Face Mask Technologies

This forum is to discuss general things concerning TSOI.
Posts: 2695
Joined: Fri Jun 26, 2020 5:22 am

Re: Face Mask Technologies

Post by trader32176 »

Study highlights the importance of mask fit when double masking to protect against COVID-19


https://www.news-medical.net/news/20210 ... ID-19.aspx

A study published today in JAMA Internal Medicine shows that wearing two face coverings can nearly double the effectiveness of filtering out SARS-CoV-2-sized particles, preventing them from reaching the wearer's nose and mouth and causing COVID-19. The reason for the enhanced filtration isn't so much adding layers of cloth, but eliminating any gaps or poor-fitting areas of a mask.

" The medical procedure masks are designed to have very good filtration potential based on their material, but the way they fit our faces isn't perfect."

- Emily Sickbert-Bennett, PhD, Associate Professor of Infectious Diseases, UNC School of Medicine and Study's Lead Author

To test the fitted filtration efficiency (FFE) of a range of masks, UNC researchers worked with James Samet, PhD, and colleagues in the USEPA Human Studies Facility on the campus of UNC-Chapel Hill. There they filled a 10-foot by 10-foot stainless-steel exposure chamber with small salt particle aerosols, and had researchers don combinations of masks to test how effective they were at keeping particles out of their breathing space.

Each individual mask or layered mask combination was fitted with a metal sample port, which was attached to tubing in the exposure chamber that measured the concentration of particles entering the breathing space underneath the researcher's mask. A second tube measured the ambient concentration of particles in the chamber. By measuring particle concentration in the breathing space underneath the mask compared to that in the chamber, researchers determined the FFE.

"We also had the researchers in the chamber undergo a series of range-of-motion activities to simulate the typical motions a person may do throughout their day - bending at the waist, talking, and looking left, right, up and down," said Phillip Clapp, PhD, an inhalation toxicologist in the UNC School of Medicine who has been testing mask FFE with Sickbert-Bennett since the pandemic began.

According to their findings, the baseline fitted filtration efficiency (FFE) of a mask differs person to person, due to each person's unique face and mask fit. But generally, a procedure mask without altering the fit, is about 40-60% effective at keeping COVID-19-sized particles out. A cloth mask is about 40% effective.

Their recent findings on doubling of face masks, shows that when a cloth mask is placed over a surgical mask, the FFE improved by about 20%, and improved even more with a snug-fitting, sleeve-type mask, such as a gaiter. When layered over procedure masks, cloth masks improve fit by eliminating gaps and holding the procedure mask closer to the face, consistently covering the nose and mouth. When a procedure mask is worn over a cloth mask, FFE improved by 16%.

"We've found that wearing two loosely fitted masks will not give you the filtration benefit that one, snug-fitting procedure mask will," Sickbert-Bennett said. "And with the current data supporting how effective mask-wearing is at preventing the spread of COVID-19, the best kind of double-masking is when you and the person you are interacting with are each correctly wearing a very snug-fitting mask."

This study was partially funded by a grant from the Centers for Disease Control and Prevention (CDC), and expands upon research conducted by the agency earlier this year, which supported the CDC's recommendation of double-masking to the public. Sickbert-Bennett and Clapp have previously discussed this recommendation and their research on the importance of mask fit with news outlets in a recorded conversation, which can be seen here.


University of North Carolina Health Care
Posts: 2695
Joined: Fri Jun 26, 2020 5:22 am

Re: Face Mask Technologies

Post by trader32176 »

Health Ranger posts new microscopy photos of covid swabs, covid masks and mysterious red and blue fibers


https://www.naturalnews.com/2021-04-25- ... ibers.html

What follows is a series of microscopy photos of covid swabs (a synthetic swab, then a cotton swab), a covid mask and some zoomed-in photos of mysterious red and blue fibers found in the masks.

The magnification range for these photos is 50X to 200X. Most were taken with white light, but several (as indicated) were taken with UV light.

The images shown here are 600 pixels wide. We have higher resolution images available to researchers and indy media journalists; contact us for those hi-res images.

