Abstract: Ether sulfonates corresponding to the following general formulaR.sup.1 -- O(C.sub.n H.sub.2n O).sub.x --R.sup.2 --SO.sub.3 M (I)wherein R.sup.1 is a C.sub.1-6 alkyl, n is an integer of 2-4, x is an integer from 0-30, R.sup.2 is a C.sub.6-22 linear alkenylene, hydroxyalkylene or hydroxyalkenylene group, and M is hydrogen or an alkali metal cation, which can be obtained by sulfonation of olefinically unsaturated fatty alkyl lower alkyl ethers or fatty alkyl (polyoxyalkyl) lower alkyl ethers with sulfur trioxide and hydrolysis of the sultones formed, are particularly suitable for use as low-foam wetting agents in aqueous acidic or alkaline commercial-grade treatment preparations.