RONGALITE C

Rongalite C is a highly efficient inorganic reducing agent based on sodium formaldehyde sulfoxylate, designed for use in aqueous industrial processes.
Rongalite C exhibits rapid solubility in water and provides controlled, selective reduction of dyes, metal ions, and oxidation-sensitive intermediates.
Because of these properties, Rongalite C is widely utilized in textile vat dyeing, polymer and latex redox systems, cosmetic decolorization formulations, and specialty chemical manufacturing.

CAS Number: 149-44-0
EC Number: 205-739-4
Molecular Formul: CH3NaO3S
Molecular Weight; 118.09 g/mol

Synonyms: Aldanil, Discolite, Formopan, Hydrolit, Leptacid, Leptacit, Rodite, Bleachit D, Rongalite C, Rongalite C, Superlite C, Hydrosulfite AWC, Redol C, Sodium methanalsulfoxylate, Natrium hydroxymethansulfinat, Natrium formaldehydesulfoxylat, Oxymethansulfinsaeuren natrium, Formaldehyde sodium sulfoxylate, Sodium sulfoxylate formaldehyde, Sodium (hydroxymethyl)sulfinate, SODIUM FORMALDEHYDESULFOXYLATE, Hydroxymethansulfinsaeure, natriumsalz, Formaldehydesulfoxylic acid sodium salt, RefChem:930878, 149-44-0, Hydroxymethanesulfinic acid sodium salt, Rongalit, Rongalite, SCHEMBL30017140, Sodium sulfoxylate, Sodium sulfinylmethanolate, Sodium methanesulfoxylate, Formalin sulfoxylate sodium, Sulfoxylate sodium formaldehyde compound, Sodium formaldehyde reducing salt, SFS (Sodium Formaldehyde Sulfoxylate), Sodium formaldehyde sulfoxylate dihydrate (commercial naming), Sodium sulfoxylate methanal, Sulfinic acid sodium salt, formaldehyde adduct, Sodium hydroxymethylsulfinate, Reductive discharge chemical (Rongalite type), Sodium sulfinylmethane salt, Sodium methanal sulfoxylate, Rongalite-based reducing agent, Sodium formaldehyde sulfoxylate powder, Textile Rongalite, Industrial Rongalite, Sodium formaldehyde sulfoxylate reducing agent, Rongalite-type sulfinate reducer

Rongalite C is an inorganic sulfur-based compound recognized for its high reducing efficiency in aqueous systems.
Rongalite C is typically supplied as a free-flowing crystalline powder with a pale white to light yellow appearance and dissolves rapidly in water to form strongly reducing solutions.

Rongalite C functions by donating electrons to reactive species, making it highly effective in breaking down chromophoric dye structures, stabilizing oxidation-sensitive formulations, and converting metal ions to lower oxidation states.
In industrial practice, Rongalite C plays a critical role in textile processing for color discharge and correction, in polymer and latex formulations to inhibit oxidative degradation, and in fine chemical production as an auxiliary reducing agent.
However, Rongalite C's chemical instability under elevated temperature and exposure to oxygen necessitates controlled storage conditions, typically in sealed containers protected from heat and humidity, to preserve its activity.

Rongalite, with the molecular formula Na+HOCH2SO2−, is a reducing salt with various names such as sodium hydroxymethylsulfinate, sodium formaldehyde sulfoxylate, and Bruggolite.
The word rongalite literally means "decolorizing agent."

In the European Cosmetics Directive, rongalite is defined as sodium oxymethylene sulfoxylate (INCI).
Rongalite C is highly soluble in water and is mostly sold commercially in dihydrate form.

Rongalite C and its derivatives are frequently used in the dye industry.

The primary use of rongalite C is as an industrial bleaching agent and a reducing agent for vat dyeing.
Rongalite C is used in vat dyeing and bleaching in the textile industry.

A second main use is as a reducing agent in redox systems for emulsion polymerization.
One of the most common examples of a redox pair is t-butyl peroxide.

