PURAIR 5 hoods exceed OSHA, ANSI and all relevant international standards. Ductless design eliminates installation costs and allows the unit to be positioned over a sink or benchtop apparatus. Three models offer a choice of 24, 36 or 48-inch width. The units operate at low noise levels and because they re-circulate, they do not exhaust conditioned and/or heated air into the atmosphere. A face velocity of 100 fpm ensures containment of fumes and particulates for operator protection. An alarm alerts the operator when the airflow falls to an unacceptable level. The hoods can be placed on any benchtop, and an optional polypropylene spillage tray can be provided when required. The rear of the unit includes lighting to illuminate the work surface.