What’s New in Antiviral/Antibacterial Disinfectants?

The COVID-19 pandemic has persisted far longer than anticipated, along with the resulting shutdowns of nonessential businesses in many jurisdictions. Accordingly, many medical facilities have seen their cleaning practices turned upside down. Reduced operating hours and social distancing requirements have disrupted normal staff scheduling, including those members responsible for keeping facilities clean. Staffing levels have also been unsettled by employees required to self-quarantine due to COVID-19 exposure or to care for infected family members. Other employees who live with high-risk family members have taken voluntary leave or even changed careers to reduce the risk of exposing their loved ones. 

At the same time medical facility managers are juggling staffing disruptions, the highly infectious nature of the SARS-CoV-2 virus, including its ability to survive on surfaces for up to 72 hours, means those medical facilities that remain open or have reopened must directly address this new threat, in addition to adhering to their existing environmental cleaning practices. The good news is that as high-tech disinfectants continue to be developed and marketed, preventing healthcare-associated infections (HAIs) from environmental sources is becoming both easier and less labor-intensive.

Preventing HAIs and COVID-19

HAIs are one of the top risks for healthcare practices. The three legs of an effective plan to prevent infections in medical offices, hospitals, clinics or other healthcare settings are proper patient care, consistent staff hygiene (including the proper use of personal protective equipment) and effective equipment and environmental cleaning that includes disinfecting and sterilization as appropriate.

But just having an anti-infection plan in place¹ isn’t sufficient. It is likely every medical facility in the country now has a well-designed set of protocols established to prevent HAIs. In fact, the U.S. Centers for Disease Control and Prevention (CDC) has been emphasizing the need to combat HAIs for the past 13 years, since initiating the multi-agency Federal Steering Committee for the Prevention of HAIs in 2008.² 

But a plan only works when it is followed consistently, and humans are fallible in this regard. Attention spans wander, focus drifts and emergencies and crises arise. CDC reports a significant portion of HAIs comes not from medical procedures, but from environmental contamination.³ And, earlier studies indicate most infections occur with an approved plan in place that is not consistently followed.

Fortunately, new technologies are coming to market that protect against human inconsistency. The latest disinfectants can provide protection for weeks or even months, reducing the need to have daily or even hourly disinfection procedures in place. However, it remains important for facility management to be aware of the different classes of disinfectants, how they are regulated by different government agencies, and how each type of product fits into a facility’s overall anti-infection plan. 

Classes of Equipment to Be Cleaned

CDC utilizes Spaulding’s Classification of Equipment and Medical Devices as the basis for all its disinfection and sterilization standards.⁴ The system organizes equipment and devices into critical, semicritical and noncritical classes.

Critical items are those that come into contact with exposed patient tissue or the vascular system, bypassing the body’s normal defenses. These items — scalpels, catheters, implants, etc. — must be sterilized before each use. (Sterilization in this context is defined by CDC as having removed or killed not only all bacteria, fungi and viruses, but also bacterial and fungal spores.) Steam or hydrogen peroxide plasma are recommended methods of sterilization, but liquid sterilants can be used on equipment that is heat-sensitive.

Semicritical items come into contact with mucus membrane or skin that has scrapes or scratches. These items — esophageal probes, rectal probes, diaphragm-fitting rings, dental tools, etc. — must be free from all microorganisms, although they don’t need to be sterilized. This level of treatment for semicritical items, which allows for spores to remain, is defined by CDC as “high-level disinfection.”⁵

Everything else in a medical facility is categorized as a noncritical item, although these items are broken down further into patient-care items (bedpans, crutches, blood-pressure cuffs, etc.) and environmental surfaces (bedside tables, bed rails, chairs, doors, floors, etc.). 

This last category is one that is often overlooked in medical facilities. While the critical and semicritical equipment used by medical professionals is incorporated into daily quality control processes, noncritical equipment is often maintained and cleaned by custodial staff with no direct medical supervision. 

