EPA researchers quantify how beards affect mask effectiveness against COVID-19

Research from the Environmental Protection Agency (EPA) suggests that although beards decrease the effectiveness of face masks for preventing the spread of COVID-19, covering the beard can help address that deficit.

Beards are known to interfere with the fit of a face mask, and multiple regulatory agencies cite facial hair as a contraindication to wearing tight-fitting respirator masks. Because of the key role of face masks in controlling the spread of COVID-19, along with the popularity of beards among young men, the EPA researchers assessed how beard length affects the fitted filtration efficiency (FFE) of multiple face mask styles. The findings were published on May 18 by the Journal of Exposure Science & Environmental Epidemiology.

Ten volunteers - five with beards ranging from 9 mm to 30 mm, and five with no facial hair - were tested while wearing different face masks. One bearded volunteer also was tested with and without a yoga-style exercise resistance band covering his beard.

The researchers found that the effect of beards on the FFE of N95 masks was variable, but that longer beards decreased the FFE in some men by up to 25% compared with no facial hair. The negative effect of beards was more notable for the KF94 and KN95 masks, which lost up to 40% of their FFE. Surgical masks and cotton masks had poor FFE regardless of beard status.

Covering the beard with an exercise band improved the FFE of the N95 respirator significantly, raising it above its rated performance level of 95%. Use of the band also produced marked improvements in the FFE of the KF94 and KN95 masks (approximately 30% and 20% improvements, respectively). The FFE of the surgical mask increased by a similar amount with the use of the band, while that of the cloth mask was raised only marginally.

"The presence of a beard is likely to impact fit parameters for many available styles and it is worth considering limiting its length, completely shaving (if feasible), or covering beards to achieve better filtration performance," the authors wrote.

Read the study: https://tinyurl.com/jj424sc8