Ammonium iron(III) sulfate, NH4Fe(SO4)2.12H2O, also known as ferric ammonium sulfate (FAS) or iron alum, is a double salt in the class of alums, which consists of compounds with the general formula NH4Fe(SO4)2.12H2O.
A 2145 (OTTO) Ammonium ferric sulphate, 99% Cas 7783-83-7 - used in a wide area of applications, including adiabatic refrigeration equipment, biochemical analysis and organic synthesis.