The Purair advanced P20 ductless fume hood provides operator protection from hazardous substances. The hood has a face velocity of 100 fpm ensuring containment of fumes, and an alarm notifies the operator when airflow falls to an unacceptable level. All mechanisms in the head section are on the clean side of the filter, preventing contamination. Users can choose the main filter from fourteen different types of carbon, including specialty media for vapors of organics, solvents, acids, mercury, and formaldehyde. HEPA filters for particulate filtration also are available to suit the application needs, and the hood can be equipped with a secondary back-up filter for added protection. The system measures 49 x 27.5 x 47.5 inches with other sizes available up to 96 inches wide.