Following the lead of the Centers for Disease Control and Prevention, the Food and Drug Administration, and other credible institutions, the global architectural firm of Perkins+Will is placing Products Marketed as Antimicrobial on its Precautionary List. The firm's decision was made after an exhaustive review of available information about the use of antimicrobial substances in building products conducted by Healthy Building Network researchers. Perkins+Will project teams will advise clients of reasonable alternatives where appropriate.
After extensive review that has spanned over 7 years,  HBN researchers were not able to turn up any evidence documenting health benefits associated with the use of antimicrobial products in building materials. These findings are published in a new white paper entitled Healthy Environments: Understanding Antimicrobial Ingredients in Building Materials.
To the contrary, the Centers for Disease Control has concluded that even in hospitals, "no evidence is available to suggest that use of [products impregnated with antimicrobial additives] will make consumers and patients healthier or prevent disease. No data support the use of these items as part of a sound infection-control strategy."  In September 2016, after studying the issue for nearly 40 years, the Food & Drug Administration (FDA) determined that manufacturers have failed to show any evidence that these additives provide a benefit to human health even when added to soaps and washes. At the same time, evidence is growing that the overuse of antimicrobial substances can have negative health and environmental impacts.
Why then are more and more building product manufacturers incorporating antimicrobial substances ---- pesticides ---- into their products? The evidence suggests that this is a marketing strategy that exploits consumers' fear of germs and their misunderstanding of how antimicrobial additives function in products. Consider marketing literature from one antimicrobial manufacturer that carefully steers clear of health claims while emphasizing that "nearly 7 out of 10 consumers are concerned about the presence of bacteria on the door handles and knobs in their homes and 8 out of 10 are interested in Microban product protection to help keep their door hardware cleaner."  However, when it comes to efficacy, the manufacturer is careful to note that "Frequent hand-washing and disinfecting of surfaces are essential steps to avoiding any potential illnesses transmitted by bacteria on doorknobs and handles, of course."  (emphasis added) In other words, no health benefit from the antimicrobial additives.
If you read product literature carefully, few antimicrobial products make explicit health claims, and those that do are exceptions that prove the general rule. For example, Sherwin-Williams' new Paint Shield Antimicrobial interior latex paint is advertised as containing an EPA-registered pesticide that has demonstrated effectiveness in killing certain bacteria. This claim is based upon laboratory testing, not real world use patterns in any of the recommended applications, such as healthcare settings. The directions for use make clear that the manufacturer is making no claims that the product will actually improve human health outcomes: "...user must continue to follow all current infection control practices, including those practices related to cleaning and disinfection of environmental surfaces. The painted surface material has been shown to reduce microbial contamination, but does not necessarily prevent cross contamination."  Emphasis added ---- because when it comes to protecting human health from bacteria on surface areas of a building, preventing cross contamination is the whole point.
To further complicate matters, numerous wet-applied products and plastics contain antimicrobial ingredients that are used as product preservatives, not as human health protection. Advertising the presence of these additives in a product, even without making an explicit health claim, can lead consumers to infer incorrectly that the product may have health-protective qualities.
Evaluating and understanding the use of antibacterials in building products is confusing. Inadequate federal laws, regulatory loopholes, and a lack of transparency drive product development based upon consumer misunderstanding and fear, rather than evidence-based design. The new Perkins+Will policy is a good rule of thumb for the building industry: avoid, where possible, products containing added antimicrobial ingredients.
 See HBN publications
 "Guidelines for Environmental Infection Control in Health-Care Facilities." Centers for Disease Control and Prevention, 2003, p.103. http://www.cdc.gov/hicpac/pdf/guidelines/eic_in_HCF_03.pdf
 Microban. "Door Hardware," n.d. https://www.microban.com/micro-prevention/applications/building-materials/door-hardware
 Microban. "Dirty Door Hardware," n.d. https://www.microban.com/blog/dirty-door-hardware
 "Paint Shield Interior Latex Eggshell Microbiocidal" [MSDS sheet]. Sherwin Williams, July 2016. https://www.sherwin-williams.com/document/PDS/en/035777245095/