AMMONIUM SULFITE

Ammonium sulfite is employed in multiple industries, including photography, textile manufacturing, and wastewater treatment, and is also used as a reducing agent and preservative.
Although Ammonium sulfite is generally recognized as safe by the FDA and used in various consumer products, it is essential to manage its environmental impact and handle it with care to prevent harm.
Ammonium sulfite is used in a variety of applications, including as a reducing agent in photography, a preservative in food coloring, and in hair straightening products.

CAS Number: 10196-04-0
EC Number: 233-484-9
Molecular Formula: H8N2O3S
Molecular Weight: 116.14

Synonyms: Ammonium sulfite, Ammonium sulphite, 10196-04-0, DiAmmonium sulfite, diazanium;sulfite, 8LF589Y5GD, Sulfurous acid, diammonium salt, Diammonium sulfonate, ammoniumsulfite, Ammoniumsulfit, diazanium;sulite, Ammonium sulfonate, UNII-8LF589Y5GD, Sulfurous acid, ammonium salt, Ammonium sulfite [MI], Ammonium sulfite [HSDB], DTXSID2064991, HSDB 1426, CHEBI:186946, EINECS 233-484-9, Sulfurous acid ammonium salt (1:2), AKOS015904487, Sulfurous acid, ammonium salt (1:2), NS00080977, EC 233-484-9

Ammonium sulfite is the ammonium salt of sulfurous acid with the chemical formula (NH4)2SO3.

Ammonium sulfite is a colorless crystalline solid.
The primary hazard is the threat to the environment.

Immediate steps should be taken to limit its spread to the environment.
Ammonium sulfite is used in the manufacture of other chemicals, in medicine, and photography.

Ammonium sulfite has a wide use of applications, such as hair straightening or waving agents, as an ingredient in carmel food coloring, as well as an reducing agent in photography.
Other applications that Ammonium sulfite is used in include lubricants for cold metal working and blast furnace linings.

Ammonium sulfite is an ammonium salt of sulfurous acid and a byproduct of the flue gas desulfuration process by ammonia.
Ammonium sulfite can be oxidized into ammonium sulfate, which can be used as a fertilizer.

Ammonium sulfite is registered under the REACH Regulation and is manufactured in and / or imported to the European Economic Area, at ≥ 100 to < 1 000 tonnes per annum.
Ammonium sulfite is used by consumers, by professional workers (widespread uses), in formulation or re-packing, at industrial sites and in manufacturing.

Ammonium sulfite is a chemical compound that is used as an additive in wastewater treatment and as a reagent in organic synthesis.
The reaction solution contains Ammonium sulfite, sodium carbonate, and water.

Ammonium sulfite has been shown to be toxic to animals when administered at high doses.
Ammonium sulfite does not react with hydrogen fluoride or water and it is not soluble in anhydrous sodium.

The polymerase chain reaction (PCR) technique has been used to study the reaction mechanism of Ammonium sulfite.
The reactions are catalysed by metal hydroxides such as magnesium hydroxide and aluminium hydroxide, which are present at the surface of the solid phase.

Sodium sulfites are compounds that contain the sulfite ion.
The sulfite ion is the conjugate base of bisulfite.

Although Ammonium sulfite is elusive, its salts are widely used.
Ammonium sulfite is used in the photography industry to protect developing solutions from oxidation, in the pulp and paper industry, in water treatment as an oxygen scavenger agent, as a desulfurizing and dechlorinating agent in the leather industry and as a bleaching agent in textile industry.

Ammonium sulfite is a component in many pharmaceuticals, which is effective to maintain the potency and stability of drugs.
Ammonium sulfite is added to a number of drug preparations as an antioxidant and antimicrobial agent.

Ammonium sulfite is used as a food preservative.
Topical, oral or parenteral exposure to sulphites has been reported to induce a range of adverse clinical effects in sensitive individuals, ranging from dermatitis, urticaria, flushing, hypotension, abdominal pain and diarrhoea to life-threatening anaphylactic and asthmatic reactions.

