Phenoxyethylammonium compounds, useful as disinfectants and preserving agents, are manufactured by (a) quaternating phenoxy-ethyldimethylamine with a quaternating agent which introduces an alkyl residue having at least 8 carbon atoms, or (b) treating phenoxy-ethylamine, containing, at the nitrogen atom, an alkyl residue having at least 8 carbon atoms and a hydrogen atom or a methyl group, with a methylating agent, or (c) treating a hydroxy-ethyldimethylammonium compound, containing, at the quaternary nitrogen atom, an alkyl residue having at least 8 carbon atoms, or a reactive derivative thereof, with phenol or a reactive derivative thereof, or (d) treating a reactive ester (especially a halide) of phenoxy-ethanol (obtainable from phenol and a reactive ester of ethylene glycol) with a dimethylamine containing, as a substituent at the nitrogen atom, an alkyl residue having at least 8 carbon atoms. As quaternating agent in method (a) or (b) may be used a reactive ester of an alcohol having at least 8 carbon atoms or of methanol, e.g. an ester of a hydrohalic acid or of an aliphatic, aromatic or araliphatic sulphonic acid. Method (c) may be carried out by reacting a halogenethylammonium compound with phenol or a hydroxyethylammonium compound with a halogenbenzene. In examples: (1) b -phenoxy-ethyldimethyldodecylammonium bromide is made by heating b -phenoxyethyldimethylamine with dodecyl bromide or by methylacting b -phenoxyethyldodecylamine with formaldehyde and formic acid and then quaternating with methyl bromide; the corresponding chloride is obtained by treating the bromide with silver chloride in alcohol or by replacing the dodecyl bromide by dodecyl chloride, and the corresponding p-toluenesulphonate by replacing the methyl bromide by p-toluenesulphonic acid methyl ester; (2) the dodecyl bromide in (1) is replaced by hexadecyl or octyl bromide. Samples have been furnished under Sect. 2 (5) of b - phenoxyethyldimethyldodecylammonium bromide prepared by refluxing phenoxyethyl bromide with dodecyldimethylamine in (I) ethyl acetate, (II) acetone and (III) water. The Specification as open to inspection under Sect. 91 comprises also the manufacture of other phenoxyethyldimethylammonium compounds derived from monohydric phenols in which the phenyl nucleus may be substituted, e.g. by halogen atoms or alkyl groups, and containing at the quaternary nitrogen atom a hydrocarbon residue having at least 8 carbon atoms, e.g. b -(p-chlorophenoxy)-ethyldimethyl-dodecylammonium bromide (from b -(p-chloro-phenoxy) - ethyldimethylamine and dodecyl bromide, or from dimethyldodecylamine and b -(p-chlorophenoxy)-ethyl bromide (obtained in turn by reacting potassium p-chlorophenolate with ethylene chlorhydrin and then replacing the hydroxy group by bromine), or from potassium p-chlorophenolate and b -bromoethyl-dimethyldodecylammonium bromide), b -(p- and o-methylphenoxy)-ethyldimethyldodecylammonium bromide (from b -(p- or o-methylphenoxy)-ethyldimethylamine and dodecyl bromide), b -(p-tert.-butyl-, -iso-octyl-and-hexyl-phenoxy)-ethyldimethyldodecylammonium bromide (similarly from the appropriate starting materials, obtainable in turn from the appropriate phenols and b - chloroethyldimethylamine), b - (p-tert.-butylphenoxy) - ethyldimethyloctylammonium bromide (from b -(p-tert.-butylphenoxy)-ethyl-dimethylamine and octyl bromide) and b -(p-tert. - octylphenoxy) - ethyldimethyldodecylammonium bromide. Reference is also made to the preparation of b -phenoxyethyldimethyl-(ethylhexyl)-ammonium bromide. This subject-matter does not appear in the Specification as accepted.ALSO:Disinfectants consist of phenoxyethyldimethylammonium compounds containing at the quaternary nitrogen atom an alkyl residue having at least 8 carbon atoms, which compounds may be used in the form of solutions or emulsion or with inert or other active substances, e.g. in salves or dry powders. In examples: (1) b - phenoxyethyldimethyldodecylammonium bromide is pressed into tablets with starch, and, if desired, substances which accelerate dissolution in water; (2) b - phenoxyethyldimethylhexadecylammonium bromide is mixed with a finely pulverized diluent such as bole, boric acid, urea or cork meal, to produce a dusting powder. The Specification as open to inspection under Sect. 91 comprises also the use of similar compounds in which the phenyl group may be substituted by halogen atoms or alkyl groups. In further examples: (4) b - (p-methylphenoxy)-is dissolved in water, and colouring and odoriferous substances may be added; (6) b - (p-iso-octylphenoxy) - ethyldimethyl - dodecylammonium bromide is dissolved in a salve base consisting of white petroleum jelly, paraffin oil, wool fat and a little water. This subject-matter does not appear in the Specification as accepted.