Disputing the Life Span of COVID-19 Pathogens on Surfaces was published for client Kaivac.
While COVID-19 is mainly spread by inhaling tiny droplets released when an infected person talks, coughs, or sneezes, large droplets can also land on surfaces. A healthy person can then unknowingly touch those surfaces, and the next thing you know, the virus has gotten a free ride to wherever and whatever [that] person touches.1
The article then answers the question of how long the virus typically lasts on various types of surfaces. They report the following:
- Glass – five days
- Wood – four days
- Plastic and stainless steel – three days
- Cardboard – 24 hours
- Copper – 4 hours (See Sidebar: Does Copper Kill Viruses?)
Scores of other reputable sites report just about the same life span for the Covid-19 virus: two to five days. However, is that correct?
Given the cleaning industry’s central role in fighting the pandemic, and the heavy use of disinfectants to do so, the answer to this question is especially crucial for cleaning professionals to know.
Disinfectants are an essential cleaning product because they kill pathogens and microorganisms. However, in so doing, they can be harmful to the user, building users, and the environment. With the uptick in their use due to COVID, those harmful effects are multiplying.
In fact, a June 2020 article in Bloomberg Law, “Rush to Disinfect Offices Has Some Environmental Health Experts Worried,” suggests we are overusing disinfectants to the point that it is replacing one problem with another.
These are “hugely toxic chemicals,” says Claudia Miller, an immunologist, allergist, and co-author of the book Chemical Exposures: Low Levels and High Stakes. “We’re creating another problem for a whole group of people and I’m not sure we’re actually controlling infections. “2
What might be the best way to address this situation is to investigate if the pathogen that causes COVID-19 does live as long as reported. If it does, we may have no choice but to amp up cleaning frequencies and use large amounts of disinfectants.
But if it does not live that long on surfaces, we may need to consider an entirely different cleaning strategy.
A study published on August 1, 2020, in the British medical journal The Lancet takes issue with the life span that has been popularly cited for the coronavirus. The study suggests the virus may, in some cases, only live a few hours on surfaces, not several days.
According to the author, Emanuel Goldman, professor of microbiology, biochemistry and molecular genetics, New Jersey Medical School at Rutgers University:
A clinically significant risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission by fomites (inanimate surfaces or objects) has been assumed based on studies that have little resemblance to real-life scenarios. (underlining added)
Goldman goes on to explain that in one study, the COVID-19 virus survived on a surface for six days. “[But] it was done by placing a very large initial … virus sample on the surface being tested.”
He says that “another study that claimed survival of four days used a similarly large sample on the [test] surface.” He then goes on to discuss other studies that used exceptionally large samples, more than we would be expected to encounter in real-life situations. Further, he says the samples were not allowed to dry out, which typically would happen if the pathogen landed on a desk or the top of an office chair.
“None of these studies present scenarios akin to real-life situations,” says Goldman. “By contrast, one study found human coronavirus 229E to survive for only 3 to 6 hours (depending on the surface tested) and human coronavirus OC43 to survive for 1 hour after drying on various surfaces including aluminum, sterile latex surgical gloves, and sterile sponges.” 3
Goldman says he does not dispute the findings of other studies when it comes to the life span of the virus on surfaces; he just does not believe they reflect real-life situations, arguing that humans would not be exposed to such large amounts of the virus. He ends his report by saying:
In my opinion, the chance of transmission through inanimate surfaces is very small, and only in instances where an infected person coughs or sneezes on the surface, and someone else touches that surface soon after they cough or sneeze, within one to two hours.
So Where Does That Leave the Cleaning Industry?
John Richter, an advisor to Kaivac, manufacturers of the No-Touch Cleaning® system, a presenter at CIRI (Cleaning Industry Research Group) and now a professor at Miami University in Oxford, OH, has two answers to this question. His first is based on what could be termed common sense.
“This is just one report by one specialist in the field. It will likely trigger other studies. If more studies come out supporting Goldman’s view, then we know the life span of the virus may be shorter than we think. Until then, we should follow current guidelines, especially those outlined by ISSA and the GBAC.”
His second answer is based on reports from the Centers for Disease Control and Prevention. The CDC states that in most cases, effective cleaning is all that is needed to stop the spread of COVID and other diseases.
However, a great deal of this effectiveness depends on how these surfaces are cleaned.
For instance, we have known since the early 1970s that mops specifically can spread contamination. From the moment they are used in the cleaning process, they begin to collect pathogens, which are then spread over the floor.
This is likely one reason a study published in the American Journal of Infection Control found that floors in hospital patients’ rooms are frequently contaminated with disease-causing pathogens. 6
One way to eliminate the use of mops when cleaning floors is by using what ISSA, the worldwide cleaning association, refers to as spray-and-vac cleaning systems (no-touch). With these machines fresh cleaning solution is applied to floors and no mops are used in the cleaning process. Further, some systems vacuum up moisture, helping to remove pathogens from the just-cleaned area completely.
Richter’s answers to the Goldman study sound solid and are good advice for the professional cleaning industry. As to the life span of the virus, more studies need to examine the issue. As to cleaning, we have known for decades the tight connection between cleaning and health.
It’s just that now with the pandemic, the stage lights are making this more evident than ever before.
Robert Kravitz is a frequent writer for the cleaning, foodservice, and facility management industries.
Sidebar: Does Copper Kill Viruses?
Copper was first reported as an infection-killing agent in a medical document published by an Egyptian doctor in 1700 BC, based on information going back as far as 3200 BC. Tests over the centuries have proven these early evaluations correct: Copper does kill viruses.