Walk-in type LEPT Series fume hoods intended to provide a standard for selection, installation, usage and maintenance of the laboratory. The exposure control system is explosion-proof in the sense of having all potential ignition sources located outside the cabinet. However, if the vapors can escape from the freezer and sink to floor-level then the potential for fire or explosion continues to exist if the vapors come in contact with other sources of heat or flame which are inherent in most laboratories. LEPT Series