As a result of the COVID-19 pandemic, even the most popular N95 mask models, including the 3M N95 masks 3M 8210, 3M 8511, and 3M 1860, have been difficult to see for sale online in the United States. Even though N95 respirators are the most affected item, other medical supplies are also needed by hospitals, like surgical masks, gloves, gowns, KN95 masks, and face shields. However, to buy them in bulk and wholesale like they need to have been very difficult lately.
While reusable cloth masks, which are the preferred choice for the general public, including kids over the age of 2, can be easily cleaned and reused and are effective in daily public situations, medical-grade masks are usually disposable face masks and are the only ones that can protect workers in high-risk situations like healthcare settings.
This is why decontamination techniques, particularly for N95 masks, have been widely talked-about during the pandemic in the USA. In this article, we’ll discuss the use of sunlight to decontaminate these masks.
What are N95 masks?
N95 respirators have been the focus of research regarding decontamination because of their status as the best face mask for virus protection. They offer antiviral filtration properties that are not found in any other type of face mask, which has made them incredibly valuable in healthcare settings where workers are constantly and closely exposed to COVID-19.
N95 masks can filter out a wide variety of particles that include dust, smoke, pollen, metals, and certain bioaerosols. Some of the viruses they can filter out include the flu virus and the SARS-CoV-2, which is the virus responsible for COVID-19. This is why the medical uses of N95 masks have gained prominence during the last 10 months, as they can provide the necessary protection needed in these high-risk environments.
First, let’s understand what an ultraviolet light is. These are commonly referred to as UV lights, and they’re invisible to the human eye. This is because they have very short wavelengths that our eyes can’t perceive. However, they’re usually adjacent to some form of visible light so we can identify them.
UV rays have a very high energy, so we can feel their effects even though we can’t see them. Many of us know that the sun is a source of UV lights and that the UV rays generated by it can tan you or even give you a sunburn, and of course, we all know that it can also lead to skin cancer.
According to the World Health Organization (WHO), UV lights can fall into one of three categories according to their wavelengths and energy:
- a) UV-A: this is the form of UV lights with the lowest energy. Around 95% of the ultraviolet light coming from the sun that reaches the Earth is UV-A light. Although it’s a low-energy light, it can penetrate the skin’s layers very deeply, leading to tanning, aging, wrinkling, and as we mentioned, skin cancer.
- b) UV-B: this light has higher energy than UV-A, and it can also permeate the superficial layers of the skin. While UV-A is responsible for early tanning effects, UV-B causes delayed tanning and burning, and it’s also a big contributor to skin aging and cancer. This type of UV light would make up around 5% of the rays that reach the Earth from the sun, as most of it is absorbed by the Earth’s ozone layer.
- c) UV-C: you probably guessed that this is the highest-energy form of UV light, meaning that it’s also the most damaging one to the skin. The ozone layer and atmosphere absorbs these rays completely, luckily for us. However, the destruction of these layers due to contamination is a big problem because it would mean UV-B and UV-C rays would teach us more.
When UV lights are used to disinfect medical devices, they use UV-C wavelengths. These lights can penetrate the pathogenic cells, like bacteria, or even smaller pathogens like viruses, and damage their genetic material, which can be either DNA or RNA. Additionally, some evidence shows that these lights could affect amino acids and proteins that protect the viruses or allows them to infect human cells.
For over a century, we’ve been disinfecting things using UV lights due to these antiviral effects. Modern devices have been used in hospitals for disinfecting patient rooms after they’ve been discharged.
Now, many people have put two and two together and concluded that, if sunlight contains UV rays, wouldn’t that be the perfect solution for the decontamination of N95 masks? It’s a natural and unlimited resource, so it would take no money and it would allow for the decontamination of countless respirators are once.
As many of you know, the COVID-19 pandemic has created such a high demand for these respirators in hospitals that the production of them hasn’t been enough, leading to shortages reported all over the USA. The reuse of N95 masks is one of the strategies used in facilities all over the country.
However, as we explained, the UV rays that reach the Earth the most are UV-A ones, which are not very high in energy. The wavelengths used for decontamination is the UV-C lights. So, even though it theoretically could work, it would take a very long time.
All the information cited here comes from this article published by the LA Times, which you can read in full for more information about this topic.