Last week the CDC published data to back its recommendation for double masking or modifying medical procedure masks for improved fit and protection against droplets from coughs and sneezes. The two masking methods tested by the CDC were:
Wearing a cloth mask over a medical procedure mask - Double Masking
Knotting the ear loops of a medical procedure mask where they attach to the mask’s edges and then tucking in and flattening the extra material close to the face - Knotted and Tucked Mask
Masks tested: A) Medical Procedure Mask, B) Double Masking, C) Knotted and Tucked Mask
Not pictured: Cloth Mask
Can Masks Filter Out Droplets? Yes, they can.
The data shows that both of these methods provide improved performance compared to an unknotted and untucked medical procedure mask. The CDC first measured the number of simulated cough particles that pass through a mask:
Medical Procedure Mask (unknotted and untucked): 56.1%
Cloth Mask: 51.4%
Double Masking: 85.4%
Knotted and Tucked Mask: 77.0%
How Much More Effective Are Double Masking and Knotted and Tucked Masks?
CDC set up two headforms 6 feet apart from each other in a small room (10ft x 10ft x 7ft) and measured the simulated particles passing through the recipient's mask (in some cases, the recipient had no mask). The experiment had multiple combinations of masked/unmasked headforms, and data shows the following:
Graphically, the data looks like this:
So What Does This All Mean?
Good question. The CDC notes a few limitations of their study, including:
They only tested one model of cloth mask and one model of medical procedure mask, so the data may not apply to all of these types of masks available for purchase.
They did not try all possible combinations of masks during the experiment.
These results do not apply to children or people who may have facial hair or features that prevent a mask from properly fitting.
Double masking or knotted and tucked masks may not work for all people. Breathing resistance increases with a second layer and changing the shape of the medical procedure mask may prevent the mask from fully covering the nose and mouth.
Here's the most important takeaway from this study:
How well your mask fits will greatly affect how well it can protect yourself and others.
The reason why double masking or knotted and tucked masks have better performance compared to a cloth mask by itself or an unknotted and untucked medical procedure mask is that they are more likely to improve how well the mask fits on the wearer. A better fit means less gaps, which results in more air forced to go through the mask material instead of leaking in or out through gaps.
How Can I Try Double Masking and/or Knotted and Untucked Masks?
Double masking is fairly simple:
Wear a medical procedure mask, cover your nose and mouth, and make sure you fit the plastic bar to your nose and face.
Wear your favorite cloth mask over the medical procedure mask. If the cloth mask has a bar to adjust fit for your nose, be sure to adjust that one as well.
CDC used a three-layer cloth mask for their tests and recommend using at least a two-layer cloth mask.
Knotted and Tucked masks are a little more complicated. Here's a video explaining how to properly tie the knots in the earloops and tuck in the extra mask material.
One Last Thing...
With many cities and states throughout the country implementing a mask mandate, don't get caught without one! Our Anti-COVID19 Kit comes with 5 medical procedure masks and disinfecting wipes, hand sanitizer, and soap and are easy to take with you while you run your errands, dine outdoors, or carry out essential business/travel. Check them out!