WFI Covered Mask Selection and Filter Testing Today

Courtesy Protective Masks for Colds is a Huge CATER Market

Mann + Hummel Air Purifiers are Suitable for Rooms Up to 200 m2

Study Proves Effectiveness of Mobile Air Purifiers

Filti Introduces Home Air Purifier

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WFI Covered Mask Selection and Filter Testing Today

Waterloo Filtration Institute in a virtual conference today covered a range of mask testing subjects followed by analyses of test methods and testing approaches. There was lots of activity in the chat room accompanying the presentations. For example what happens to a droplet  captured on a mask or filter? The consensus was that although the droplet may evaporate and cause virus to escape from a mask it is already dried out and in the salt form when it reaches the HVAC Filter.

But wait a minute you cannot on one hand say that virus aerosols reaching the filter are between 1 and 10 microns and at the same time say that what is reaching the filter are sub-micron salts.  So this discussion is worth a separate webinar.

Here is a report of the speeches.

Specifications and Ideal Performance of Masks for Protection against COVID-19, Dr. Peter Tsai, Univ of Tenn.

General: The masks used to protect against COVID-19 are cloth, three-fold, and N95. Cloth and threefold do not have tight fit, usually called a mask, but N95 does, usually called a respirator. In addition, N95 has a submicron efficiency of 95% or higher based on 42 CFR Part 84. Some three-fold masks like cloth masks do not have specifications for general use. The specifications of medical masks are based on ASTM F2100-19.Electrostatically-charged meltblown microfiber fabrics are commonly used to achieve the specifications of the masks and the respirators. Charges can be retained for longer than ten years. Depending on the charging method, the efficiency can be ten or 20 times improved compared to the uncharged one at the same basis weight and pressure drop. The measured surface charge potential shows that the charged media is a bipolar electret. Therefore, it attracts both positive and negative particles by Columbic force, as well as neutral particles by image force. Several N95 sterilization methods have been validated by NIH, in which some will degrade the charges and/or the shape of the respirators, while others will not. Cloth masks are primarily used to block the virus. Nonwoven media can block and filter the virus. The combination of cloth sandwiched with a nonwoven filter is an ideal design of DIY masks.

Insight: The fact that the efficiency can be improved by better charging and that the effectiveness of the mask can be nine years or more is a significant improvement. Masks subjected to hydrocharging showed efficiencies at 99.98% efficiency and only 2.5 mm H20 resistance.

Respiratory Filtration using Nanofibers, Dr. Jayesh Doshi, eSpin

General: Covid-19 has created massive demand for masks and air filters resulting in a shortfall of nonwoven filtration media all over the world. Nanofibers has become material of choice for many mask manufacturers as a result of its ability to capture small aerosol drops while providing superior breathability. This presentation covered nanofiber media production for face masks and air filters to rapid prototyping and manufacturing of masks and respirator filters.

Insight: Nanofiber layer is added to a MERV 8 substrate to achieve MERV 13 efficiency. Production has increased 40 fold to meet demands in both air filters and masks.

Fashion in Efficient Consumer Masks, Wendover Brown, Ohlone Press, LLC, Creator of Vogmask®

Face masks have played an increasingly critical role in keeping people safe during the current pandemic. It has become a new norm to wear masks and there is a clear trend of fashion design in the efficient, comfortable, and reusable face masks. Since 2011, Vogmask® has provided filtering face masks for helping to protect from microscopic airborne particles in poor air quality, natural disaster, dust, mold, and biologics, while supporting clean air awareness efforts worldwide. Vogmask is highly efficient for filtering 0.3-micron particles, tight-fitting for a good seal, comfortable to wear with easy breathing, available in many designs, and manufactured under Quality Plan for confirming safe and effective products. In this presentation, the importance of design in consumer masks for protection, comfort, compliance, and sustainability was addressed.

Insight: Vogmask does not claim to be certified for medical or workplace environments but it has taken advantage of test methods used in these applications to insure that its masks are Comfortable, Attractive, Tight Fitting, and Efficient.  The masks are used  for a variety of applications including volcanic dust, wildfires, poor air quality, asthma, allergies, travel, and outdoor work

Pandem-trepreneurship, Mike Atkinson, T3Gear

General: T3gear.com has some of most flexible sewing capacity in the U.S. It designed a cut and sewn mask with high efficiency

Insight: The Readimask has a silicone seal which is strong enough that ear loops are not required and leakage is minimal. The company also sells inefficient cloth masks and questions why local, State, and National decision makers are not requiring high efficiency.

