… by weight. Phenol of lower purity is excluded ( heading 27.07 ). (2) Cresols (CH 3 C 6 H 4 OH)* . These phenols … together. Cresols of lower purity are excluded ( heading 27.07 ). (3) Octylphenol, nonylphenol and their isomers . … together. Xylenols of lower purity are excluded ( heading 27.07 ). (5) Thymol (5-methyl-2-isopropylphenol). Found in …