Safe Bubble Initiative can be Widely Implemented in Second Quarter

Combination of CATER and Upgraded Disposable Masks Supplied Initially

Lots of Sealing Options

Determining Mask Fit and the Amount of Unfiltered Air

Standard Masks Result in Twice the Leakage When Worn by Women

An Inefficient Mask can be Worse Than No Mask

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Safe Bubble Initiative can be Widely Implemented in Second Quarter

The  Safe Bubble Initiative can quickly provide the low COVID risk of lockdowns  but with near normal activity and the use of tight fitting efficient masks along with placement of air purifiers and fan filter units in locations where mask wearing is inconvenient.

Evidence provided in the previous Alerts shows that the substitution of tight fitting masks for the average mask being worn today will make a huge difference.

 

In this chart the options are rated on the basis of the most attractive options rated 100% and the others on a comparative basis. the impact is the amount of transmission reduced. Cost is the cost of the product or approach. In the case of lockdowns the cost is the disruption to the economy.  Speed rates the ability to quickly incorporate the product or technology. Fit is the percentage of air filtered as opposed to bypassed.  M. Efficiency is the filtration efficiency of the mask media.  FFU refers to fan filter units. 

CATER masks or disposable masks with special sealing additions can be made available to everyone within just two months. There are billions of N95 masks being treated as disposable. If these are made reusable and tight fitting with additional straps or seals, they can provide a temporary solution. Masks are already being disinfected and reused in hospital settings. The cleanliness requirements for public masks are much lower.

The challenge for meeting mask efficiency needs is the shortage of meltblown media. In the short term this can be solved by reusing the meltblown media and using nanofibers and other media alternatives.

The achievement of a tight fit and efficient mask media will have maximum impact in the short term. As shown in the previous alert the reduction in risk by restricting occupancy to 25 % but allowing ineffective masks results in 25% of the virus in circulation. When both emitter and recipient are wearing tight fitting efficient masks only 1% of the virus is in circulation.  So a facility in a Safe Bubble  and near normal activity can be up to 25 times less risky than a facility operating with low occupancy and inefficient masks.

Longer term upgrading HVAC systems with greater air recirculation and higher efficiency filters is justifiable.  However, the speed with which this can be achieved is limited by filter shortages for MERV 13 and higher. However, fan filter units, and room air purifiers are available in sufficient quantities to make a real difference in the next six months.

When the air quality in the safe bubble is monitored for particulate, CO2, and air flow in each area assurance of the efficacy of the safe bubble is affirmed. If entrants to the safe bubble are screened there is assurance that safety will not be reduced.

 

Combination of CATER and Upgraded Disposable Masks Supplied Initially

Forecasts were previously provided for the mask needs assuming that everyone wore a reusable mask for 90 days but that only wealthy people had access to them until the demand dropped due to vaccines.

More than nine in 10 U.S. adults (93%) say they sometimes, often or always wear a mask or face covering when they leave their home and are unable to socially distance, including more than seven in 10 (72%) who said they always do so.

The Philippines have introduced a new rule forcing everyone in the country to wear a face shield, as well as a face mask, while out in public. Announcing the new rule on December 15, 2020 , the Philippine government said that all people would be required to wear both. Previously, face shields had only been required in malls and enclosed areas, but now they will need to be worn at all times outside the house.

Slovakia and Vietnam made face masks compulsory in many public spaces in the spring of 2000. In other places, like Hong Kong, masks were understood to be an effective means to stop the spread of disease before the coronavirus emerged. Many businesses mandated them early on, and many people wore them in public even in the absence of an official rule. In Japan, where the government initially faced criticism for not doing enough to prevent a massive outbreak, people quickly adapted to everyday mask use, made easier in part because face coverings were already in common use.

It is therefore likely that somewhere between 3 billion to 5 billion people will be wearing masks  through September 2021.

A forecast was compiled based on the assumption that mask use will be steady  over the 2021-22 period at 3 billion people wearing masks. Four categories of masks are plotted. CATER refers to  the comfortable, attractive, tight fitting, efficient reusable masks which have been analyzed.  Disposable masks have been divided into those which are upgraded to provide fit. A surgical mask with adhesive seals or additional straps would be an example of an Upgraded Disposable or Upgrade D masks.  The poor D refers to the typical inefficient, loose fitting mask now being used.

