BS 135; 458; 805:1977

One grade of benzene and three grades each of xylene and toluene. Appendices give test methods for measurement of colour, determination of density at 20°C, total sulphur content (reduction, Wickbold and lamp methods), free sulphur, residue on evaporation (ordinary and air-jet methods), crystallizing point (of benzene), tests for acid wash, presence of hydrogen sulphide and mercaptans (Doctor test), examination for neutrality, GLC method of analysis (of toluene), details of STPTC thermometers.