Sodium Bisulfite
Sodium Bisulfite Supplier
Sodium Bisulfite (NaHSO₃) is a versatile reducing agent, antioxidant, and preservative with broad applications in water treatment, food processing, pulp and paper, and photography. Its ability to neutralize chlorine, prevent oxidation, and inhibit microbial activity makes it an essential chemical across a wide range of industrial and food-grade processes. With more than 75 years of experience as a pioneering innovator, Alexander Chemical supplies top-quality Sodium Bisulfite in liquid and solid forms, backed by expert technical guidance and reliable bulk delivery services. Safety and compliance are our top priorities.
Key Characteristics of Sodium Bisulfite
Chemical Properties
- Sodium Bisulfite Formula: NaHSO₃
- Appearance: Clear to slightly yellow aqueous solution (typically 38–40%) or white crystalline powder
- Odor: Faint sulfur dioxide (SO₂) odor
- Solubility: Highly soluble in water
- pH (solution): Acidic (pH 4–5)
- Related Compound: Closely related to sodium metabisulfite (Na₂S₂O₅), which converts to bisulfite in water
Storage & Handling Requirements
- Store in cool, sealed, ventilated areas in HDPE or stainless steel containers
- Keep away from strong oxidizers, acids, and chlorine-containing compounds
- Protect from air exposure — oxidizes to sulfate over time
Sodium Bisulfite is a hazardous material. Releases toxic sulfur dioxide gas (SO₂) when exposed to acids or heated. Reacts vigorously with strong oxidizers including bleach and peroxides. Sulfite sensitivity may affect individuals with certain medical conditions. Mishandling can lead to serious safety and environmental risks. Always rely on certified professionals for storage, handling, and transportation.
What are the Uses of Sodium Bisulfite?
Sodium Bisulfite is one of the most widely used sulfite compounds in industrial and food applications, prized for its reducing power, rapid chlorine neutralization, and broad preservative effectiveness.
Water Treatment & Dechlorination
One of the primary applications of sodium bisulfite is the dechlorination of treated water and wastewater prior to discharge or reuse. It reacts rapidly with free chlorine and chloramines, providing precise residual removal. It is also used to condition boiler feedwater and protect reverse osmosis membranes from chlorine damage.
Food Preservation
Sodium bisulfite (E222) is approved as a food additive for use as an antioxidant and preservative. It prevents enzymatic browning in shrimp, dried fruits, and cut vegetables, and is used to preserve the color, flavor, and shelf life of numerous processed foods and beverages.
Pulp & Paper
In the pulp and paper industry, sodium bisulfite is used in sulfite pulping processes to break down lignin and separate cellulose fibers from wood. It is also used as a bleaching agent and to control pH in various papermaking operations.
Photography
Sodium bisulfite is used in photographic developing solutions as a preservative, preventing oxidation of developer chemicals and extending solution life. It acts as a mild restrainer and is a standard component of many developing formulations.
Other Industrial Applications
In metallurgy, sodium bisulfite is used to precipitate heavy metals from wastewater streams. It serves as a reducing agent in dye manufacturing and textile processing, and plays a key role in the Wellman-Lord process for sulfur dioxide recovery from industrial flue gases.
Bulk Sodium Bisulfite Delivery & Support Services
The professionals at Alexander Chemical bring decades of experience and expertise to managing Sodium Bisulfite with precision and care. We supply and deliver to municipal utilities, industrial facilities, and specialty operations across the country.
What We Offer
- Supplying and delivering Sodium Bisulfite in bulk tankers, totes, or drums tailored to your specific requirements
- On-site technical support for optimal dosing and application
- Regulatory compliance guidance and safety training
- Regular tank inspections and maintenance recommendations
A Brief History of Sodium Bisulfite
Sulfite chemistry emerged as a significant area of industrial chemistry in the 19th century. The wood pulping and textile industries drove early adoption of sodium sulfite and bisulfite compounds, taking advantage of their reducing and bleaching properties. The sulfite pulping process — credited to Benjamin Tilghman and industrialized by Carl Daniel Ekman in the 1860s — made sodium bisulfite a critical industrial material and helped transform the paper industry. Its use in food preservation expanded in the late 19th and early 20th centuries as food safety regulation developed and the demand for reliable preservatives grew. The Wellman-Lord process, developed in the 1970s, further elevated the role of sodium bisulfite in industrial SO₂ recovery and emissions control. Today, sodium bisulfite remains a widely produced and applied industrial and food-grade chemical.
