Antimicrobial Additives
Offer Second Line of Defense
By Dan Rustin

he COVID-19 pandemic has shown just how vulnerable we are to microscopic threats that can cause tremendous harm worldwide. The failure to gain control of this virus has instilled fear about its long-term impacts and our ability to prevent future disease outbreaks. Fortunately, there are new technologies, strategies and products being developed and implemented today that aim to reduce the threats posed by harmful microbes such as COVID-19.

The first line of defense against the spread of coronavirus today involves practicing guidelines established by the Centers for Disease Control (CDC), National Institutes of Health (NIH), World Health Organization (WHO) and other agencies. These guidelines include disinfection, social distancing, use of personal protective equipment (PPE)/masks and handwashing. Such precautions, along with medical testing and self-quarantine of confirmed and suspected cases, are our primary methods for controlling and reducing COVID-19 transmission until an effective vaccine reaches the public.

In this first line of defense, disinfection kills bacteria, viruses, mold, mildew and other harmful microbes, while distancing and physical barriers assist in reducing the spread of harmful airborne germs. A second line of defense focuses on interrupting a microbe’s ability to propagate and survive on surfaces using antimicrobial agents. The CDC recognizes that a significant percentage of illness-causing germs are transferred by touching contaminated surfaces. Antimicrobials offer an effective second line of defense against harmful organisms by disrupting the mechanisms of reproduction on inanimate objects and surfaces, thereby suppressing their growth and ultimately causing them to die.

Antimicrobial additives in soaps, lotions, topical medications, bandages, clothing and packaging have been available for a long time and have employed countless strategies to impart their microbe-eliminating properties. However, prior to the pandemic, widespread use of these additives was virtually non-existent due to cost and the perception that it wasn’t worth the additional investment.

However, in the United States alone, the estimated cost to insurance companies for treating secondary infections resulting from a hospital stay ranges from US$28 – US$45 billion per year. Complications and infections caused by germs commonly known as staph, MRSA, C-Diff and VRE are among the most common and costly of these preventable illnesses and deaths. Starting in 2009, the U.S. government stopped covering the cost of Medicare claims for preventable conditions, mistakes and infections resulting from a hospital stay. Many private health insurance providers have since followed suit.

Fast-forward to today, and the economic damage of this virus-induced pandemic is staggering due to shutdowns of countless businesses and public spaces; international and domestic travel restrictions; and continuous impact on hospitality, long-term care, daycare, public transit, food preparation facilities and the entertainment industry. Clearly, the financial consequences of contagions require new and better strategies for mitigation. The potential benefits far exceed the additional costs associated with antimicrobial additives because the microbial load that bypasses the first line of defense can now be reduced on surfaces. Global manufacturers of performance plastics are introducing polymers using various antimicrobial technologies that demonstrate efficacy in destroying various bacteria, molds, fungus and viruses. However, in the United States, the Environmental Protection Agency (EPA) regulates antimicrobial additives as pesticides, which limits the claims manufacturers can make in their ads. While in Europe and other parts of the world, it is acceptable to say that these products actively kill harmful microbes — as has been confirmed in many clinical trials — manufacturers are not permitted to make these same claims in the United States.

The extent to which a U.S. company can proclaim the efficacy of antimicrobials is that “they protect the surfaces of products against attack from or colonization of bacteria, molds and mildew that cause stains and odors or degradation of the product.” This understates the effectiveness of antimicrobial additives and is partly responsible for the market’s reluctance to embrace these products. However, growing awareness of the full benefits of these additives is beginning to grow. While antimicrobial additives have demonstrated efficacy against a long list of bacteria, molds, mildew and some viruses in laboratory testing, no antimicrobial products on the market can claim they are effective against COVID-19 specifically, as they have not yet been sufficiently tested.

Uses of antimicrobial plastics range from wall cladding for medical suites, food preparation areas, hospitality and pharmaceutical applications, to furniture, laminates, signage, partitions, barriers, PPEs, fixtures, equipment coverings and device enclosures. Essentially, any “high-touch” application can be produced using antimicrobial performance plastics.

A common method of infusing plastics with antimicrobial benefits is to incorporate ionic metals — such as ionic silver, copper, zinc or titanium — into the core resin or applied as a surface coating.

Concerns have arisen in regards to the widespread use of antimicrobial agents potentially causing resistant strains of microorganisms. Given the rise in antibiotic-resistant strains of bacteria and superbugs, these concerns are reasonable. However, prior to the advent of modern antibiotics, the use of silver and copper as a natural antimicrobial and healing agent is very well documented. Over the past several decades, and through extensive use in commercial, consumer and healthcare applications, there has not been clear evidence of the development of antimicrobial metal resistant strains.

