Use of a biomolecule having the protein sequence or coding DNA sequence of HheD3 having NCBI, GenBank accession number ABM93639 as halohydrin dehalogenase in the conversion of at least a part of the amount of a halohydrin of formula into an epoxide of formula wherein X is a halogen atom selected from Cl, Br, I; R 1, R 2, R 3, R 4 are independently hydrogen, halogen (F, Cl, Br, I) or substituted or unsubstituted C1-C12-alkyl, C2-C12-alkenyl, C2-C12-alkinyl, C1-C12-alkoxy, C3-C12-cycloalkyl, C3-C12-cycloalkenyl, C6-C12-cycloalkinyl or C5-C12-aryl, or C1-C3-alkyl-C(=O)-O-R 5 or -C1-C3-alkyl-O-R 5, with R 5 selected from hydrogen, C1-C6-alkyl, C2-C6-alkenyl, C2-C6-alkinyl, C1-C6-alkoxy, C5-C13-alkylaryl, C5-C13-arylalkyl, C5-C13-aryloxy, C5-C13-arylalkoxy, C5-C13-heteroalkyl, C5-C13-aryl, C5-C13-heteroaryl, C3-C12-cycloalkyl, C3-C12-cycloalkenyl, C6-C12-cycloalkinyl or C5-C13-cyclic heteroalkyl, wherein in case of more than one aliphatic or aromatic ring system the ring systems are condensed or separated and R 5 may have at least one further substituent R 6 with R 6 selected from hydrogen, hydroxyl, -C(=O)-NH 2, halogen (F, Cl, Br, I), -C1-C3-alkyl, -C(=)O-Cl-C3-alkyl, -C(=)O-C1-C3-alkyl, -NH-C(=)O-C1-C3-alkyl, -C1-C3-alkyl-O-C1-C3-alkyl, C2-C3-alkenyl, -O-C2-C3-alkenyl, C5-C7-cycloalkyl, C5-C7- cyclic heteroalkyl, C5-C7-aryl or C5-C7-heteroaryl and/or two of R 1, R 2, R 3, R 4 together form a cyclic structure selected from C3-C12-cycloalkyl, C4-C12-cycloalkenyl, C6-C12-cycloalkinyl, C3-C12-cyclic heteroalkyl, C4-C12-cyclic heteroalkenyl or C6-C12-cyclic heteroalkinyl, preferably a C4-C8-cycloalkyl, or C4-C8-cycloalkenyl group, more preferred a C5-C7-cycloalkyl, or C5-C7-cycloalkenyl group, most preferred a C5-C6-cycloalkyl, or C5-C6-cycloalkenyl group wherein in case of more than one ring system the ring systems are condensed or separated, and wherein the number of C-atoms as indicated for the cyclic structure always includes the 2 C-atoms of the halohydrin structure bearing the OH and the X, and wherein each cyclic group in R 1, R 2, R 3, R 4 or cyclic structure formed by two of R 1, R 2, R 3, R 4 optionally has at least one further substituent different from hydrogen, preferably selected from R 6, most preferred halogen (F, Cl, Br, I) or C1-C3-alkyl (R 7). X is a halogen atom selected from Cl, Br, I; R 1, R 2, R 3, R 4 are independently hydrogen, halogen (F, Cl, Br, I) or substituted or unsubstituted C1-C12-alkyl, C2-C12-alkenyl, C2-C12-alkinyl, C1-C12-alkoxy, C3-C12-cycloalkyl, C3-C12-cycloalkenyl, C6-C12-cycloalkinyl or C5-C12-aryl, or C1-C3-alkyl-C(=O)-O-R 5 or -C1-C3-alkyl-O-R 5, with R 5 selected from hydrogen, C1-C6-alkyl, C2-C6-alkenyl, C2-C6-alkinyl, C1-C6-alkoxy, C5-C13-alkylaryl, C5-C13-arylalkyl, C5-C13-aryloxy, C5-C13-arylalkoxy, C5-C13-heteroalkyl, C5-C13-aryl, C5-C13-heteroaryl, C3-C12-cycloalkyl, C3-C12-cycloalkenyl, C6-C12-cycloalkinyl or C5-C13-cyclic heteroalkyl, wherein in case of more than one aliphatic or aromatic ring system the ring systems are condensed or separated and R 5 may have at least one further substituent R 6 with R 6 selected from hydrogen, hydroxyl, -C(=O)-NH 2, halogen (F, Cl, Br, I), -C1-C3-alkyl, -C(=)O-Cl-C3-alkyl, -C(=)O-C1-C3-alkyl, -NH-C(=)O-C1-C3-alkyl, -C1-C3-alkyl-O-C1-C3-alkyl, C2-C3-alkenyl, -O-C2-C3-alkenyl, C5-C7-cycloalkyl, C5-C7- cyclic heteroalkyl, C5-C7-aryl or C5-C7-heteroaryl and/or two of R 1, R 2, R 3, R 4 together form a cyclic structure selected from C3-C12-cycloalkyl, C4-C12-cycloalkenyl, C6-C12-cycloalkinyl, C3-C12-cyclic heteroalkyl, C4-C12-cyclic heteroalkenyl or C6-C12-cyclic heteroalkinyl, preferably a C4-C8-cycloalkyl, or C4-C8-cycloalkenyl group, more preferred a C5-C7-cycloalkyl, or C5-C7-cycloalkenyl group, most preferred a C5-C6-cycloalkyl, or C5-C6-cycloalkenyl group wherein in case of more than one ring system the ring systems are condensed or separated, and wherein the number of C-atoms as indicated for the cyclic structure always includes the 2 C-atoms of the halohydrin structure bearing the OH and the X, and wherein each cyclic group in R 1, R 2, R 3, R 4 or cyclic structure formed by two of R 1, R 2, R 3, R 4 optionally has at least one further substituent different from hydrogen, preferably selected from R 6, most preferred halogen (F, Cl, Br, I) or C1-C3-alkyl (R 7).