Abstract
Biosafety Level 2 (BSL-2) and Biosafety Level 3 (BSL-3) facility lab personnel routinely perform procedures that are capable of producing respirable aerosols. While these procedures are considered safe when performed in the closed environment of a biosafety cabinet (BSC), there are, nevertheless, limited data regarding the nature of the aerosols these procedures produce. This lack of aerosol data poses a significant challenge to biosafety professionals, who are charged with assessing the risks associated with handling infectious materials and communicating the importance of proper engineering controls to BSL-2/BSL-3 facility staff. This article characterizes the extent and nature of respirable aerosols produced during routine laboratory procedures when these procedures are performed in an open environment (i.e., outside a BSC). As demonstrated, homogenization, vortexing, and pipetting each produce aerosols of differing characteristics and aerogenic potentials. These characteristics have led to the development of an Exposure Risk Model for routine lab methods to assist biosafety professionals in their efforts to prevent inhalation exposures.