The manipulation of human, animal and plant pathogens in the laboratory may pose a significant risk to laboratory personnel and the environment. In general, the risk posed by the agent is a factor of its risk group level (pathogenicity and niche), laboratory procedures and processes and immune status of laboratory staff (host-parasite interactions). A risk assessment should be conducted which must consider if the agent used techniques used to study the agent that may energize the material leading to spills, splashes and the generation of infectious aerosols, sanitization and hygiene. The risk assessment may be complicated by the use of animal models to study the pathogenic agents. Often the model itself may be a source of uncharacterized pathogenic organisms, allergens or a means of transmitting the agent via shedding or direct inoculation as a result of bites or scratches.  Registration with the Institutional Biosafety Committee is required prior to initiating work with agents known to cause disease in humans, animals or plants. Depending on the nature of the proposed research, approval may also be required by the IACUC, and Institutional Review Board.