Another use of Rongalite C is as a water conditioner in aquariums, as it rapidly reduces chlorine and chloramine and reacts with ammonia to form the harmless aminomethylsulfinate ion.
Rongalite C also acts as an antioxidant in pharmaceutical formulations.

Furthermore, despite its role in the production of formaldehyde, a well-known carcinogen, Rongalite C is increasingly used commercially in cosmetic hair dye decolorizers.
Rongalite C has applications as a special reagent in organic chemistry syntheses.
Rongalite C is used as an antidote for heavy metals (Hg, Au, Cu, Ba, Sb, Pb, Bi).

Rongalite C is a white crystalline chemical characterized by high purity and strong reducing properties.
Easily soluble in water, Rongalite C's controlled reaction capability makes it a preferred choice in many industrial processes.

Rongalite C's stable structure and effective chemical behavior make it a reliable component.
Rongalite C's high purity ensures the production of homogeneous solutions.

Offering stable results during reactions, Rongalite C plays a crucial role in sensitive production processes.
Rongalite C maintains its stability for a long time when stored under appropriate conditions.

Rongalite is a chemical compound with the molecular formula Na+HOCH2SO2−.
Rongalite This salt has many additional names, including Rongalit, sodium hydroxymethylsulfinate, sodium formaldehyde sulfoxylate, and Bruggolite.

Rongalite is listed in the European Cosmetics Directive as sodium oxymethylene sulfoxylate (INCI).
Rongalite C is water-soluble and generally sold as the dihydrate.

Rongalite and its derivatives are widely used in the dye industry.
This reaction proceeds quantitatively, such that dithionite can be determined by its conversion to Rongalite, which is far less O2-sensitive and thus easier to handle.

Rongalite C use of the compound was as industrial bleaching agent and as a reducing agent for vat dyeing.
Another large-scale use is as a reducing agent in redox-initiator systems for emulsion polymerization.

Rongalite C one of the typical redox pair examples is t-butyl peroxide.
A niche use is its use as water conditioner for aquaria as Rongalite C rapidly reduces chlorine and chloramine and reacts with ammonia to form the innocuous aminomethylsulfinate ion.
Rongalite C is also used as an antioxidant in pharmaceutical formulation.

Rongalite C is chemically known by its trade name sodium dithiosulfate.
This white substance, usually in crystalline or powder form, is widely used in many industries due to its high solubility and reducing properties.

Rongalite C is an important chemical, especially in areas such as dye reduction, textile processes, and the paper and leather industries.
Thanks to its strong reducing capacity, Rongalite C acts as both a decolorizer and a stabilizer.

Rongalite is a chemical compound with the molecular formula Na+HOCH2SO2−.
This salt has many additional names, including Rongalit, sodium hydroxymethylsulfinate, sodium formaldehyde sulfoxylate, and Bruggolite.

Rongalite C is listed in the European Cosmetics Directive as sodium oxymethylene sulfoxylate (INCI).
Rongalite C is water-soluble and generally sold as the dihydrate.

Rongalite C and its derivatives are widely used in the dye industry.
The structure of this salt has been confirmed by X-ray crystallography.

Uses of Rongalite C:
Rongalite C is widely used in the textile industry as a reducing and discharge agent in dyeing and printing processes, particularly for vat, sulfur, and reactive dyes, where it enables color stripping, decolorization, and pattern development.
Rongalite C is also applied as a bleaching auxiliary and reducing agent in chemical processing, helping to prevent oxidation and control color formation.

In polymer, resin, and latex formulations, Rongalite C functions as a stabilizer and antioxidant by inhibiting oxidative degradation during processing and storage.
Additionally, Rongalite C is used in chemical synthesis and industrial cleaning applications where strong, water-soluble reducing properties are required.

