This Recommended Practice (RP), IEST-RP-CC034.4, covers definitions, equipment, and procedures for leak-testing high-efficiency particulate air (HEPA) filters and ultralow-penetration air (ULPA) filters in the factory as they are produced, at the job site before they are installed, and after they are installed in cleanrooms and in unidirectional-flow, clean-air devices. When used in conjunction with other RPs, including IEST-RP-CC001, IEST-RP-CC002, IEST-RP-CC006, IEST-RP-CC007, IEST-RP-CC021, and IEST-RP-CC028, this RP may be used to define the basis of an agreement between customer and supplier in the specification and procurement of HEPA and ULPA filters, and in the testing of unidirectional-flow, clean-air devices and cleanrooms.

This RP also includes procedures for measuring the uniformity of the aerosol challenge approaching the filter under test.

First printing, October 2009 (Supersedes previous versions, including IEST-RP-CC034.3, IEST-RP-CC034.2, IEST-RP-CC034.1)

HEPA and ULPA Filter Leak Tests was prepared by Working Group 034 of the IEST Contamination Control Division (WG-CC034).