Between the article and cited references, this is probably everything you want to about wearing face masks—and maybe a bit more.
The ideal mask for you depends upon your health, age, profession, and geography. A good face mask is primarily the equipment of medical personnel, scientists, carpenters, spray painters, food service, and other industry workers. To keep from breathing in unwanted contaminates, it should cover both the nose and mouth.
As a result of the coronavirus, face masks are part of standard attire for the general population. New Yorkers must cover their noses and mouths with a mask or cloth face covering when in a public space where they cannot socially distance. There are similar laws around the world. Children under age 2 or those who cannot “medically tolerate” the mask are exempt in New York and other places.
In Kentucky, children who are 5 or younger and any person with a disability, or physical or mental impairment, that prevents them from safely wearing a face covering are exempt. Rapidly changing personal protective equipment (PPE) mandates are resulting in compliance confusion and a mask shortage in many hospitals.
If you can get your hands on one, which is best for public use? The variety of different face masks and other PPE is mind-boggling. This page presents the most useful categories of masks available to control the spread of viruses.
Standards for medical and industrial compliance vary from one country to the next. In the United States, respirators must meet NIOSH (National Institute for Occupational Safety and Health) standards. Within this standard, there are several classes of respirators depending on the degree of oil resistance. Here is everything you need to know about face masks but do not know how to ask.
N95 Masks
American citizens have become quite savvy in distinguishing the highest quality PPE. N95 masks filter out ≥95% of aerosolized particulates that are 0.3 microns or larger, including the new coronavirus. For this reason, they are PPE for medical personnel and carpenters—people around germs or fine dust.
These masks come in a variety of shapes and sizes to custom-fit the user. All FDA-cleared N95 respirators are labeled as “single-use,” disposable devices.
With a proper seal, it is virtually impossible to breathe comfortably through the dense filters of N95 masks. Without oxygen circulating, it can get warm under the mask, fogging up glasses and causing condensation.
It is tempting to pull the mask down periodically for fresh air. This is problematic during exposure to harmful elements. Medical care workers endure the discomfort to help patients.
People with chronic respiratory, cardiac, or other medical conditions that make breathing difficult should check with their healthcare provider before using an N95 respirator because the N95 respirator breathing obstruction.
N95 masks may include at least one ventilator valve to exhale carbon dioxide. Those with exhalation valves should not be used in sterile conditions. Some doctors, wear a surgical mask and face shield over the valved N95 mask.
An N95 respirator (not a surgical mask) is needed for the following aerosolizing procedures:
BIPAP, CPAP, and high flow (for the duration of therapy)
Intubation and bronchoscopy
Sputum induction or endotracheal aspirate collection
Nebulizers
Tracheostomy
Chest physiotherapy
Trach and airway suctioning
Bronchoalveolar lavage
It defeats the purpose of collecting germs and particulates on the external mask surface, then touching that surface with bare hands, transferring contaminants to the next patient, or bringing it into your home and reusing it.
During mask removal, do not touch your eyes, nose, or mouth, and wash your hands immediately after removing the coverings. With increasing demand for N95 masks, health officials request that the non-medical population use other masks.
KN95 Masks
KN95 masks are N95 manufactured to Chinese regulations, with slight variation in particulate thresholds. During the initial N95 mask shortage, the U.S. Food and Drug Administration (FDA) delayed China’s large donation of KN95 masks destined for hospitals.
On April 3, 2020 the FDA relented. The CDC lists KN95 masks as a suitable alternative when N95s are not available. Meanwhile, 3M, Foxconn, and companies around the world are stepping up production or retooling the manufacturing process to produce more N95 masks.
FFP1masks filter ≥80% of aerosol (inward leak < 22%)
FFP2masks filter ≥94% of aerosol (inward leak < 8%)
FFP3masks filter ≥99% of aerosol (inward leak < 2%)
Filtering Facepiece Particles (FFP) masks protect the wearer from inhaling infectious agents or pollutants in the form of aerosols, droplets, or small solid particles. They are up to 50 times more effective than surgical masks.
Disposable FFP2 masks are similar to KN95 masks. Reusable versions are made of washable fabric with an internal pocket for a PM2.5 charcoal filter (Atmospheric particulate matter that has a diameter of fewer than 2.5 microns. This is about 3% the diameter of a human hair.) The mask with 3 layers of protection plus the filter produces an 8-layer barrier against ≥94% of particulates ≥0.3 microns.
Use discretion when wearing masks with removable filters. Person-to-person transmission of COVID-19 is within 3 feet while talking or 6 feet if coughing. During aerobic activities like brisk walking or jogging, extra filter layers can inhibit deep breathing. People with asthma, bronchitis, or COPD should speak to a physician before wearing masks that make breathing more difficult.
