One pharmaceutical company tested a chlorine dioxide gas generator for its sporicidal activity on a prototype La Calhene aseptic fill isolator equipped with two half-suits. Twenty biological indicators were used as the microbial challenge for each test. They were placed throughout the isolator on representative surfaces such as the exhaust vent, HEPA fan grill, and accumulator. The biological indicators were either used in their original glassine envelopes or removed from the glassine envelope and transferred into Tyvek/film pouches. The variables of humidification time, CD concentration and CD exposure time were manipulated. Charging time to an exposure concentration of 5mg/L took approximately 9 minutes. Aeration time to safe exposure levels of 0.1ppm took less than an hour. Several exposure cycles were shown to be successful using biological indicator spore strips each having a population of 106 spores. Additionally, chlorine dioxide gas penetrated into dead-leg areas and hard to reach areas of the isolator, such as deep vents, half-suit armpits and beneath other structures. Chlorine dioxide has proven itself to be a practical and effective method for disinfecting isolators as demonstrated by the high-level spore reduction.
To read this company’s isolator decontamination study in full, click here. For more about this specific application, click here.