Certified Healthcare Safety Professional (CHSP) Practice Exam

Biosafety level 3 is designated for work with potentially hazardous microbes that can cause serious or potentially lethal disease through inhalation. In this level of biosafety, all manipulations of infectious agents are carried out in biological safety cabinets (BSCs) to provide containment and protection. The use of BSCs minimizes the exposure risk to laboratory personnel and the environment by providing a controlled environment where aerosols and spills can be effectively managed.

Biosafety level 1 involves work with well-characterized agents that are not known to consistently cause disease in immunocompetent adult humans and typically does not require BSCs. Biosafety level 2 requires some manipulations in a BSC but does not mandate it for all procedures. Biosafety level 4 is the highest containment level, where manipulations are performed in class II or higher BSCs or in full-body, air-supplied suits, but the defining characteristic of level 3 is the use of BSCs for all manipulations of microbes due to their higher risk. Thus, biosafety level 3 is the correct choice for the requirement that all manipulations of microbes be performed in safety cabinets.