More microscopy investigations are under way, and new images will be posted as they are finalized.

(Please refer to the original article for photos)
Posts: 2695
Joined: Fri Jun 26, 2020 5:22 am

Re: Face Mask Technologies

Post by trader32176 »

Disposable face masks release potentially dangerous chemical pollutants


https://www.news-medical.net/news/20210 ... tants.aspx

Swansea University scientists have uncovered potentially dangerous chemical pollutants that are released from disposable face masks when submerged in water.

The research reveals high levels of pollutants, including lead, antimony, and copper, within the silicon-based and plastic fibres of common disposable face masks.

The work is supported by the Institute for Innovative Materials, Processing and Numerical Technologies (IMPACT) and the SPECIFIC Innovation & Knowledge Centre

Project lead Dr Sarper Sarp of Swansea University College of Engineering said:

"All of us need to keep wearing masks as they are essential in ending the pandemic. But we also urgently need more research and regulation on mask production, so we can reduce any risks to the environment and human health".

Outlined in a recent paper, the tests carried out by the research team used a variety of masks - from standard plain face masks to novelty and festive masks for children with many currently being sold in UK retail outlets.

The rise in single-use masks, and the associated waste, due to the COVID-19 pandemic has been documented as a new cause of pollution. The study aimed to explore this direct link - with investigations to identify the level of toxic substances present.

The findings reveal significant levels of pollutants in all the masks tested - with micro/nano particles and heavy metals released into the water during all tests. Researchers conclude this will have a substantial environmental impact and, in addition, raise the question of the potential damage to public health - warning that repeated exposure could be hazardous as the substances found have known links to cell death, genotoxicity and cancer formation.

To combat this, the team advise further research and subsequent regulations be put in place in the manufacturing and testing process.

Project lead Dr Sarper Sarp explained:

" The production of disposable plastic face masks (DPFs) in China alone has reached approximately 200 million a day, in a global effort to tackle the spread of the new SARS-CoV-2 virus. However, improper and unregulated disposal of these DPFs is a plastic pollution problem we are already facing and will only continue to intensify."

"There is a concerning amount of evidence that suggests that DPFs waste can potentially have a substantial environmental impact by releasing pollutants simply by exposing them to water. Many of the toxic pollutants found in our research have bio-accumulative properties when released into the environment and our findings show that DPFs could be one of the main sources of these environmental contaminants during and after the Covid-19 pandemic.

It is, therefore, imperative that stricter regulations need to be enforced during manufacturing and disposal/recycling of DPFs to minimise the environmental impact.'

"There is also a need to understand the impact of such particle leaching on public health. One of the main concerns with these particles is that they were easily detached from face masks and leached into the water with no agitation, which suggests that these particles are mechanically unstable and readily available to be detached.

Therefore, a full investigation is necessary to determine the quantities and potential impacts of these particles leaching into the environment, and the levels being inhaled by users during normal breathing. This is a significant concern, especially for health care professionals, key workers, and children who are required to wear masks for large proportions of the working or school day."


Swansea University
Posts: 2695
Joined: Fri Jun 26, 2020 5:22 am

Re: Face Mask Technologies

Post by trader32176 »

Single-use face masks are a ticking time bomb of global pollution, experts warn


https://science.news/2021-05-07-face-ma ... perts.html

Single-use face masks are a ticking plastic bomb for the environment, according to a commentary published in Frontiers of Environmental Science and Engineering. Zhiyong Ren, a professor of civil and environmental engineering from Princeton University, and Elvis Xu, an environmental scientist from the University of Southern Denmark, authored the commentary.

Based on recent studies, the authors estimated that some 129 billion single-use face masks are used per month worldwide. This figure corresponds to three million masks used per minute. Most of these masks are made from plastic microfibers, typically ranging in size from five millimeters (mm) to microscopic lengths.

There have been increasing reports as well of the inappropriate disposal of soiled face masks. The authors said it is urgent to recognize single-use face masks as a potential environmental threat to prevent them from becoming the next big plastic problem.

