tert-Butylcatechol (TBC) is an efficient inhibitor of parasitic polymerization of many monomers during their transportation and storage. Just before the monomers are used, removal of the inhibitor is often necessary and can easily be achieved by adsorption on alumina, The influence of the main physical parameters of the alumina on its performance has been particularly studied. The accessibility of the TBC molecule into the internal porous network of the alumina beads or extrudates appears to be the key parameter, clearly more than the specific surface area. Procatalyse＇s specially optimized Spheralite 538E performs particularly well in removing TBC from hydrocarbon streams.