Latest Update of HVAC Air Cleaner Testing, Kathleen Owen, ASHRAE Fellow and 52.2 Chair

General: This talk was of a work in progress with an update on the recommendations for using filtration to battle COVID19 and on filter test methods.  Kathleen referred us to the new guidance from the Emergency Task Force document from ASHRAE

Insight:  SARS-CoV-2 virus, and other similar pathogens, may spread through various transmission routes, including direct or indirect contact with contaminated surfaces and exposure to respiratory droplets. While not initially considered, more data are becoming available that indicates that the potential for exposure from aerosolized particles must also be addressed. Both the World Health Organization (WHO) and the Center for Disease Control (CDC) have now made public statements recognizing the potential for airborne transmission. This has led to ASHRAE developing the formal position (https://www.ashrae.org/technical-resources/ashraestatement-regarding-transmission-of-sars-cov-2

Transmission of SARS-CoV-2 through the air is sufficiently likely that airborne exposure to the virus should be controlled. Changes to building operations, including the operation of heating ventilation, and air conditioning systems, can reduce airborne exposures.

Initially, the laboratory environment was considered low risk for aerosol transmission because these facilities are already designed with the safety of occupants as a key performance indictor; typically through the use of 100% outside air (i.e., no recirculation) supply systems, higher air change rates, and exhaust systems designed to minimize re-entrainment of contaminated air. However, these same systems provide unique operating conditions that require distinct mitigation strategies to minimize the risk of transmission of aerosolized particles.

Several recommended mitigation strategies that may be prudent for other building types should not be employed in a lab environment because they may adversely impact the air flow patterns within the lab and/or the performance of existing containment devices. Therefore, the objective of a new document is to address the mitigation strategies that are unique to the laboratory environment and to define those strategies that may be applicable to non-lab environments that should not be implemented within a laboratory or to its HVAC systems.

Comparing test methods for respirators, medical masks and barrier face covering to improvised methods used during COVID-19, Tim Johnson, TSI

General: The masks used to protect against COVID-19 have varied widely. There are 3 main categories. NIOSH approved respirators, Medical masks (ASTM method and FDA requirements) and face coverings (not currently covered by any standard). These are tested to different standards and methods. There has recently been an effort to standardize how these devices are tested. In thi the different test methods and the changes that are occurring to standardize at least some aspects of how the testing is done were described. Within the ASTM standards there is a proposal out for ballot to adopt a version of the NIOSH respirator test method for PFE (particulate filter efficiency) testing in place of the method of using PSL particles and optical particle counters that has been used until now. Tim gave an update on the status of that proposed change. There is also an ASTM task group working on a standard for testing barrier face coverings for use by the general public. Tim discussed the status of this effort. If this proposal does become a standard it will create a category of face coverings that have the potential to be significantly better in terms of source control and protection for the user compared to the many products that have been in use during the pandemic.

Insight: Many people do not understand the difference between the 0.3 micron rating for minimum particle penetration size and the fact that the actual testing is on the capture of particles only 0.075 microns in diameter.

An outline of current medical face mask performance requirements and testing, Janelle R. Bentz, Nelson Labs

General: Medical face masks and respirators have taken the spotlight during the current pandemic. With the increased emphasis on wearing of face coverings an understanding of the testing required for approval of these products is imperative. An understanding of the difference between these two products and the test methods used to prove compliance is important for choosing the appropriate product to ensure the right mask is used for each purpose. Test methods can range from simple air differential tests to complicated bacterial filtration efficiency tests; each of these tests gives important information about the functionality of the product. Medical face masks are manufactured and tested with the patient in mind, and testing demonstrates this. Testing for these products is directed toward expected conditions in a medical environment, and includes bacterial filtration efficiency testing, flammability testing, and synthetic blood penetration testing. NIOSH approved respirators are generally used in industrial settings and are meant to protect the user. Testing for these products focuses more on expected conditions when protection is needed from small particulates.

Insight: There are many different tests and approaches to determining efficiency.  There are many formulas for ways to normalize the diameter of particles which are not spheres or to count the particles on a plate in an Anderson Sampler. In this case testing labs rely on a formula created by the cascade impact sampler supplier. As a result no numbers should be considered to be absolute.

