Diverse information abounds when it comes to how long SARS-COV-2, the virus that causes COVID-19, can live on a surface. First, it was “a long time”; next, came a shopping list of surfaces with various virus survival times. Then, it was “up to seven days on some surfaces.” Most recently, according to Australian research, the virus can live up to 28 days on some surfaces—in the dark.
Similarly, there has been a lot of back and forth regarding how the virus is spread. The droplets were initially thought to be heavier than air, making the surfaces they landed on the prime method of transference. This was reversed when it was discovered the virus was communicable through a finer mist that lingers in the air after an infected person coughs or sneezes.
Follow the Facts
Speculation aside, somethings are certain:
- Gravity plays a role. Lighter or heavier, at some point the virus droplets fall down and land on a surface, whether a counter, table, desk, or the floor.
- Carriers will touch surfaces. People who have contracted COVID-19 will touch surfaces, unknowingly contaminating them, and other people will come along, in some cases immediately, and touch these same surfaces.
- People can be contaminated from surfaces. Based on the above two points, some percent of people can/will contract COVID-19 from a SARS-CoV-2 contaminated surface. And let’s not forget that surface transmission has been scientifically proven when it comes to colds, the flu, MRSA, Ebola, and a host of other viruses.
- Disinfectants can’t work unless a surface is cleaned first. Given the risk of infection, the tendency of many people, even—or especially— cleaning professionals, is to grab for the heavy disinfectant artillery and start spraying and wiping, especially the high touch points.
However, the vital first step for infection prevention is thorough cleaning, a fact that cannot be ignored.
Cleaning: The No. 1 Defense
Surfaces must be cleaned before they can be effectively disinfected for many reasons, including:
- Dirt and debris can shield potentially harmful pathogens from the disinfectant and create an environment that actually exacerbates the situation by allowing them to multiply. This is especially true for the SARS-CoV-2, which is an “enveloped” virus, i.e., it is surrounded by a lipid membrane. This membrane is easily broken down by a disinfectant approved by the EPA to fight SARS-CoV-2. However, if the virus cells are hiding under dirt or dust, the disinfectant can’t reach the membrane to kill the virus, which is then able to continue to multiply on the surface.
- Germs reside in cracks and crevices and can be overlooked by disinfectants, especially in porous surfaces. This is why cleaning’s agitation, such as scrubbing, is important.
- Continuing to spray a disinfectant on a surface that has not been cleaned allows the chemical to build up, creating a biofilm that can protect and attract pathogens and encourage them to multiply. Cleaning removes this leftover residue and allows the disinfectant to do its intended job.
- Disinfectants are chemicals that can be dangerous to health and the environment. This is why every disinfectant used in the United States must be registered with the EPA and have a safety data sheet (SDS) and label outlining its potential dangers. Obviously, disinfectant use is necessary on some surfaces and areas such as high-touch points or where there is known case of COVID-19 or a cold, flu, or other outbreak. However, for less-used surfaces and areas where there is no known contamination, thorough cleaning is preferable. In fact, the CDC recommends never disinfecting outdoor areas, such as playgrounds, and parks, where disinfectants are ineffective, and therefore pose unnecessary health and environmental risks.
- In addition to being healthier, avoiding unwarranted disinfecting also saves time and money through less product use and labor, especially considering most disinfectants require a “dwell” time—or wet contact time—of 3 to 10 minutes to disinfect a surface.
Disinfecting plays a major role in infection prevention, but without cleaning first, you can’t keep your facility and its occupants safe.