High-touch environmental surfaces (HITES) in healthcare and other settings can acquire infectious agents during contact with hands or by the settling of airborne contaminants. Exposure of susceptible individuals to pathogens may occur directly from HITES or indirectly via contaminated secondary vehicles such as hands. While HITES are routinely decontaminated by physical or chemicals means to mitigate the risk of spread of pathogens, such decontamination may not be frequent enough due to limitations of cost, personnel and facility access. Therefore, another approach would be to confer on HITES the ability for ‘self-sanitization’, meaning the potential for continual inactivation of pathogens as and when they land on the surface.
Copper alloys were the first type of self-sanitizing surfaces formally recognized by the U.S. Environmental Protection Agency (EPA). The validity of the test protocols used for the registration of those claims remains controversial. The only other protocol that the EPA and Health Canada accept to test the self-sanitizing activity of hard, non-porous HITES was developed by the Clorox Company (1). That protocol is designed to test the impact of repeated wiping of HITES experimentally contaminated with bacteria. It cannot be readily adapted for work with viruses, nor does it simulate the action of repeated contact between HITES and human hands.
Here, we propose an alternative protocol to assess the longevity of self-sanitizing potential of hard, non-porous HITES coated with a disinfectant. The protocol is suitable for work with all major classes of human pathogens as well as a wide variety of surfaces common in healthcare and other settings. The method being proposed is based on ASTM International’s E2197 (2) acceptable to Health Canada for testing environmental surface disinfectants.
The objectives of this project are to:
1) enable a quantitative assessment of the longevity of the test substance’s activity against representative human pathogens on hard, non-porous surfaces, and
2) test the influence of repeated hand contact with the treated surface on its microbicidal activity.