EPA Filters
1.1 General
Filter elements are classified in groups and classes according to their filtration performance (efficiency or penetration).
1.2 Groups of filters
According to this standard, filter elements fall into one of the following Groups:
Groups and Classes of filters Filters are classified in Groups and Classes. For each group a slightly different test procedure applies. All filters are classified according to their filtration performance
Group E filters are subdivided in three Classes:
