Figure 1: Typical zone of inhibition or no zone of inhibition on agar surfaces with a lawn of Staphylococcus aureus surrounding 2 cm × 1 cm sections of Viton endoscope bending rubber exposed from left to right to GA-IPA, GA, or OPA for 10.0 minutes, and then rinsed three times each with 100 mL of water. These positive control sections of the endoscope materials were then placed onto the trypticase soy agar surfaces with bacterial lawns. Negative control sections of the endoscope materials were soaked in water, without exposure to any disinfectant, and then placed onto the agar with bacterial lawns, and the result determined that there were no chemicals in the insertion tube materials able to give a ZOI in these tests (not shown).