Release agents perform the key task of preventing bonding of material to mold. They also perform additional functions during the molding process such as reducing production time, facilitating cleanup and extending the life of the mold. Release agents are needed during concrete production to prevent concrete from sticking to the formwork and to ensure easy removal of formwork without surface damage. It also enhances the appearance of precast by minimizing the inconsistencies, such as blow/bug holes on the surface.

Concrete release agents consist of a base fluid in which the required additives are dissolved. The base fluid can be mineral oil or water. Petroleum oil has traditionally served as a base fluid for the active ingredients in solvent-based release agents.

Chemically active release agents include a wide variety of proprietary materials. Chemically active means that an active ingredient in the release agent chemically combines with calcium (lime) in the fresh cement paste. Typically, the active ingredient (chemically active part) of a release agent is some type of fatty acid. Fatty acids, even when chemically combined with other materials, whether in water based products or oil based products, still prefer to react with the calcium in the cement paste. This calcium/fatty acid product (grease or metallic soap) is very stable and causes the form to release from the concrete.