Antimicrobial, Antibacterial, and Antiviral: What’s the Difference? // Material ConneXion

Every day we see more materials and chemicals claim antimicrobial, antibacterial, or antiviral properties. But what does that mean exactly?

Let’s lay the groundwork.

The Merriam-Webster dictionary defines antimicrobial as “destroying or inhibiting the growth of microorganisms and especially pathogenic microorganisms,” antibacterial as “directed or effective against bacteria,” and antiviral as “acting, effective, or directed against viruses”.

It’s also helpful to understand what a microbe is. The Genetic Science Learning Center explains: “The term [microbe] is very general. It is used to describe many different types of life forms, with dramatically different sizes and characteristics: Bacteria, Archaea, Fungi, Protists, Viruses…”

The differences seem simple enough when you break them down, but it’s important to clarify just how those definitions relate to a material or chemical – especially as we navigate through a pandemic.

Correct terminology, please.

During July’s #ExpertHour webinar, Drs. Gayatri Keskar and Andrew Dent were asked to further explain the difference between these three terms. Dr. Dent explained the terms are commonly used interchangeably – though not always correctly:

“Basically, all bacteria are microbes; not all microbes are bacteria. Antimicrobial can mean fungi and other microbes as well as bacteria. So antibacterial just does bacteria. Antimicrobial will do a bacteria as well as fungi and others. They are different from antiviral.

Antiviral is specifically for things such as COVID-19, and they’re a different type of cell. The main difference being that the viruses tend to have a fatty surround, so in order to kill viruses you often have a two-part process where you basically have to … get through the fatty part and get through to the virus itself.

So something can be both antibacterial and antiviral and antimicrobial – it can be anti-everything. Silver and copper both do these things. But just because something says it’s antimicrobial does not necessarily mean it’s antiviral. You have to also specify which virus as well.

Often when we’re talking to clients or working with manufacturers they will say specifically, ‘Oh, this one has been proved to kill H1N1 or avian flu,’ that sort of thing. Just wanted to clear that up.

So yes, there are differences between the three: antimicrobial, antibacterial – pretty similar; very different from antiviral. But there are biocides, such as silver or copper, which do kill all…”

Of course, all this talk led us to Material Library and the online database for a quick search of innovative antimicrobial materials.

Here are a few materials from the database that caught our eye…

MC 1020501 // Non-toxic, patent-pending antimicrobial technology that is ‘powered by light and fueled by air’. This technology creates ‘singlet oxygen’ on fabrics and surfaces, which kills bacteria and viruses including methicillin-resistant staphylococcus aureus (MRSA).

MC 570901 // Powder coatings for metal that incorporate silver (Ag) for antimicrobial protection. These polymer-based paints can use a wide variety of binder systems including acrylic, epoxy, urethane, or polyester. The have virtually no VOCs, are hard wearing, scratch-resistant, and offer a high gloss surface.

MC 1057201 // Rubber flooring that has a tactile indicator made from para-natural rubber, intended for the visually impaired. This durable flooring tile material is produced from a 100% natural rubber-based compound with a patent-pending “Microbial resistance or antimicrobial materials” and available in customized patterns and colors