Coronavirus Technology Solutions
December 9, 2020

 

People With Severe Allergies Will Not Receive the Vaccine

New Coronavirus Cases in Seattle Jail with MERV 10 Filters

ASTM Base Efficiency Requirement can be Combined With More Efficient Masks to Greatly Reduce COVID Transmission

ASTM Working with CDC on a Minimum 20% Efficiency Mask

Are Nanofiber Media Masks More Comfortable?

International Filtration News Insights

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People With Severe Allergies Will Not Receive the Vaccine

People with a history of significant allergic reactions should not have the Pfizer/BioNTech Covid jab, regulators say. It came after two NHS workers had allergic reactions on Tuesday. The advice applies to those who have had reactions to medicines, food or vaccines, the Medicines and Healthcare products Regulatory Agency said.


The two people had a reaction shortly after having the new jab, had treatment and are both fine now. They are understood to have had an anaphylactoid reaction, which tends to involve a skin rash, breathlessness and sometimes a drop in blood pressure. This is not the same as anaphylaxis which can be fatal. Both NHS workers have a history of serious allergies and carry adrenaline pens around with them.

In terms of needs for HVAC and masks this new development needs to be taken into account.
 

·      Worldwide, adverse drug reactions may affect up to 10% of the world’s population. 

·      Worldwide, the rise in prevalence of allergic diseases has continued in the industrialized world for more than 50 years.

·      Worldwide, sensitization rates to one or more common allergens among school children are currently approaching 40%-50%.

It is possible that other vaccines will be recommended for these individuals. Another variable is the length of vaccine protection. Is it months or years? A third variable is infection transmission from vaccinated patients. All of these impact the long term filtration needs.

 

New Coronavirus Cases in Seattle Jail with MERV 10 Filters

King County Jail’s downtown Seattle location has confirmed 16 new cases of COVID-19, according to a press release sent to reporters on the afternoon of Dec. 7.

The press release said that an inmate at the jail “reported flu-like symptoms” on Dec. 6. This person had been at the jail for more than a month, and initially tested negative, when they were first jailed, the press release said. 

This means that this person caught the novel coronavirus and developed COVID-19, while they were in jail.

The press release said that everyone jailed in the same unit — all adults — was tested as soon as the case was reported. Of the 69 people jailed in the same unit, 15 others tested positive for COVID-19. The press release said that these 15 people have been “transferred to medical isolation at the Maleng Regional Justice Center [MRJC] in Kent. The other 54 have been placed in quarantine housing at [King County Correctional Facility].”

“This is the first time we have confirmed cases of COVID-19 from coronavirus exposures that occurred within our jails,” the press release said. “Public Health contact tracers are working to identify any inmates, staff or visitors who may have had close contact with the recently identified cases among our in-custody population. Before testing positive, this inmate had been in a wing that houses inmate-workers – those who help in jail operations.”

In an email to the Emerald on Dec. 8, King County Jail Public Information Officer Noah Haglund said that those who tested positive were between the ages of 20 and 54. This falls in line with the state Department of Health’s demographics chart that shows this age range currently has the highest case rate throughout the state.

The press release also said that staff have decontaminated the wing of the jail where the sick people had been jailed, as well as hallways, elevators, and transport vehicles they may have used.

Haglund said in his Dec. 8 email that “cleaning and disinfection occurs daily in all areas of the jail facilities. Paper towels and disinfectant are available in general population for inmates to do additional cleaning as necessary.” However, he did not address the Emerald‘s question regarding exactly what cleaning procedures were in place before the outbreak, and if they have changed since.

He also said that those jailed at the Seattle King County Jail “receive, at minimum, a clean cloth mask daily. These masks have two layers. Cloths masks are washed and dried in the jail’s laundry program following industry standards.”

In response to the Emerald‘s question about what kinds of masks those in quarantine receive, Haglund said that “inmates identified as droplet precaution and COVID+ receive surgical (procedure masks) prior to their transfer to droplet precaution and COVID+ housing. Inmates in quarantine – those who test negative for COVID, but who have been in close contact with someone who tested positive – currently receive cloth masks.”

