, and Sodium Hydrogen Sulphite also reacts with carbonyl compounds to form bisulfite adducts used in purification.

Sodium Hydrogen Sulphite can be oxidized to sulfate during storage and use, so sealed storage and controlled dosing help maintain reducing capacity.
Sodium Hydrogen Sulphite dust can irritate eyes and respiratory tract, and sensitive individuals can react to sulfites, so exposure control and allergen communication are important.
Sodium Hydrogen Sulphite should be kept away from strong oxidizers and should not be mixed with strong acids unless the process is designed and ventilated due to SO2 release.

Sodium Hydrogen Sulphite should be stored in tightly closed containers in a cool, dry place and protected from moisture contamination and air exposure.
Sodium Hydrogen Sulphite solutions should be protected from heat and should be kept in compatible containers to avoid corrosion and strength loss.
Sodium Hydrogen Sulphite should be used according to applicable regulations and specifications for the intended market and product category.

PROPERTIES

Chemical Formula: NaHSO3
Molecular Weight: 104.06 g/mol
Common Name: Sodium Hydrogen Sulphite (Sodium Bisulfite)
Chemical Type: Inorganic bisulfite salt; reducing agent; antioxidant; dechlorination agent
Appearance: White crystalline powder or clear aqueous solution (grade dependent)
Odor: Slight sulphur dioxide-like odor possible, especially in acidic conditions
Solubility: Highly soluble in water
Reactivity: Reducing agent; releases SO2 under acidic conditions; forms bisulfite adducts with carbonyls; incompatible with strong oxidizers
pH Behavior: Forms mildly acidic solutions; bisulfite predominates at lower pH
Stability: Oxidizes to sulfate over time, especially with air exposure; solutions can lose strength
Health Considerations: Irritant; sulfite sensitivity possible; manage exposure and labeling
Storage Temperature: 10–25°C, tightly closed; protect from heat and air exposure
Shelf Life: Typically 12–36 months depending on form and packaging (supplier dependent)

FIRST AID

Inhalation:
Move to fresh air if dust or vapors are inhaled.
Seek medical attention if respiratory irritation persists.
Monitor sensitive individuals for asthma-like reactions and bronchospasm.

Skin Contact:
Wash with soap and water after contact.
Remove contaminated clothing and wash before reuse.
Seek medical advice if irritation develops or persists.

Eye Contact:
Rinse cautiously with water for several minutes.
Remove contact lenses if present and easy to do, then continue rinsing.
Seek medical attention if irritation persists.

Ingestion:
Rinse mouth with water.
Seek medical attention if discomfort occurs or if a significant amount is swallowed.
Never give anything by mouth to an unconscious person.

Note to Physicians:
Treat symptomatically.
Consider sulfite sensitivity and bronchospasm risk in susceptible individuals.
Provide supportive care based on exposure route and symptoms.

HANDLING AND STORAGE

Handling:
Use appropriate PPE including gloves and safety glasses, and use respiratory protection if dust or SO2 exposure is possible.
Avoid generating dust and avoid inhalation of fine particles.
Do not mix with acids unless the process is designed and ventilated because sulphur dioxide can be released.

Ventilation:
Use local exhaust or general ventilation where dust or vapors may be generated.
Maintain good airflow during weighing, charging, and solution preparation.
Avoid enclosed spaces where SO2 could accumulate if acid contact occurs.

Storage:
Store in tightly closed containers in a cool, dry place.
Protect from air exposure and moisture to reduce oxidation and maintain strength.
Keep away from strong oxidizers and store away from acids.

Spill and Leak Procedures:
Avoid dust generation and collect spilled solid into suitable containers.
For solutions, contain spill, absorb with inert material, and ventilate area if SO2 odor is present.
Dispose of waste according to local regulations and facility procedures.

Handling Precautions:
Control pH in solutions to minimize SO2 release and to maintain desired bisulfite behavior.
Implement allergen and sensitivity awareness where Sodium Hydrogen Sulphite is used in food or consumer products.
Rotate stock using FIFO practices and monitor solution concentration where dosing accuracy is critical.