Catalyzes the hydrolysis of epoxide-containing fatty acids. Active against epoxyeicosatrienoic acids (EETs) including 8,9-epoxy-(5Z,11Z,14Z)-eicosatrienoate (8,9-EET), 11,12-epoxy-(5Z,8Z,14Z)-eicosatrienoate (11,12-EET) and 14,15-epoxy-(5Z,8Z,11Z)-eicosatrienoate (14,15-EET) and the linoleic acid metabolites 12,13-epoxy-(9Z)-octadecenoate (12,13-EpOME) and 9,10-epoxy-(12Z)-octadecenoate (9,10-EpOME). These epoxides function as lipid signaling molecules, the enzyme can deplete the supply of the epoxide signal by transforming them into diol species that are more readily eliminated through excretion. an epoxide + H2O = an ethanediol 8,9-epoxy-(5Z,11Z,14Z)-eicosatrienoate + H2O = 8,9-dihydroxy-(5Z,11Z,14Z)-eicosatrienoate 11,12-epoxy-(5Z,8Z,14Z)-eicosatrienoate + H2O = 11,12-dihydroxy-(5Z,8Z,14Z)-eicosatrienoate 14,15-epoxy-(5Z,8Z,11Z)-eicosatrienoate + H2O = 14,15-dihydroxy-(5Z,8Z,11Z)-eicosatrienoate 12,13-epoxy-(9Z)-octadecenoate + H2O = 12,13-dihydroxy-(9Z)-octadecenoate 9,10-epoxy-(12Z)-octadecenoate + H2O = 9,10-dihydroxy-(12Z)-octadecenoate kcat is 12 sec(-1) with trans-1,3-diphenylpropene oxide as substrate. kcat is 0.11 sec(-1) with 12,13-epoxy-9-octadecenoate as substrate. kcat is 0.22 sec(-1) with 9,10-epoxy-12-octadecenoate as substrate. Lipid metabolism. RNAi knockdown of both ceeh-1 and ceeh-2 results in the accumulation of 9,10-EpOME and 12,13-EpOME. Belongs to the AB hydrolase superfamily. Epoxide hydrolase family.