A polymeric compound resulting from the reaction of 4-(1,1,3,3-tetramethylbutyl)phenol with formaldehyde to give a chain in which 6-8 molecules are linked together by CH2 groups ortho to the phenolic hydroxy groups, which have then undergone reaction with oxirane to give polyoxyethyleneoxy moieties, Ar(OCH2CH2)xOH, where x = 8-10. A nonionic liquic polymer, it inhibits lipoprotein lipase and hence clearance of triglyceride from the plasma, so is used to induce hyperlipidaemia in test animals. Also used as a surfactant to aid liquefaction and removal of mucus- and pus-containing bronchopulmonary secretions.