Rongalite C is used as a stripping and discharge agent for textiles, bleaching agent for molasses and soap, and reducing agent.
Rongalite C is also used in vat color printing pastes, to polymerize ethylenic compounds, and to make arsphenamines

Rongalite C is an indirect food additive when used in adhesives.
Rongalite C is used to treat mercury poisoning.

The original use of Rongalite C was as industrial bleaching agent and as a reducing agent for vat dyeing.
Another large-scale use is as a reducing agent in redox-initiator systems for emulsion polymerization.

One of the typical redox pair examples is t-butyl peroxide.
A niche use is its use as water conditioner for aquaria as Rongalite C rapidly reduces chlorine and chloramine and reacts with ammonia to form the innocuous aminomethylsulfinate ion.
Rongalite C is also used as an antioxidant in pharmaceutical formulation.

Rongalite C has been used increasingly in commercial cosmetic hair dye colour removers despite the generation of formaldehyde, a known human carcinogen.
Rongalite C has a variety of specialized applications in organic synthesis.

Rongalite C has functional properties as a catalyst, emulsifier, raw material, and reducing agent.
Rongalite C is actively used in the pharmaceutical, textile, rubber, plastics, and adhesives industries.

In the plastics industry, Rongalite C is used as a catalyst and polymerization regulator during manufacturing.
Rongalite C is used as a redox activator in rubber manufacturing.

Rongalite C is used as a reducing agent for redox-catalyzed polymerization.
In other words, Rongalite C is also a reducing agent.

Rongalite C is used as a dye raw material in dye manufacturing.
In the textile industry, Rongalite C is used as a stripping and discharge agent.

Rongalite C is used as a reducing agent in VAT dyeing processes.
Rongalite C is used as a bleaching agent in soap and molasses manufacturing.

Rongalite C is used as an antioxidant in the manufacture of some pharmaceutical drugs.
Rongalite C is used as an active ingredient in drugs used to treat mercury poisoning.

Rongalite C is used in the manufacture of adhesive products for packaging used in the food industry.
Rongalite C is used in the polymerization process of paperboard manufacturing that comes into contact with watery and oily foods due to its catalytic effect.

In fabric production, Rongalite C is used to make the resulting fabric softer and more flexible.
Rongalite C is used in the manufacture of sealing gaskets for food containers.

Rongalite C is used in the manufacture of rubber products that come into contact with food for repeated use.
Rongalite C is used as an emulsifier in the manufacture of food contact products.

In the textile industry, Rongalite C is used as a strong reducing agent, especially in the application of sulfur and vat dyes.
Rongalite C makes colors more vibrant and permanent, while also preventing unwanted oxidation reactions during the dyeing process.

In paper and cellulose production, Rongalite C plays an active role in bleaching processes.
By removing lignin residues, Rongalite C helps to obtain brighter and purer paper surfaces.

In polymer production and chemical synthesis, Rongalite C is used as a reaction initiator and control agent for carrying out controlled reactions.
This property contributes to the preservation of product quality and molecular homogeneity.

In the photography sector, Rongalite C acts as a developing agent in film and printing processes.
By maintaining chemical balance, Rongalite C ensures clear and high-contrast images.

In metal surface treatment, Rongalite C is used as an oxide remover to dissolve oxide layers and prepare surfaces for better coating.
Thus, surface quality and adhesion performance are increased.

In the paint and pigment industry, Rongalite C acts as a color lightener.
Rongalite C helps achieve the desired homogeneous appearance by softening color tones.

In chemical formulations, Rongalite C creates a stable reduction environment, especially in systems where controlled reduction reactions are required.
This increases the efficiency of the reactions and preserves purity.
Rongalite C is used in various industries and processes, primarily due to its properties as a reducing agent.

Textile Industry—Fabric Dyeing:
Rongalite C is used to reduce dyes, allowing them to adhere to the fabric more effectively.
This is particularly useful in vat dyeing, where insoluble dyes are converted into their soluble, colorless leuco forms.

Printing Fabrics:
Rongalite C is used in the printing process to achieve bright and clear prints with certain types of dyes.

