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Sodium Bisulphite

NaHSO₃  |  CAS: 7631-90-5  |  HS: 28321000

Product Description

Sodium Bisulphite is an acidic sulphite reducing agent used in aqueous solution form for textile discharge printing, paper de-inking, water dechlorination, and food preservation. Its lower pH versus sodium sulphite makes it preferred for applications requiring mild acidic reduction. In discharge textile printing, sodium bisulphite solution reduces dyed areas to produce white or coloured discharge patterns. In food applications (E222), it is used as a preservative and anti-browning agent. MITCHEM supplies solution and powder grades with food and technical certifications.

Applications by Industry

Textile Discharge Printing

Applied in discharge printing pastes to selectively reduce and decolour dyed fabric areas, creating white or colour-discharge print patterns on pre-dyed textile substrates.

Dechlorination (Water Treatment)

Liquid bisulphite solution is conveniently metered by pump for continuous dechlorination of potable water, aquaculture systems, and industrial process water.

Food Preservation (E222)

Used as a food preservative and colour stabiliser in fruit juices, wine musts, seafood, and vegetable products; provides antimicrobial and anti-browning protection at lower pH than sulphite.

Paper De-inking & Pulp Processing

Applied in paper de-inking processes and as a reducing agent in chemical pulp and paper production to remove residual chlorine and peroxide from bleached pulp.

Packaging Options

200 L HDPE Drums (solution)1000 L IBC (solution)25 kg Bags (powder)

Technical Specifications

Molecular FormulaNaHSO₃
Molecular Weight104.06 g/mol
CAS Number7631-90-5
HS Code28321000
AppearanceWhite to pale yellow powder or cream-coloured solution (38–40%); pungent SO₂ odour
Available GradesSolution 38–40% / Powder Technical 55–58% SO₂ / Food Grade (E222)

Need a CoA, MSDS/SDS, or sample? Email info@mitchemindustries.com — full documentation available for all grades.

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