Characteristics of an ideal surface damage testing protocol study — extract

All manufacturers of healthcare patient care equipment should provide instructions for use (IFU) that list compatible disinfectants for cleaning equipment. However, compatibility testing is not standardised across the industry, does not use validated methods, does not generally include newer disinfectant technologies, often is only qualitative, and may only list active ingredients which does not take into account the other ingredients in a disinfectant that may cause surface damage. This makes it challenging to compare surface damage information among disinfectant manufacturers and equipment manufacturers.

In some cases, equipment manufacturers list ingredients not compatible with their equipment in the IFU, yet recommend disinfectants including the same ingredients, resulting in confusion for healthcare facilities to evaluate and choose disinfectant products.

It is difficult to predict the clinical impact of surface damage because there is no clear definition of what constitutes surface damage. In theory, surface damage can cause equipment to fail to operate correctly and can shelter microorganisms, thus preventing proper disinfection. Both types of surface damage can create safety risks for patients and staff in healthcare facilities.

Surface damage can be defined as a quantifiable physical or chemical change from the original manufactured state of an object (surface or device). Surface damage that results in aesthetic changes, such as colour loss or change in colour, may not affect the performance of the equipment and thus may not be of any clinical significance.

We recommend using surface roughness as an appropriate parameter to determine surface damage. Changes in surface roughness can indicate a loss of material from the surface, an increase in the number of cracks or fissures, or irreversible changes in the chemical bonding in organic surface materials, which can change the performance of the surface.

The link between surface roughness and microbial risks has been explored by previous studies. Data has shown that surface roughness can create defects in the surface that provide protection from shear forces, such as from cleaning, and may provide more secure adhesion points for bacteria.

Another study showed that the amount of bacteria on a surface was positively correlated with the surface roughness. Notably, the size scale of the change in surface roughness is often below the detection limit of humans via sight or touch. Surface damage can make it more difficult to disinfect a surface or create some other definable safety risks (such as surface damage exposing wiring or cracking tubing), both of which have clinical significance. When surface damage is minor, it may be detectable, but not have achieved any clinical significance. However, if the surface damage continues, it may reach a point of clinical significance at some later time. Even minor surface damage should be considered important because of the potential for surface damage to reach the threshold point. Therefore, surface roughness, which is related to the ability to disinfect the surface, is an appropriate parameter to address the question of proper disinfection to avoid surface damage.

Full paper: http://www.diverseyvericlean.com/images/DiverseyHumming/Coronavirus/63313_LIT_Surface_Damage_Article_A4-en_LR.pdf.