Image courtesy Perkins and Will
Perkins and Will and the nonprofit Healthy Building Network (HBN) reiterate building products with antimicrobial treatments have not been proven to be a safe or effective means of controlling the spread of COVID-19.
The organizations recently issued a joint statement reaffirming the conclusion of their March 2017 white paper on antimicrobial building products that concluded antimicrobial additives have not been proven to have the health benefits they promote, and alternatives should be sought wherever possible.
“We have been receiving an uptick in questions from clients and colleagues across every sector about how to prevent the spread of pathogens like SARS-CoV-2, which is the virus that causes COVID-19, in the built environment,” said Mary Dickinson, associate principal of the Material Performance Lab at Perkins and Will. “As champions of material health and transparency, we knew a part of our response needed to address the questions surrounding the use of materials with antimicrobials. While we published a robust white paper on the matter in 2017, we needed to ask if the science and governmental feedback was still valid under the current circumstances. It was important to put out research-backed guidance and best practices on this matter as soon as possible.”
Findings from their research include the following.
Human health impacts
Despite marketing claims suggesting otherwise, no scientific evidence demonstrates additional human health benefits from antimicrobial additives in building products and materials. Such products include textiles, furnishings, flooring, tiles, and other surfaces and interior finishes. In fact, science has shown with repeated human exposure, antimicrobials can inadvertently contribute to the formation of ‘superbugs’—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 water treatment facilities. Since wastewater treatment sludge is sometimes spread as crop fertilizer in some jurisdictions, contamination of the surrounding environment becomes a risk. In fact, certain antimicrobials, such as nano silver, are considered toxic to humans and entire aquatic ecosystems.
“It can be challenging to completely avoid antimicrobials if manufacturers provide little or no transparency into their products’ ingredients,” said Max Richter, senior associate of the Perkins and Will Material Performance Lab. “But designers and architects can make more informed decisions through resources such as the Perkins and Will Transparency portal and Precautionary List, as well as HBN’s Pharos website.”
The importance of proper cleaning
Another negative consequence of using building products with antimicrobial additives is the false sense of security they may create when overly relied upon as a part of an infection control plan. 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. In fact, the U.S. Centers for Disease Control and Prevention (CDC) say human health is best ensured through proper cleaning practices—such as wiping down surfaces with soap and water before treating them with a disinfectant approved by the U.S. Environmental Protection Agency (EPA)—and through proper maintenance of building engineering systems. Until the CDC issues guidance regarding the efficacy of building products treated with antimicrobials, Perkins and Will and HBN advise design professionals to avoid their use whenever possible.
We should be particularly careful on the materials, surfaces, chemicals and compounds that we introduce into the built environment as they can have long term effects on the health and safety of building occupants, the performance of the building, and the environment (in use and in production). We should also be very careful to allow scientific efficacy, data, and proof drive our decisions and not allow the current pandemic to drive decisions that could lead to unintended consequences. And, we should be making those decisions based on current science.
There is a wealth of published science on the importance of surfaces in the transmission and spread of infectious disease. This route of transmission may be secondary to direct person-to-person spread (such as in respiratory agents like SARS CoV-2), however considering such surfaces can harbor and allow infectious organisms to grow and proliferate for days, weeks and months makes them no less important as potential mitigation points.
We are doing a disservice to building owners, occupants and visitors if we do not become more sophisticated in how building decision makers evaluate and deploy antimicrobial solutions and surfaces. There are a variety of materials, like copper, that are inherently antimicrobial, do not rely on antimicrobial chemicals or additives, or require continual reapplication to achieve scientifically proven, positive antimicrobial efficacy. In addition, there are emerging surface treatment techniques that without any antimicrobial chemical additives are proving to provide similar positive antimicrobial effects. Indiscriminately lumping inherently antimicrobial materials or surfaces together with nano-materials or chemical additives unnecessarily denigrates solutions that can provide positive antimicrobial benefit without the associated negative impacts of nano- or chemical additives or treatments. Decades of growth of healthcare acquired infections in the face of ever-improving social engineering, hand washing and disinfection protocols should be evidence enough that additional antimicrobial protection should be considered a positive benefit of building surfaces.
The world looks to architects, specifiers and other building decision makers for evidence-based leadership in consideration of the health, safety, and sustainability of building systems, materials, and products. It is therefore incumbent on those leaders to take care to ensure that institutional opinions do not persist in the face of contrary evidence.