He did not address the contention by protestors who were jailed over the summer that they were denied clean masks.

The press release said that there had been 47 total cases of COVID-19 amongst its jail staff and inmates, before this past weekend’s outbreak. It also claims that the King County jail system has been taking “aggressive” measures to prevent and limit infection.

This past summer, the King County Jail was in the process of upgrading its MERV 10 filters to MERV 13 filters with the aim of finishing by August, Haglund told the Emerald in a July 21 email. The United States’ Environmental Protection Agency webpage on the topic of indoor air filters that can help protect people from COVID-19 says that MERV 13 filters — the highest-rated kinds of filters — can “trap smaller particles, including viruses.”

In the July 21 email, Haglund also said that the jail’s 13 medical cells were “designed with positive-airflow capability,” which means that air can leave the room without circulating back in, filtering out any airborne particles that originate in the rooms.

When asked how those who tested positive were being housed, given that there were only 13 such cells available, Haglund said that there is a 32-bed unit at the MRJC “dedicated for housing COVID+ inmates.”

“Medical isolation for COVID+ patients does not require directional airflow. Patients who test positive for COVID-19 are housed in individual cells and are kept separate from direct interactions with other patients,” Haglund said.

Haglund said that the 54 people who tested negative were not given their own cells at the King County Jail in downtown Seattle.

“The inmates will remain in dorms and continue to maintain social distancing, wear masks, clean and disinfect daily and as appropriate, and quarantine in place for up to 14 days,” he said.

It is unclear how people jailed at the King County Jail could maintain social distance, if they are sharing cells, but the Emerald has followed up with this question. It has also asked again what cleaning procedures are in place, both at the King County Jail and at the MRJC.



ASTM Base Efficiency Requirement can be Combined With More Efficient Masks to Greatly Reduce COVID Transmission


There are presently many masks being worn where even with a perfect fit the efficiency will be well less than 20%.  So an ASTM standard which would result in all masks being somewhat effective will be a contribution. With CATER Mask Decisions we hope to guide a majority of purchasers to purchase much more efficient masks. 

 

Mask Efficiency by Percentage of Wearers

At the very least we should be able to achieve a distribution where 20% are wearing masks which are 80% efficient or greater and 10% are wearing very efficient masks. The masks are part of the swiss cheese defense program. The fewer holes in the mask layer, the less need there is to eliminate holes in the ventilation layer or in quarantine.

The ASTM working group struggled to find compromise on inward leakage testing. There is no consideration of quality control. So the reality in terms of virus protection ranges roughly from 5 to 80%


 

Mask Effectiveness by Percentage of Wearers

It is therefore important that the ASTM standard be supplemented by evaluation systems which provide net effectiveness even if it is a range such as shown in the following chart.

 

Effectiveness Rating  %

 

Minimum

Maximum

Level 1

0

10

Level 2

10

30

Level 3

50

70

Level 4

70

95

 

This effectiveness rating could be  net efficiency as calculated in the following example.

Mask

Efficiency %

Unfiltered %

Defects

Net Efficiency %

CATER 99

98-99

-2-8

0-1

89-97

CATER 95

92-97

-2-8

0-1

83-95

CATER 93

90-95

-2-8

0-1

82-93

Cloth

50-60

-30-50

5-10

15-37

Surgical

92-97

-25-40

0-1

40-72

 

 

ASTM Working with CDC on a Minimum 20% Efficiency Mask

Obtaining agreement of mask standards is difficult considering the revenues for inefficient masks are many billions of dollars per year. So the fact that ASTM has been working with CDC and can probably have a consensus on a minimum 20% efficiency mask is significant.  Also the clarification of methods to test efficiency is also an important part of the effort

This week the group received a  request to vote on Ballot Action: Working Draft #7, Standard Specification for Barrier Face Coverings


This draft incorporates recommended changes from the work group provided on Draft #6. A number of specific changes have been made in response to recent teleconferences to find potential areas of consensus. Many of these comments are substantial particularly as related to leakage assessment, labeling, and conformity assessment.

