BIOAEROSOL EXPOSURE METHOD FOR PACKAGE INTEGRITY TESTING

Test organism motility, concentration, aerosol exposure time, hole dia meter and length were evaluated to determine their influence on microb ial ingress into a flexible plastic pouch. Microtubes with 10- and 20- mu m hole diameters and of 5- and 10-mm lengths were used as defects i n 128 flexible pouches. A bioaerosol with a 2.68-mu m mean particle si ze comprised of 10(2) or 10(6) CFU/ml source concentrations of motile or nonmotile Pseudomonas fragi TM 849 was introduced into a 119,911-cm (3) chamber for exposures of 15 or 30 minutes. Six pouches showed test organism growth after a 72-h incubation period. Microbial ingress was significant (P < .05) for motile test organisms with source concentra tions of 10(6) CFU/ml.