Involved in the detoxification of xenobiotics and in the activation of ester and amide prodrugs. Involved in the extracellular metabolism of lung surfactant (By similarity). a carboxylic ester + H2O = a carboxylate + an alcohol + H(+) Optimum pH is 7.0. Active from pH 4.0-8.0. Microsomal membrane, lumen of endoplasmic reticulum. Belongs to the type-B carboxylesterase/lipase family.