Alk(en)yl glycerol ether carboxylic acids which are prepared by reacting, in the presence of alkali, (a) an alk(en)yl glycerol ether compound of the general formula (I): R1O(A)nCH2CH[(A)mOR2]CH2(A)pOH  (I) wherein R1 and R2 each independently represents a hydrogen or an alk(en)yl group having from 4 to 22 carbon atoms, with the proviso that at least one of R1 and R2 represents an alk(en)yl group having from 4 to 22 carbon atoms, each A independently represents a C2H4O and/or C3H6O group and n, m and p each independently represents a number of from 0 to 10; and (b) an α-halocarboxylic acid of the general formula (II): XCR3R4COOH  (II) wherein R3 represents a hydrogen or a —CH3 group, R4 represents a hydrogen or an alk(en)yl group having from 1 to 6 carbon atoms and X represents a halogen; are described along with various uses for the same.