Bioaerosol Exposure Method for Package Integrity Testing .

Test organism motility, concentration, aerosol exposure time, hole diameter and length were evaluated to determine their influence on microbial ingress into a flexible plastic pouch. Microtubes with 10- and 20μm hole diameters and of 5- and 10-mm lengths were used as defects in 128 flexible pouches. A bioaerosol with a 2.68-μm mean particle size comprised of 10 or 10 CFU/ml source concentrations of motile or nonmotile Pseudomonas fragi TM 849 was introduced into a 119,911-cm chamber for exposures of 15 or 30 minutes. Six pouches showed test organism growth after a 72-h incubation period. Microbial ingress was significant ( < .05) for motile test organisms with source concentrations of 10 CFU/ml.