In the second quarter 500 million people could be wearing CATER masks. One billion people could be wearing upgraded disposable masks.  1.5 billion people would still be wearing the Poor D masks.  The upgraded mask would be a temporary initiative and would peak in the third quarter. Volume would then decrease as CATER mask availability increases.

CATER mask production would grow continuously and would be worn by 2.8 billion people masks in the fourth quarter 2022.  At this point in time a significant portion of the use would be for wildfires, air pollution, and special health protection.

CATER masks can be worn for up to 90 days. Upgraded disposable masks could be worn for shorter periods. The life of the poor disposable masks is highly variable.  In the Alert tomorrow we will convert this forecast of the number of people wearing masks by type to number of masks and revenue.

 

Lots of Sealing Options

There are lots of sealing options. Subscribers to the Coronavirus Technology Solutions can conduct a more complete search than those with access only to CMD.  Here is an example of a search under both seal and mask with 60 articles identified

Six pages of results.

Sorted by relevance / Sort by date

1. McIlvaine Coronavirus Market Alert

... , 2020 Dony is a Large Vietnamese Mask Producer Statistical Studies Showing Advantages of Masks Without ... the end of the month, we sealed the first export order from the Middle East ...

Terms matched: 2  -  Score: 363  -  7 Jul 2020  -  URL: http://www.mcilvainecompany.com/coronavirus/subscriber/Alerts/2020-07-06/Alert_20200706.html

2. McIlvaine Coronavirus Market Alert

... 2020 Millions of Lives Saved with Intelligent Mask Program Millions of Lives at Risk Billions of ... masks can be fitted for a tight seal but when worn by general public they are ...

Terms matched: 2  -  Score: 360  -  24 Nov 2020  -  URL: http://www.mcilvainecompany.com/coronavirus/subscriber/Alerts/2020-11-24/Alert_20201124.html

3. McIlvaine Coronavirus Market Alert

... 10, 2020 Overview June 10 Face Mask News Membrane Mask with Silver Being Developed by ... resistant Malleable noseband ensures custom, secure seal Soft and hypoallergenic Masks feature three-ply construction for ...

Terms matched: 2  -  Score: 350  -  10 Jun 2020  -  URL: http://www.mcilvainecompany.com/coronavirus/subscriber/Alerts/2020-06-10/Alert_20200610.html

4. McIlvaine Coronavirus Market Alert

... Solutions October 15, 2020 Experts say Masks are More Important Now than Vaccines but Fail ... "a 'fit test' tests the seal between the N95 mask's, or respirator's, ...

Terms matched: 2  -  Score: 318  -  16 Oct 2020  -  URL: http://www.mcilvainecompany.com/coronavirus/subscriber/Alerts/2020-10-15/Alert_20201015.html

5. McIlvaine Coronavirus Market Alert

... is the Leakage around a Typical N95 Mask Inward Leakage of Air into Face Masks is ... at protecting you because they are not sealed. The main reason surgical masks fail to ...

Terms matched: 2  -  Score: 314  -  6 Nov 2020  -  URL: http://www.mcilvainecompany.com/coronavirus/subscriber/Alerts/2020-11-05/Alert_20201105.html

6. McIlvaine Coronavirus Market Alert

... Filtration Resources Needed to Fight COVID Face Masks will be the Focus on Wednesday at the ... resistance [?P, cmH2O] across sealed surgical masks (means: 0.1865 and 0.1791 ...

Terms matched: 2  -  Score: 306  -  14 Dec 2020  -  URL: http://www.mcilvainecompany.com/coronavirus/subscriber/Alerts/2020-12-14/Alert_20201214.html

7. McIlvaine Coronavirus Market Alert

... of COVID Evolving to Resist Vaccines UK Mask Production Cleanroom Built on Accelerated Schedule Comfort and ... equipment was being installed the ceilings were sealed and the room tested and validated. From ...

