HEPA and ULPA Filters
|Publication Date:||1 April 2016|
SCOPE AND LIMITATIONS
This Recommended Practice (RP) covers basic provisions for HEPA (high efficiency particulate air) and ULPA (ultra-low penetration air) filter units as a basis for agreement between customers and suppliers.
Filters that meet the requirements of this RP are suitable for use in clean air devices and cleanrooms that fall within the scope of ISO 14644 and for use in supply air and contaminated exhaust systems that require extremely high filter efficiency (99.97% or higher) for submicrometer (μm) particles.
This RP describes 11 levels of filter performance, or types, and five grades of filter construction. For the types and grades that require scanning, these filter types generally apply to rectangular filters. Semi-circular, cylindrical, Vbank filters and other construction configurations may not be readily scanned and thus will not meet the requirements of the filter types requiring scanning. While many of the performance measurement techniques can be adapted to other filter configurations, the filter types as described in this RP should be applied only to rectangular, flat panel filters. The customer's purchase order should specify the level of performance and grade of construction required. The customer should also specify the filter efficiency required if the efficiency level is not covered by the performance levels specified in this RP.
NOTE: Products and procedures discussed in this RP may involve hazardous materials, operations, and equipment. This RP does not purport to address all of the safety problems associated with its use. It is the responsibility of the user to consult and establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to use of this RP.