A process for reducing free aldehydes in dispersions, suspensions, emulsions and solutions which comprises including therein thioamine compound of the formula IV and optionally a thioamine of the formula III: where R1 is a C1-5 alkyl radical, an aryl radical or hydrogen, R2 is —(COO)a —E or —(CONH)a—E where a is 0 or 1 and E, R3, R4, and R5 are independently R4 and R5 together containing at least one carbon atom, and n being 0 or 1.