The Biological Flight Research Laboratory (BFRL) includes a large (approximately 2.5 meter) diameter centrifuge, biospecimen habitats, a microgravity habitat holding unit, a glovebox, a unit for the routine servicing of biospecimen chambers, and generic laboratory equipment. It is being designed to support non-human life sciences research on Space Station Freedom. To assure the health and welfare of biospecimens and flight crew, the BFRL must provide containment of particulate, microbial and potentially hazardous chemical substances as well as isolation of the inhabitant biospecimens from the cabin environment. There are currently no clear definitions within NASA of what constitutes a biological hazard or how such material should be contained and handled. This paper defines many of the risk concepts of concern to NASA and recommends requirements for the design and operation of life sciences spaceflight hardware and experiments. It concludes with a discussion of how these proposed requirements are being applied to the BFRL.