The invention comprises quaternary ammonium thioglycollates, having the general formula R1R2R3R4N+ -OOC,CH2,SH wherein R1R R2, R3 and R4 are the same or different and each is an alkyl or hydroxy-alkyl group, the total number of carbon atoms in the four groups being at least 10. Preferably R1 contains at least 8 carbons in a straight chain.  R2 may be a hydroxy alkyl group and each of R2, R3 and R4 preferably contains not more than 4 carbons.  The quaternary salts may be prepared by reacting the corresponding quaternary ammonium hydroxides with thioglycollic acid.  Those containing a hydroxy alkyl group may also be prepared by forming the thioglycollate of an appropriate tertiary amine R1R2R3N and thereafter reacting the p thioglycollate with a 1 : 2-alkylene oxide, preferably at 60-70 DEG C. in a closed reactor.  The quaternary salts may be used as bactericidal agents, textile modifying agents and as hair-waving agents (see Group IV(c)) and depilatory agents.  They react with ferric compounds, molybdates and iodine.  In Examples: (1) hexadecyl trimethyl ammonium thioglycollate is prepared by treating a methanolic solution of the corresponding quarternary ammonium chloride with KOH in methanol, filtering off precipitated potassium chloride, neutralising the solution to pH7,0 with thioglycollic acid and then evaporating off the methanol; (2) hexadecyl dimethyl b -hydroxyethyl ammonium thioglycollate is prepared by reacting dimethyl hexadecylamine with ethylene oxide in aqueous ethanol at 60 DEG -80 DEG  C. under pressure and neutralising the resultant quaternary ammonium hydroxide to pH7,0 with thioglycollic acid; (3) dibutyl b -hydroxy ethyl octadecyl ammonium thioglycollate is prepared from dibutyl octadecyl amine by the method of (2); (4) dodecyl dimethyl b -hydroxyethyl ammonium thioglycollate is prepared by adding aqueous thioglycollic acid to an ethanolic solution of dimethyl dodecylamine, adding thereto ethylene oxide at 0,5 DEG  C. and then heating in a closed vessel at 60-70 DEG  C.  Other ammonium thioglycollates obtainable by the methods of the examples are the tributyl-b -hydroxyethyl-, dodecyl di- (b -hydroxyethyl)-methyl-, trimethyl-octyl-, dodecyl-b -hydroxypropyl-dimethyl-, and hexyl-b -hydroxy ethyl-dimethyl-ammonium thioglycollates.ALSO:Hair and other keratinous fibres are treated, e.g. waved, by a process comprising applying an aqueous solution of a quaternary ammonium thioglycollate of the general formula: R1R2R3R4+OOC,CH2SH wherein the Rs are the same or different and represent alkyl or hydroxyalkyl groups, the total number of carbon atoms in the four groups being at least 10; the solution is applied to the hair or other keratinous fibres at a pH of 7-10 and at a solution concentration not exceeding 25% by weight to relax the fibres, which are deformed whilst they are relaxed, and thereafter, if desired, treated with a mild oxidising solution, e.g. of sodium bromate. Specified quaternary ammonium thioglycollates are the hexadecyl trimethyl, hexadecyl dimethyl b - hydroxyethyl, dibutyl b - hydroxyethyl octadecyl, dodecyl dimethyl b - hydroxyethyl, tributyl b - hydroxyethyl, dodecyl methyl di(b - hydroxyethyl), trimethyl octyl, dodecyl b - hydroxyethyl dimethyl and hexyl-b - hydroxyethyl dimethyl ammonium thioglycollates.  Their preparation is described (see Group IV(b)).