What’s the catch?
Currently, the use of antimicrobial metal is believed to be safe and non-toxic to humans and animals at the levels they are used against microbes. The risks appear to be extremely low, while the benefits offered can be substantial. For plastic producers, distributors and processors, these benefits also provide an added value to otherwise commoditized products. Antimicrobial performance plastics offer demonstrable benefits in their respective applications, allowing for greater opportunities to increase revenue. Additionally, one can infer the associated reduction in incidents of infection or illness from contact with contaminated surfaces translates into savings to consumers, healthcare providers, facilities, insurers and more. However, manufacturers of performance plastics are prohibited by the EPA from making such claims in the United States.

Below are some examples of new performance plastic products and uses in various markets. This is only a partial listing, as the opportunities for antimicrobials are growing with each day.

Palboard 3D Max Revlon Makeup
Palram’s PALBOARD HYG is an antimicrobial multilayer polymer sheet. It is printable while maintaining its full antimicrobial properties that are actively protecting the sheet’s surface. It can be used to create displays, signs and sanitizer dispensers.
Sneaker Store Sanitation Station Model
Due to superior ink adhesion, formability, durability and resistance to chemical cleaners, PALBOARD 3D MAX HYG is the ideal antimicrobial multilayer sheet for creating entire displays, exhibits and kiosks used in high touch environments.
Antimicrobial print substrate
One manufacturer of polyvinyl chloride (PVC) sheet offers a silver ion infused, multi-layered PVC sheet product; two outer layers of rigid, type 1 PVC faces infused with silver ions are co-extruded over a foam PVC core, yielding antimicrobial benefits on surfaces with added rigidity and light weight. As a print substrate, the antimicrobial surface protection of the sheet are unaffected by the lay down of ink covering its surface during wide format digital printing. This eliminates the need to add antimicrobials to the ink formulation. Since no antimicrobial over laminate or coatings are required, printers can print and go without changing or adding costs to their process. Compared to cardboard and other multilayered substrates, the PVC composition withstands repeated cleanings with soap and water, as well as harsh chemicals that would damage cardboard or metal, and allows for easy fabrication.
Antimicrobial wall cladding
Several manufacturers now offer silver ion infused formulations for wall cladding applications in rigid polyvinyl chloride (RPVC), unplasticized polyvinyl chloride (UPVC) and PVC/polymethyl methacrylate (PMMA, also known as acrylic) alloys, many available in a variety of colors and surface textures. When used with color matched welding rods, seamless installations are possible. This is ideal for surgical suites and clean room environments where dirt, mildew and germs might collect in unfilled joints and seams. These thermo plastic sheets can also be heat bent around outside corners and formed to inside corners for increased sanitation and to eliminate butt joints in corners.
Brochure Cover medical office
This radiology exam room is taking full advantage of PALCLAD PRO HYG’s antimicrobial surfacing technology. Whether used as a laminate for cabinet doors or wall cladding, or a thermoformed exam table, these solid polymer panels can prevent the growth of stain and odor causing bacteria, mold and mildew on their surfaces.
Antimicrobial sheets for forming and fabrication
The list of opaque materials is getting longer: acrylonitrile-butadiene-styrene (ABS), PVC, PVC/PMMA, high-density polyethylene (HDPE), acetals, polytetrafluoroethylene (PTFE) and more are being developed every day. Applications range from orthotics, MRI housings, medical carts, device covers, tool trays and hospital beds, to use in school lockers, bookcases, closet interiors, displays, interactive kiosks and classroom tabletops.

In aerospace and transportation, non-flammable antimicrobial performance plastics are needed for improved sanitation and resistance to frequent disinfection. Aircraft, trains and bus interiors are using more of these products in wall panels, tray tables, seats and interior glazing. Similarly, public transport waiting areas are being redesigned, thus the demand for surfacing materials that can be easily disinfected and prevent the growth of microbes on their surfaces is rapidly growing.

In food service, cutting boards, food carts, buffet service, trays, tables, seats, sneeze guards and cabinet faces are all using materials listed above due to improved sanitation benefits.

Acceptance and implementation of antimicrobial plastics
Many producers of antimicrobial plastics still have yet to see the widespread adoption of these products in the applications for which they were designed. Lack of a perceived problem, as well as the extra upfront costs associated with these products has created a myth that they are mainly for discretionary use. But now, the coronavirus pandemic is highlighting the importance of providing as many lines of defense as possible, in as many places as possible. Although we may never be clear of facing similar threats in the future, adoption of these antimicrobial tools and technologies may help to mitigate exposure to opportunistic microbes in the future.
Dan Rustin is a career professional in the plastics industry. He can be contacted at (862) 684-0730.