Here are some  of the notes and clauses relative to leakage assessment.

Note 4 – The leakage assessment represents the total inward leakage likely to occur during wear.  Whether measured quantitatively or assessed qualitatively, the leakage assessment does not represent the likely outward leakage of particles generated by the wearer. Thus, no claims may be made with respect to the degree of source control offering by the barrier face covering based on the leakage assessment.

Note 5 – Leakage assessment, if measured quantitatively on a barrier face covering that rests closely on the face and thus has minimal inward volume, may not be representative of true inward leakage.

4.1.3 Sub-micron particulate filtration efficiency and air flow resistance do not account for the leakage of air around the perimeter of the barrier face covering. A leakage assessment using a design analysis of the product is required to assess the ability of the barrier face covering design to minimize inward leakage and provide appropriate coverage for a range of wearer faces of different dimensions. The design analysis can be conducted by the manufacturer in a number of different ways. The standard also permits supplemental the use of quantitative information obtained from a modified form of Test Method F3407 using test subjects. This test yields a reportable ratio of outside particulate concentration to the concentration of particles in the wearer’s breathing zone. Thus, a leakage ratio of 1.0 indicates the outside and inside environments are equal and that particulate flow through gaps in the barrier face covering (in addition to any particulate that pass through the filtration materials of the product

5.4 Leakage Assessment

5.4.1 The leakage assessment shall be reported by the manufacturer through a product design analysis self-declaration. 

5.4.2 The required self-declaration shall report that the product minimizes leakage around the edges or other areas of the product based upon an analysis of the product design. This statement can be included on any self-declaration required as part of Guide F3050, under Section 12 of this specification.   

5.4.2.1 The manufacturer is permitted to conduct quantitative testing  to supplement its product design analysis self-declaration. When used, the leakage ratio shall be evaluated using Test Method F3407, with the modifications specified in 8.3.

5.4.3 Where barrier face coverings are reusable and intended for laundering or cleaning, the product design analysis shall be applied to barrier face coverings both in a new condition and after the maximum of laundering or cleaning cycles as specified by the manufacturer according to the manufacturer care instructions.

Note 13 – Examples of means to accomplish a leakage assessment could include dimensional analysis, computer modeling, placement of barrier face coverings on standardized head or head-torso forms and judging their respective areas of coverage and conformity to the head or head-torso form face showing conformance to the fit and sizing characterizations of AATCC M14-2020, or performing a quantitative analysis.[1]

A minimum particulate efficiency is cited

 

Performance Property

Criteria

Test Method Section

Sub-micron particulate filtration efficiency

≥ 20%

8.1

Air flow resistance, inhalation

≤ 15 mm H2O

8.2

 

Subsequently in the draft is an example showing  a better level 2 performance.

TABLE 2 Separate Classification of Face Covering Performance PropertiesA

 

Performance Property

Level 1 (Acceptable)

Level 2 (Better)

Sub-micron particulate filtration efficiency

(Effectiveness of barrier face covering for capturing small particles from wearer; larger percentages indicate higher performance)

≥ 20%

≥ 50%

Air flow resistance

(Indicative of ease of breathing while wearing barrier face covering; lower resistances indicate more breathable products)

≤ 15 mm H2O

 ≤ 5 mm H2O

 

This ASTM standard is a sign of progress.  It alerts buyers that all masks are not equal. Suppliers of 95% efficient masks with less than 8% inward leakage can use this standard as a base and provide evidence as to why their product achieves their claims,

 

Are Nanofiber Media Masks More Comfortable?

Revolution fibres make a  case that not only do nanofibers have efficiency and breathability advantages they are also more comfortable.

