Safe Touch – Antimicrobial Surfaces for Retail and Beyond
You all know by now how the Coronavirus typically spreads. An infected person coughs or sneezes and creates droplets that get inhaled or land in the eyes, nose and mouth of others. Or the droplets land on surfaces where people can pick them up by hand and then infect themselves by touching their mouth, nose or eyes.
So how long the virus stays infectious on common surfaces – like those used at retail and in tradeshows and museums – is a big question. In early April of 2020 an article published in The Lancet Microbe revealed that in a 71° Fahrenheit room at 65% relative humidity (a typical room environment) the virus disappeared from printing and tissue paper in three hours. It took two days for wood and cloth fabric. Four days for glass or paper money. And up to seven days for stainless steel and plastic. While other studies have produced somewhat different results, they are all bad news for retail stores where wood, glass, plastic and metal feature prominently.
That’s led to a tremendous growth in interest in antimicrobial materials and coatings as a way to help make stores and exhibits safer – and that retailers and the manufacturers who produce displays, samples and exhibits can use to make marketable claims of being safer. So we’ve begun to explore three basic categories of products and their efficacy against the current Coronavirus:
- Materials and coatings that disinfect themselves – that can be used in manufacturing everything from doorknobs, railings and counters to samples and displays
- Surfaces that are easier to disinfect because they can tolerate some of the more effective cleaning methods like chlorine-based cleaners and steam cleaning
- Cleaning products that continue to disinfect surfaces they’ve been used on for some residual period of time
Some of products currently available that offer one of more of these qualities are discussed briefly below.
Antimicrobial additives can be introduced into a paint, coating, ink or lacquer during the manufacturing process to make it resistant to microbes. These can also be tailored to suit the type of paint or coating, the material it may be used to treat, and the manufacturing process employed. There are specialty additives currently available for solvent, water-based, liquid, oil or powder paints and coatings, including specialty coatings, specialty inks and varnishes. Some can also be added to plastics and polymers to give them similar properties. Some have proven anti-viral qualities but not necessarily against the current Coronavirus. A perfect example is a product called ModoShelf – easy clean plastic shelving for use in produce aisles with an antimicrobial additive. It makes some powerful claims about stopping E.coli and other bacteria, but nothing about viruses.
Nano-coating – also known as a ceramic coating – is the process of applying a surface layer that offers different characteristics depending on the need. For instance, a nano coating can make a surface scratch resistant, resistant to corrosives, improve surface hardness, or make it resistant to bacteria, mold or viruses. Antiviral, bacterial and fungal nano coatings can be applied by spraying or dipping and adhere to various surfaces such as glass, metals and various alloys, copper and stainless steel, marble and stone slabs, ceramics and tiles, fabric and plastics. In the case of viruses they typically work by messing with a virus’s surface structure so it can no longer recognize the receptor site on host cells. There is a lot of work going on in this area targeting the current Coronavirus.
Naturally Antimicrobial Materials
As we all know now, bacteria and viruses survive longer on some materials, and less long on others. A perfect example is copper which seems to be extremely effective against bacteria and viruses including the current Coronavirus. The New England Journal of Medicine reported that the current Coronavirus survived for only four hours on copper versus 72 hours on stainless steel. According to the Smithsonian reports of copper’s efficacy against infection go back as far as 1700 BC. It has been used in a variety of remedies for centuries. The Chinese reportedly used copper coins to treat heart and stomach pain as well as bladder diseases. This could make copper a favorite replacement option for the stainless steel currently used in so many applications. Think doorknobs, sinks and handrails in places like hospitals, offices, restaurants, retail and the home. See an all copper bathroom in the photos above.
Materials that Are Easier to Clean
An important factor in choosing any material for use in homes, stores or offices is its clean-ability. Materials that are easier to clean and able to tolerate the quickest and most efficacious cleaning methods like bleach or steam are receiving increased interest. So understanding what can be cleaned with what is important. Two examples. Stainless steel – the poster child for easy cleanability – can actually be damaged by exposure to chlorine in cleaning products. On the other hand, some types of flooring including ceramic tile and luxury vinyl flooring (basically hard waterproof plastic) – can typically be safely cleaned with both bleach and steam unlike some alternative flooring products such as laminate, hardwood, sheet vinyl or carpet.
Antimicrobial Cleaning Products that Offer Residual Protection
These are cleaning products that typically promise to kill 99.9% of germs – and then continue to prevent their spread and growth for some period of time. An example is Microban 24 which promises 24-hour residual protection against a range of microorganisms. But while some Microban products are initially effective against the Coronavirus, they have not been proven to offer residual protection. Other products are in test. Prague is testing two different disinfecting products based on nanopolymers in its transit system that claim to offer up to 21 days of residual protection against a broad range of bacteria and viruses. A photo above shows one being applied in a tram. No claim was made specific to the current Coronavirus.
What We’ve Learned
To be cautious. Because something claims to be antimicrobial, antibacterial, sanitizing, disinfecting – or to kill 99.9% of bacteria and viruses – doesn’t mean it’s effective against the current Coronavirus. Many products have not been thoroughly tested yet and testing can only be done in Biohazard Safety 3 certified labs which makes testing challenging. As a result some companies – concerned about both transparency and legal ramifications – have published statements specifically saying their products are not effective against the current Coronavirus. But that situation will undoubtedly change as testing proceeds and new materials are introduced specifically targeting it.
We’ll continue to watch for the latest developments.