Face masks could be worse than plastic bottles

More than 300 million tons of plastic were being produced worldwide per year before the pandemic. However, recent estimates show that face masks are now being produced worldwide at an unprecedented rate, with China leading the way.

In fact, China, now the world’s largest face mask producer, increased its face mask production by a factor of 10 last March to meet the surge in demand. That put the production of single-use face masks on a similar scale as plastic bottles. (Related: Plastic BAN List highlights the 9 top sources of plastic pollution.)

But unlike plastic bottles, single-use masks can neither be reused nor recycled. In fact, 25 percent of all bottles produced are recycled thanks to official guidance from local and national governments. On the other hand, there is no official guidance for the recycling of masks. So it’s not surprising that most soiled masks end up polluting both terrestrial and aquatic environments.

Moreover, the masks’ materials make them more likely to persist and accumulate in the environment. A single-use mask typically has three layers: a polyester outer layer, a polypropylene or polystyrene middle layer and an inner layer made of an absorbent material like cotton.

Polypropylene is notorious for being one of the most problematic plastics. It is typically used to produce various plastic products, such as plastic containers, reusable water bottles, plastic furniture, medical components, luggage and even car parts.

As a ubiquitous material, polypropylene is also typically found accumulating in the environment. According to Xu and Ren, masks are able to resist degradation even when subjected to heat and solar radiation in nature because of polypropylene’s recalcitrant properties.

They also explained that masks can generate large numbers of microscopic polypropylene particles as they become weathered in the environment. These particles can break down further into nanoplastics.

Products like plastic bottles and plastic bags would take centuries to break down into micro- and nanoplastics. But since single-use face masks are already made from micro-sized plastic fibers, they may release those fibers into the environment more readily, explained Xu and Ren.

The authors also pointed out that nanomasks could further compound this problem. Nanomasks are new-generation masks that use nano-sized plastic fibers to protect the wearer from inhaling pathogens. But as is the case with the standard single-use masks, these nanomasks may be another source of plastic pollution.

However, Xu and Ren said they do not know how masks contribute to the large number of plastic particles detected in the environment because no data on mask degradation in nature exists.

That said, it’s safe to assume that, like other plastic waste, masks accumulate in nature. They may even release harmful chemicals and pathogenic microorganisms that threaten plants, animals and humans.

Despite this grim outlook, Xu and Ren said there are several things that citizens, officials and scientists can do to minimize the impact of face masks on the environment. These include:

Set up mask-only trash bins for collection and disposal
Replace disposable masks with reusable ones
Develop biodegradable face masks
Consider standardization, guidelines and strict implementation of waste management for mask wastes
Posts: 2695
Joined: Fri Jun 26, 2020 5:22 am

Re: Face Mask Technologies

Post by trader32176 »

Scientists assess the filtration efficacy of 227 models of face masks sold in Brazil


https://www.news-medical.net/news/20210 ... razil.aspx

The novel coronavirus is transmitted mainly via inhalation of saliva droplets or respiratory secretions suspended in air, so that face covering and social distancing are the most effective ways to prevent COVID-19 until enough vaccines are available for all.

In Brazil, fabric masks are among the most widely used because they are cheap, reusable and available in several colors or designs. However, this type of face covering's capacity to filter aerosol particles of a size equivalent to the novel coronavirus can vary between 15% and 70%, according to a study conducted in Brazil by the University of São Paulo (USP).

The study was supported by FAPESP, and the principal investigator was Paulo Artaxo, a professor in the university's Physics Institute (IF-USP). It was part of an initiative called (respire! to assure access to safe masks for the university community. The results are reported in an article in the journal Aerosol Science and Technology.

" We appraised the filtration efficacy of 227 models sold by drugstores and other common types of store in Brazil to see how much genuine protection they afford the general public."

- Paulo Artaxo, Professor, Physics Institute (IF-USP), Agência FAPESP

The scientists conducted a test using a device that contained a sodium chloride solution and emitted aerosol particles of 100 nanometers. SARS-CoV-2 is about 120 nanometers in diameter. A burst of aerosols was triggered, and particle concentration was measured before and after the mask.

