Antimony trichloride is an inorganic chloride salt with formula SbCl3. It is used as a reagent for detecting vitamin A and related carotenoids, reacting with the carotenoid to form a blue complex that can be measured by colorimetry (the Carr-Price test). Solutions of antimony trichloride were formerly used for dissolving and removing horn stubs from calves and goats. It has a role as a Lewis acid, an apoptosis inducer and a colorimetric reagent. It is an antimony molecular entity and an inorganic chloride. It derives from a hydride of a stibane.