Exploring New Options

Most hospital-grade disinfectants used to clean noncritical equipment and infrastructure fall into a handful of categories: alcohols, bleaches, phenolics, ammonium and benzalkonium chloride. (To be listed as “hospital grade,” a product must show efficacy against both Pseudomonas aeruginosa and Staphylococcus aureus.⁶) Each of these disinfectants chemically interacts with the molecules of a bacteria, fungi or virus to kill it. These same properties can pose significant health risks if a person accidentally ingests or inhales too much of them, so accidental poisonings are rare but not unprecedented.

Now, there is a new alternative for noncritical equipment that attacks bacteria and fungi physically rather than chemically through the use of tiny, microscopic spikes that puncture the membranes of any single-cell organisms that fall onto a surface treated with the product. Jason Winkleblech, vice president of infection control products for FFF Enterprises, the nation’s leading supplier of critical-care biopharmaceuticals, plasma products and vaccines, says FFF will be distributing one of these new classes of biostatic surface treatments known as Penetrexx Antimicrobial. “The surface treatment product creates a colorless, odorless, positively charged polymer that bonds to a treated surface,” explains Winkleblech. “That treated surface looks like a field of spikes, if you will. The spikes will puncture the cell membrane and render the microorganisms dead.

“It’s really the missing step in any good cleaning and disinfecting protocol. You clean to remove dirt and grime, you disinfect to kill everything on the surface and then you apply this product on the surface after disinfecting to create this long-term active antimicrobial shield. It doesn’t lose its strength; it’s a mechanical interaction, not a chemical reaction. The barrier will only be degraded by extended contact. If you apply it to a door handle that’s constantly being touched, that layer will break down in time.”

Interestingly, nonabrasive cleaning of treated surfaces won’t degrade the product’s protective shield. In fact, regularly removing grime and dead microbes from surfaces will prolong the life of the treatment by keeping the microscopic spikes clear for the next group of microbes to fall upon. And, due to the way human skin is structured, the spikes will not scratch or irritate anyone coming in contact with a coated surface. The caveat, though, is since this product is not an antiviral, other products need to be used in conjunction with it to protect against viral transmission, including SARS-CoV-2.

According to Winkleblech, with regular light cleaning of treated surfaces, Penetrexx Antimicrobial can remain effective for three months after application. And, once it has been applied and dried, there is no risk of exposure to staff or patients.

Types of Cleaners

Winkleblech points out that while the U.S. Food and Drug Administration handles the certification process for antibiotics and some products used to sterilize or provide a high-level disinfection of medical instruments and other equipment that comes in direct contact with patient tissue, the Environmental Protection Agency (EPA) oversees facility cleaning products used to disinfect noncritical equipment on the CDC list. But, he adds, facility managers need to be sure the products used to clean floors, doorknobs, countertops and other public areas meet EPA standards for the specific application for which they are being used. (EPA maintains the lists of products approved for use versus specific pathogens.⁷)

For its part, EPA notes that due to the nature of healthcare, cleaning staff is often required to disinfect patient rooms or common areas where feces, urine or even blood may have been spilled. In addition to fully removing the waste and any other dirt using an approved disinfectant to kill germs, facility managers must also ensure they are complying with the Occupational Safety and Health Administration’s requirements for occupational exposure to bloodborne pathogens. Also, when disposing of urine, waste or bodily fluids, staff must conform to the Resource Conservation and Recovery Act.⁷ 

The types of hospital-grade disinfectants approved by EPA for use in environmental cleaning are:

Alcohol. Alcohols kill cellular organisms (bacteria, fungi) by dissolving their outer membrane. Ethyl alcohol can also disable many classes of viruses, and isopropyl alcohol is highly effective against lipid viruses.⁸ Alcohols tend to disinfect rapidly, but have little long-lasting effect since they evaporate quickly as well; therefore, surfaces being disinfected with alcohol will need frequent applications.

Alcohol-based disinfectants are highly toxic if accidentally ingested, highly flammable and can mar the surface of some materials. As such, they should be tested on a small sample of a surface before being used.

When used as a hand sanitizer, alcohol-based products are very effective and quick-acting, but they generally must be reapplied frequently, which can lead to dry and even chapped hands among users.