As expected, surgical masks were most effective in the test, as were the FFP2 or N95 models certified for professional use, filtering 90%-98% of the particles. Next came masks made of non-woven fabric (TNT) or polypropylene and sold in many kinds of store, with an efficiency of 80%-90%, followed by those made of ordinary cotton, spandex or microfiber, which filtered 40% on average (15%-70%).

Several factors were critical in enhancing or reducing the degree of protection. "Generally speaking, masks with a central seam protect less because the sewing machine makes holes that increase the passage of air. A tightly fitting top edge improves filtration significantly.

Some masks made of fabric include fibers of nickel, copper or other metals that inactivate the virus and hence protect the wearer more effectively.

There are even electrically charged models that retain more particles. In all cases, however, efficacy drops when the mask is washed because of wear and tear," said Fernando Morais, first author of the article. Morais is a PhD candidate at IF-USP and a researcher at the Nuclear and Energy Research Institute (IPEN), an agency of the São Paulo State Government.


According to Artaxo, dual-layer cotton masks filtered considerably better than single-layer models, but efficacy was hardly altered by a third layer, which reduced breathability.

"The study innovated in several ways. One was its evaluation of breathability or resistance to air passage," Artaxo said. "TNT and cotton masks were best in this regard. The FFP2 and N95 models were not as comfortable, but paper masks were the worst. This is important because if a person can't bear wearing a mask even for five minutes, it's useless."

The authors of the article note that although mask efficacy varies, all types help reduce transmission of the virus, and mask-wearing in conjunction with social distancing is fundamental to control the pandemic.

They advocate mass production of FFP2/N95 masks for distribution free of charge to the general public. This "should be considered in future pandemics", according to Vanderley John, penultimate author and coordinator of (respire!, which is organized by USP's Innovation Agency.

"Transmission of the virus is demonstrably airborne and wearing a mask all the time is one of the best prevention strategies, as well as leaving doors and windows open to ventilate rooms as much as possible," Artaxo said.


Fundação de Amparo à Pesquisa do Estado de São Paulo

Journal reference:

Morais, F. G., et al. (2021) Filtration efficiency of a large set of COVID-19 face masks commonly used in Brazil. Aerosol Science and Technology. doi.org/10.1080/02786826.2021.1915466.
Posts: 2695
Joined: Fri Jun 26, 2020 5:22 am

Re: Face Mask Technologies

Post by trader32176 »

Nanotech antimicrobial masks filter 99.9% of bacteria, viruses, and haze particles


https://phys.org/news/2021-06-nanotech- ... teria.html

Materials scientists from Nanyang Technological University, Singapore (NTU Singapore) have developed a reusable "nanotech mask" that can filter out 99.9 percent of bacteria, viruses and particulate matter (PM), as well as kill bacteria.

Its novel antimicrobial coating kills bacteria within 45 seconds and is effective for at least 144 hours (six days).

Its filtration efficiency surpasses those of N95 masks (95 percent filtration of PM0.3) and can be washed and reused over 10 times.

In mid-May, Singapore tightened its COVID-19 measures as the country was facing an increase in the number of infections, and the population was advised to use face masks with high filtration capability to help curb the spread of the coronavirus.

The made-in-NTU mask comprises two key components: an antimicrobial coating made from copper nanoparticles developed and patented by Professor Lam Yeng Ming, coated on a fabric mask invented by Associate Professor Liu Zheng, which has a unique dielectric property that attracts all nanoparticles and germs.

Prof Lam, who is also the Chair of NTU's School of Materials Science and Engineering, said their mask prototype combines the two most desired properties needed to fight COVID-19, into a single filter.

"In experiments, our copper nanoparticle coating has an extremely fast and sustained antibacterial activity, with a killing efficiency of up to 99.9 percent when it meets multi-drug resistant bacteria. This coating will help to reduce the spread of bacteria as it kills microbes in droplets trapped by the mask fibers, which provide excellent filtration efficiency. This should give users a double layer of protection compared to conventional surgical masks," explained Prof Lam.