Terms matched: 2  -  Score: 285  -  12 Nov 2020  -  URL: http://www.mcilvainecompany.com/coronavirus/subscriber/Alerts/2020-11-12/Alert_20201112.html

8. McIlvaine Coronavirus Market Alert

... has Delivery Problems Microwave can Sterilize N95 Masks Lots of Decontamination Investigations Lysol Approved as a ... is necessary and no matter how well sealed a class l cleanroom is it helps if ...

Terms matched: 2  -  Score: 284  -  14 Jul 2020  -  URL: http://www.mcilvainecompany.com/coronavirus/subscriber/Alerts/2020-07-13/Alert_20200713.html

9. McIlvaine Coronavirus Market Alert

... Technology Solutions August 18, 2020 Some Masks are Found to Generate Far Reaching Leakage Jets ... . Only masks that form a tight seal with the face were found to prevent the ...

Terms matched: 2  -  Score: 278  -  19 Aug 2020  -  URL: http://www.mcilvainecompany.com/coronavirus/subscriber/Alerts/2020-08-18/Alert_20200818.html

10. McIlvaine Coronavirus Market Alert

... , 2020 A $450 Billion Attractive Mask Market Airinum Supplies Masks with Valves Totobobo Masks ... be both comfortable to wear and also sealed around the edges to ensure that air only ...

Terms matched: 2  -  Score: 274  -  27 Oct 2020  -  URL: http://www.mcilvainecompany.com/coronavirus/subscriber/Alerts/2020-10-27/Alert_20201027.html

Result Pages: 1 2 3 4 5 6 Next >>

 One of the articles covers the Totobobo  mask which the manufacturer says can be used for  years because of its filter inserts and achieves a very tight fit.

A company in Thailand offers a face sealer for surgical masks which eliminates most of the leakage.

The Cross Strap Spongy Face Mask Sealer is not intended to be used alone, it is intended to be used on top of something else, such as a surgical mask to seal it. 

This may be an awkward solution but as a temporary option for people in Thailand and possibly elsewhere in the world it is far better than a lockdown.

The Banale reusable mask has filter inserts and emphasizes the tight fit design.

 

Determining Mask Fit and the Amount of Unfiltered Air

There has been very extensive testing of filter media. Fit testing for medical N 95 masks has been refined and is reliable. Both qualitative and quantitative tests are being used.

A few companies offering  masks to the public have done fit testing. It is very time consuming and expensive. There are four variables

·         mask design

·         number of different sizes available

·         individual face shapes

·         activities while using the mask

One company has five different mask sizes and has conducted fit testing through BSI Group (British Standards).

Alert November 5 - Surgical Mask Leakage Often Exceeds 25%

Surgical mask material is fairly good for trapping viruses, but surgical masks as normally worn by themselves are not very effective at protecting you because they are not sealed. The main reason surgical masks fail to protect people is air leakage around the mask, whereby viruses can just easily go around the mask and into your nose and mouth. The amount of air going around a mask is known as "total inward leakage (TIL)" in scientific research.

For example, a study of manikins wearing face masks showed that typical total inward leakage often exceeded 25%.

Alert November 16 - University of Tokyo; Net Efficiency: Cloth 17%, Surgical 47%, N95 79%

Researchers in Japan say they have confirmed that face masks are effective in both retarding the spread of viruses and reducing the intake of them. They used actual coronaviruses and mannequins to reach that conclusion.

The finding was made by a group led by Professor Kawaoka Yoshihiro and Project Assistant Professor Ueki Hiroshi at the University of Tokyo's Institute of Medical Science.

In their experiments, they placed two mannequins face-to-face in a laboratory. One was designed to discharge airborne droplets containing the coronaviruses. The other had a mechanism enabling it to take in air, imitating human breathing.

In one experiment, the researchers put a mask on the inhaling mannequin. They say the amount of viruses it absorbed was cut by 17 percent with a cloth mask and by 47 percent with an ordinary surgical mask. When they put an N95 medical mask on the mannequin so it fitted snugly, the amount declined by 79 percent.

Alert October 15 - University of Chicago -Vogmask 95%, Respro and Totobobo 85%

The 3M masks consistently performed the best in these tests. The Vogmask performed fairly well, capturing 95% of pollutants. Big-name masks like the Respro and Totobobo masks both captured less than 85% of pollutants.

