Evaluation of the efficacy of a 3.2% glutaraldehyde product for disinfection of fibreoptic endoscopes with an automatic machine

The efficacy of 'Cider Plus' 3.2% alkaline glutaraldehyde was evaluated for the disinfection of fibreoptic endoscopes. The glutaraldehyde concentration in 'Cider Plus', stored in an automatic machine (Olympus EW-20), remained higher than 2% (2.21%) even after a total of 102 disinfection cycles during 28 consecutive days. The results of the in-vitro study on antimicrobial activity showed that this alkaline glutaraldehyde product had a greater activity against 20 test organisms, including vegetative bacteria, bacterial spores, mycobacteria, and fungi, than 2% glutaraldehyde alone. The presence of 10 or 30% human serum did not appear to affect the activity of glutaraldehyde adversely. Instrument samples made from a variety of materials such as stainless steel, glass, teflon, etc. were not damaged after 168 h of immersion in alkaline glutaraldehyde, although it contained approximately 1.7 times more glutaraldehyde than 2% glutaraldehyde alone. Based on these results, 3.2% alkaline glutaraldehyde is considered to be a more effective disinfectant for fibreoptic endoscopes, with the use of an automatic machine, than 2% glutaraldehyde.