The Fail-Safe CFD Cleanroom Troffer is enclosed and gasketed to maintain ceiling integrity and protect against infiltration of particles and airborne bacteria. The housing and door are designed to work with 1 inch inverted T-Grid ceilings. The sealed, hole-free housing prevents air exchange between the fixture and plenum and allows relamping without contamination of clean areas. These luminaires are UL/cUL listed for wet locations for covered ceiling applications, and are manufactured in accordance with U.S.D.A., F.D.A., and Federal Standard 209E.