In-Place Measure, Monitor and Manage Air Filtration System Associated with COVID-19, Stephen Nicholas, Past President of NAFA, Life Member of ASHRAE

General: The presentation highlighted the updates of air filtration requirements associated with COVID-19 for actual field applications, such as hospitals and schools. Guidelines and examples were provided on how to select air filters and schedule filter change-out, and how to select proper air filter clips, latches, and gaskets to insure an airtight filter seal. Three T’s (Technical Tips – Tricks of the Trade and Traps to Avoid) and 3M’s (Measure, Monitor and Manage) to secure an effective air filtration system were discussed.

Insight:  Used hospital filters do not have to be treated as toxic waste but can be doused with bleach and then discarded in bags.  Some hospitals have installed HEPA filters in the HVAC systems but the pressure drop can be several inches w.g As a result the inclination is to choose MERV 16 but use HEPA in  certain types of operating rooms and to use HEPA room air purifiers in isolation rooms

 

Courtesy Protective Masks for Colds is a Huge CATER Market

In many parts of Asia anyone with a cold is expected to wear what is labeled a “courtesy” mask

There are 3-5 billion severe cases of influenza year and more than 0.5 million deaths. A large percentage could be prevented with masks. In addition there are over 15 billion colds per year or just under 2 colds per person

More than 200 viruses are to blame for the estimated 1 billion common cold cases each year in the United States, according to the National Institutes of Health (NIH). With numbers that large, it’s no wonder the common cold is so, well, common.

“The common cold is a viral infection that is highly contagious,” said Angelia Mickle, DNP, with Jamestown Family Medicine, a Premier HealthNet practice. “It is estimated that children will get up to seven colds a year, resulting in 22 million missed school days. Adults can expect to get up to two to three colds a year. In the fall and winter months, the majority of cases we see walking in our office are for the common cold.”

The common cold is caused by hundreds of different viruses of which three are mainly to blame. Rhinovirus accounts for 40 percent of cold cases, followed by the coronavirus which accounts for 20 percent and respiratory syncytial virus (RSV) which makes up another 10 percent. Symptoms of the cold can vary, but usually include sneezing, sore throat, coughing and congestion and mild fatigue. A cold can lasts up to 14 days.

“Unlike many other illnesses, the average person can work through a cold or go to school while they are fighting the illness,” Ms. Mickle said. “Not many people could afford to miss the amount of days from work or school that it would take to fully recover from the minor illness. However, it’s for this reason that the cold is so quickly spread among groups of people.”

The use of courtesy masks would be quite effective in preventing this spread.

There is no cure for the common cold, and medications such as antibiotics do not make a difference since a cold is a virus, not a bacterial infection. The best thing an individual can do is treat the symptoms and know the signs that may signal if additional medical attention is needed. He should also be advised to wear a “courtesy” mask.

 

Mann + Hummel Air Purifiers are Suitable for Rooms Up to 200 m2

The MANN+HUMMEL Group, based in Ludwigsburg near Stuttgart, has succeeded in developing comprehensive solutions to contain the corona pandemic: The HEPA H14 filters (individually tested according to ISO 29463 & EN 1822) installed in the two new mobile and stationary high-performance room air purifiers, OurAir TK 850 and OurAir SQ 2500, are capable of reliably filtering more than 99.995 percent of viruses, bacteria, and micro-organisms from the air. As such, they help to minimize the risk of infection in internal spaces. The devices are modern in their design, and thanks to the innovative ePTFE medium, they operate at high performance with particularly low noise levels. This allows infectious virus particles such as SARS-CoV-2, which can attach themselves to aerosols, to be almost completely filtered out.

At a virtual press conference, the two new high-performance room air purifiers were presented to the media in Austria and Switzerland, following a successful product launch in Germany in mid-September. These create almost completely virus-free air in internal spaces. The stationary room air purifier OurAir SQ 2500 is suitable for rooms of up to 200 m² and the mobile room air purifier OurAir TK 850 for rooms of up to 70 m². Both devices replace the air contained within the specified room sizes five times per hour, allowing the aerosol concentration in rooms to be quickly reduced by a significant amount, and kept at a constantly low level. Further added value is created thanks to the energy efficiency of the devices. The high energy consumption, which occurs especially in the winter time with frequent ventilation and thus a constant cooling of the room, can be reduced to a minimum with the air purifiers. The technology also helps to protect against infections caused by colds, flu viruses and mold spores. Beyond that the devices filter free allergens from the air and thus also help against allergy complaints in the pollen season.

