Mask-making, as protection against dangerous pathogens, is both a science and an art. First, they must block &/or capture airborne pathogens while also minimizing how much inhaled or exhaled air can bypass the mask. But, they must do this while being comfortable to wear for long enough periods of time and also as attractive as possible. If any of these characteristics are not met, the overall effectiveness of masks is lowered, if only because people refuse to wear them consistently.
If you are planning on buying a lot of masks to ensure the health of the people in your company or community, we urge you to become a “mask scientist”, by reviewing the following info about what makes masks good or and how the major types of masks vary in regard to their effectiveness and acceptance by wearers.
COMPETING REGIONAL MASK STANDARDS ARE ALL TRUSTWORTHY: All regional mask standards primarily define the % of particles of 0.3 microns (or larger) that a complying mask must physically block. Most commonly this is 95% or 99%. Respectively, these US, Euro & Chinese standards are: N95-N99; FFP2-FFP3 & KN95-KN99. We suggest that you should not presume that the foreign standards are significantly less strict than US criteria, which includes the Chinese standards. Previously, the CDC disapproved of Chinese masks as substitutes for US masks. But that was recognition of “junk” Chinese masks that were actually being imported at the time. It was not a rejection of the Chinese standards themselves, But, some “experts” are still referencing a study of masks, from almost a year ago, that said that the inferior Chinese masks tested allowed 30% of the breathed air to bypass the mask. (Of course, it failed to note that flat surgical/civilian masks allow +/- 50% of the air to bypass them.) In reality, we have no issue with recommending masks that pass the CE-FFP3 or KN95 standards as equivalent to the US N95 type.
In addition, please keep in mind that the standards are defined by functionality, not by shape, color, etc. Thus a cup “respirator” N95 mask is not inherently more protective than a folding N95 mask. If fact, because it is intentionally relatively rigid, it is harder for a particular size to conform to all size faces and the suggestion is that they be custom fitted. That is not the case with self-conforming folding masks! On the other hand, no matter how much you “fiddle” with it, a flat, “disposable”, civilian or surgical mask can only be made to fit so well. But, remember, they were designed to catch splashes of fluids during surgery…not to catch dust or to stop airborne pathogens.
WHAT MAKES FOR GOOD MASK FILTERING ABILITY: You can’t be faulted if you demean the value of masks, since the coronavirus is smaller than the tiny pores in even the best masks…so, theoretically, they could all pass thru even N100 masks! But, keep in mind that are primary reason for wearing masks is to block cough spray & micro-droplets that are physically filtered out by the masks. But, what about the smaller particles? That is where the importance of the middle “melt-blown” filter fabric layer(s) come in: The standard call for these to be an “electret”…treated so that they are imbued with a static electric charge which grabs the smaller particles “like fly paper” as they pass by. These melt-blown filter fabric layers are more expensive than the inner & outer “spun-bond” mask fabric, so bargain masks often omit them. So, what the type of layers there are is more important than how many layers there are! A common idea is that multiple layers of cloth can be as effective as intentionally designed filters. But, when tested using NIOSH testing standards, they rated +/-N5. But, one can’t argue that they are not better than nothing! (hence, even homemade cloth masks should incorporate a purpose-designed filter layer.)
MASK FIT VS FILTERING ABILITY: The filtering ability of a mask is at least somewhat defeated if the fit is bad. The air you inhale or exhale is going to take the path of least resistance. So, that air will tend to go around the filter is possible. That means virus particles and contaminated breath droplets can go around mask entirely, if they are loose fitting, or they will pass thru the mask if the whole mask doesn’t have a filter layer. An issue with masks is how comfortable they are. Respirator masks can be uncomfortable, with tight straps and a rigid rim pressed into the face to ensure a tight fit; disposable 3-ply” masks are inherently loose & “leaky” they, plus all other masks, have elastic ear straps the irritate the ears upon long wearing. Carolen Group’s solution is provide free mask adjuster straps (a/k/a “buckles”) which take the ear loops off the ears, increasing comfort for also improving fit and reducing looseness even of civilian “flat” masks,
WHO’S PROTECTING WHOM & HOW PROTECTED ARE YOU? This is an important consideration when choosing a mask: Health pros need to be concerned about being infected by their patients, so they should be concerned about what they inhale. Thus, they need masks whose fit forces all air they breathe thru a fine-pore “electret” filter. “Civilians”, on the other hand, are told that they need to be most concerned about infecting others since so many people infected with Covid-19 show no symptoms. Thus, the common advice (which is better than nothing) that limits the spread of those droplets from ourselves to others: “covering your mouth when you cough”; “coughing into your elbow”; or wearing anything over your face, whether it is a bandana, a cloth mask or a “flat” disposable mask. But, the “Feds” are covering their unpreparedness for a pandemic by making “civilians” to feel guilty if they wear N95 masks; health pros are re-using scare “respirator” masks too many times because they are made to feel that only those meet N95 specs for protection. The result is that astronomical prices are being charged for respirators while the bulk of the population is only partially protected against Covid-19 by “social distancing” & hand-washing, because their masks don’t protect them from breathing IN the virus, and only partially protect others from what they breath OUT..
OUR LAST WORDS TOWARD SAVING MONEY & IMPROVING PROTECTION WHEN MASK SHOPPING & WEARUBG: Recognize worthless mask-marketing ploys: NO copper-infused mask, currently being sold, contains a high enough percentage of copper for it to have any protective effect whatsoever. More mask layers are less important than the quality of the filter layers (ideally “melt-blown”) that are provided. Recognize that the fit is as important as the mask’s construction, because loose masks only reduce (but not stop) the spread of the virus outward, while offering little protection against what might be inhaled. Our final advice is: Buy certified masks (including CE or KN types, which can be effective & affordable); and use the nose wire” to conform to fit around the now. If the attachment method is “ear loops”, use mask adjusters which provide a better fit for all masks, even flat disposable type, if that is all that is available or affordable. In addition to better fit, mask adjusters also improve comfort, taking the annoying ear loops off the ears…encouraging mask-wearing. But, recognize that flat masks cannot be made to fully conform to the face, no matter how tight they are, and note that the filtering ability of regular woven cloth masks will not approach that of certified masks unless they include a purpose-designed filter layer.