Stabilizer (chemistry)

In chemistry a stabilizer is a chemical which tends to inhibit the reaction between two or more other chemicals. It can be thought of as the antonym to a catalyst. It can be also a chemical that inhibits separation of suspensions, emulsions, and foams.

Some kinds of stabilizers are:
* antioxidants, preventing unwanted oxidation of materials
* sequestrants, forming chelate complexes and inactivating traces of metal ions that would otherwise act as catalysts
* emulsifiers and surfactants, for stabilization of emulsions
* ultraviolet stabilizers, protecting materials, especially plastics, from harmful effects of ultraviolet radiation
** UV absorbers, chemicals absorbing ultraviolet radiation and preventing it from penetrating the materials; principially the same as sunscreens
** quenchers, dissipating the radiation energy as heat instead of letting it break chemical bonds; often organic nickel salts, e.g. nickel phenolates
** scavengers, eliminating the free radicals formed by ultraviolet radiation; often hindered amine light stabilizers (HALS)

ee also

* Corrosion inhibitor