Intracellular D-(-)-3-hydroxybutyrate oligomer hydrolase (also known as 3HB-oligomer hydrolase 3HBOH) functions in the degradation of poly-3-hydroxybutyrate (PHB). It catalyses the hydrolysis of D(-)-3-hydroxybutyrate oligomers (3HB-oligomers) into 3HB-monomers.