Experiments on the antibacterial effectiveness of the mask were conducted in collaboration with scientists from the National University of Singapore (NUS). They simulated real-life conditions by introducing multi-drug resistant bacteria in droplet form onfabric surfaces and observed that almost all the bacteria were dead by 45 seconds.

The reason for the effectiveness of the antimicrobial coating was two-fold: the first is the extremely small size of the nanoparticles, which are about 1,000 times smaller than the width of a human hair. Collectively, millions of nanoparticles provide a huge surface area for the viruses and bacteria to contact, compared to bigger particles.

The second is the high level of oxidative damage caused by the copper oxide material. Copper oxide induces the generation of reactive oxygen species, resulting in DNA damage of important cell structures in the bacteria, such as the cell membrane, severely damaging it and causing the bacteria to die.

To make it easy to apply, the antimicrobial nanoparticle solution is designed to be spray-coated on all soft and hard surfaces.

Various peer-reviewed studies have shown that copper oxide is effective in killing viruses, such as the recent study published in ACS Applied Materials & Interfaces by The University of Hong Kong and Virginia Tech, where door handles were coated with a layer of copper oxide material.

The NTU team tested their nanoparticle coating in harsh conditions for120 washing cycles(inthe presence of soap or its active componentsat 45 degC) and found that there was almost no copper loss—posing very little risk of toxicity to humans.

The nanoparticles are also bonded to the fibers within the mask, so there is no contact with human skin when the mask is worn.

Superior trapping capabilities of the mask

Killing viruses and bacteria would only work if the mask is able to trap and stop them from passing through. This is where Assoc Prof Liu's breakthrough came in handy.

Last year, his team developed a way to integrate dielectric materials to plastic fibers during the manufacturing process of an unwoven fabric filter made from Polypropylene (PP), commonly used in disposable surgical masks used by hospitals. This was done in collaboration with Prof Guan Li from the Renmin University of China.

The dielectric materials have excellent electrostatic capabilities, which can attract and bind to particles possessing a negative or positive charge, similar to how magnets attract metal particles.

Made from fibers with a diameter of 200 to 300 nanometres, the mask has a higher surface area that lowers the breathing resistance—making it easy for its wearer to breathe as compared to conventional N95 respirators, which are denser.

In tests, the next-generation dielectric composite fabric had 50 percent higher filtration efficiency than pure PP masks, which are commonly rated at 95 percent BFE (Bacterial Filtration Efficiency).

Assoc Prof Liu said: "With our new composite filter, we can achieve up to 99.9 percent BFE, trapping almost all microbes and particulate matter from smoke or haze. Its filtration efficiency surpasses a N95 mask but allows the wearer to breathe much easier.

"More importantly, it can be mass-produced easily using the current production process. It is also washable for more than 10 times before losing filtration efficiency, making it more sustainable than current one-use disposable masks."

In experiments, the mask was able to attract and trap a broad range of particulate matter: from PM10 (average particle size of 10 microns) to PM0.3 (0.3 microns—about 0.3 percent the diameter of a human hair) with a filtration efficiency of 99.9 percent.

The antimicrobial coating has a patent filed through NTU's enterprise and innovation company, NTUitive, and Prof Lam's team is already working with a local company to coat it on their products.

Assoc Prof Liu's dielectric composite fabric material is now used by an overseas manufacturer to make N95 masks that are as easy to breathe as disposable surgical masks and are available commercially.

The team is now looking to work with local industry partners who are keen to license and scale up the production of their 2-in-1 mask and are currently preparing scientific papers for submission in scientific journals.

NTU scientists have been working on developing solutions in the global fight against COVID-19.

These include innovations such as autonomous disinfection robots, COVID-19 rapid test kits and a breathalyzer device, a smart mask, antimicrobial coatings, as well as fundamental research on the coronavirus to find new drug targets for treatment and vaccine development.

Healthcare is one of humanity's grand challenges that NTU seeks to address under theNTU 2025 strategic plan.

More information: Mohsen Hosseini et al, Cupric Oxide Coating That Rapidly Reduces Infection by SARS-CoV-2 via Solids, ACS Applied Materials & Interfaces (2021). DOI: 10.1021/acsami.0c19465
Post Reply