A chemical designed to react with organic fatty acids, such as rosin, some oils and greases, to form a water-soluble soap. This is a solvent-free method of defluxing and degreasing many parts. Saponifiers are usually alkaline and may be mineral (based on sodium hydroxide or potassium hydroxide) or organic (based on water solutions of monoethanolamine).

That which saponifies; any reagent used to cause saponification.