With the shortage of N95 protective masks, there has been an interest in recycling existing masks. Indeed, several local hospitals are doing so. Nevertheless, masks get dirty, moisture-saturated, and potentially infected with bacteria, mold, or with COVID-19 virus. Thus, the question of sterilization of used masks has arisen.
Disinfection is the process in which all forms of life like fungi, bacteria, viruses, and spores are eliminated, killed, removed, or deactivated off a specific object, surface, or fluid. There are many ways to attain such results depending on the item requiring sterilization including boiling, incineration, filtration, dry heat, high pressure, microwave, chemicals, and ionizing irradiation,
In sterilizing protective masks, an individual cannot use excessive heat; hence, he would be sterilizing using chemicals and using them to maximize safety and sterilization. These fumigating agents would be based on the chemistry that oxidative processes with low molecular weight molecules when used under-tested methodologies, kill all bacteria, mold, and viruses.
Vaporized hydrogen peroxide is one technique of sterilizing masks. Liquid hydrogen peroxide is transformed to vapor form. The vapor is then placed into a chamber vacuum. The decontamination leads to minimal toxic byproducts as the peroxide is broken down into the water. Devices for such sterilization are available to some hospitals already. It is noted that water would also be essential for the system to avoid potential explosions with hydrogen peroxide radicals.
Ethylene oxide is the other method for sterilization that also is available in some settings. Ethylene oxide is a recurring ether and is flammable and a potential explosive. Although an effective method has a long cycle time, it is relatively costly and associated with side effects to exposed humans.
Activated oxygen is another method for disinfection for objects that cannot withstand high temperatures or extreme heat. It is also known as ozone sterilization. Ozone is a naturally occurring gas in which three atoms of oxygen are united, instead of the typical two. These devices are often used as room disinfectants and food sanitizers.
Ozone has been confirmed to destroy bacteria, fungi, viruses, and protozoa. In the case of viruses, activated oxygen diffuses through their protein coat, into the nucleic acid, damaging and eliminating the organism. Ozone destroys the unsaturated lipid envelope of the virus by damaging existing numerous bond configurations. The nuclear content of the virus cannot survive without an intact lipid envelope; COVID-19 virus is an enclosed virus. At even higher concentrations of oxidation, the capsid is also eliminated. Viruses that have been susceptible to activated oxygen comprise poliovirus 1 and 2, human rotavirus, Norwalk virus, Parvoviruses, and Hepatitis A, B, and non-A Non-B.1.
Besides, non-enveloped viruses are also destroyed by ozone by interacting with amino acids in the form of capsid proteins, protein hydroxides, protein hydroxides, and protein hydroperoxides. Ozone also has been proven to interfere with carbohydrates and nucleic acids. Thus, viruses have no protection against oxidative stress.
The fumigation process with the SoClean system is with activated oxygen. SoClean is basically sold for use with CPAP machines, and thus is readily available to many people. The device is a self-contained device that can easily accommodate several surgical masks at a time. It generates activated oxygen, which then moves through the CPAP tube and all chambers of the unit. The air hose requires it to be inserted before starting the machine so that space is closed off to the environment. There is a filter to make sure that no activated oxygen escapes until it is all converted to normal oxygen. Of note, one never opens the apparatus before 20 minutes after the cleansing process because the toxic activated oxygen is released into the environment, which would prove to be toxic.
I have tested the SoClean device to see if it would sterilize without damaging used n95 masks or cloth masks. By all clinical criteria, the procedure is functional. The contaminated mask was cleansed, and when removed, it certainly had the pungent chlorine smell with a metallic twist that is associated with ozone and sterilized products. Moreover, it caused no damage to the functional usage of the mask.
Ozone gas has been shown to destroy the SARS coronavirus in at least seventeen separate studies. Because the SARS coronavirus structure is almost identical to COVID-19, it is sound to assume that it will also kill COVID-19. Research being performed at the Institute of Virology in Hubei is working to confirm that activated oxygen also kills COVID-19.
In short, the SoClean will kill the COVID-19 virus, and hence, reusing n95 masks or any cloth mask can be achieved with this method.