Sodium Bisulfite Facts
- Chlorine Neutralizer: Sodium bisulfite reacts almost instantaneously with free chlorine in water — making it a precise and efficient dechlorination tool used daily in water treatment plants worldwide.
- Shrimp Preservative: The fresh appearance of commercially processed shrimp often owes something to sodium bisulfite, which prevents the enzymatic blackening (melanosis) that causes shrimp to discolor after harvest.
- Wellman-Lord Process: Sodium bisulfite is a key reagent in the Wellman-Lord SO₂ recovery process — used in power plants and industrial facilities to capture and recycle sulfur dioxide from flue gases, helping reduce acid rain-causing emissions.
- Pulp & Paper Pioneer: The sulfite pulping process — relying on bisulfite compounds to break down wood into cellulose pulp for paper — was one of the dominant papermaking technologies from the 1870s through much of the 20th century.
- RO Membrane Protector: Sodium bisulfite is routinely dosed in reverse osmosis water treatment systems to neutralize residual chlorine before it reaches sensitive polymer membranes — preventing oxidative damage that would shorten membrane life.
Frequently Asked Questions about NaHSO₃
What is sodium bisulfite?
Sodium bisulfite (NaHSO₃) is an inorganic salt that functions as a reducing agent, antioxidant, and preservative. It is commonly supplied as an aqueous solution (38–40% concentration) or as a white crystalline powder, and is closely related to sodium metabisulfite (Na₂S₂O₅), which converts to bisulfite in water.
What is sodium bisulfite used for?
Sodium bisulfite is widely used for dechlorination in water and wastewater treatment, food preservation (preventing browning and spoilage), pulp and paper processing, photographic developing, heavy metal precipitation, and as a reducing agent in chemical manufacturing.
What is the difference between sodium bisulfite and sodium metabisulfite?
Sodium bisulfite (NaHSO₃) is typically supplied as an aqueous solution, while sodium metabisulfite (Na₂S₂O₅, E223) is more commonly available as a dry crystalline powder. In water, metabisulfite converts rapidly to bisulfite and releases SO₂ — the active agent in both. They are functionally similar, with minor dosing adjustments needed for molecular weight differences.
Is sodium bisulfite food safe?
Yes. Sodium bisulfite (E222) is approved as a food additive for use as an antioxidant and preservative in many jurisdictions. As with all sulfite food additives, it requires labeling on food products because some individuals — particularly those with asthma or sulfite sensitivity — may react to sulfite-containing foods.
How is sodium bisulfite delivered?
Alexander Chemical delivers sodium bisulfite via bulk tankers, intermediate bulk containers (totes), and drums based on your volume and site requirements. All deliveries are handled through Circle Transport, our dedicated logistics partner.
How should sodium bisulfite be stored?
Sodium bisulfite should be stored in cool, sealed, ventilated HDPE or stainless steel containers, away from strong oxidizers, acids, and chlorine-containing compounds. Solutions oxidize gradually when exposed to air — containers should remain sealed. Alexander Chemical provides tank inspection and maintenance support as part of our delivery and compliance services.
What industries use sodium bisulfite?
Sodium bisulfite is used in municipal water and wastewater treatment, food processing and preservation, pulp and paper manufacturing, photographic processing, textile and dye manufacturing, and metallurgical and industrial chemical applications.
Where to buy sodium bisulfite in bulk?
Alexander Chemical supplies bulk sodium bisulfite with nationwide delivery. Contact our team to discuss your volume requirements, delivery schedule, and pricing.