Thoroughly wash the cloth FFP mask and dispose of any removable filter after use. Lacking NIOSH standards, FFP2 masks are not approved for use in U.S. hospitals. Given the alternatives, they are more suitable for the general population desiring optimum protection.
P95 Elastomeric Respirators
3M Medium Thermoplastic Elastomer Series 5000 Half Mask Organic Vapor/Acid Gas Disposable Air Purifying Respirator pictured.
Elastomeric Respirator masks are large, full- or partial-face masks with removable filter elements designed to be reusable. These are more common for firemen, coal miners, professional woodworkers, or machinists.
The B2 is a reusable respirator that filters 99% of common contaminants and reduces filter cost and waste by half. Unlike existing consumer masks, the B2 features a flexible, patent-pending facepiece.
Incubating from Kickstarter with $500,000 pledges, the B2 Mask price is north of $40 each including two disposable filters. It is designed to comply with NIOSH N99 standards per 42 CFR Part 84, but to date, the B2 Mask has not yet received regulatory approval with either FDA or NIOSH. During normal use, the B2 filters offer 40–50 hours of protection before filtration efficiency starts to drop.
Low use (occasional use while going out in public): Change every 2–3 weeks
Medium use (wearing consistently over a week): Change weekly
High use (wearing for multiple hours a day): Change daily for best protection
Surgical Masks
A disposable surgical mask is a loose-fitting, disposable device. It creates a physical barrier between the mouth and nose of the wearer and potential contaminants in the immediate environment. Surgical masks usually have a filter sandwiched between two layers of non-woven textile. An optional thin wire on the bridge closes the upper gap.
The pleated mask opens to extend below the chin, adjusting to fit different faces. Sides, which are not airtight, have elastic loops that go around ears. These disposable masks should not be worn for more than 3 to 8 hours. They are sometimes worn over N95 masks by healthcare workers.
Head coverings and clear face shields are often worn during surgery for additional protection. CDC says recontamination and subsequent reuse of filtering facepiece respirators (FFRs) should only be practiced as a crisis-capacity strategy. CDC and NIOSH do not recommend that FFRs be decontaminated and then reused as standard care.
A genuine surgical mask will hold the water without leaking. Similar paper masks are commonly worn in public or nail salons. However, they do not filter airborne infectious agents or toxic fumes.
Inadequate Protection
Japanese Pitta Masks or Korean K57 Masks: Among the dishonorable mentions are Pitta masks (pictured above), made of porous sponge polyurethane. With poor filtration (≥57%), they absorb—not repel—moisture, including saliva droplets, and are not effective at filtering small particles. Don’t let the sleek looks fool you. A surgical mask provides more protection from tiny particulate matter than a Pitta mask.
CDC recommends wearing cloth face coverings in public settings where other social distancing measures are difficult to maintain. Absorbent cotton T-shirt fabric is even suggested. Breathing through a damp cloth while crawling on the floor of a smoke-filled room reduces smoke inhalation. But this something-is-better-than-nothing recommendation has many wondering if this is a false sense of security for an aerosolized virus.
CDC Recommends DIY Bandana Face Mask
DIY Bandana Covering: In an unprecedented public service announcement, the CDC demonstrates how to make a DIY face covering with a bandana and rubber bands. According to the American Lung Association, using a homemade cloth face covering when near other people can help block large particles that you might eject through a cough, sneeze, or unintentionally launched saliva (e.g., through speaking). This might slow the spread of transmission to others if you don’t realize you are sick.
People of color may refuse to wear bandanas—particularly of certain colors. This can associate them with gangs or criminal intent leading to harassment. For said risk, cloth bandanas are not designed to protect against viruses.
DIY Cotton Mask: Masks with just one layer of permeable fabric or those that expose the nose are ineffective in protecting against airborne viruses. A polyester or silk scarf without insulation is largely decorative. If light easily passes through the fibers, virus particles can pass through. Individuals following DIY patterns with scrap fabric often produce masks that fall into this category.
People around the world are fashioning makeshift PPE of everything from paper napkins to plastic water bottles. A study reveals that homemade masks are better than nothing but not as good as surgical masks. And surgical masks are not as good as N95, KN95, or FFP2.
Masks having many layers of filtration but no ventilator valve can hinder breathing. So wearers who remove them within a few minutes have no protection. With extended use of masks sans appropriate ventilation, there is a risk of suffocation—especially among young children and those with weak lungs. In sterile environments, doctors might not wear masks with respirators or wear a surgical mask over a respirator mask.
