The Purair 20 Ductless Fume Hood has been designed to provide operator protection when using hazardous substances. A face velocity at 100 fpm ensures containment of fumes and an alarm will alert the operator when the airflow falls to an unacceptable level. All mechanisms in the head section of the Purair 20 are on the clean side of the filter, thus preventing contamination. Switches and electrical components are totally isolated from the dirty airflow and away from any contamination. The work area has a removable spillage tray which can be easily cleaned. Optional integral lighting is available.