Exposure to the sulphites arises mainly from the consumption of foods and drinks that contain these additives; however, exposure may also occur through the use of pharmaceutical products, as well as in occupational settings.
Ammonium sulfite is accepted for use as a food additive in Europe.

Ammonium sulfite is generally recognized as safe by FDA.
Ammonium sulfite is included in FDA Inactive Ingredients Database (epidural, IM, IV, and SC injections; inhalation solution; ophthalmic solutions; oral syrups and suspensions; otic solutions; topical creams and emulsions).
Included in nonparenteral medicines licensed in the UK.

Ammonium sulfite has been shown to be toxic to animals when administered at high doses.
Ammonium sulfite does not react with hydrogen fluoride or water and Ammonium sulfite is not soluble in anhydrous sodium.

Uses of Ammonium Sulfite:
Ammonium sulfite is an additive used in the production of caramel.

Ammonium sulfite is used in photography and in the production of caramel, refractory bricks, lubricants, medicines, permanent wave solutions, ammonium thiosulfite, and ammonium chloride
Ammonium sulfite is used in photography; as reducing agent; in bricks for blast furnace linings; in lubricants for metal cold-working.

Ammonium sulfite is used in production of ammonium thiosulfite.
Ammonium sulfite is the precursor to ammonium thiosulfate, by reaction with elemental sulfur.

Niche:
For cosmetics, Ammonium sulfite is used as a hair straightening agent and a hair waving agent.
Ammonium based hair products have been made to replace sodium hydroxide-based products due to the destructive nature of sodium hydroxide on hair.

The most common food product with Ammonium sulfite is caramel coloring E150d.
According to the FDA, caramel coloring contains ammonium, potassium, or sodium sulfite.

Ammonium sulfite is used as a preservative for fixers in photography.
When film photographs are being developed Ammonium sulfite can be one of the reducing agents used to preserve the hypo (sodium thiosulfate or ammonium thiosulfate).

Ammonium sulfite can also be used in the making of bricks.
The bricks made using Ammonium sulfite are mainly used for blast furnace linings.

Ammonium sulfite can be included in lubricants for cold metal working.
The lubricants are intended to reduce friction to keep heat production down and keep impurities out of the metals.

Widespread uses by professional workers:
Ammonium sulfite is used in the following products: adsorbents, metals, coating products, fertilisers, metal surface treatment products, non-metal-surface treatment products, hydraulic fluids, inks and toners, pH regulators and water treatment products, leather treatment products, lubricants and greases, metal working fluids, paper chemicals and dyes, photo-chemicals, polishes and waxes, textile treatment products and dyes, washing & cleaning products, water treatment chemicals and welding & soldering products.
Ammonium sulfite is used in the following areas: mining, agriculture, forestry and fishing and printing and recorded media reproduction.
Ammonium sulfite is used for the manufacture of: food products, textile, leather or fur, wood and wood products, metals and furniture.

Release to the environment of Ammonium sulfite can occur from industrial use: formulation of mixtures, as processing aid, manufacturing of Ammonium sulfite and in processing aids at industrial sites.
Other release to the environment of Ammonium sulfite is likely to occur from: indoor use as reactive substance and outdoor use as reactive substance.

Industry Uses:
Oxidizing/reducing agents
Intermediate
Agricultural chemicals (non-pesticidal)
Processing aids, not otherwise listed
Soil amendments (fertilizers)

Uses at industrial sites:
Ammonium sulfite is used in the following products: textile treatment products and dyes.
Ammonium sulfite has an industrial use resulting in manufacture of another substance (use of intermediates).

Ammonium sulfite is used in the following areas: mining and formulation of mixtures and/or re-packaging.
Ammonium sulfite is used for the manufacture of: textile, leather or fur, pulp, paper and paper products and chemicals.