Paper Industry—Wood Pulp Bleaching:
Rongalite C is used in the bleaching of wood pulp, helping to lighten the pulp and prepare it for the production of paper.

Chemical Synthesis—Pharmaceuticals and Fine Chemicals:
Rongalite C serves as a reducing agent in the synthesis of certain pharmaceuticals and fine chemicals, where it helps to maintain specific chemical conditions needed for reactions.

Industry Uses:
Reducing agent
Stabilizing agent

Consumer Uses:
Reducing agent

Production of Rongalite C:
The production of Rongalite C is described below on a small scale.
This production is very similar to the commercial industrial production process, but at the micro level.

In the production process, Rongalite C was determined that a very different reaction occurs when 1 mole of formaldehyde reacts with 1 mole of sodium hydrosulfite in the presence of sodium hydroxide.

If 1 mole of sodium hydrosulfite solution, 1 mole of sodium hydroxide solution, and 1 mole of formaldehyde solution are shaken, an exothermic reaction occurs.
In Rongalite C production, the reduction potential of the solution disappears after a while compared to the indigo carmine solution when cold.

In the continuing process, if the solution is mixed with an equal volume of alcohol, the neutral sodium hydrosulfite will precipitate.
When this solution is evaporated, a chemical in syrup form is formed.

In this process, Rongalite C is recrystallized from hot ethanol as well as from water, where it is highly soluble.
At this stage, Rongalite C initially forms prism-shaped crystals.

Later, large, silvery leaves are formed.
The chemical formed here is NaSCO3H3•2H2O.

The reaction for the production of Rongalite C is as follows:
CH2O + Na2S2O4 + NaOH → NaSCO3H3 + Na2SO3.

Synthesis and Reactions of Rongalite C:

Although available commercially, the salt can be prepared from sodium dithionite and formaldehyde:
Na2S2O4 + 2 CH2O + H2O → HO-CH2-SO3Na + HO-CH2-SO2Na

This reaction proceeds quantitatively, such that dithionite can be determined by its conversion to Rongalite, which is far less O2-sensitive and thus easier to handle.

The hydroxymethanesulfinate ion is unstable in solution towards decomposition to formaldehyde and sulfite.
Addition of at least one equivalent of formaldehyde pushes the equilibrium towards the side of the adduct and reacts further to give the bis-(hydroxymethyl)sulfone.
Such solutions are shelf-stable indefinitely.

Sodium hydroxymethanesulfinate was originally developed in the early 20th century for the textile industry as a shelf-stable source of sulfoxylate ion, where the latter can be generated at will.
In use, when sodium hydroxymethanesulfinate is made acidic, the reducing sulfoxylate ion and formaldehyde are released in equimolar amounts.
For safety reasons the generation of formaldehyde must be taken into consideration when used industrially.

NaHOCH2SO2 can essentially be considered to be a source of SO22−.
As such Rongalite C is used both as a reducing agent and as a reagent to introduce SO2 groups into organic molecules.

Treatment of elemental Se and Te with NaHOCH2SO2 gives solutions containing the corresponding Na2Sex and Na2Tex, where x is approximately 2.
As a nucleophile, NaHOCH2SO2 reacts with alkylating agents to give sulfones.

HO-CH2-SO2Na + 2 C6H5CH2Br → [C6H5CH2]2SO2 + NaBr + CH2O + HBr

Occasionally, alkylation will occur also at oxygen, thus xylylene dibromide gives both the sulfone and the isomeric sulfinate ester.

Related Compounds of Rongalite C:
The zinc complex Zn(HOCH2SO2)2 is marketed under the trademarks Decroline, Decolin, and Safolin.
Rongalite C is an additive in polymers and textiles

Stability and Reactivity of Rongalite C:

Chemical Stability:
Rongalite C is chemically stable under normal ambient temperatures when stored in a dry, airtight environment.
Stability decreases in the presence of moisture, heat, or prolonged exposure to air, leading to gradual decomposition and loss of reducing power.

