The at-home hack that helps face masks fight COVID-19 better

It’s a smart look for a home invader — and an even smarter one for the COVID cautious.

Pantyhose are perhaps the unlikeliest weapon in the fight against the respiratory virus, but a new study by University of Cambridge researchers shows that stockings can help improve KN95 mask filtration by creating a better fit.

The study, published last week, tested a variety of masks and additional materials that might help improve the masks’ efficacy. Along with the pantyhose-over-the-mask trick, researchers tested other “fit hacks” including using rubber bands to shape the mask over the face and taping down the edges of the mask to the face.

Volunteers tested the masks by performing various exercises to mimic the motions of real life, such as talking, nodding and taking deep breaths. Then, each mask combination was given a “fit factor” score.

Pantyhose yielded the best fit for KN95 wearers, and thus most reliable protection, with a fit factor rating of 27.7, followed by the tape method, with 14.7. A hack using gauze to stuff the masks’ gaps around the face yielded only a “minor” improvement of 2.7.

The polyester undergarment did the same for paper surgical masks, improving them by a factor of 7.2.

One common solution to ill-fitting surgical masks has been to bind the two ends of the band so the masks are more taut. Unfortunately, this technique didn’t hold up quite as well in tests, with the fit improved by just 2.5 points.

But the most effective approach may also be one of the most intolerable, as participants reported “high levels of discomfort” while wearing the pantyhose, though none of the mask combos tested saw high marks for wearability.

Still, these hacks are “accessible to the general public,” researchers emphasized, and they encouraged health care and other essential workers to consider boosting their protective-gear game.