It’s important to make clear: masks that fit my face well might not fit other people’s faces well. However, there is evidence from a broader population that masks fit most people well. A scientific study of 3M models on 22 Chinese people found a median fit score of 99.5%–essentially the same as the top results from Dr. Saint Cyr and me.

Alert July 28 - 66% Leakage with Chinese Masks

Chinese masks which showed that even if the efficiency rating was high, the leakage during normal activity could be 66%. Researchers first tested each mask’s filtration efficiency by drawing airborne diesel exhaust through a section of the material for 30 minutes and measuring the particulate matter and black carbon concentrations on both sides. They also tested four masks on 10 volunteers who were exposed to diesel exhaust in a lab while performing tasks such as talking, sitting, standing, bending over and walking in place.

In the filtration tests, the average particle and carbon penetration ranged from 0.26 percent to 29 percent, depending on the mask material. In the volunteers, the average leakage around mask edges ranged from 3 percent to 68 percent during sedentary tasks and 7 percent to 66 percent in active tasks. Only one mask had an average leakage below 10 percent in both active and sedentary tests.

Alert August 14 - With Leaks, Droplets Temporarily Captured are Later Transmitted

One of the subjects for discussion will be the measurement of one stop mask efficiency vs direct flight. An airline passenger can fly from Seattle to Atlanta where he infects the recipient.  Without a mask the Atlanta recipient receives the full virus load. But most Seattle to Atlanta flights stop in Denver. So in this example with the mask being Denver the full virus load lands in this hub. But what happens to it subsequently?

As the millions of deposited viruses start to evaporate or catch the flight from the hub some will end up in Atlanta but others will end up in Chicago and Dallas. In all likelihood an inefficient mask acts as a hub and distributes all the virus passengers in a cough in many different directions.

The original guidance of CDC that masks should be used primarily to catch the large cough and sneeze droplets is based on the assumption that it takes millions of viral particles to infect someone. Furthermore it was originally presumed that viruses will not be airborne and if they are they die quickly. All of these assumptions have been proven to be inaccurate.

With the one stop or hub and spoke flight pattern you more than likely have only thousands or hundreds of virus particles reaching  Kansas City or Albuquerque.

However, if every infected cougher is wearing a cloth mask there will be many transmitters generating hundreds or thousands of viral particles. The recipient may be receiving the millions of virus particles over time from many different transmitters.

Some studies in hospitals address the cumulative effect and conclude that it is significant. Others establish the long distance travel and survival of viruses. Other studies show that some viruses become dormant but are revived by the moisture in the lungs. This deep penetration can lead to more serious infection than larger virus droplets in the nasal passages.

Another way to analyze the problem would be the example of an infected healthcare worker and an elderly non infected patient. The worker is with the patient for an hour and coughs into a mask. Over the hour the patient may receive as many virus particles from the worker as he would have received in the initial cough if the health care worker had been mask less.

Alert November 25 - Vogmask Shows Inward Leakage of 2-8% with a Variety of Movements

Fit testing for the public requires a different system than for healthcare workers. For someone in a hospital setting there are both qualitative and quantitative fit testing methods. But they require tests of individuals.

For masks used by the public the best approach is to use a panel of people of different sizes, provide appropriate masks for each and then test leakage under various conditions.  One company has invested heavily in this approach.

Vogmask has Quantitatively Fit Tested human subjects to ensure the filtering efficiency is retained over a series of motions like walking, head movements, bending over, talking, etc. Here is a sample of the fit testing on Test Subjects.

  

The determination of a leakage rating is therefore more subjective and requires a different validation approach. An expert reviewing the Vogmask data would have confidence that the leakage range is within the 1-8% range.  It is therefore recommended that a validation group be formed to provide impartial judgements on data submitted by mask makers

