Abstract: Process for denaturating water-dilutable paints and solvent-based paints, wherein said paints are treated by washing with the assistance of an aqueous denaturation phase whose pH is from 4.5 to 7 and preferably from 5 to 6 and which contains an effective quantity of at least one denaturation agent consisting of an amine molecule of formula ##STR1## or of formula: ##STR2## in which the substituents R.sub.1 to R.sub.7, which may be identical or different, represent:a hydrogen atom,a radical of formula --O--Re in which Re is chosen from the group comprising hydrogen and a C.sub.1 to C.sub.4 saturated aliphatic hydrocarbon chain, it being understood that the substituents R.sub.5 to R.sub.7 are not simultaneously all hydrogen atoms,or of a hydrate or else of a salt of an organic or inorganic acid salt of said amine molecule, preferably a salt of sulfuric acid, phosphoric acid or hydrochloric acid.