Microparticle performance rating
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The Microparticle Performance Rating (MPR) system rates an Air filter’s ability to capture the smallest airborne particles—from 0.3 to 1 µm in size from the air passing through the filter. The rating system was developed by 3M. The MPR system helps in comparing filters based on the level of air filtration needed. The higher the MPR, the better the filter’s ability to capture particles from the air as it passes through the filter.
MPR is different from MERV, the Minimum Efficiency Reporting Value. The MERV system measures a filter’s ability to capture large particles. The MPR only takes into account the microscopic particles between 0.3 and 1 µm.