Thermo Scientific explosion-proof upright freezer 3552-1A is manufactured to be used in areas where ignitable materials are normally present. This manual defrost freezer features sparkfree enameled steel interior and a tough white enameled steel exterior to reduce the risk of explosion. It provides protection from explosions caused by vapors from improperly sealed containers, by fumes leaking from interior, or from vapors found in the surrounding area. Unit has wiring, thermostats, relays, and compressor motor safely housed within UL listed explosion-proof enclosures. This 240 volt freezer also features a solid door with key lock, magnetic vinyl gasket for positive door seal, and CFC-free insulation and coolants. Suitable for use in Class I, Division I Group C and D hazardous environments, the Thermo Scientific unit also meets OSHA and National Fire Protection Association safety requirements.