Reactivity:
Rongalite C is a strong reducing agent and readily reacts with oxidizing substances.
Under normal handling conditions, no hazardous polymerization occurs.

Conditions to Avoid:
Avoid exposure to moisture, high humidity, elevated temperatures, acids, and direct contact with air or oxygen for extended periods, as these conditions accelerate decomposition.

Incompatible Materials:
Strong oxidizing agents, acids, heavy metal salts, peroxides, and halogenated oxidants should be avoided due to the risk of rapid reaction or degradation.

Hazardous Decomposition Products:
Thermal or oxidative decomposition may release sulfur dioxide (SO₂), formaldehyde, carbon oxides (CO, CO₂), and other sulfur-containing gases.

Handling and Storage of Rongalite C:

Safe Handling:
Handle Rongalite C in well-ventilated areas to minimize dust and vapor exposure.
Avoid generating dust and prevent contact with skin and eyes.

Use closed or controlled transfer systems where possible.
Keep material away from ignition sources and oxidizing chemicals.

Hygiene Measures:
Wash hands and exposed skin thoroughly after handling.
Avoid eating, drinking, or smoking in handling areas.
Remove contaminated clothing before reuse.

Storage Requirements:
Store in tightly sealed, moisture-resistant containers in a cool, dry, and well-ventilated area.
Protect from humidity, heat, and direct sunlight.

Packaging Integrity:
Keep containers tightly closed when not in use.
Avoid damaged packaging that may allow moisture or air ingress.

Shelf Stability:
Shelf life is limited and highly dependent on storage conditions; prolonged exposure to humidity or air significantly reduces product stability and effectiveness.

First Aid Measures of Rongalite C:

Inhalation:
Move the exposed person to fresh air immediately.
Keep at rest and monitor breathing.
If coughing, respiratory irritation, or breathing difficulty persists, seek medical attention.

Skin Contact:
Wash affected areas immediately with plenty of soap and water.
Remove contaminated clothing.
Seek medical advice if irritation or redness develops.

Eye Contact:
Rinse eyes cautiously with clean water for several minutes, holding eyelids open.
Remove contact lenses if present and easy to do.
Seek medical attention if irritation persists.

Ingestion:
Rinse mouth with water.
Do not induce vomiting.
Seek immediate medical attention due to the potential toxicity of decomposition products.

Notes for Physician:
Treatment should be supportive and based on symptoms.
Exposure may involve reducing agents and sulfur-containing compounds.

Firefighting Measures of Rongalite C:

Flammability:
Rongalite C itself is not highly flammable but may decompose under fire conditions.

Suitable Extinguishing Media:
Use water spray, foam, dry chemical powder, or carbon dioxide (CO₂), depending on surrounding materials.

Hazardous Combustion Products:
Fire may release toxic gases such as sulfur dioxide, formaldehyde, and carbon oxides.

Special Protective Equipment for Firefighters:
Firefighters should wear self-contained breathing apparatus and full protective clothing.

Specific Hazards:
Avoid inhalation of decomposition fumes.
Cool containers exposed to fire with water spray to prevent rupture.

Accidental Release Measures of Rongalite C:

Personal Precautions:
Avoid breathing dust and prevent contact with skin and eyes.
Ensure adequate ventilation and wear appropriate personal protective equipment.

Environmental Precautions:
Prevent large quantities from entering drains, surface water, or soil.

Cleanup Methods:
Carefully collect spilled material using non-sparking tools and dust-minimizing methods.
Place in suitable, sealed containers for disposal according to local regulations. Avoid washing into drains.

Additional Advice:
Clean contaminated surfaces with water after material removal and ventilate the area thoroughly.

Exposure Controls and Personal Protective Equipment of Rongalite C:

Engineering Controls:
Use adequate general ventilation or local exhaust ventilation to control airborne dust and vapors.

Respiratory Protection:
Use a suitable particulate or combination respirator if dust or decomposition gases may be generated.

