Sulfamic acid

Sulfamic acid is an inorganic solid acid formed by the substitution of a hydroxyl group with an amino group. Its chemical formula is NH₂SO₃H, with a molecular weight of 97.09. It generally appears as white, odorless rhombic flake crystals with a relative density of 2.126 and a melting point of 205°C. It is soluble in water and liquid ammonia. At room temperature, as long as it remains dry and avoids contact with water, solid sulfamic acid does not absorb moisture and is relatively stable.^[1] The aqueous solution of sulfamic acid exhibits strong acidity equivalent to that of hydrochloric acid, hence it is also known as solid acid. It is characterized by being non-volatile, odorless, and having low toxicity to humans. However, its dust or solution can irritate the eyes and skin, causing burns, with a maximum allowable concentration of 10 mg/m³. Sulfamic acid is used in the synthesis of herbicides, flame retardants, sweeteners, preservatives, metal cleaning agents, and more, making it a common chemical raw material.