“Our air purifiers are a complementary measure to the existing hygiene and distance regulations and an important component for a speedy resumption of our habitual everyday life. We are proud that our technologies are able to help schools, hospitals and other institutions to continue operating as normal. In order to make the purchase of our devices easier, we offer attractive leasing models,” explained Jan-Eric Raschke, Director & Chief Product Owner Public Air Solutions. “Air purifiers are a sensible long-term investment, because they filter not only the SARS-CoV-2 virus, but also flu and cold viruses and free allergens. As a result, they can make a decisive contribution to reducing absenteeism due to illness or allergies in the future.”

 

Four of the podium participants at the virtual press conference to present MANN+HUMMEL's antiviral air purifiers: f.l.t.r. Frank Spehl, Director Engineering Life Sciences & Environment Airfiltration MANN+HUMMEL; Gunnar-Marcel Klein, Vice President Engineering Life Sciences & Environment MANN+HUMMEL; Kathrin Sauter, Director Marketing Communications Life Sciences & Environment MANN+HUMMEL ; Jan-Eric Raschke, Director & Chief Product Owner Public Air Solutions MANN+HUMMEL

Study Proves Effectiveness of Mobile Air Purifiers

Current measurements carried out by Prof. Achim Dittler from the Institute for Mechanical Process Engineering and Mechanics at Karlsruhe Institute of Technology, including in the classroom of a primary school, prove that the devices are highly efficient in reducing the aerosol concentration and therefore the risk of infection with viruses and bacteria. “The filter quality is the deciding factor when it comes to air purifiers. At MANN+HUMMEL, we fondly look back on our 80 years of experience in filtration, and more than 40 years of expertise in the field of clean room filtration and OP filtration. Thus we have been specialized in particularly sensitive areas for many years. Our quality standards are reflected in the durability of our devices,” said Dr. Gunnar-Marcel Klein, Vice President Engineering Life Sciences & Environment. The areas of application range from gastronomy to public institutions such as schools or care homes, offices, retail, airports, hospitals, shopping centres and industrial businesses, right through to event venues and transportation.

In addition to mobile antiviral air purifiers, MANN+HUMMEL also offers the conversion and upgrading of air conditioning and ventilation systems, which also significantly reduces the risk of infection in internal spaces. Based on decades of experience in the field of cleanrooms and operating rooms, MANN+HUMMEL were able to develop a new ePTFE HEPA filter in the H14 class. With filtration efficiency of more than 99.995 percent according to EN 1822, it offers optimum protection against viruses, bacteria, and microorganisms. The new medium makes it possible to reduce the differential pressure by 50 percent compared to HEPA filters made of micro glass fibre media and is thus on a par with a “pre-corona” filter system in terms of the operating costs of an air conditioning and ventilation system. The filter also meets the requirements of class E fire protection according to EN 13501.

 

Filti Introduces Home Air Purifier

Filti, an air filtration and nanofiber technology company, has launched the 9500 Home Filter. The patent-pending 9500 Home Filter is an HVAC filter constructed using nanofiber technology, an N95-quality material that is proven to filter 95% of aerosolized, airborne particles – like COVID-19 – moving through the material.

Why is an N95-quality HVAC filter important? Air conditioners and heaters recirculate air throughout a room or building. Typically, HVAC filters are designed to trap dirt, debris, allergens, and other impurities from recycling into the airflow. However, microscopic viruses, such as COVID-19 which studies have proven to be airborne, can easily move through most low-efficiency HVAC filters. Without a filter material that can successfully trap the smallest pollutants, aerosolized particles can be recirculated in the building.

"We wanted to provide people with a similar level of safety and protection within their homes that they get from wearing an N95 mask," says Dakota Hendrickson, co-founder of Filti. "We knew we could use our expertise in filtration to truly make a difference, and it was important to give people a way to better protect themselves and their families at home."

The replaceable filter is the only MERV 16 (Minimum Efficiency Reporting Value) residential HVAC filter on the market, according to the company. The extremely efficient yet highly air permeable nanofiber fabric, allows for an increased airflow ratio that won't put additional stress on a residential HVAC system.

The launch of the 9500 Home Filter is a return to Filti's core products after pivoting in March to produce N95-quality nanofiber material that could be made into face masks. After selling enough material to make nearly 15 million masks, the company now hopes its new N95-quality HVAC filter will provide the next level of protection nationwide.