August 15, 2014
Carina Clark, LEED AP BD+C, EDAC

In today’s pandemic of bacteria and microorganisms seemingly overtaking our healthcare environments, vendors and product reps are more frequently using phrases like “antimicrobial”, “antibacterial”, “silver ion technology”, “copper” and so on, when representing their products. As designers, these words seem fantastic in the way they are presented, and seem to offer our clients exactly what they need and want: built-in 24 hour cleaning systems. It’s the perfect combination of design and science – using premium materials to help reduce HAI (Hospital Acquired Infections) which could reduce the length of stay for patients, making them more satisfied in their stay, freeing up patient beds for new patients, and creating more profit for the client through positive satisfaction ratings and reduction in cleaning staff.  Since now hospitals are being held increasingly accountable for HAI's, the benefit of reducing HAIs for a hospital has direct financial ramifications.

But what do these words really mean?

By definition, when a product claims to be “antimicrobial” or “antibacterial”, it literally means it will inhibit the growth, or is destructive, to microorganisms or bacteria (antibacterial). Exactly what we, as designers and specifiers, would consider a ‘gold mine’ for a hospital environment. But when we take a closer look at how these manufacturers are making this classification, we need to recognize a few things:

1)       How is this tested?

2)      What part of the product has these properties?

3)     How will maintenance affect these properties over time?

How is this tested?

Let’s face the fact head on: products are tested in a controlled clinical environment.

With just the right conditions, the right levels of humidity and temperature, left to cure for just the right amount of time with little to no outside influences, of course research can drastically affect how the results are reported and interpreted. Research has indicated that bacteria is susceptibly influenced by antibacterial agents depending on the cultivation conditions of the organisms; meaning, under the right conditions, an organism can simply appear to be susceptible or resistant to an antibacterial agent during testing (Anwar, Dasgupta, & Costerton, 1990). So, if every project has just the right conditions for the product to work, in every specific setting and location, the product should perform as promised.

What part of the product has these properties?

So now that we know that how the research is conducted can influence whether or not a product truly has “anti” properties based on real-world conditions, what if where that property occurs, wasn’t where it needs to be?

Let’s take a step back for a moment and think about the defroster on your car. Typically, the back windshield has a series of rows of heating elements for the warmth to travel through, allowing for a greater surface area to warm up and rid the window of frost. This technique allows for the source of the solution to be constant and abundant, creating a positive result to the task at hand within a reasonable timeframe. However, on the flip side, the windshield of many cars only have air flowing through the dashboard of the car to get this same effect. In many cases, only a small area will defrost until the inside of the vehicle reaches a temperature to help the process; which begs the question: is the defroster doing the job, or the interior temperature?

This example can be used similarly to the use of antibacterials & antimicrobials. In a number of products, although marketed as fully “anti”-this or that, only a small percentage of the product actually contains the properties needed to reduce microorganisms. Fabrics may use bands of special threads, while hard surfaces may use pieces of aggregates within their composition.

How will maintenance affect these properties over time?

It’s one thing to understand how testing occurs, and another to understand how the product itself is made; but, the real question is what happens after the product is installed?

It’s a common issue with clients: select something pretty and useful, have it installed, and wait a few months to see how the products really hold up, then . . . come to find those costly “anti” products aren’t really doing what they said they would do. Unfortunately, not all maintenance staff gets proper instruction and training on newly-installed products, and will either use a single cleaning agent for almost everything, or use the wrong one. These cleaning agents can strip away potential antibacterial properties in the products, or possibly leave residue blocking the very microorganism-inhibiting property for which the product was specifically specified.

What can we do?

Ask Questions! As designers, don’t be afraid to ask your reps how the product is reducing or eliminating bacteria growth. If it’s a topical application, it may be a good idea to consider then where the product could, or could not, be installed.

Don’t be afraid to read! There are hundreds of white papers, case studies, research articles, etc. out there for the taking, many of them make great light reads over lunch. Make sure to note who exactly has written the information - if it is from, or supported by, the manufacturer of the product, there may be biases to final information released. Academic research is a fantastic place to get the outside information about these topics, and many of them are non-biased.

Don’t over-think being “anti”. Not everything has to be covered in plastic wrap. There is some research that indicates that not all bacteria is bad bacteria, and our hospitals may even have their own immune system of nonpathogenic bacteria that could actually protect patients from HAIs (Arnold, 2014).


antibacterial. (n.d.).   Unabridged. Retrieved July 15, 2014, from website:

Anwar, H., Dasgupta, M. K., & Costerton, J. W.   (1990, Nov). Testing the Susceptibility of Bacteria in Biofilms. Antimicrobial   Agents and Chemotherapy, 34(11), 2043-2046.

Arnold, C. (2014, July). Rethinking Sterile: The   Hospital Microbiome. Environmental Health Perspectives, 122(7),   182-187.