Wet chemical extinguishers employ a pressurized solution of alkali salts in water and are particularly effective against fats and cooking oils but not against petroleum products.
Vedelkemikaalkustuti sisaldab rõhu all olevat hüdroksiidsoolade vesilahust ning on eriti tõhus rasvade ja toiduõlide (kuid mitte naftatoodete) põlengu kustutamiseks.