uaternary ammonium salts of formula N+R???R???R??????R??????Y??? in which the radicals R???, R???, R??????, and R?????? are, independent of one another, optionally hydroxylated hydrocarbon radicals, and Y??? is an anion of a strong acid, such as halide, sulphate and sulphonate anions; including in particular cetyltrimethylammonium bromide;the amine salts of formula N+R???R???R?????? in which the r