Comparison between Glutaraldehyde and Ortho-Phthalaldehyde Air Levels during Endoscopic Procedures

Abstract

BACKGROUND: Glutaraldehyde (GTA) has been used as a disinfecting agent for over 30 years, but irritative effects on the skin and respiratory tract have been described. The risk to healthcare personnel and emerging of GTA-resistant microorganisms have highlighted the need to develop new agents. One possible alternative to GTA is ortho-phthalaldehyde (OPA), which has a similar capacity to kill bacteria and a very good toxicological profile. OBJECTIVE: To compare air levels of GTA and OPA during high-level disinfection of endoscopes. METHODS: The comparative study was carried out in ten endoscopy units of the San Matteo Hospital, where GTA and OPA were routinely used for the low-temperature disinfection of endoscopes. GTA and OPA were used under the same operating procedures and for the same exposure time (4 hours). The monitoring of air levels was performed with both HPLC-UV (High Performance Liquid Chromatography with UV detection) and Infrared Spectroscopy (IR). RESULTS: The HPLC method gave a much lower aldheyde value when using OPA (8.4 mg/m 3) compared to that obtained when GTA was used to disinfect endoscopes (21279.3 mg/m 3). These results were confirmed with IR detection method (the mean values being below 10 mg/m 3). In addition, we studied the resistance of various glove types to OPA. Tests showed that OPA-permeated vinyl gloves more rapidly (26628 ng/cm 2 per hour) than nitrile gloves (13.9 ng/cm 2 per hour). CONCLUSION: This study showed a very low air concentration of OPA compared to GTA. These findings confirm the excellent safety profile of OPA used as a high-level disinfectant in the hospital setting.