Nanofibers are incredibly small, synthetic fibers – each measuring one thousand times thinner than a human hair. Nanofibers form complex strength through spiderweb-like structures, which have an advantage over conventional or even natural fibers due to their extraordinarily large surface area and tiny pore size. This combination creates maximum air flow and particle capture – significantly more than other synthetic or natural filters, achieving greater efficiency down to PM0.3 microns. 

Nanofiber closeup

 

This image helps us visualize the size of a nanofiber when compared to both hair and a speck of pollen:

 

Its small size provides an array of benefits when utilized in face mask technology – including advanced protection and better comfort.

Featuring a weaving design closely packed together so microscopically that we are unable to see them with the human eye, nanofibers craft a small pore size and high surface-to-volume ratio. This means the surface area and pores of a face mask with nanofiber technology will not allow cells to pass through to reach the wearer. Simply, due to the unique and tough threading of the nanofibers, everyday dangers such as pollution, viruses, bacteria and more will be unable to cross the threshold of the mask, thereby enhancing protection from the outside world. Not even water or liquid can penetrate the surface, which is why it is such an essential component of any truly effective face mask.

Additionally, this works two ways, as a mask is not only a protector of the individual wearing the mask, but it also serves to halt the spread of germs as well. When you’re sick, you should have a mask on – especially if there are other people in your household or if you are traveling out to an appointment with a doctor. Nanofibers block larger cells from escaping the mask, which helps to ensure less spread of any unpleasant or harmful ailment to unsuspecting passersby or loved ones.

While many are aware of the advanced protection that nanofibers provide in face mask technology, what may come as a surprise is that this material is also significantly more comfortable than other fibers. The complexity of the microscopic hair-like design makes the mask lightweight and, therefore, extremely breathable. It’s not simply a cloth over your face – it’s a material that works with your body to trap cells out but allow air to flow in, so you don’t feel cramped or suffocated. This also allows for better temperature regulation. More airflow means less of a “humid” feeling, as if the mask were a part of your face rather than your face feeling as if it’s sweating into the mask. The light, soft and airy material of nanofibers ensures both short-term and long-term wear is much more comfortable.

Overall, nanofibers have revolutionized the way we keep people safe – with transformational applications in healthcare advancements such as tissue engineering, wound dressings, face masks and more.

 

International Filtration News Insights

International Filtration News has lots of good information relative to masks We work closely with Matt Migliore who is the editor. He just wrote an article on nanofibers which is quite relevant. Here are some excerpts.

According to Dr. Vijayakumar, to truly deliver on the benefits of increased efficiency and decreased resistance in the filter, nanofibers need to be in the ~100nm size range.

 

NXTNANO’s HYPR spinning production process is capable of scaling to produce approximately 150 million square meters of Level 1 mask material per year, according to McDowell. Described as a derivative of electrospinning, the HYPR spinning process allows NXTNANO to produce more and finer fiber, more consistently, and with better bonding than other nanofiber material options on the market. It also permits flexibility to spin multiple polymers simultaneously. “All of the general issues you would see with electrospinning we think we’ve pretty well solved; for throughput, controllability, and uptime,” said McDowell.

 

You can find the full article at  

https://www.filtnews.com/nanofiber-filtration-challenges-and-opportunities/

 

There is an important article by Adrian Wilson titled Facemask materials, surface treatments, intelligent sensors & carbon nanotubes. Here is an excerpt.

NWI executive director Benham Pourdeyhimi explained that the new media development arose from reactivated work on microfibrillation, which was initially undertaken for the filtration industry.

N95 efficiency can be achieved with just two layers of the new spunbond fabric. A combination of one spunbond layer and a meltblown layer can further achieve N99 efficiency.

The media also requires no electrostatic charging, which has been another bottleneck in the production of facemasks this year, and, because the materials are strong – unlike traditional meltblown materials – they can also be cut and sewn by traditional techniques. Further, they have the potential to be reused a number of times after cleaning.

The full article is found at   https://www.filtnews.com/filtration-innovations-in-2020/