IEC 60666:2010 provides methods concerning the detection and determination of specified additives in unused and used mineral insulating oils. The detection methods may be applied to assess whether or not a mineral insulating oil contains an additive as specified by the supplier. The determination methods are used for the quantitative determination of additives known to be present or previously detected by the appropriate detection method. The main changes with respect to the previous edition are listed below: - a change in the title from 'Detection and determination of specified anti-oxidant additives in insulating oils'; - new Annexes B and C which provide methods for the determination of two additives different from the anti-oxidants.