The COVID-19 pandemic has forced the global population to adopt new ways of living, including the wearing of masks as a new norm. With the pandemic dragging into 2022, the general public has begrudgingly become more aware of the quality of protection available from face masks available on the market.
It has even accelerated R&D efforts in mask materials and design to offer better protection for users against airborne pollutants and pathogens. What this protection amounts to are standards. Whether it’s the food we eat, the products and technologies we use, or how we get to work, every aspect of our lives is affected by standards.
Standards and conformity assessment provide confidence in the quality and safety of products and services, and they also play an integral role in improving the overall health and safety of Canadians and their environment.
In the world of manufacturing surgical face masks, it’s all about standards and producing a compliant product that can offer the maximum amount of protection. American Society of Material and Testing (ASTM) is the global authority for determining surgical masks’ criteria for a professional environment.
Several factors determine the quality of protection provided an ASTM surgical masks. These factors include, among other things, the source of the raw materials used to create medical-grade masks and how those materials are tested and certified for use in a professional environment.
Crown Mutual Medical is thrilled to be aligned with the Kinectrics testing facility in Toronto, Ont. Kinectrics offers testing of respiratory personal protective equipment (PPE) for industrial and medical applications.
For CMG, fostering a relationship with Kinectric was vital in creating a clear path to the highest certification standards we could have our mask endure. Kinectrics has developed their own ASTM F2100 test methods accredited to ISO 17025 by the Standards Council of Canada.
Extremely important because it also aligns with the compliance regimen developed by ASTM. The ASTM F2100 standard specification for performance of materials used in medical face masks is the following criteria:
What is the difference with 3ply?
The 3-ply surgical mask is commonly used in the COVID-19 pandemic. The 3-ply surgical mask is made up of 3 different layers of nonwoven fabric with each layer having a specific function.
The outermost layer (typically blue) is waterproof and helps to repel fluids such as mucosalivary droplets. The middle piece is the filter, which prevents particles or pathogens above a certain size from penetrating in either direction.
The innermost layer is made of absorbent materials to trap mucosalivary droplets from the user. This layer also absorbs the moisture from exhaled air, thus improving comfort.
Together, these 3 layers effectively protect both the user and the surrounding people by limiting the penetration of particles and pathogens in both directions.
What are the ASTM levels?
What exactly are raw materials?
Raw materials used to make surgical masks are made from a fabricated material called Spunbond and Melt-blown. The process to create the material involves bonding a mass of fibres together using heat, chemical, or mechanical means. The remainder of the mask consists of rubber earloops and a plastic nose bridge. Spunbond and Melt-blown make up the 3 different layers of nonwoven fabric with each layer having a specific function. The fabric is made of felt, an ideal material for manufacturing surgical masks.
The Spunbond process combines the spinning and sheet formation process into one continuous, nonwoven manufacturing system. Meltblown is similar in structure however due to the finer pore size, melt-blowing is the typical process used to fabricate the middle filtering piece of the 3-ply surgical mask.
The major difference between Spunbond and Melt-blown is in the die process which is the most important element responsible for the smaller diameter microfibres.
Testing Criteria Overview
The science behind the testing process involves the engineers’ combined experience and the technology they have created to deliver these standards.
EN14683:2019 Annex C (Differential Pressure)
When we measure differential pressure, comfort and breathability are at the top of the list. How breathable the mask fabric is will be determined by a “Pressure drop” test. A pressure decay leak tests involve measuring the drop in pressure on the interior of a part.
Air is injected into the test part until it reaches the target pressure. The air source is then cut to isolate the stress, and the loss of pressure (decay) is measured over a specified period. A loss in pressure indicates the presence of a leak.
ASTM F2299 PFE (Particle Filtration Efficiency).
PFE testing evaluates the nonviable particle retention or filtration efficiency of filter media and other filtration devices at sub-micron levels. This test is performed on face masks and all filter material that allows one cubic foot per minute (CFM) flow to pass through it.
The particles on the other side of the mask are then analyzed.
This procedure involves generating a particle aerosol using NIST traceable polystyrene microspheres with a Particle Measurement Systems (PMS) Model PG-100 particle generator. The particles are counted with a PMS Model LASAIR II-110 or 310 laser particle counter.
ASTM F2101 BFE (Bacterial Filtration Efficiency).
Testing for Bacterial Filtration Efficiency (BFE) is performed on filtration materials and devices designed to protect against biological aerosols. The bacterial filtration efficiency test determines the filtration efficiency by comparing the bacterial control counts to test article effluent counts.
The test is conducted using Staphylococcus aureus as the challenge organism. After the filtration media is preconditioned, a liquid suspension of S. aureus is aerosolized and delivered to the filtration media at a constant flow rate of 28.3 litres per minute (LPM) or 1 cubic foot per minute (CFM).
The aerosol droplets are drawn through a six-stage Andersen sampler for collection. The number of bacterial aerosol droplets contacting the filter media is determined by conducting challenge controls without filter medium in the test system. Challenge controls are maintained at 1700 – 3000 colony-forming units (CFU) with a mean particle size (MPS) of 3.0 ± 0.3 µm. This allows filtration efficiencies to be reported up to >99.9%.
ASTM F1862 (BF) Resistance to Blood Penetration.
Blood splatter testing involves 2 mL of synthetic blood sprayed through a small cannula onto the face mask’s surface. At the conclusion of the test, the medical face mask’s backside is observed for synthetic blood penetration.
Face masks can be evaluated at three different velocities corresponding to a human blood pressure of 80, 120, and 160 mm Hg. If the mask passes at the highest stress, there is no need to test at a lower pressure.
The surface tension range for blood and body fluids is approximately 42 – 60 dynes/cm. Simulating the wetting characteristics, the synthetic blood is adjusted to the lower end of this range (40 ± 5 dynes/cm).
16 CFR Part 1610 (FR) Flammability.
Flammability testing standards are developed across multiple industries and involve several factors. The test results measure the burn time.
Burn time occurs when the specimen ignites, and the flame travels up the specimen, breaking the stop thread. When the stop thread breaks, the stop weight falls and stops the timing device.
Another measurement logically is no burn time, which occurs when the specimen: 1) Does not ignite. 2) Ignites but self-extinguishes before reaching the stop thread. 3) Ignites, but the flame travels under the stop thread without breaking it.
Why certification and testing work for Crown Mutual Group.
Health officials are now warning the general public to brace themselves for the worst part of the pandemic. The United States will soon mandate mask covering nationwide, and in some parts of the world, we are being encouraged to wear two masks in some instances as we endure even more lockdown and precious life is taken by COVID 19.
Crown Mutual Group wants to be the barrier against the virus, and we have mandated ourselves to sell the highest quality surgical masks in North America. We intend to earn consumers’ and healthcare professionals’ trust by offering a compliant product certified by international standards.
Please visit our website for more information on our products. We will be happy to assist you with any questions.