As some states have begun to lessen social distancing restrictions and begin phased re openings of more and more non-essential businesses, the most noticeable difference while beginning a phased return to normal may be the new garb -- you know, the smile-blocking, condensation-creating, newly wardrobe essential masks. Since the major onslaught of the novel virus COVID-19 (or Corona virus) first hit the United States and forced a major shut down of many businesses, restaurants, and public areas, the CDC has recommended that people wear face coverings that shield their mouths and nose whenever exiting their homes or during all social interactions.
With this recommendation came a mask mania, which sparked an advent in our new age of masks -- clothing brands began selling their own unique masks, sports teams were endorsed across people’s faces, and surgical and N-95 masks and respirators became hot commodities, causing an initial shortage that prompted the CDC to ask people to buy or sew their own cloth masks, so as to preserve surgical and filtered masks for those working on the pandemic’s front lines in the healthcare industry or as essential workers.
So as far as masks go, does one kind really work better than the other in preventing the spread of COVID-19? What do all the numbers and letters mean? We’re going to filter through the facts, starting with the various kinds of masks available.
The masks you’ve probably seen most often due to their affordability, initial accessibility, and easily DIY-able nature are the basic, unfiltered cloth masks. These are what the CDC initially asked people to wear, so as to preserve more industrial-grade masks for essential workers.
Coming in all shapes, sizes, and variations, cloth masks range anywhere from $1 to about $20. These basic models do NOT function as respirators, nor do they offer air filters. However, the CDC has said this is fine for most civilians in the midst of the pandemic. The novel Corona virus is spread primarily via respiratory droplets -- you know, the condensation in your breath, or the droplets in a sneeze or cough. These types of masks function mostly as a containment rather than preventative mechanism -- one that is only truly effective if everyone adheres strictly to wearing masks properly (covering BOTH mouth and nose at all times) when in contact with others. That is, cloth masks prevent infected persons from spreading COVID-19 by stopping the transfer of respiratory droplets while speaking, coughing, or sneezing; they do NOT, however, protect those who are not already infected from getting the disease from anyone not wearing a mask or social distancing.
This brings us to our second type of mask, a surgical mask. Surgical masks work similarly to cloth masks, but are not reusable or washable. Rather, they feature a breathable, porous, gauzy material and elastic loops to attach around the wearer’s ears. Like cloth masks, they’re
effectiveness relies primarily on containing particles; however, they are able to filter out larger viral particles from the air. They can’t block some of the tiny air particles that carry the virus.
Respirators are distinct from masks in 2 primary ways. Firstly is appearance. Respirators are tightly fit around the nose and mouth area in a dome-like shape that covers the lower half of the face and fastens behind the ears. Unlike masks, respirators are fit and sealed around the nose and mouth, and are typically made of a thicker material. Secondly is filtration. While masks contain particles, and may even filter out some of the larger ones from the airs, respirators actively filter the air the wearer breathes. The degree of this filtration differs, but you can decipher it based on the combination of letters and numbers used to describe the product. For example, a mask or respirator marked “N95” indicates that the fibers in the product will filter out 95% of air particles that are between 100 and 300 nanometers in size. N99 respirators can filter out 99% of these same particles, and N100 can filter up to 99.7% of them. Now, you may be wondering what the difference between an N95 and a KN95 mask or respirator is. The short answer is that the N95 indicates an American-made product, while a KN95 is Chinese in origin, design, and manufacture. In terms of filtration, function, and effectiveness, they are identical. Some of these respirators also feature a valve that allows the wearer to let exhaled air out of the respirator, thus facilitating ease of breath. The downside of this, though, is that the exhaled air may put others who are not wearing filters at risk. Therefore, it doesn’t prevent the wearer from spreading the virus, and has been banned by some places.
More new to the scene are face shields, the clear, plastic wall that covers someone’s face, extending downward from a sort of plastic headband. With the summer months upon us and the gradual lift of social distancing guidelines in some areas, face shields seem to remedy some of the practical flaws of masks or respirators. While masks or respirators can be hot and stuffy, and make a glasses-wearer’s life foggy and miserable, face shields allow for more breath ability and do not block peripheral vision. Furthermore, masks can muffle voices, making it difficult for those who are hard of hearing to understand the wearer, and they cover the face, which certainly changes human interaction. Face shields remedy these social kerfuffles, allowing for better and easier auditory and visual communication. But the more pressing concern is not their appearance, but their efficacy. Studies are still being conducted to measure the efficacy of face shields, but some simulations have found them to be able to reduce airborne viral particle exposure by up to 96% when within 18 inches of a cough, and can reduce the inhaled virus from 6 feet away by 92%. It is important to note that face shields would not be appropriate protection for those who are not social distancing, are at-risk, or working in healthcare, but they may be an appropriate and effective form of protection for trips to the grocery store or pharmacy, when coupled with hand-washing and other preventative measures.