Ozone disinfection of respirator masks for front-line workers coping with COVID-19

Great article on the use of ozone to disinfect respirator masks. See original article HERE.

Researchers at Yale School of Medicine and collaborators have successfully used ozone to disinfect the respirator masks used by healthcare workers to protect against respiratory diseases such as coronavirus disease 2019 (COVID-19).

The development could be used to address a shortage in the availability of this critical piece of personal protective equipment, caused by the COVID-19 crisis.

The authors say that, to their knowledge, their study is the first to report successful disinfection of the masks with ozone and the first to identify the conditions necessary to do so, without damaging mask function.

A preprint version of the paper is available on the server medRxiv*, while the article undergoes peer review.

Supplies of the masks are dwindling

Supplies of the NIOSH-certified N95 filtering facepiece respirators (commonly shortened to“N95 respirators”) have dwindled with the increasing strain placed on healthcare systems due to the COVID-19 pandemic.

This had prompted front-line medical workers to resort to reusing the respirators and experimenting with their own methods of disinfection, which some researchers have described as generally ineffective and damaging to filter performance.

What does the CDC say?

The Centers for Disease Control (CDC) has recognized that the reuse of personal protective equipment such as N95 respirators may be necessary to protect healthcare personnel and to lower the risk of transmitting infection in the workplace.

However, the organization says four essential points must be addressed when considering potential ways to achieve this. The method must be effective at killing the organisms being targeted; must not degrade the function of the equipment; must not introduce new risks to healthcare workers and must be practical in the setting of emergency pandemics such as COVID-19, where resources may be too limited to ensure adequate supplies of the equipment.

Some organizations have described potential protocols, including disinfection with dry heat or using vaporized hydrogen peroxide (VHP) and UV-C light.

Ozone is an appealing option

However, Manning and colleagues were interested in the possibility of disinfecting the respirators with ozone as an alternative for healthcare personnel who may not have access to VHP or other disinfection devices.

The team says that not only is ozone attractive as a potential disinfector because it is a strong oxidant that can deactivate viruses, but it can be generated from air, can quickly be destroyed, and does not leave any residue.

Now, the researchers have tested using ozone to kill Pseudomonas aeruginosa on three types of N95 respirators, namely the 3M 1860, 3M 1870, and 3M 8000.

They point out that P. aeruginosa is a bacterium that the CDC has previously referred to as more difficult to kill than viruses such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Top row: cultures from respirators inoculated with bacteria culture, exposed to 400 ppm ozone 80% humidity for two hours, and incubated for 24 hours. Bottom row: cultures from respirators inoculated with bacterial culture, exposed to ambient air 35% humidity for two hours, and incubated for 24 hours. Columns are labeled to identify respirator types tested. Tests were performed in duplicate for each respirator type. Serial dilutions were performed to enumerate the numbers of live bacteria.
Top row: cultures from respirators inoculated with bacteria culture, exposed to 400 ppm ozone 80% humidity for two hours, and incubated for 24 hours. Bottom row: cultures from respirators inoculated with bacterial culture, exposed to ambient air 35% humidity for two hours, and incubated for 24 hours. Columns are labeled to identify respirator types tested. Tests were performed in duplicate for each respirator type. Serial dilutions were performed to enumerate the numbers of live bacteria.

The ozone disinfector the team used

The device comprised an airtight chamber than could generate ozone from ambient air at a concentration of 500 parts per million (ppm). This ozone UV analyzer could accurately determine ozone levels in the chamber and an ozone destruction unit.

The team reports that exposing the respirator to ozone at a concentration of 400ppm at a humidity of 80% over two hours successfully killed bacteria on all three types of respirators.

Image of N95 respirator after ten treatments with 450 ppm ozone for 2 hours at 75-90% humidity. There is little noticeable wear on the respirator after extended exposure to ozone.

Furthermore, exposure to ozone at this concentration with a relative humidity of 75-90% at room temperature did not degrade the filtration capability of the 1860 and 1870 type respirators for up to 10 cycles of two-hour treatments.

A practical way to decontaminate the respirators

Manning and colleagues advise that ozone disinfection using the small devices could serve as an effective way to decontaminate N95 respirators, especially in rural areas and in cases where healthcare workers and institutions have no access to large-scale disinfection facilities.

