Acids & Salts Available — Bulk Only

Ammonium Sulfite (Ammonium Sulfite Monohydrate)

CAS 7783-11-1 · Formula H10N2O4S · MW 134.16 g/mol

A reducing-chemistry inorganic salt supplied in purified monohydrate form. Industry references record its use in photographic processing, in caramel-color production, in refractory-brick manufacture, in lubricant production, and as an intermediate toward ammonium thiosulfate and ammonium chloride.

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HS Code
2832.20
At a Glance
Material Family
Acids & Salts
Record Type
Pure compound
Primary Role
pH Adjustment · Preservation
Applications & Use Cases
  • Photographic processing: reducing agent in photographic chemistry
  • Caramel color: process input in caramel production
  • Refractory manufacture: additive in refractory-brick production
  • Chemical intermediate: feedstock for ammonium thiosulfate and ammonium chloride
Safety & Handling
Full SDS available on request

A grade-specific Safety Data Sheet (SDS) — with the complete hazard classification, handling precautions, and transport information — is supplied with every shipment and available on request. Confirm all safety and regulatory details against the SDS for your specific grade.

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HS / Tariff Classification
Harmonized System (HS) Code — 6-digit international heading
2832 . 20
Chapter 28
Inorganic chemicals; compounds of precious metals and rare-earth metals
Heading 28.32
Internationally harmonized (WCO HS)
Subheading 2832.20
6-digit international code — national tariff line adds further digits
Chemical Identity
CAS Number
7783-11-1
Molecular Formula
H10N2O4S
Molecular Weight
134.16 g/mol
IUPAC Name
diazanium;sulfite;hydrate
PubChem CID
InChI Key
ASPXBYAQZVXSNS-UHFFFAOYSA-N
Synonyms & Trade Names
Diammonium sulfite monohydrate AMMONIUM SULFITE MONOHYDRATE Sulfurous acid, diammonium salt, monohydrate diazanium;sulfite;hydrate ammonium sulphite monohydrate
Full Description

Ammonium sulfite (ammonium sulfite monohydrate, (NH4)2SO3·H2O; CAS 7783-11-1) is a water-soluble reducing agent and oxygen scavenger. As a source of sulfite, it removes dissolved oxygen and reduces other species, which makes it useful in boiler and process-water treatment, photography, pulp and paper, leather and as a chemical intermediate. Identity: PubChem.

What is ammonium sulfite?

Ammonium sulfite is the ammonium salt of sulfurous acid, supplied as the monohydrate. In water it provides the sulfite ion, a reducing agent that scavenges dissolved oxygen and reduces oxidized species; it also supplies ammonia/nitrogen chemistry. It must be kept from acids, which liberate sulfur dioxide.

Applications by sector

Water treatment. An oxygen scavenger and reducing agent for boiler and process water, protecting metal from oxygen corrosion. Pulp & paper. A sulfite source in pulping and bleaching chemistry. Photography & imaging. A reducing agent/preservative in processing solutions. Leather & industrial. A reducing and processing agent and a chemical intermediate. Dose to the oxygen load or reaction; verify by residual testing.

Forms and grades

Supplied as the crystalline monohydrate or as a solution at a stated concentration; confirm form and grade on the RFQ. The CoA documents the lot.

Handling and documentation

Keep ammonium sulfite away from acids, which release toxic sulfur dioxide; store cool and handle per the current Safety Data Sheet (SDS). Each lot ships with a Certificate of Analysis (CoA).

Bulk supply and RFQ

RawSource supplies ammonium sulfite in bulk to water-treatment, pulp/paper and industrial buyers, with CoA and SDS per lot. Submit an RFQ with your form, concentration and target quantity.

Typical Properties

Typical reference values, not a specification; the Certificate of Analysis (CoA) for the lot governs.

Property Typical Value
Chemical Name Ammonium sulfite monohydrate
CAS Number 7783-11-1
Molecular Formula (NH4)2SO3·H2O
Appearance White crystals or aqueous solution
Solubility Soluble in water
Function Reducing agent; oxygen scavenger; sulfite source
Incompatibilities / handling Keep from acids (releases SO2); refer to the current SDS

Frequently Asked Questions

What is ammonium sulfite used for?

Ammonium sulfite (CAS 7783-11-1) is a reducing agent and oxygen scavenger used in boiler and process-water treatment, pulp and paper, photographic processing, leather and as a chemical intermediate.

How does ammonium sulfite scavenge oxygen?

Its sulfite ion reacts with dissolved oxygen (oxidizing to sulfate), removing the oxygen that drives corrosion in boiler and process water.

Is ammonium sulfite hazardous?

It must be kept away from acids, which release toxic sulfur dioxide gas. Store cool and handle with appropriate PPE and ventilation per the SDS.

What is the CAS and formula of ammonium sulfite?

It is ammonium sulfite monohydrate, CAS 7783-11-1 (PubChem CID 21701053), formula (NH4)2SO3·H2O. The CoA documents form and grade.

How is bulk ammonium sulfite supplied and quoted?

RawSource supplies it as crystals or solution in bulk with CoA and SDS per lot. Pricing is quote-based on form, concentration and volume; submit an RFQ with your target quantity.

Disclaimer. Information on this page — including chemical properties, identifiers, hazard, transport (DOT/UN) and tariff (HS) classifications, and applications — is provided for general reference and is compiled from authoritative public sources (e.g. PubChem). Values are typical and are not a guaranteed specification; the Certificate of Analysis (CoA) for the lot you purchase governs. Products are sold for industrial and professional use only. Nothing here is a medical, health, or efficacy claim, or advice. Always consult the current Safety Data Sheet (SDS) before handling, storage, transport or disposal, and confirm regulatory status, classification and suitability for your application and jurisdiction. Hazard, transport and tariff classifications must be verified for your specific shipment. RawSource makes no warranty, express or implied, and assumes no liability for use of this information.

Disclaimer. Information on this page — including properties, identifiers, hazard, transport (DOT/UN) and tariff (HS) classifications, and applications — is provided for general reference and is compiled from authoritative public sources (e.g. PubChem/ECHA, 49 CFR 172.101, the Harmonized Tariff Schedule). Values are typical and are not a guaranteed specification; the Certificate of Analysis (CoA) for the lot purchased governs. Products are sold for industrial and professional use only. Nothing here is a medical, health, or efficacy claim or advice. Always consult the current Safety Data Sheet (SDS) before handling, storage, transport or disposal, and confirm regulatory status, classification and suitability for your application and jurisdiction. Hazard, transport and tariff classifications must be verified for your specific shipment. RawSource makes no warranty, express or implied, and assumes no liability for use of this information. Trademarks. Third-party trademarks and brand names are the property of their respective owners; any reference is nominative — used only to identify a comparable product — and does not imply affiliation with, sponsorship by, or endorsement by the trademark owner.