3. Laboratory processes creating aerosols

As previously indicated, the actual causative event cannot be identified in the majority (80%) of laboratory infections. Most experts believe that infections are caused by exposure to infectious aerosols, or by coming into contact with surfaces (benches, equipment, etc.) contaminated by aerosols. Any time that an air-liquid interface is disturbed, an aerosol is created. As the energy of disturbance increases, the aerosol increases.

Most laboratory procedures can be shown to produced aerosols; simple laboratory techniques, like pipeting, centrifuging, homogenizing and blending all produce aerosols. If the aerosol particle size is in the range of 1-10 mm, a fraction of the particles inhaled will be retained in the respiratory tract (especially the alveoli). Infection is almost inevitable if the particles contain viable infective agents.