What the Published Test Shows
Bosch states that its HEPA cabin filters are tested using ISO 29463-3 and reports 99.97% efficiency at 0.3 microns for that range. This is manufacturer-specific information, not proof that every aftermarket cabin filter achieves the same result.
Fitment and Airflow
Before substituting a filter, confirm dimensions, sealing and the listed vehicle application. Ask for product-specific efficiency and pressure-drop test conditions. A HEPA label alone does not establish compatibility with a vehicle’s HVAC system.
Evidence for Procurement
MANN-FILTER describes several cabin-filter media options, including particle and activated-carbon types. Select the required function and verify it against the proposed SKU. The cited sources do not establish that HEPA has become the U.S. aftermarket standard or that retailer shelf space increased by 20% in Q1 2026.
