Air Science USA has introduced the Purair 20, a ductless fume hood that protects operators when handling hazardous substances. A face velocity at 100 ft/min ensures containment of fumes, and an alarm alerts the operator when the airflow level becomes unacceptable. All mechanisms in the head are on the clean side of the filter, preventing contamination. Switches and electrical components are isolated from the dirty airflow, and the work area has a removable spillage tray that can be cleaned. The main filter can be chosen from 14 types of carbon, including media for vapors of organics, solvents, acids, mercury and formaldehyde. Optional integral lighting is available. The hood measures 1245 x 699 x 1207 mm, with other sizes available up to 2438 mm wide.