Ozone is a potential treatment for the Corona Virus

A paper was recently published by the Journal of Infection Diseases and Epidemiology that is promoting the use of ozone as a treatment for the Corona virus. Worth a read for sure.

Abstract:

Many viruses require reduced sulfhydryl groups for cell fu-sion and entry. Corona viruses, including SARS-CoV-2 (the cause of the condition now named coronavirus disease 2019 or COVID-19), are rich in cysteine, which residues must be intact for viral activity. Sulfhydryl groups are vulner-able to oxidation. Ozone therapy, a very inexpensive and safe modality may safely exploit this critical vulnerability in many viruses, inclusive of SARS-CoV-2

Read full paper HERE

Does ozone sterilization kill the Coronavirus which causes COVID-19?

This article was originally published by Aeroqual

No medical event in recent history has made a bigger impact on global health and the economy, than Coronavirus, and the COVID-19 disease.

At the time of writing, most major economies are entering into some form of lockdown, causing significant disruption to businesses and drastically changing the way we live our lives for the next few months. 

Governments, Industry and Citizens are united in trying to slow the spread of COVID-19, to give health services time to prepare for the explosion in the demand for care. Sanitizing our homes, workplaces and public spaces is a key tactic in the fight against Coronavirus, to stop the spread of COVID-19. One method of sterilization is by using ozone. Ozone sterilization is commonly used in hospitals to sanitize equipment and significantly reduce or eliminate the spread of bacteria. Hence the question being asked is – “Can ozone sterilization kill the Coronavirus which causes the COVID-19 disease?” 

This blog post looks at the evidence and highlights the benefits of sterilizing environments with ozone, as well as it’s associated risks. 

OZONE STERILIZATION PROVEN TO KILL SARS-COV VIRUS 

There are currently no examples in the public domain, of ozone sterilization being used to kill the current strain of Coronavirus, SARS-CoV-2 (technical name of the Coronavirus which causes the COVID-19 disease). However, there are reasons to believe it would be effective: 

  • During the SARS epidemic of 2003, ozone sterilization was successfully used to purify environments infected with the deadly Coronavirus, SARS-CoV-1, the virus which causes the SARS disease. 
  •  As SARS-Cov-1 is also a member of the Coronavirus family, it is highly likely that ozone sterilization would be effective at killing SARS-CoV-2, the Coronavirus which causes the COVID-19 disease. 

HOW DOES OZONE STERILIZATION KILL CORONAVIRUSES? 

Coronaviruses are classified as “enveloped viruses”, which are typically more susceptible to “Physico-chemical challenges”. In other words, they don’t like being exposed to ozone.   

Ozone destroys this type of virus by breaking through the outer shell into the core, resulting in damage to the viral RNA. Ozone can also damage the outer shell of the virus in a process called oxidation. Put simply, exposing Coronaviruses to sufficient ozone dose (ppm x time) can result in them being 99% damaged or destroyed.

WHAT ARE THE RISKS OF OZONE STERILIZATION? 

Breathing even small amounts of ozone can be harmful. Symptoms include coughing, shortness of breath, and aggravation of lung diseases like asthma. At higher concentrations you can smell ozone, but it becomes harmful even at lower doses. For that reason, many countries have set an 8-hour exposure limit of 70 ppb (parts per billion) ozone. In the EU the limit is set even lower. Ozone is one of six common pollutants limited by the United States Environmental Protection Agency and other country’s Environmental regulators. Exposure to ozone in the workplace is controlled by the Occupational Safety and Health Administration and their counterparts around the world.  

REDUCE THE RISK OF OZONE EXPOSURE BY MONITORING 

Although ozone can sterilize coronavirus infected environments, residual ozone could also cause respiratory issues for people who breathe it in. To stop this from happening it is important to measure and control indoor and outdoor levels of ozone after sterilization has taken place. 

The problem is that the equipment for measuring ozone is either a) accurate but too expensive, or b) affordable but not accurate. This is why Aeroqual came up with option c) monitors that are both accurate and affordable

Please contact us if you have any further questions on monitoring ozone.