PT - JOURNAL ARTICLE AU - Ingmar Juhlin AU - Sten Börje Lindqvist AU - Rolf Nystrand TI - Post-Cycle Sporicidal Effect of Ethylene Oxide–A New Concept DP - 1985 Nov 01 TA - PDA Journal of Pharmaceutical Science and Technology PG - 223--230 VI - 39 IP - 6 4099 - http://journal.pda.org/content/39/6/223.short 4100 - http://journal.pda.org/content/39/6/223.full SO - PDA J Pharm Sci Technol1985 Nov 01; 39 AB - An investigation was performed in order to determine if ethylene oxide (EO) absorbed in plastic material during EO sterilization had any sporicidal effect on spores of Bacillus subtilis ATCC 9372 during the degassing period. This effect was called Post-Cycle Sporicidal Effect (PCSE). Blood lines of polyvinylchloride (PVC) were used as test products. Biological indicators (BI’s) with spores of B. subtilis ATCC 9372 on paper carriers were built into blood lines in different positions and exposed to EO (500 mg/liter and 725 mg/liter, respectively, at 40 ° C) for different lengths of time. BI’s were analyzed directly after finished exposure times as well as after different times of storage in the aeration area (7 air changes per hour, 20 ± 2 ° C). It was found that the desorbing EO had a great killing capacity. BI’s built into the products after finished sterilization showed a decreasing number of survivors when analyzed after different storage times. Microorganisms isolated during determination of the presterilization bioburden (Pseudomonas sp., Micrococcus sp., and Bacillus sp.) were exposed to the desorbing EO and showed a reduction similar or greater than spores of the BI’s. Therefore, PCSE not only means post-cycle sporicidal effect but also post-cycle sterilization effect.