Evaluating Cloth Masks and HVAC Filters as Aerosol Generators

Efficiency of Masks Compared

Let’s Review Mask Types

Two U.S N95 Sources Evaluated by FastLifeHacks

BSN Supplies Masks  for Surgical and Other Hospital Operations

Owens + Minor Doubling  N95 Mask Production

UV Part of Multi Tactic COVID Approach

______________________________________________________________________________

Evaluating Cloth Masks and HVAC Filters as Aerosol Generators

Bob Burkhead of Blue Heaven Technologies tests filters to determine efficiency. He has proposed that in addition to testing filters on a once through basis, they be tested over a period in which the exhaust is recycled back into a chamber and then refiltered.  This will show the true value of the filter. Multiple cycles will continue to reduce the particulate levels in the chamber as long as less new particulate is added to the system than is being extracted.

One of the important aspects is the ability to filter as the load of particulate increases. For filters relying on mechanical filtration, the filter efficiency may increase as will the pressure drop. For those filters relying on electrostatic charging there may be a loss in efficiency.

One aspect that also needs to be considered is the re-emission of captured viruses. If a MERV 8 filter captures a 20 micron cough or sneeze droplet what happens to it? It will evaporate and the vapor will pass through the filter. We need to establish what percentage of virus will also pass through. UCSD has done modeling of large cough droplets in the air (see our previous Alerts).  They form smaller droplets which contain virus.

The fate of cough and sneeze droplets is much more significant when captured in a cloth mask. We know from air pollution science that small particles bind with each other and are hard to separate. On the other hand changing rooms in Wuhan  show that particles do become airborne as they are dislodged from surfaces. But we also know that the evaporation of droplets will result in small aerosols. 

Relative to testing filters for aerosol generation it would seem that Bob has the ability to do so.  Relative to testing masks it would be a matter of testing mask emission over time. Possibly the control of droplets sprayed on the mask interior could be a variation of the blood splatter test.  Nelson Laboratories would certainly be one organization with this capability.

 

Efficiency of Masks Compared

Researchers at several universities collaborated on a study to compare mask efficiency vs percent of aerosols infective and time.

Comparing no protection (baseline) for 20-min and 30-s exposures, it was predicted that the mean risk of infection was reduced by 24–94% and 44–99% depending on the mask. Risk reductions decreased as exposure durations increased. The greatest reduction in estimated mean risk of infection was for FFP3 masks, which reduced baseline mean risks by 94% and 99% for 20-min and 30-s exposures, respectively (Figure 1). Of non-traditional materials, the vacuum cleaner bag resulted in the greatest reduction in mean risk of infection (20-min exposure 58%, 30-s exposure 83%), while scarves offered the lowest reduction (20-min exposure 24%, 30-s exposure 44%) (Figure 1). However, large variability in filtration,

There is a direct correlation between mask efficiency and infection risk This leads to the conclusion that mask choice can be as important as social distancing and other safety measures.  People should be advised not to just wear a mask but to wear the most efficient mask available.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7264937/

 

Let’s Review Mask Types

There is a technical difference between a “mask” and a “respirator”. In day to day language we often say mask, when referring to what are technically called respirators.

Uses for Masks:

§  Masks are loose fitting, covering the nose and mouth

§  Designed for one way protection, to capture bodily fluid leaving the wearer

§  Example – worn during surgery to prevent coughing, sneezing, etc. on the vulnerable patient

§  Contrary to belief, masks are NOT designed to protect the wearer

§  The vast majority of masks do not have a safety rating assigned to them (e.g. NIOSH or EN)

Uses for Respirators:

§  Respirators are tight fitting masks, designed to create a facial seal

§  Non-valved respirators provide good two way protection, by filtering both inflow and outflow of air

§  These are designed to protect the wearer (when worn properly), up to the safety rating of the mask

§  Available as disposable, half face or full face

§  The most commonly discussed respirator type is N95. This is an American standard managed by NIOSH – part of the Center for Disease Control (CDC).

§  Europe uses two different standards. The “filtering face piece” score (FFP) comes from EN standard 149:2001. Then EN 143 standard covers P1/P2/P3 ratings. Both standards are maintained by CEN (European Committee for Standardization).

Let’s see how all the different standards compare:

Some U.S. associations have found it useful to list all categories with N ratings. So an FFPI would be an N80. McIlvaine is forecasting revenues of respirator types by efficiency.

