This part of ISO 6743 establishes the detailed classification of fluids of family H (Hydraulic systems) which belong to class L (Lubricants, industrial oils and related products). It should be read in conjunction with ISO 6743-0. This classification excludes, for the time being, automotive brake fluids and airborne fluids. However, this edition includes environmentally acceptable fluid categories, i.e.: HETG, HEPG, HEES and HEPR.