Alert December 3/4 - Face Seal Leakage Documented for Surgical Masks

The efficiency and face seal leakage characteristics of two half masks equipped with particle filters or gas filters, and of two surgical masks were studied by means of a test head connected to a breathing machine. Filtration and leakage were studied as a function of particle size over a diameter range of 0.3-10 micron with corn oil aerosol and an optical particle counter. The filtration efficiency of the filter materials was good, over 95%, for particles above 5 micron in diameter but great variation existed for smaller particles. The face seal leakage was manifested as decreased efficiency for large particles and also for total mass, while the particles in the micrometer range contained the major part of the test aerosol mass. The particle number efficiency diagrams obtained can be used both in filter material studies and in leak detection of valves or filter housings

https://pubmed.ncbi.nlm.nih.gov/4014006/

Standard Masks Result in Twice the Leakage When Worn by Women

Computer modelling by researchers in the US reveals that standard recommended
face masks have more leaks when used by women.
Photo: Shutterstock

Standard face masks recommended by US health authorities are not a good fit for women – or the elderly or thin people, according to a new study.

Researchers led by Dr Kourosh Shoele at Florida State University found that masks recommended by the US Centres for Disease Control and Prevention to stop the spread of the coronavirus fit people with masculine facial features very well.

But “leakage” from the mask of the suggested size and design doubled when used by women because the protective equipment was too big. This was also the case with thin or elderly users.

“Different mask designs should be recommended for different categories of people, especially based on weight, age, and gender,” the team said in a non-peer-reviewed paper posted on the preprint site medRxiv.org 

Shoele’s team also found that a mask’s fit over the chin was a problem for people who were underweight. For the same reason, the elderly also had a greater gap than the young during routine daily activities such as talking and breathing, according to the computer simulation.

Women in the United States are already more likely than men to wear a face mask, according to a separate study.

They also do so with greater care. Across the US, more 55 per cent of women wore masks as recommended compared with 38 per cent of men, researchers at New York University and Yale University said in a paper published in the journal Behavioural Science and Policy.

 

An Inefficient Mask can be Worse Than No Mask

This is a conclusion of an article appearing last week in the American Institute of Physics. Air flow patterns when wearing inefficient masks are such as to cause more sub-micron particles to penetrate deeper into the respiratory system.

 

Pressure and particle motions with and without a mask. Credit: Jinxiang Xi

In Physics of Fluids, by AIP Publishing, researchers from the University of Massachusetts Lowell and California Baptist University examined the effect of wearing a three-layer surgical mask on inspiratory airflows and the mask’s effects on the inhalation and deposition of ambient particles in the upper respiratory airways.

“It is natural to think that wearing a mask, no matter new or old, should always be better than nothing. Our results show that this belief is only true for particles larger than 5 micrometers, but not for fine particles smaller than 2.5 micrometers,” said author Jinxiang Xi. (The SARS-CoV-2 virus that causes COVID-19 is about 0.1 micrometers. — ed.)

The researchers found that wearing a mask with low (less than 30%) filtration efficiency can be worse than wearing none.

They developed a computational face mask model using a physiologically realistic model of a person wearing a surgical mask with pleats and then using numerical methods to track the particles through the mask. They examined the behavior and fates of aerosols passing through the mask, onto the face, into the airway, and, eventually, where they deposit in the nose, pharynx, or deep lung.

The model showed a mask changes the airflow around the face, so that instead of air entering the mouth and nose through specific paths, air enters the mouth and nose through the entire mask surface but at lower speeds.

The lower speed near the face favors the inhalation of aerosols into the nose, so even though masks filter out certain numbers of particles, more particles escaping mask filtration can enter the respiratory tract.

They found the filtration efficiency of the three-layer surgical mask can vary from 65%, if new, to 25%, when used, so wearing a 65% mask properly will provide good protection but wearing a 25% filtration mask can be worse than not wearing one at all.

“We hope public health authorities strengthen the current preventative measures to curb COVID-19 transmission, like choosing a more effective mask, wearing it properly for the highest protection, and avoid using an excessively used or expired surgical mask,” said Xi.

The researchers found the pleats of a surgical face mask significantly affect airflow patterns, suggesting that mask shape should also be considered as an important factor when estimating mask protection efficiency and designing new masks. Xi said they will further study the effects of mask shapes on human airway protection efficiency.

Reference: “Effects of mask-wearing on the inhalability and deposition of airborne SARS-CoV-2 aerosols in human upper airway” by Jinxiang Xi, Xiuhua April Si and Ramaswamy Nagarajan, 15 December 2020, Physics of Fluids.
DOI: 10.1063/5.003458