The coronavirus pandemic has gotten most of us in the habit of being more aware of the things we touch throughout the day. We wash our hands and use hand sanitizer to avoid picking up or depositing coronavirus and other germs onto the surfaces we touch, and we also clean and disinfect those surfaces for the same reasons. Lately, though, with mounting evidence that coronavirus spreads most easily through the air, many have begun to wonder if all the increased sanitation of surfaces is overkill.  Really, what this boils down to is a balancing of sanitation costs and health benefits.

A surface that becomes contaminated with germs is called a “fomite”. For well over a century, we’ve understood that many diseases are transmitted between people through fomites. Cold and flu viruses are notorious for being commonly spread this way, despite also causing infected individuals to sneeze the virus into the air for airborne transmission. A study by our own Dr. Charles Gerba called “Germs in the Workplace”(1) found that when a harmless tracer virus was dosed onto a door handle or conference table in an office or hospital, in a couple of hours about ½ of the people in the building had contaminated hands, and about ½ of the commonly-touched surfaces were contaminated (fomites). This is concerning, because many viruses (including SARS-CoV-2) can survive on surfaces for several days, while bacteria can actually multiply on dirty surfaces. To put this contamination into perspective, a typical office desk has 400 times as many bacteria as a toilet seat.

Another study by Dr. Gerba’s team(2) found that daily disinfection of surfaces in schools reduced absenteeism by more than half. In the US, K-12 students miss on average 4.5 days of school each year due to being sick. Since public school funding is usually based in part on attendance, a few tens of dollars per student per day can easily add up to the (avoidable) loss of several tens of thousands of dollars of school funding for the year. Similarly, absenteeism has been estimated to cost companies $2,660 per year per shift worker (3). What would you be willing to do to cut that cost in half?

As the studies show, properly disinfecting all of the surfaces in your business or school every day has demonstrated benefits, but that isn’t always practical. It takes considerable time and resources to coat everything with disinfectant, and the chemicals used can be skin and lung irritants, creating new health problems to deal with. For these reasons, many schools and businesses have begun hiring crews (like ours at Azenity Labs) to quickly and safely coat large areas with disinfectant by using electrostatic sprayers. The tricky part is that it can be cost-prohibitive to have such services performed daily, and disinfectants can only kill the germs ALREADY on the surface when it is sprayed.

This conundrum has led to the development of an array of antimicrobial coatings that are able to kill germs that land on a surface for days or weeks after the coating was applied. As a result, professionals can apply the coating with electrostatic sprayers less frequently, saving on labor and chemical costs while providing forward facing protection. Unfortunately, when the coronavirus pandemic hit, the only antimicrobial coatings commercially available were never shown to be effective against viruses, only against bacteria. Fortunately, a couple of coatings are starting to be offered with test results demonstrating effectiveness against viruses like coronavirus.

EPA Registered Disinfectants have been lab-tested to kill over 99% of germs when properly used on surfaces. Additionally, those disinfectants on the EPA’s List N have also demonstrated effectiveness against coronavirus. Because antimicrobials aren’t disinfectants, the EPA isn’t adding them to the List N. For this and other reasons, antiviral antimicrobials can be hard to find. Because of their power to prevent infections, Azenity Labs has made it a priority to secure our own steady supply. Be careful when shopping around. Many service providers will use language that implies that the chemicals they use provide forward protection against viruses, but often they will use a disinfectant with antiviral claims along with a typical antimicrobial coating that provides no forward protection against viruses. In the future, I suspect that more antiviral antimicrobial coatings will become the norm for all sorts of shared surfaces in workplaces, schools, entertainment venues, and other communal spaces.

 

References

1) Gerba CP. Germs in the Workplace. Clorox Company study. 2002.

2) Bright KR, Boone SA, Gerba CP. Occurrence of bacteria and viruses on elementary classroom surfaces and the potential role of classroom hygiene in the spread of infectious diseases. J Sch Nurs. 2010 Feb;26(1):33-41.

3) Cooke C. Shift Work & Absenteeism: The Bottom Line Killer. Circadian 24/7 Workforce Solutions. Shifting Work Perspectives. 2014.

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