In-hospital evaluation of 7.5% hydrogen peroxide as a disinfectant for flexible endoscopes

The effectiveness of Sporox (Reckitt and Colman Inc, New Jersey), a 7.5% solution of hydrogen peroxide, was compared with that of Cidex (Johnson & Johnson), a 2% solution of alkaline glutaraldehyde, in the manual disinfection of flexible endoscopes at a large general hospital. For disinfection with Sporox, a soaking time of 10 mins at room temperature was used. The same disinfectant bath was used for nearly seven weeks and the Sporox level was monitored using reagent strips supplied with the product. Controls included endoscopes with precleaning (enzyme-detergent) but without any disinfection, and endoscopes that were precleaned and disinfected in Cidex only. A total of 3 mL of sterile normal saline was used for sampling each channel and immediately plated to detect aerobic and anaerobic bacteria as well as mycobacteria. There were 76 endoscopes sampled. Of these, 55 were disinfected in Sporox, 13 were disinfected in Cidex and eight were precleaned but not disinfected. None of the samples from endoscopes disinfected with either Sporox or Cidex yielded isolates generally regarded as pathogenic for humans. The findings of this in-hospital study indicate that Sporox is at least as efficacious as Cidex in the disinfection of flexible endoscopes between patients. In addition, the exposure time to Sporox was half as long compared with Cidex, and hydrogen peroxide is much less toxic to humans and the environment. Therefore, Sporox appears to have considerable potential as a safer substitute for glutaradehyde-based products in the decontamination of flexible endoscopes.