Disclosed is a luminaire including a ceiling mountable housing that defines an inner cartridge-receiving cavity accessible at an opening that is accessible in a healthcare space. A cartridge is provided to be received in the housing. The housing and the cartridge are configured to establish a first NSF-compliant sealing interface formed by at least one first barrier member extending along a first peripheral region between the housing and the cartridge to establish a first NSF-compliant pathogen barrier. The cartridge includes a light output region that is configured to locate an interior light guide and an exterior lens with an optical spacing therebetween. A second NSF-compliant sealing barrier interface is provided between the lens and the light guide formed by at least one second barrier member extending along a second peripheral region between the lens and light guide, and which is configured to establish a second NSF-compliant pathogen barrier therein.