Phenolics. These hydrocarbons, chemically similar to alcohols, work by penetrating the cellular wall and bonding with various enzymes inside of a bacteria or fungus. They are also effective as virucides. If they are used to clean areas where infants are treated, the surfaces must be thoroughly cleaned following the disinfection.⁸

Bleaches. Bleaches work by causing a chemical reaction to the proteins of microbes, similar to cooking: They cause the proteins to “unwind” and stop working. As in frying an egg, the process cannot be undone by the microorganism. Bleaches can take longer to disinfect than alcohols, and they can discolor materials with which they come into contact.⁸ Hydrogen peroxide, a weak bleach, has shown to be effective at decontaminating soiled fabrics in patient rooms. Bleaches should not be used as hand sanitizers.

Ammonium. These are ions of ammonia whose mode of disinfecting is not as well understood as that of alcohols and bleaches. It is thought ammonium kills microorganisms by disrupting cellular membranes or penetrating the membrane and reacting with various cellular enzymes.⁸ They are effective against bacteria, fungi and viruses, but not all ammonium variants are equally effective against all pathogens. One quaternary ammonium cation, benzalkonium chloride, has been approved by CDC as a hand sanitizer effective at killing the SARS-CoV-2 virus, along with those that contain at least 60 percent ethanol or 70 percent isopropanol as active ingredients.⁹

Benzalkonium chloride. Popularly known as BKC, BZK or BAC, benzalkonium chloride is the active ingredient in MediDefense mPulse Hand Sanitizer, another product FFF Enterprises distributes. “These BZK-based hand sanitizers don’t dry your skin,” explains Winkleblech. “Folks who work in the medical field are constantly using hand sanitizer, and their skin becomes dry, cracked and uncomfortable.” And, he adds, unlike the alcohol-based sanitizers, the MediDefense mPulse product is nonflammable and hypoallergenic: “It doesn’t strip away natural oils, it can last longer and it’s approved for food handling.”

Revealing Research

While a wide swath of effective products to disinfect common areas and other noncritical environments in healthcare facilities already exists, many products have significant risks in terms of toxicity or discoloring equipment on which they are applied. Others are only effective for a short time, requiring frequent reapplications, and most require keeping surfaces moist for up to a few minutes to effectively kill all microbes. But, some promising research may help to solve these issues.

A research team at the University of Central Florida is working on a spray-on nanoparticle disinfectant that would work almost instantly, and then leave behind a disinfecting film that would be nontoxic to people and nondetectable to touch or the naked eye.¹⁰ And a team at the Technion Israel Institute of Technology in Haifa, Israel, has been studying antiviral polymers that can effectively kill viruses for two weeks or more from a single application.¹¹

Another study, jointly conducted by EPA and New York City’s Metropolitan Transportation Authority, field-tests current EPA-authorized disinfectants for long-term effectiveness. While no new products are currently being tested, any current disinfectants that show effectiveness will be allowed to update their labeling and marketing.¹²

In Hong Kong, researchers building on previous antibacterial polymers have developed a heat-sensitive antiviral polymer named MAP-1. When the polymer coating detects a rise in temperature, which could indicate the surface is being touched by a hand, it releases antivirals. The scientists at Hong Kong University of Science and Technology say the polymer has been shown to be active for 90 days after application.¹³

Finding the Right Products Is Key

As with all aspects of managing medical operations — whether a primary care practice, an urgent care clinic or other type of facility — a mountain of regulatory red tape is associated with developing and implementing an environmental cleaning plan as part of a larger facility cleaning plan.

While there are plenty of products available to fulfill every requirement, finding the right products to fulfill facilities’ cleaning protocols is the first challenge. And, learning about newer products with longer efficiency can help with both labor costs and consistent compliance.

Winkleblech says his team at FFF Enterprises works with clients to help them navigate the maze of regulations surrounding environmental cleaning and disinfecting in medical settings. “We want to provide that sense of security and confidence, as well as improve navigation for our customers in this antimicrobial space,” he explains. “We understand there can be a lot of challenges in this marketplace, and we strive to ensure our products are properly registered and marketed.”