ÖNORM EN 1822-4

This European Standard applies to high efficiency air filters and ultra low penetration air filters (HEPA- and ULPA-filters) used in the field of ventilation and air conditioning and for technical processes, for example, for clean room technology or applications in the nuclear or pharmaceutical industry. It establishes a procedure for the determination of the efficiency on the basis of a particle counting method using a liquid test aerosol, and allows a standardized classification of these filters in terms of their efficiency. Part 4 of this standard applies to the leak testing of filter elements. The scan method which is described in detail regarding procedure, apparatus and test conditions is valid for the complete range of HEPA- and ULPA-filters. The oil thread test according to annex A may be used alternatively only for HEPA-filters (see EN 1822-1).