Release to the environment of Ammonium sulfite can occur from industrial use: formulation of mixtures, as processing aid, manufacturing of Ammonium sulfite, in processing aids at industrial sites, as an intermediate step in further manufacturing of another substance (use of intermediates), for thermoplastic manufacture and of substances in closed systems with minimal release.
Other release to the environment of Ammonium sulfite is likely to occur from: indoor use as reactive substance and outdoor use as reactive substance.

Consumer Uses:
Processing aids, not otherwise listed
Soil amendments (fertilizers)
Oxidizing/reducing agents
Agricultural chemicals (non-pesticidal)

Background information on use in cosmetics:
Preservatives protect cosmetic products against microbial spoilage and hence make a major contribution to consumer health.
Preservatives are particularly required in cosmetic formulations containing water, because microorganisms can colonise and reproduce in an aqueous (water-containing) environment.

Cosmetics often contain more than one preservative substances and these preservative systems act simultaneously against different bacteria, yeasts or moulds.
Each of these substances has been comprehensively tested and assessed for safety (individually and in combination).
Manufacturers always use only the lowest possible effective concentration in a product so that an optimum shelf life and safe application are ensured.

Information on safe use:
Ammonium sulfite is expressly approved and / or subject to a restriction as a result of an entry in Annex III of the EC Cosmetics Regulation after an assessment by the Scientific Committee on Consumer Safety of the EU Commission (SCCS).
Restrictions can relate eg to purity criteria, a maximum concentration or the restriction to certain product categories.
Subject to the conditions possibly imposed in Annex III, the use of Ammonium sulfite in cosmetic products is safe.

In accordance with the EC Cosmetics Regulation (Regulation (EC) No. 1223/2009), which applies to the entire EU market, preservatives means substances which are exclusively or mainly intended to inhibit the development of microorganisms in the cosmetic product.
Annex V of the Regulation defines Ammonium sulfites which may be used as preservatives in cosmetic products.
In this so-called positive list of preservatives, maximum concentrations are defined for the use of these substances in cosmetic products as well as the permissible uses.

Preservatives are examined in respect of their toxicological safety prior to their approval in Annex V and undergo extensive tests.
Manufacturers must prove the health safety in extensive scientific studies.

Experimental Properties of Ammonium Sulfite:

Chemical properties:
Ammonium sulfite is a reducing agent.
Ammonium sulfite emits sulfur dioxide and oxides of nitrogen upon heating to decomposition.

The specific gravity of Ammonium sulfite is 1.41.
The refractive index of Ammonium sulfite is 1.515.

Ammonium sulfite is a colorless to yellow crystalline (sand-like or sugar-like) solid, normally sold or used in a 40% solution.
Ammonium sulfite is used both as a reducing agent and in photography.

Ammonium sulfite is a salt that can form from the reaction of ammonia and sulfur dioxide or hydrogen sulfide.
Ammonium sulfite is frequently found in the overhead of crude distillation units and can be quite corrosive to steel equipment.
Chemical corrosion inhibitors are often used to control corrosion from Ammonium sulfite and other ammonium salts.

Physical properties:
Ammonium sulfite is colorless monoclinic crystals.
Ammonium sulfite is soluble in water, its aqueous solution is alkaline.

Ammonium sulfite is slightly soluble in alcohol.
Ammonium sulfite is insoluble in acetone and carbon disulfide.

Ammonium sulfite is easily oxidized to ammonium sulfate in air.
Ammonium sulfite can be decomposed into ammonia and sulfur dioxide when heated.

Preparation of Ammonium Sulfite:

Ammonium sulfite can be prepared by the reaction of ammonia with sulfur dioxide in aqueous solution:
2 NH3 + SO2 + H2O → (NH4)2SO3

Ammonium sulfite is produced in gas scrubbers, now obsolete, consisting of ammonium hydroxide to remove sulfur dioxide from emissions from power plants.
The conversion is the basis of the Walther Process.
The resulting Ammonium sulfite can be air oxidized to give ammonium sulfate.

