What is Sulfamic Acid and what is it used for ?


Sulfamic acid is a white crystalline solid which is stable and non-hygroscopic. It is soluble in water and formamide and slightly soluble in methanol, ether, acetone and concentrated sulphuric acid. It is classified as a strong inorganic acid and is commercially produced from urea and fuming sulphuric acid. At room temperature, dilute aqueous  acid solution is stable for a long time but rapid hydrolysis occurs at elevated temperatures. It’s solution is less corrosive toward metals than other mineral acids like hydrochloric acid.

Sulfamic acid is used as an acidic cleaning agent, typically for metals and ceramics. It is a replacement for hydrochloric acid for the removal of rust. In households, it is often found as a descaling agent in detergents, cleaners and toilet cleaners for the removal of limescale.

Properties of Sulfamic acid

  • Synonyms: suphamic acid; Amidosulfonic acid; Amidosulphonic acid; sulphamidic acid;
  • CAS No: 5329–14–6
  • EINECS No: 226–218–8
  • Appearance: white crystalline solid
  • Minimum quality: 99.8%
  • Molecular formula: NH2SO3H
  • Molar mass: 97.09 g/mol
  • Density: 2.15g/cm3
  • Solubility in water: 213 g/L (20C)
  • Melting point: 190 – 225 C
  • Boiling point: decomposes
  • pH: 1.2 (1% solution @ 20C)
  • Refractive index: 1.553

Where to Buy Sulphamic Acid / Sulfamic Acid online UK


  • Descaler, Cleaner & Rust Remover
  • removing excess grout on tiles, efflorescence and other mineral deposits
  • Cleaner & descaler for Dairy equipment (pipeline milkers, milk evaporators)
  • Cleaner & descaler for Brewery equipment (pipelines, Vats, etc)
  • Catalyst for esterfication process process
  • Used in dye and pigment manufacture
  • Used as a herbicide
  • Effecticve against Foot and Mouth (approved bty Defra)
  • Ingredient in Denture Tablets
  • Coagulator for urea-formaldehyde resins
  • Ingredient in fire extinguishing media
  • Pulp and paper industry as a chloride stabilizer
  • Synthesis of nitrous oxide by reaction with nitric acid

Sulfamic acid in descaling

Sulfamic Acid is super efficient descaling agent and is used for cleaning a variety of industrial equipment and domestic appliances. It is used for cleaning boilers, heat exchangers, condensers, jackets and coils, descaling toilets, removing excess grout on tiles, efflorescence and other mineral deposits etc (See below for details on how to use). It helps remove hard water scale, protein deposits, beer and milk stone, light rust and copper corrosion

Sulfamic acid in paper & pulp Industry

Sulfamic Acid prevents pulp degradation due to temperature at the chlorination and hydrochloride stage. It permits bleaching at higher temperature and lower PH without loss of strength.

Sulfamic acid is used in manufacturing of Dyes, Pigments and in the dyeing of leather

Sulfamic Acid removes excess of nitrides used in the diazotization reactions in the manufacturing of dye stuffs and pigments. Nitrides if present in process water of effluents can also be removed by using Sulphamic Acid

Sulfamic acid in Chlorine Stabilization

Chlorine gas in water form HOCL which reacts with Sulfamic Acid form N-Chloro-Sulphamic Acid to N-ChloroSufamic Acid more stable and yet has active chlorine, Because of this, Sulphamic Acid is used for stabilizing chlorine in swimming pools and cooling towers.

Sulfamic acid in Electroplating and Electro-refining

Metal sulphamate electrolytes values for their high solubility cadmium, cobalt nickle, lead silver and radium sulphamte deposits are bright and dense. Lead sulphamate is used in refining lead when a high quality is desired.

Sulfamic acid in Sulphation and Sulphamation

Sulfamic acid is used for sulphation and sulphamation of many organic compounds. Sulphation of aklyl pheno-ethylen oxide condensation products 9for detergents and sulphation of ethoxylated phenol-formaldehyde resins is preferable with Sulphamic Acid. Stronger agents cause unwanted ring sulphomation.

How to use Sulfamic Acid for cleaning & descaling:

For removing excess grout from tiling or dissolving efflorescence from walls, floors etc: Make up a solution of sulfamic acid by dissolving 80–100g per litre of warm water. Apply to surface using a cloth or brush and allow to work for a few minutes. Agitate with brush if necessary and rinse with clean water. Please Note: if using around coloured grout use a weaker solution of approx 2% (20g per litre of water) to reduce the risk of leaching out any colour from the grout.

For descaling equipment use a 10% solution. Sulfamic acid is safe for steel, iron, glass and wood equipment, and may be used with caution on copper, aluminium, and galvanized metal surfaces. Clean in a soak tank or by circulation. For surfaces, apply to surface using a cloth or brush and allow to work for a few minutes. Agitate with brush if necessary and rinse thoroughly with clean water.

For Boiler systems & Cooling Towers use a circulation treatment of a 10% to 15% solution depending on how bad the system is. Before applying flush out system and refill with clean water. Determine the volume of water and mix in the sulfamic acid at a rate of 100g to 150g per litre of water. Circulate the solution at room temperature or heated to a maximum of 60C for heavier cleaning. Note: Do not use at boiling point or product will undergo hydrolysis and not work. After cleaning rinse thoroughly and check system. Repeat applications may be necessary for heavily soiled systems. After cleaning Periodic flushing of the system to remove loosened scale and contaminants will be necessary.

For rust removal use a solution of 10%-20%.

Health & Safety

R-phrase(s): R36/38 Irritating to eyes and skin. R52/53 Harmful to aquatic organisms, may cause long-term adverse effects in the aquatic environment.

S-phrase(s): S26 In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S28 After contact with skin, wash immediately with plenty of soap and water. S61 Avoid release to the environment. Refer to special instructions/ Safety data sheets.

See MSDS for Sulfamic acid for full details.


Where to Buy Sulphamic Acid / Sulfamic Acid online UK


About mistralhowto

formulation chemist

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