This is a sensitive one, which is important to get right; as such we’ve provided a link to all source materials, research and white papers used in the creation of this article below.
“Antimicrobial additives incorporated into flooring can make any environment a cleaner place!”
WRONG.
This is a casual and reckless example of one of the many misleading marketing claims that the Living Building Challenge (LBC) was referring to when they slapped antimicrobials marketed with a health claim onto the Red List of “worst-in-class” substances prevalent within the construction industry.
No evidence yet exists to demonstrate that products intended for use in interiors, which incorporate antimicrobial additives, result in healthier spaces. In fact, quite the opposite, we now know that that these can have a negative environmental impact and lead to unrealistic expectations amongst end user clients. A position that not even the antimicrobial additive manufacturers are denying.
Here are just two recent updates from prominent manufacturers of the antimicrobials Microban and Ultrafresh:
“. . . Our built-in antimicrobial technologies are effective against a plethora of product damaging microbes, but are not currently proven to have any antiviral properties when built-into products. The active technology itself may be effective against viruses in pure state, but not when incorporated into a product. Microban antimicrobial product protection is not intended to control disease pathogens.”
A message from Microban International about Coronavirus (COVID-19)
“…Our antimicrobial technologies are effective against a broad range of product-damaging microbes, but are not currently proven to have any antiviral properties when built into products. The active technology itself may be effective against viruses in pure state, but not when incorporated into a product…”
A message from Thomson Research Associates, Inc. (TRA)’s regarding their product “Ultrafresh” and its built-in and textile antimicrobial technologies
Human health impacts
Where’s the evidence? Despite many manufacturers overstating the effectiveness of antimicrobial additives in building materials, there is no scientific evidence to suggest that products such as textiles, furnishings, flooring, tiles, and other surfaces and interior finishes that incorporate these additives have a positive health impact.
After all, antimicrobial agents by definition and design are toxic substances to certain organisms such as bacteria, viruses, and fungi. They are incorporated into products to preserve the lifespan of the product itself; rather than to provide added value benefits in the environment where they will be used.
More worrying still, science has shown that with repeated human exposure, antimicrobials can inadvertently contribute to the formation of ‘superbugs’, in other words germs that are resistant to medical treatment.
Environmental impacts
Antimicrobial additives have also been shown to leach out of materials during use, entering drains and, from there, our water systems.
Since wastewater sludge is sometimes spread as crop fertiliser, contamination of the surrounding environment also becomes a risk. In fact, certain antimicrobials, such as nano silver, are considered toxic to humans and entire aquatic ecosystems and so inclusion in products should be carefully considered.
What about resin flooring specifically?
Resin flooring is seamless and impervious, ergo has the potential to be inherently more hygienic than other types of flooring as it provides an impenetrable seal across the surface of the floor. Coving and bunds can also be used to contain spillage and moisture until it is cleaned away, preventing the build-up of dirt, dust, mould, mildew and other nasties.
The ISO 22196 standard (Japanese test method JIS Z 2801) is often cited in relation to resin flooring as a method of determining antibacterial activity on plastic or other non-porous surfaces over a specific duration and subject to wash cycles.
However, some studies have described this test as inappropriate, since the temperature of incubation (~35 ± 1°C) and the relative humidity (higher than 90%) do not reflect real conditions. ISO 22196, without modifications, therefore, fails to accurately simulate real environmental and usage conditions and allows for inflated values or erroneous claims of antimicrobial activity, thus compromising the validity of the efficacy result.
The importance of cleaning
Which leads us nicely to the crux of the issue, which is that one of the most worrying consequences of promoting building products with antimicrobial additives is the false sense of security they may create when overly relied upon as a part of a cleaning programme. In some cases, the use of these products creates the potential for less diligent facility maintenance.
Marketing claims that antimicrobial building products reduce the transmission of disease are scientifically unfounded. They do not have magic cleaning powers; they do not kill microbes on contact, and they aren’t a substitute for good old fashioned cleaning protocols.
In this time of great unknowns, it is tempting to be reactionary… In the case of antimicrobial treatments in building products, the science says that this will not help, and it may be harmful. For detailed information on how to properly clean and maintain resin flooring, refer to the FeRFA Guide to cleaning Synthetic Resin Floors.
Sources
‘About The Red List’, Living Building Council – https://living-future.org/red-list/
‘Understanding Antimicrobial Ingredients in Building Materials’, Perkins & Will – https://s3.amazonaws.com/hbnweb.prod/uploads/files/Fj4p_COVID_Antimicrobial_WhitePaper_PerkinsWill.pdf
‘Are Silver Nanoparticles in Anti-bacterials Harmful to Humans?, Consensus – https://consensus.app/home/blog/are-silver-nanoparticles-in-anti-bacterials-harmful-to-humans/
FeRFA Guide to cleaning Synthetic Resin Floors, FeRFA – https://ferfa.org.uk/resources/
Assessing Antimicrobial Efficacy on Plastics and Other Non-Porous Surfaces: A Closer Look at Studies Using the ISO 22196:2011 Standard, Universidade Católica Portuguesa – https://pmc.ncbi.nlm.nih.gov/articles/PMC10813364/