A good analysis of masks vs respirator from which some of the above material is excerpted is shown at https://fastlifehacks.com/n95-vs-ffp/?utm_source=wppp

 

Two U.S N95 Sources Evaluated by FastLifeHacks

Below the FastLifeHacks editor listed two US retailers who currently have stock, ship to mainland USA, and says he has bought from personally with no issues:

Health Bodyguard Store

KN95 rated respirators stocked in Ohio. From $4 to $6 per respirator, depending on quantity. See his brief review of their KN95 for more info.

 

N95 Mask Co
Stocking actual NIOSH approved N95 respirators. More expensive than KN95s, at $9 – $12 per respirator, depending on quantity.

They’re named “Respokare” (link) and are manufactured by Innonix, who are, crucially, on the NIOSH approved N95 manufacturer list here (scroll down to “Innonix”).

Note that N95 Mask Co ships the respirators direct from China (via UPS International Express). He received his five working days from initial order and will write a product review shortly.

 

BSN Supplies Masks for Surgical and Other Hospital Operations

BSN Medical is a global leader in the worldwide healthcare market specializing in Wound Care & related Vascular diseases, Lymphology and non-invasive Orthopedic products. It is home based in  Germany.

Founded in 2001, it is focused on the development of world-class branded products that offer high quality solutions for  caregivers and patients.

BSN medical aims to provide an integrated therapy-driven approach – grounded in a broad portfolio of products, enhanced by insights into current therapeutic areas and complemented by a progressive approach to partnerships.

BSN medical has production facilities in Germany, France, Mexico, Pakistan, South Africa, Colombia, New Zealand and the U.S, operating all over the world via affiliates, joint ventures and distribution agents.

Only facial masks with a high level of filtration performance can protect patients from infections. The mask should also be breathable and skin-friendly. The new Carpex^® OP mask assortment meets these requirements according the EN 14683.

The new Carpex^® OP mask assortment includes three different mask types as per the EU Standard. Three Carpex^® OP mask types, I, II and IIR are available with different levels of bacterial filtration efficiency, differential pressure and splash pressure resistance. The proven Carpex^® OP mask forms meet every demand, reasonable and reliably. The wearing comfort of the Carpex^® OP masks has also been improved.

Every new Carpex^® OP mask features a new, and particularly skin-friendly, inner cover stock. The material does not lose fibres and shows good pilling properties in use (lint-free).

·         reliable bacterial barrier

·         high level of filtration efficiency

·         particularly skin-friendly

·         breathable

Carpex^® OP masks prevent transmission of pathogenic microorganisms from the wearer to the environment:

·         in surgical applications

·         in ICU applications

·         in infection, premature and neonate ward applications

·         in delivery room applications

 

Owens + Minor Doubling N95 Mask Production

Owens & Minor, Inc. is a global healthcare solutions company with integrated technologies, products, and services aligned to deliver significant and sustained value for healthcare providers and manufacturers across the continuum of care. With approximately 15,400 dedicated teammates serving healthcare industry customers in 70 countries, Owens & Minor helps to reduce total costs across the supply chain by optimizing episode and point-of-care performance, freeing up capital and clinical resources, and managing contracts to optimize financial performance.

A FORTUNE 500 company, Owens & Minor was founded in 1882 in Richmond, Virginia, where it remains headquartered today. The Company has distribution, production, customer service and sales facilities located across the Asia Pacific region, Europe, Latin America, and North America. The company says that control over the supply chain provides a unique advantage as it continues to address unprecedented demand for PPE.  The company is a

• Leading manufacturer of surgical & infection prevention products with Americas based manufacturing footprint

 • Leading national distributor of medical surgical supplies to the acute care market

 • Leading distributor of medical supplies to the home healthcare market

• Strong operating cash flow; deleveraging balance sheet

• Pending sale of Movianto allows for debt pay down and increased focus on core business: distribution, products, and services

 • Nimbleness to adjust and leverage across all three pillars – distribution, products, and services

• Company recently reaffirmed guidance despite significant reduction in surgical procedures expected to continue through the end of Q2 with partial recovery expected in 2H20

 • Strong foundation established in 2019 and long term reinvestment in the business position the Company to generate sustainable, double-digit earnings growth beyond 2020

• Leading provider of PPE with Americas based manufacturing footprint

• Quickly aligned with customers, suppliers, and various state and federal agencies to optimize supply chain

• Significant increase in production of our PPE products 24/7 to meet increased demand

• N95 production increased > 300%

• Standard mask production increased > 50% • Isolation gown production increased > 300%

• Expect a negative impact on revenue for the remainder of 2020 due to net reduction in surgical procedures Q2-Q

Named by Department of Health & Human Services as one of five manufacturers to provide N95 respirator masks over the next 18 months

• Participated in Operation Local Production to supply 1 million cubic yards of fabric to NYC garment workers to make medical gowns for NYC hospitals • Working closely with FEMA’s Supply Chain Task Force

• Plan to double the production capacity of N95 respirators with the addition of multiple new production lines in Del Rio, TX

As demand continues to grow exponentially, the Virginia-based company is ramping up production of face masks and other medical gear to keep up, CEO Ed Pesicka told CNBC’s Jim Cramer Friday.

