Yes, There are More Updated Mask Usage Recommendations

the staff of the Ridgewood blog

Ridgewood NJ,  according to Johns Hopkins Center for Health Security on February 10, the US CDC published updated guidance regarding ways to improve the efficacy of facemasks, which supplements existing mask guidance. The recommendations focus on 2 principal factors in how masks provide protection: fit and filtering ability. The CDC continues to recommend wearing a “mask [that] fits snugly against your face” and selecting masks that have multiple layers to filter respiratory droplets. The new guidance includes several additional recommendations and tips for improving both aspects of mask use.

Under the new guidance, the CDC now recommends selecting a mask with a “nose wire” that can be bent to mold the shape of your nose, which reduces the air that can escape around the top edge of the mask. The CDC also recommends using a “mask fitter or brace” on the outside of the mask to hold it more snugly to your face and provide a better seal around the edges. And finally, the CDC recommends adding layers of filtering material to your mask, including selecting a mask constructed of multiple layers of fabric or “double masking.” In the new guidance, double masking specifically refers to wearing a reusable cloth mask on top of a disposable mask (eg, medical, surgical mask). The CDC explicitly recommends against wearing multiple disposable masks or combining any kind of disposable or reusable mask with a respirator (eg, N95, KN95). The guidance also provides tips for determining whether your mask fits properly. The new guidance follows recent attention on double masking as a potential technique to reduce transmission risk in the face of emerging highly transmissible SARS-CoV-2 variants.

The updated guidance is based on findings from a study by the US CDC COVID-19 Response Team on improving the fit of facemasks. The researchers tested “double masking” and “knotting and tucking” to evaluate the extent to which they affected mask efficacy. Knotting and tucking refers to tying the straps/ear loops in a knot to bring the corners of the mask together and then tucking in the extra material “to minimize the side gaps.” One simulation compared the efficacy of double masking by comparing the combination of a cloth mask worn over a medical mask to each mask worn alone, and a second simulation compared various mask configurations, including double masking, to evaluate the effect of knotting and tucking. The simulations tested breathing and coughing and tested the effect for both exhalation and inhalation (ie, source and receiver, respectively). In the first experiment, the double masking configuration (unknotted) “blocked 92.5%” of cough particles, compared to 42% for the medical mask alone and 44.3% for the cloth mask alone. In the second experiment, when either the source (exhaling) or receiver (inhaling) utilized the double masking or knotted configuration (ie, only one of the two), the exposure to the receiver was reduced by approximately 82% and 63%, respectively. When either configuration was used on both the source and receiver, the receiver’s exposure was reduced by approximately 96%. A number of variables factor into the efficacy of these configurations, but this study provides evidence that these techniques can increase the level of protection for mask wearers. Notably, the new CDC mask guidance does not explicitly address knotting and tucking. See a quick tip from Sr. Scholar Caitlin Rivers to make your mask fit better.