This specification applies to passive filter units for electromagnetic interference suppression which fall within the scope of the Generic Specification EN 133 000. The scope of this specification is restricted to passive filter units for which safety tests are appropriate. This implies that filters specified according to this specification will either be connected to mains supplies, when compliance with the mandatory tests of Table 2 is necessary, or used in other circuit positions where the equipment specification prescribes that some or all of these safety tests are required.