Check the listing for details. Ferric Chloride, Lab Grade, Anhydrous 500g, Patina, Etching. Condition: New. Listed at 24.95 USD. Ferric Chloride, 500g Patina, Copper, Bronze, Brass, Etching : Chemical Grade: Lab, Anhydrous powder. Formula: FeCl3 CAS: 7705-08-0 U.S. DOT: UN1773, Class 8, PG III Ferric Chloride is also called Iron(III) Chloride. It is soluble in water and alcohol and is non-combustible. When dissolved in water, ferric chloride undergoes hydrolysis and gives off heat in an exothermic reaction. The resulting brown, acidic, and corrosive solution is used as a flocculant in sewage treatment and drinking water production, and as an etchant for copper-based metals in printed circuit boards. If you are looking for an etchant, see our Ferric Chloride Etchant Solution. Used in our Patina formula No. 4 for Florentine Brown. Ferric Chloride only ships to destinations within the 48 contiguous US states and Canada using Standard Ground, limited quantity service. No air deliveries allowed.