Description
The sodium hydrogen sulfite salt, intermediate between Sodium Sulfite and Sodium Metabisulfite in both pH and SO2-release profile. Delivers active sulfite preservative chemistry in a moderately acidic solution suitable for fruit and beverage applications.
White to off-white powder or 38 to 40 percent aqueous solution, with characteristic sulfur dioxide odor. Highly water-soluble. One gram of solid product releases approximately 0.6 grams of sulfur dioxide on acidification.
We supply food-grade and industrial-grade Sodium Bisulfite from manufacturers in China holding ISO, Halal, Kosher and other certifications relevant to the product and production.
Common market grades include Standard Food Grade Solution (38 to 40 percent SO2 aqueous, the workhorse for fruit and winemaking applications), Food Grade Powder (FCC compliant), Photographic Grade, and Industrial Grade for water treatment, pulp processing, and chemical synthesis.
Bulk and reduced-MOQ shipments. Batch-level COA covering assay, iron, heavy metals, and microbiology.
Introduction
Sodium Bisulfite (NaHSO3) is the monosodium hydrogen salt of sulfurous acid. Pure crystalline Sodium Bisulfite is unstable and tends to disproportionate; most commercial Sodium Bisulfite is actually a solution containing Sodium Bisulfite and Sodium Metabisulfite in equilibrium, or a solid Sodium Metabisulfite product traded under the Sodium Bisulfite name. The two forms are functionally equivalent and convert into each other in solution.
Industrial production proceeds by reaction of sodium carbonate with sulfur dioxide gas in controlled stoichiometry, followed by solution standardization or careful crystallization. Most commercial product is supplied as 38 to 40 percent solution where the equilibrium issue does not affect end use.
Regulated as E222 in the EU within the sulfite family, classified as Generally Recognized as Safe by the U.S. FDA with the same restrictions on raw fruit and vegetable use, and approved by JECFA under the group Acceptable Daily Intake of 0.7 mg per kg body weight expressed as sulfur dioxide.
The molecule's preservative chemistry is identical to other sulfites: antimicrobial activity at low pH, antioxidant activity through oxygen scavenging, and enzymatic-browning inhibition. The practical advantage over Sodium Metabisulfite solid handling is the convenience of liquid dosing in fruit-processing and winemaking operations, where solution dosing pumps allow precise control of SO2 addition without dust handling.
Strategic positioning concentrates on liquid-handling food processing applications and on industrial uses where liquid sulfite solutions are operationally preferred. Solid food applications dominantly use Sodium Metabisulfite for its better solid-state stability and shipping economics.
Where it is used
- Fruit preservation: maraschino cherries, glace fruit, and dried fruit color and shelf-life maintenance
- Wine making: must treatment and fermentation control where liquid sulfite handling is preferred over solid Metabisulfite
- Soft drink and beverage antioxidant
- Sugar refining: clarification and decolorization
- Photographic developer and fixer preservation
- Pulp bleaching in paper manufacturing
- Water treatment: dechlorination of process and waste water; oxygen scavenging in boiler feedwater
- Mining: gold and silver ore processing
- Tannery dehairing and leather processing
- Textile dyeing reducing agent
Technical data
| Item | Specification |
|---|---|
| Appearance | White powder or clear pale yellow solution |
| Assay (as NaHSO3, dry basis) | ≥ 58.5% (solid) or 38.0% to 40.0% (solution) |
| Sulfur dioxide content | ≥ 60.0% (solid basis) |
| pH (1% solution) | 4.0 to 5.5 |
| Iron | ≤ 30 mg/kg |
| Selenium | ≤ 10 mg/kg |
| Heavy metals (as Pb) | ≤ 5 mg/kg |
| Arsenic | ≤ 3 mg/kg |
| Thiosulfate | ≤ 0.1% |
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