Ammonium Sulfamate

The Chemical Company’s Ammonium Sulfamate (AMS) is a white crystalline solid — the ammonium salt of sulfamic acid — readily soluble in water and freely miscible with polar solvents. It is produced commercially by reacting ammonia with sulfur trioxide, or alternatively from urea and sulfuric acid. Stable under normal storage conditions, AMS decomposes exothermically above ~160°C, releasing ammonia, nitrogen oxides, and sulfur oxides — a property relevant to both safe handling and flame retardant performance.

AMS is a versatile industrial and specialty chemical serving agriculture, fire protection, textiles, printing and dyeing, and analytical chemistry. Its most prominent use is as a non-selective herbicide, particularly effective against woody weeds, tree stumps, and brambles. It works by blocking glutamine synthetase, causing toxic ammonia accumulation in plant tissue while starving it of essential amino acids. At agronomic concentrations, this same mechanism inhibits soil nitrification, a property leveraged in slow-release nitrogen management. AMS also performs well as a flame retardant, paper softener, and fine chemical intermediate.

In emerging photovoltaic research, AMS has been identified as an effective interface modifier for perovskite solar cells, passivating surface defects, suppressing non-radiative recombination, and improving charge carrier mobility, delivering gains in both power conversion efficiency and long-term device stability.