Class 0 Equipment (Prohibited in the Netherlands)

Electrical equipment that relies solely on basic insulation for protection against electric shock, without a protective conductor (PE), without double/reinforced insulation (as in Class II) and without SELV/PELV supply (as in Class III) — in contrast to Classes I, II and III, each of which provides an explicit additional protective measure in case the basic insulation fails. With Class 0 equipment, a single insulation fault leads directly to a hazardous touch voltage on accessible conductive parts, with no second layer of protection. Although Class 0 is still listed in the classification of IEC 61140 internationally, its use in the Netherlands (and most other European countries) has been prohibited for newly manufactured and marketed equipment for decades; older Class 0 equipment still in use must be upgraded to at least Class I upon replacement.