Manufacturing Methods of Ammonium Sulfite:
In the ATS process, sulfur dioxide is absorbed from incinerated Claus tail gas in aqueous ammonia to produce Ammonium sulfite and ammonium bisulfite in solution.

Identifiers of Ammonium Sulfite:
CAS Number: 10196-04-0
ChemSpider: 23404
ECHA InfoCard: 100.030.428
EC Number: 233-484-9
PubChem CID: 25041
UNII: 8LF589Y5GD
UN number: 3077
CompTox Dashboard (EPA): DTXSID2064991
InChI: InChI=1S/2H3N.H2O3S/c;;1-4(2)3/h2*1H3;(H2,1,2,3)
Key: PQUCIEFHOVEZAU-UHFFFAOYSA-N

SMILES:
[H][N+]([H])([H])[H].[H][N+]([H])([H])[H].O=S([O-])[O-]
[O-]S([O-])=O.[NH4+].[NH4+]

HS Code: 2832 20 00
Quality Level: MQ200

CAS Registry Number: 10196-04-0
Molecular Formula: H8N2O3S
Molecular Weight: 116.14
Percent Composition: H 6.94%, N 24.12%, O 41.33%, S 27.61%
Line Formula: (NH4)2SO3

Molecular weight: 116.14 g/mol
Formula: (NH4)2SO3
Purity: Min. 95%
Color/Form: Powder
MDL: MFCD00066094
HS code: 2832200000

Properties of Ammonium Sulfite:
Chemical formula: (NH4)2SO3
Molar mass: 116.14 g/mol
Appearance: colourless hygroscopic crystals
Melting point: 65 °C (149 °F; 338 K) decomposes
Solubility in water: 35 g/100 mL
32.4g/100mL at 0 degrees Celsius
60.4g/100mL at 100 degrees Celsius
Solubility: Insoluble in acetone and alcohol
Refractive index (nD): 1.515.

Density: 1.19 g/cm3 (20 °C)
Melting Point: 4 - 8 °C
pH value: 7.5 - 7.6 (H₂O, 20 °C)

Molecular Weight: 116.14 g/mol
Hydrogen Bond Donor Count: 2
Hydrogen Bond Acceptor Count: 4
Rotatable Bond Count: 0
Exact Mass: 116.02556330 g/mol
Monoisotopic Mass: 116.02556330 g/mol
Topological Polar Surface Area: 84.4Å²
Heavy Atom Count: 6
Complexity: 18.8
Isotope Atom Count: 0
Defined Atom Stereocenter Count: 0
Undefined Atom Stereocenter Count: 0
Defined Bond Stereocenter Count: 0
Undefined Bond Stereocenter Count: 0
Covalently-Bonded Unit Count: 3
Compound Is Canonicalized: Yes

Specifications of Ammonium Sulfite:
Assay (iodometric): 37.0 - 40.0 %
Density (d 20 °C/ 4 °C): 1.195 - 1.205

density: 1.19 g/cm3 at 20 °C
form: liquid
mp: 4-8 °C
pH: 7.5-7.6 (20 °C in H2O)
Quality Level: 200
storage temp.: 2-30°C

Names of Ammonium Sulfite:

IUPAC name:
Ammonium sulfite
Ammonium sulfite Monohydrate
ammonium sulphite
diAmmonium sulfite
diazanium sulfite
Sulfurous acid, diammonium salt

Regulatory process names:
Ammonium sulfite
Ammonium sulphite
ammonium sulphite
Sulfurous acid, diammonium salt

Other names:
Ammonium sulphite
DiAmmonium sulfite
Diammonium sulfonate
Sulfurous acid
Diammonium salt
Sulfurous acid
ammonium salt(1:2)

Other identifiers:
10196-04-0