The laboratory in which the equipment was located had a drop ceiling. As chlorine dioxide gas can penetrate cracks and crevices extremely well, it is able to go around and above the ceiling tiles and travel to other parts of the facility. To mitigate the risk of leakage, the drop ceiling was covered in plastic to fully seal it off. Inactivating the initial eight beta-lactams tested against required a dosage ten times what is required to provide a 6-log sporicidal reduction. This meant that the use of biological indicators, our usual go-to verification method, was mostly irrelevant. However, some biological indicators were still placed around the room in order to provide an additional data point. In order to check for efficacy, plates were placed throughout the room with a measured inoculation of the target beta-lactam. These plates were recovered upon completion of the chlorine dioxide gas treatment and sent to a third party laboratory for recovery testing.
The treatment itself went according to plan, with a dosage of over 7240 ppm-hrs being delivered to all surfaces within the space. Testing came back with no recovered amounts of the target beta-lactam, showing a successful inactivation cycle had been performed. This allowed the facility to safely repurpose the production equipment for its new use.
