In recent months, many creative approaches have been developed as a part of the global effort to overcome the COVID-19 pandemic. One of these is the fogging technology, used as a basis for some solutions like sanitation passages. However, because the technology is at the early stage of development, there is still much misunderstanding about it. In this article, we will answer the most common questions about the technology and evaluate its contribution to overcoming the ongoing pandemic.

What is Fogging?

In the context of the COVID-19 health crisis, the word “fogging” is often used to describe a disinfection procedure in which certain items or the environment are sanitized with a disinfectant fogger machine. In a more general sense, the term refers to the technology of atomizing liquids into a mist-like substance known as dry fog. The technology itself is not new – atomizing nozzles have actually been used extensively in numerous industries for temperature and humidity control, dust suppression, and food sterilization.

Eventually, the approach was picked up by the healthcare sector, where it was used by hospitals and dental offices to sterilize equipment. It was also suggested as a way to disinfect hospital rooms to kill air-born pathogens. Despite showing its effectiveness as a decontamination technology, it didn’t gain much traction because other well-established means of air disinfection were available at that time.

With the onset of the SARS-CoV-2 epidemic in 2020, the demand for no-touch disinfection methods became apparent. Fogging technology was considered as one of the possible solutions. Not only did it allow for thorough treatment of complex surfaces, it also made the disinfection process seamless and efficient. Today, it is used in a range of ready-made solutions, from a portable fogger to a large mist disinfection tunnel.

How Do Disinfectant Fogger Machines Work

The chief component of a fogger is the atomizing nozzle, which disperses the liquid into ultra-fine droplets and ejects them into the air. Depending on the area of application, atomization systems may use pressurized air, ultrasound, or a combination of both. The size of the particle varies from 3 to 10 microns – approximately ten times smaller than regular “wet” mist and fifty times smaller than a light rain droplet.

Why Is It Dry?

Because dry fog particles are so small, they behave differently from the water that most people are familiar with. Their surface tension is higher than in regular droplets, so instead of bursting on contact with a surface and wetting it, they bounce off it. Interestingly, this property also makes them more effective at disinfection than sprayed liquid, as they are more likely to collide with microscopic particles that transfer pathogens.

In addition to that, the process is more efficient in terms of disinfectant consumption. Dry fogging an item in a fog unit disinfection tunnel takes only a fraction of liquid compared to the amount needed for spraying while ensuring a more homogeneous coverage.

Why is Fogging Effective at Killing Pathogens?

There are two sides to the effectiveness of fogging technology. The first one stems from its mechanical properties. As was mentioned above, dry fog is both denser and smaller than regular spray, so it covers surfaces more thoroughly and misses fewer impurities that can harbor pathogens. In the case of SARS-CoV-2 and other viruses with airborne transmission route, water droplets with the virus can remain suspended in the air for several hours or settle on nearby surfaces. In this situation, the atomized disinfectant is more likely to intercept the pathogen and bind to it.

From the strategic perspective, it is also more efficient on the organizational scale. First, devices based on this technology are robust and require very little maintenance, which minimizes delays and prolongs their life cycle. It also allows for seamless operation, which means more decontaminated surfaces in a shorter time. On top of that, due to its low disinfectant consumption, a disinfection gateway requires fewer resources. Simply put, fogging technology lets you complete the disinfection faster without depleting your supply.

Of course, such results are only possible with an appropriate disinfectant. While there are many solutions on the market that are effective at killing viruses, not all of them can be applied via fogging. Some substances react differently with the environment once they are atomized and either lose their effectiveness or become hazardous. For the best results, check whether the product is labeled as compatible with this application method, like Sani Pass disinfectant.

Is Fogging Safe for People’s Health?

One of the contentious points of fogging technology is its effects on human health. At the outset of the pandemic, the idea of a disinfection gateway gained some notoriety after early crude implementations that used sodium hypochlorite and similar hazardous substances to spray people. The important thing to understand is that the technology itself is not in any way harmful for humans – what matters is the solution that is being atomized.

Fortunately, many disinfectants exist that are completely safe for use in populated areas. One example is hypochlorous acid, also known as electrolyzed water. This substance is listed on EPA’s List N as approved for healthcare, institutional, and residential use. Due to its chemical properties, it is extremely efficient against the coronavirus as it is proven to kill harder-to-kill pathogens than SARS-CoV-2. At the same time, it has no effect on humans or other complex life forms, which is why it is widely used in food production and similar areas. Not only that, it is biodegradable and non-accumulative, which makes it an environmentally conscious solution.

Which Environments are Suitable for Fogging?

In the context of sanitation, fogging is a delivery method for the disinfectant, so its effectiveness depends on how much area comes in contact with the mist. For this reason, it works best in enclosed environments where the loss of disinfectant is minimized. Tiny particles are sensitive to air movement, so the majority of the disinfectant will be lost during outdoor use. This is not a problem for room disinfection or equipment sterilization, where the target area can be sealed for the duration of the procedure.

Of course, in many public spaces, this is not possible, either due to the building size or the way the facility operates. To address this limitation, many fog-based solutions have an enclosure where the fog is applied. The sanitizer tunnel for COVID-19 is probably the most familiar example: a person enters the compartment which is then filled with dry fog for several seconds. As the compartment is closed off, the fog settles on surfaces inside it. This approach has been successfully used for commercial applications like luggage disinfection equipment in airports.

Final Thoughts

Fogging is a classical example of innovation where old technology was creatively adapted for a new purpose. Not only is it more efficient at applying the disinfectant to complex surfaces and loose particles, it also helps to reduce the duration of the procedure and is compatible with a range of liquid sanitation solutions. On top of that, it is not harmful to either people or equipment and can even reduce costs of sanitation procedures on the level of organization. All in all, it has a great potential for overcoming the coronavirus outbreak and may become an integral component of the response to the ongoing public health crisis.