Sulphamic Acid

Sulfamic Acid
HS Code: 28111940


Chemical Formula: H3NSO3

Sulfamic acid, also known as amidosulfonic acid, amidosulfuric acid, aminosulfonic acid, and sulfamidic acid, is a molecular compound with the formula H3NSO3. This colorless, water-soluble compound finds many applications. Sulfamic acid melts at 205 °C before decomposing at higher temperatures to water, sulfur trioxide, sulfur dioxide and nitrogen. Sulfamates are derivatives of sulfamic acid.


Formula: H3NSO3
Molar mass: 97.1 g/mol
Solubility in water: Moderate, with slow hydrolysis
Solubility: Moderately soluble in DMF,  Slightly soluble in MeOH, Insoluble in hydrocarbons


Sulfamic acid is mainly a precursor to sweet-tasting compounds. Reaction with cyclohexylamine followed by addition of NaOH gives C6H11NHSO3Na, sodium cyclamate. Related compounds are also sweeteners, such as acesulfame potassium.

Sulfamates have been used in the design of many types of therapeutic agents such as antibiotics, nucleoside/nucleotide human immunodeficiency virus (HIV) reverse transcriptase inhibitors, HIV protease inhibitors (PIs), anticancer drugs (steroid sulfatase and carbonic anhydrase inhibitors), antiepileptic drugs, and weight loss drugs.

Cleaning agent

Sulfamic acid is used as an acidic cleaning agent, sometimes pure or as a component of proprietary mixtures, typically for metals and ceramics. It is frequently used for removing rust and limescale, replacing the more volatile and irritating hydrochloric acid, which is cheaper. It is often a component of household descaling agents, for example, Lime-A-Way Thick Gel contains up to 8% sulfamic acid and has pH 2.0–2.2, or detergents used for removal of limescale. When compared to most of the common strong mineral acids, sulfamic acid has desirable water descaling properties, low volatility, and low toxicity. It forms water-soluble salts of calcium and ferric iron.

Sulfamic acid is preferable to hydrochloric acid in household use, due to its intrinsic safety.It also finds applications in the industrial cleaning of dairy and brewhouse equipment. Although it is considered less corrosive than hydrochloric acid, corrosion inhibitors are often added to the commercial cleansers of which it is a component. It can be used for descaling home coffee and espresso machines and in denture cleaners.

Other uses

Catalyst for esterification process
Dye and pigment manufacturing
Coagulator for urea-formaldehyde resins
Ingredient in fire extinguishing media. Sulfamic acid is the main raw material for ammonium sulfamate which is a widely used herbicide and fire retardant material for household product.
Pulp and paper industry as a chloride stabilizer
Synthesis of nitrous oxide by reaction with nitric acid