What Is an Antimicrobial Coating?

An antimicrobial coating is a surface treatment that inhibits the growth of microorganisms, such as bacteria, mould, yeast and, for some chemistries, viruses. The active ingredient either sits in a thin layer applied to the surface or is mixed into the material itself, so the surface keeps acting between cleans rather than only at the moment it is wiped.

There are two main mechanisms. Leaching, or release-based, coatings slowly give off an active agent, most often silver ions, which damage the cell membranes, enzymes and DNA of microbes that land on the surface. Contact-killing, or non-leaching, coatings are bonded to the surface and kill microbes that touch it, for example quaternary ammonium compounds that puncture cell walls. A third group, photocatalytic coatings based on titanium dioxide, uses light to produce reactive oxygen that breaks down organic matter.

Antimicrobial is the broader term. An antibacterial coating targets bacteria only, while an antimicrobial claim can also cover fungi and, where tested, viruses.

Coatings are named after their active agent. The agent decides how fast the surface works, how long it lasts and which materials it can go on.

On walls, floors and furniture, the antimicrobial agent is usually sprayed, painted or powder coated on. On electronic equipment it is more often added to the material during manufacture: the silver compound is blended into the plastic before moulding, or ion-exchanged into the surface of the cover glass. An additive runs through the whole part, so it is not removed by wiping and abrasion the way a thin applied layer can be.

For anything that is cleaned many times a day, the chemistry of the housing matters as much as the antimicrobial claim. Repeated wiping with alcohol, quaternary ammonium, chlorine or hydrogen peroxide disinfectants can craze or crack ordinary plastics, and a cracked housing is harder to keep clean. Medical computers therefore pair antimicrobial plastics with materials and seals chosen for disinfectant resistance, and with a flat, sealed front, often rated IP65, that leaves no gaps for fluid or dirt to collect.

Claims should be backed by a recognised test, and the test report should name the agent and the organisms used. The common methods are:

Antimicrobial surfaces are used to reduce the microbial load on high-touch surfaces between cleans, which is why they appear on touchscreens, keyboards, carts and door furniture in hospitals. Their limits are just as important. They act over hours rather than seconds, so a surface touched a moment ago is not instantly safe. Dirt and grease cover the active surface. Leaching coatings can lose strength over time. Clinical evidence that coated surfaces cut infection rates is mixed, so infection prevention guidance still relies on cleaning, disinfection and hand hygiene.

Claims are regulated. In the EU, and in Great Britain under its own version of the rules, the Biocidal Products Regulation treats a product with a built-in antimicrobial as a treated article: the active substance must be approved for that use and the claim labelled. In the US, the EPA’s treated article exemption only allows claims that protect the product itself; claims about protecting people from germs need a registered product. That is why datasheets often word the feature as an antimicrobial housing or additive rather than promising infection control.

Our medical grade monitors range includes surgical monitors and medical panel PCs with antimicrobial housings, IP65 fronts and flat, edge-to-edge glass, suited to a medical cart or a wall arm. For food and pharmaceutical lines, our stainless steel panel PCs are built for daily washdown, and our guide to washdown computer and monitor applications covers the cleaning processes they face. We supply and integrate the right model for your cleaning regime as standard.