Aerosol vulnerability testing

There are two general approaches, wet tests and aerosol challenge tests. Wet tests consider penetration of microorganisms in liquid suspension into sealed containers usually previously filled with sterile medium. The basic assumption is that the most vulnerable route for penetration of liquid filled containers by microorganisms is in the event of a continuous liquid film or bridge forming between the outside and the inside of a container. Aerosol challenge tests are less critical than wet tests and should be applied only when total exclusion of moisture from the containment system can be ensured by secondary barriers. 

An increased susceptibility to Streptococcus zooepidemicus aerosol was not observed in mice exposed to 5 ppm phenol for 3 hours, or for 5 daily 3-hour periods (Aranyi et al. 1986). Neither did the phenol exposures affect pulmonary bactericidal activity towards Klebsiella pneumonia. Although tests for vulnerability to infectious agents do not represent a comprehensive evaluation of immunological competence, the 5-ppm level can be considered a NOAEL for this specific immunological effect, and is recorded in Table 2-1 and plotted in Figure 2-1. 

---