Calcium oxide (quicklime) is made into a dry, colorless crystalline powder by reacting it with water in a process called slaking. Hydrated lime is also called slack lime or pickling lime. It is used in the manufacture of cements, plasters, paint, rubber products, etc. Hydrated lime is used primarily in steel manufacturing to remove impurities. Other metals can also be made with hydrated lime. In handling hydrated lime powder, you need to ensure that it is not released into the surrounding atmosphere and that it is not contaminated by any airborne particles. It should be protected from moisture or contaminants that contain moisture, as this could cause a chemical reaction that produces unexpected heat.