Involved in the detoxification of xenobiotics and in the activation of ester and amide prodrugs. Hydrolyzes aromatic and aliphatic esters, but has no catalytic activity toward amides or a fatty acyl-CoA ester. Displays fatty acid ethyl ester synthase activity, catalyzing the ethyl esterification of oleic acid to ethyloleate. Converts monoacylglycerides to free fatty acids and glycerol. Hydrolyzes of 2-arachidonoylglycerol and prostaglandins. Hydrolyzes cellular cholesteryl esters to free cholesterols and promotes reverse cholesterol transport (RCT) by facilitating both the initial and final steps in the process. First of all, allows free cholesterol efflux from macrophages to extracellular cholesterol acceptors and secondly, releases free cholesterol from lipoprotein-delivered cholesteryl esters in the liver for bile acid synthesis or direct secretion into the bile. a carboxylic ester + H2O = a carboxylate + an alcohol + H(+) cholesteryl (9Z-octadecenoate) + H2O = (9Z)-octadecenoate + cholesterol + H(+) 2-(5Z,8Z,11Z,14Z-eicosatetraenoyl)-glycerol + H2O = (5Z,8Z,11Z,14Z)-eicosatetraenoate + glycerol + H(+) H2O + prostaglandin E2 1-glyceryl ester = glycerol + H(+) + prostaglandin E2 a cholesterol ester + H2O = a fatty acid + cholesterol + H(+) H2O + prostaglandin F2alpha 1-glyceryl ester = glycerol + H(+) + prostaglandin F2alpha Homotrimer and homohexamer. Binds to beta-glucuronidase (By similarity). Moves from cytoplasm to lipid droplets upon lipid loading. Associates with lipid droplets independently of triglycerides (TG) content of the droplets and hydrolyzes cholesteryl esters more efficiently from mixed droplets. Detected in kidney, liver and lung. Up-regulated in liver upon feeding a diet enriched in cholestyramine or cholate. Belongs to the type-B carboxylesterase/lipase family.