It is used for sewerage treatment of industrial wastes, chloride hydrometallurgy (Silgarin process for the production of silicon), drinking water production, production of precursor for polyvinyl chloride (PVC), and copper-based metals in printed circuit boards. Iron (III) chloride is used as catalyst for the reaction of ethylene with chlorine, as a leaching agent, and as a drying reagent in certain reactions. It is a mild oxidizing agent and converts copper(I) chloride in to copper(II) chloride. As a moderately strong Lewis acid, it catalyzes chlorination of aromatic compounds and Friedel-Crafts reactions. Along with sodium iodide, it brings about reduction of organic azides to corresponding amines. It is useful in the detection of phenols and phenolic derivatives, gamma-hydroxybutyric acids, and also in Trinder spot test for detecting salicylic acids.

This Thermo Scientific Chemicals brand product was originally part of the Alfa Aesar product portfolio. Some documentation and label information may refer to the legacy brand. The original Alfa Aesar product / item code or SKU reference has not changed as a part of the brand transition to Thermo Scientific Chemicals.