Can You Spot the Difference between: KN95, N95, Surgical, and Cloth Face Masks?
Face Mask: the cause of much debate, protests, and claims of infringement upon civil liberties. States around the nation are, some with more success than others, imposing the mandatory use of wearing facial coverings. So, despite our own personal preferences, as a society we all shoulder the responsibility in slowing and/or stopping the spread. This is especially the case with a new administration being sworn in today, new restrictions and mandatories could be forthcoming.
Let us refresh our memories on the different masks currently on the market.
The Centers for Disease Control (CDC) recommends the wearing of a simple cloth face mask when in public places. This is to help slow the spread of the SARS-CoV-2 virus from people who may not know they are infected from transmitting it to others.
However, the best way to mitigate exposure and transmission of the SAR-CoV-2 virus is make use of all the recommendations of the CDC. Those are namely, thorough hand washing with warm water and soap and social distancing of 6’ (1.5m to 2m) to help prevent respiratory diseases from spreading.
Droplet &. Aerosols
Droplets are large particles of liquid usually produced by someone who has coughed or sneezed. Due to their size, droplets do not travel long distances before falling on a surface. This is how cross contamination occurs when one sneezes, and droplets fall onto their phone and then they touch a doorknob. Aerosols, on the other hand, are tiny particles that can suspend in the air due to their lightness. Aerosols can stay in the air for long periods of time. For example, droplets can be compared to rain or any other form of precipitation. While aerosol is like fog that floats and occupies almost any space.
Cloth masks are designed to be cleaned and reused. These are easy to make and obtain. Some have cloth face coverings have one-way valves or vents that make exhalation easier for the wearer. However, according to the CDC these do not prevent the transmission of COVID-19 to others. That is why these are not recommended for public use. Furthermore, these masks may not protect against aerosols. But by practicing the recommendations for mitigating the spread of the disease by the CDC – the amount of protection provided by a cloth mask sufficient.
When wearing a cloth mask, ensure that it completely covers the nose and mouth and is secured around the ears without gaps at the sides. It is recommended, like with the other masks discussed, not to touch it while it is being worn. If one does happen to touch it, they should immediately wash or sanitize their hands. After each use follow the manufacturer’s instructions on how to properly wash and sanitize the cloth mask. For a downloadable infographic please see this post.
Surgical masks are loose fitting, disposable devices that create a physical barrier between one’s nose and mouth from potential contaminants in their immediate environment. These types of masks are regulated under 21 CFR 878.4040. Surgical masks are commonly used masks. Surgical masks are made in different thicknesses and with different abilities to protect wearers from contact with liquids. But these properties can affect how easily one can breathe through the face mask and how well will protect.
The benefit though, from wearing a surgical mask is that it is fluid-resistant and can protect its wearer from large droplets or splashed bodily fluids. When worn properly, a surgical mask can help block splashes, sprays, or splatter that may contain germs (viruses and bacteria) and keep these contaminants from reaching the nose and mouth. Lastly, they do not require fit testing.
Surgical masks are disposable and therefore, should not be worn more than once. If the mask is damaged and/or soiled or if breathing becomes difficult, one should remove the mask, discard it properly, and replace it with a new one. To safely discard disposable masks, please read this post.
Unlike N95 masks, surgical masks do not protect against aerosols. Therefore, they are not adequate or sufficient protection when a person is in direct contact with COVID-19 patients during aerosol-generating procedures.
An N95 face mask is a protective device designed to achieve an extremely close facial fit and is very efficient filtration of airborne particles. To learn more on airborne particles read this post. The edges of an N95 are designed to form a tight seal around the nose and mouth. The N95 respirator are named for their ability to filter 95% of particles in the environment using static electricity.
Surgical N95s are most worn in healthcare settings and are the subset of N95 Filtering Facepiece Respirators (FFRs). To ensure their safety and efficacy, all N95s must be tested and be approved by the National Institute for Occupational Safety and Health (NIOSH). These masks are not recommended by the CDC for use by the public since they are critical supplies for health care workers and other medical first responders.
The KN95 is China’s equivalent of the N95 respirator. It is made from multiple layers of synthetic material (typically a polypropylene plastic polymer) and are designed to be worn over the nose and mouth. It must filter out and capture 95% of tiny of 0.3-micron particles in the air. Hence the “95” in the name. The difference between the two is the NIOSH has certified the N95 respirator, while the KN95 meets Chinese government standards. Also, N95s are more breathable than KN95 which is indicated by inhalation and exhalation pressure.
Per OSHA guidance, KN95s, for most industries except healthcare, are an acceptable alternative when N95 respirators and other foreign-made equivalents are not available. Like the N95 masks, KN95s should be worn only once and disposed of properly. However, there are studies that have indicated after spraying the mask with ethanol, air drying it and then vacuum drying it, showed more effective filtration afterward.