CDC Says Double-masking Offers Additional Protection Against COVID-19

In a recent report, the Centers for Disease Control and Prevention (CDC) released findings on maximizing the fit of cloth and medical procedure masks to reduce COVID-19 transmission and exposure. Notably, the research found that double-masking substantially improved source control of COVID-19 and reduced wearer exposure.

According to the CDC’s report, double-masking refers to fitting a cloth mask over a medical procedure mask. Additionally, the findings discussed knotting the ear loops of a medical procedure mask and then tucking in and flattening the extra material close to the face. The report states that each of these modifications substantially improved source control and reduced wearer exposure.

The CDC conducted experimental simulations in January, and found that double-masking decreased aerosol particle transmission by around 95% at a 6-foot radius.

According to the CDC, these experiments highlight the importance of a good fit to maximize mask performance, stating that there are multiple simple ways to achieve better fit of masks to more effectively slow the spread of COVID-19.

The CDC stated that this research did face limitations, including that the research on double-masking focused on fitting a cloth mask over a medical procedure mask. CDC research has not yet addressed additional combinations such as cloth-over-cloth double-masking.