“We are in the process of actually expanding capacity, but that’s going to take probably 5 to 6 months to make sure that you have the capability to expand that capacity,” he said in a “Mad Money” interview. “So that’s the time frame that we’re looking at for additional expansion, beyond what we’ve done already by running 24/7.”

Pesicka said Owen & Minor, which operates both domestic and foreign facilities, in January began running plants nonstop and in February expanded to four daily shifts as hospitals needed more face masks and surgical gowns to care for an high rate of patients diagnosed with the novel COVID-19, which has spread from China to across the globe. The company is considering adding a fifth shift as not to “wear our employees out and our teammates out during this time,” the chief executive said.

For example, one hospital client in New York that used as many as 20,000 masks per week on average is now using as many as 300,000 weekly, Pesicka said. New York is the epicenter of the coronavirus epidemic in the U.S. and demand for a range of more medical equipment has been met by a shortage in supply, particularly of ventilators to help mitigate breathing complications caused by the deadly virus.

“That demand isn’t just here in the U.S. That demand is in other parts of the world, too,” Pesicka explained. “That global demand has increased exponentially.”

UV Part of Multi Tactic COVID Approach

Ultraviolet light technology is becoming more popular among companies who are implementing a multi-tactic approach to combat the coronavirus.

On July 29, JetBlue Airways revealed the Honeywell UV Cabin System, a robot the size of a beverage cart with arms that extend over the top of seats to sweep the cabin and treat aircraft surfaces. It can disinfect the entire cabin in roughly 10 minutes.

Troutbeck, a historic retreat set on 250 acres in New York’s Hudson Valley, upgraded all of the resort’s HVAC systems with a new HEPA filtration system that includes UV light for extra germ-fighting.

New York’s public transportation system, the Metropolitan Transportation Authority, worked with Columbia University to test UV light in vehicles and other fixed locations, such as break rooms and operation centers.

There are four subcategories to UV light based on their wavelengths: UVA, UVB, UVC and vacuum-UV.

UVA wavelengths are the longest and fall between 400 to 315 nanometers. Most of blacklight falls into this category, except for a small fraction that falls into the violet spectrum, which is why people using it see a purple color. 

On the other side of the spectrum, vacuum-UV has the shortest wavelengths Jim Malley, professor of civil and environmental engineering at the University of New Hampshire, said germicidal UVC light has been used for decades to disinfect surfaces and kill viruses.

While studies have yet to confirm if UVC light is able to kill SARS-CoV-2, the virus that causes COVID-19, multiple studies have shown that it can kill other viruses including influenza and other seasonal coronaviruses.

But, how can a light kill a virus? One theory, Malley said, is that the UVC light damages the virus’s RNA so that it is no longer able to reproduce and infect. It can also damage the protein that coats the virus, disabling it to attach to a host cell.

Typical germicidal UVC light kills viruses at a wavelength of 254 nanometers. However, all viruses are different and some respond to shorter or longer wavelengths. They also require a different UV dose, which is measured by light intensity and exposure time.

A recent study suggests there may be a spectrum of UVC light that kills viruses but isn't harmful to humans. 

Researchers at Columbia University Irving Medical Center found that more than 99.9% of seasonal coronaviruses present in airborne droplets were killed when exposed to a wavelength called far-UVC light at 222 nanometers. The results were published in June in the peer-reviewed journal Nature. 

According to the study, far-UVC light can't penetrate the tear layer of the eye or the outer dead-cell layer of skin. This means it's unable to reach and damage living cells in the body.

“Because it’s safe to use in occupied spaces like hospitals, buses, planes, trains, train stations, schools, restaurants, offices, theaters, gyms, and anywhere that people gather indoors, far-UVC light could be used in combination with other measures... to limit the transmission of SARS-CoV-2 and other viruses," said the study’s lead author David Brenner, director of the Center for Radiological Research at Columbia University Irving Medical Center.

https://www.usatoday.com/story/news/health/2020/08/03/covid-does-uv-light-kill-viruses-germs-what-to-know/5546413002/