The Fail-Safe CFR is designed for use in horizontal or non-laminar air flow clean rooms. The enclosed and gasketed housing and one-piece flanged door protect against infiltration of airborne bacteria. The extruded aluminum inset door and the hole-free design of the housing prevent air exchange between the fixture and plenum, allowing relamping without contamination of the clean areas. An emergency battery pack is available as an option. It is UL/CUL listed.