Bleaching powder is chemically, calcium oxychloride (CaOCl2). Bleaching powder is manufactured using Backmann’s plant in which slack lime and Chlorine are made to react to create Bleaching Powder.

Bleaching powder is a yellowish white powder with a strong smell of chlorine. When exposed to air, bleaching powder gives a smell of chlorine. This is because bleaching powder reacts with carbon dioxide from the atmosphere to produce calcium carbonate and chlorine.