The US Centers for Disease Control and Prevention website now reflects the agency’s new mask data showing double masking can significantly improve protection. The data was published in a CDC report on Wednesday.
The site uses colorful illustrations to outline different types of masks and educates the public on how to “Improve How Your Mask Protects You.”
It describes wearing two masks- a disposable mask underneath a cloth mask for better fit and extra protection. The CDC still encourages the use of a single cloth mask that is multi-layered.
Also suggested on the site: wearing masks with a nose wire and using a mask fitter or brace to prevent air leakage from gaps in loose masks.
The website now instructs to the public to ensure the snug fit of a mask by cupping their hands outside the edges of a mask to make sure no air is flowing out of the sides or top.
The page tells consumers to avoid masks with gaps or exhalation valves or vents.
Beginning in January 2021, the CDC tested two simple methods, double masking and knotting, to evaluate mask performance protection. Researchers found the effectiveness of cloth and medical procedure masks can be improved by ensuring they are well fitted to the contours of the face to prevent air and particles from escaping from gaps around the mask’s edges.
Researchers found that layering a cloth mask over a medical procedural mask, such as a disposable blue surgical mask, can block 92.5% of potentially infectious particles from escaping by creating a tighter fit and eliminating leakage.
Researchers also found that overall performance of medical procedure masks alone can be improved by folding mask edges inward and knotting ear loop strings where they meet mask fabric to reduce gaps. A knotted medical mask can block 63% of aerosols that may contain coronavirus, a significant improvement from blocking only 42% of particles when unknotted.