The degradative effects of germicidal light on flexible endoscope material : the safety and suitability of UVC and 405nm light sources

Irving, Daniel and Grant, M. Helen and MacLean, Michelle and Lamprou, Dimitrios and MacGregor, Scott and Anderson, John (2014) The degradative effects of germicidal light on flexible endoscope material : the safety and suitability of UVC and 405nm light sources. In: The 9th Healthcare Infection Society International Conference 2014, 2014-11-16 - 2014-11-18, Lyon Convention Centre.

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The use of germicidal ultraviolet (UVC) light in flexible endoscope storage has been linked with material degradation, leading to device failure and increased risk to patients. 405nm germicidal light presents a possible alternative, potentially providing bacterial inactivation without material damage. The aim of this study was to investigate the degradative effects of UVC light on flexible endoscope material, and investigate the potential use of 405nm light as a non-damaging alternative. Samples of flexible endoscope insertion tube material were exposed to both germicidal light sources. Material properties were monitored using Fourier Transform Infrared Spectroscopy (FTIR), Atomic Force Microscopy (AFM), contact angle goniometry and confocal microscopy. The adhesion of Pseudomonas aeruginosa on exposed and unexposed samples was investigated to determine the potential impact of material damage on biofouling. Samples exposed to UVC light showed significant changes: variations were observed in FTIR spectra indicating changes in polymer structure; average water contact angle decreased from 82.6° to 61.4°; average surface roughness increased from 2.34nm to 68.7nm, and visible cracking of the surface was observed. In contrast, no significant changes were seen in samples exposed to 405nm light. Bacterial adhesion tests showed an 86.8% increase in P. aeruginosa adhesion on UVC-exposed samples relative to unexposed material, and no significant increase in adhesion on samples exposed to 405nm light. UVC light can cause notable degradation of flexible endoscope material, impacting material properties and microbiological interactions. Results indicate 405nm germicidal light represents a potential safe alternative for use in flexible endoscope storage.


Irving, Daniel ORCID logoORCID:, Grant, M. Helen ORCID logoORCID:, MacLean, Michelle ORCID logoORCID:, Lamprou, Dimitrios ORCID logoORCID:, MacGregor, Scott ORCID logoORCID: and Anderson, John ORCID logoORCID:;