The Ultra-Web® nanofiber cartridge filters have a MERV 13 efficiency rating The MERV rating system, based on ASHRAE Standard 52.2-1999, is the most current and accurate measurement of filter efficiency and ability to capture submicron dust. Filters with a MERV 13 efficiency rating are considered pre-HEPA suitable for capturing submicron and larger dust particulates. Ultra-Web filters provide 40 percent lower emissions on 1 micron dust particles and 58 percent lower emissions on 0.5 micron dust particles.

Donaldson Company Inc.
High Purity Products
1400 West 94th Street, P.O. Box 1299
Minneapolis, MN, 55440-1299