Hand Protection:
Wear chemical-resistant gloves such as nitrile or PVC to prevent skin contact.

Eye Protection:
Use safety goggles or face shields to protect against dust or splashes.

Skin and Body Protection:
Wear appropriate protective clothing to minimize repeated or prolonged contact.

Hygiene Measures:
Wash hands thoroughly after handling and before breaks.
Avoid eating, drinking, or smoking in work areas.

Identifiers of Rongalite C:
CAS number: 149-44-0
EC number: 205-739-4
Molecular formula: CH3NaO3S
Ionic formula: Na⁺HOCH2SO2⁻
Molecular weight: 134.11 g/mol (anhydrous)
Appearance: White to pale yellow crystalline powder
Physical form: Solid
Solubility: Highly soluble in water
Chemical class: Inorganic sulfur-containing reducing agent
Functional group: Sulfinate
Typical commercial form: Dihydrate

CAS number: 149-44-0
PubChem: 8999
ChemSpider: 8649
UNII: X4ZGP7K714
RTECS number: PB0380000
Molecular formula: CH3NaO3S
Molar mass: 118.10 g/mol 154.14 g/mol, dihydrate
Appearance: colorless crystals
Density: 1.75 g/cm3, dihydrate
Melting point: 64.5 °C, dihydrate
Water solubility: 600 g/L, dihydrate (approx.)
Acidity (pKa): Decaying. Low pH
Structure: Molecular shape

CAS Number: 149-44-0
ChEMBL: ChEMBL2107242
ChemSpider: 8649
ECHA InfoCard: 100.005.219
EC Number: 205-739-4
PubChem CID: 23689980
RTECS number: PB0380000
UNII: X4ZGP7K714
CompTox Dashboard (EPA): DTXSID7027120
InChI: InChI=1S/CH4O3S.Na/c2-1-5(3)4;/h2H,1H2,(H,3,4);/q;+1/p-1
Key: XWGJFPHUCFXLBL-UHFFFAOYSA-M
InChI=1/CH4O3S.Na/c2-1-5(3)4;/h2H,1H2,(H,3,4);/q;+1/p-1
Key: XWGJFPHUCFXLBL-REWHXWOFAH
SMILES: [Na+].[O-]S(=O)CO

Properties of Rongalite C:
Physical state: Solid
Appearance: White to pale yellow crystalline powder
Odor: Odorless to faint sulfurous odor
Chemical nature: Inorganic sulfur-based reducing agent
Chemical class: Sulfinate salt
Molecular formula: CH3NaO3S
Ionic formula: Na⁺HOCH2SO2⁻
Molecular weight: 134.11 g/mol (anhydrous)
Commercial form: Commonly supplied as dihydrate
Solubility in water: Very high (readily soluble)
Solubility in organic solvents: Insoluble in most organic solvents
pH (aqueous solution): Slightly alkaline to neutral (typically ~6.5–8, concentration dependent)

Molecular Weight: 119.10 g/mol
Hydrogen Bond Donor Count: 2
Hydrogen Bond Acceptor Count: 4
Rotatable Bond Count: 1
Exact Mass: 118.97788444 Da
Monoisotopic Mass: 118.97788444 Da
Topological Polar Surface Area: 76.7 Ų
Heavy Atom Count: 6
Complexity: 42.2
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: 2
Compound Is Canonicalized: Yes

Chemical formula: CH3NaO3S
Molar mass: 118.10 g/mol
Appearance: colorless crystals
Density: 1.75 g/cm3, dihydrate
Melting point: 64.5 °C (148.1 °F; 337.6 K) dihydrate
Solubility in water: 600 g/L, dihydrate (approximate)
Acidity (pKa): decomposes at low pH

Names of Rongalite C:

IUPAC name:
Sodium hydroxymethanesulfinate

Other names:
Sodium formaldehydesulfoxylate
sodium oxymethylene sulfoxylate
Brüggolit