Can sunlight disinfect your face mask? It depends

Masks. Everywhere you look, masks, especially in public places. When you step out of your house and go anywhere… from the grocery store to the gas station, masking up has become a necessary step, like it or not.

In fact, experts across the globe have recommended wearing face masks thanks to their ability to filter nanoscale aerosol particles, like the ones that fly out when you cough or sneeze, in order to reduce the spread of COVID-19.

As the pandemic drones on, we’re learning more about them, from how they help and even what materials may work best.

However, while mask-wearing has the potential to help keep you safe, the truth is, they may also help spread germs…

A magnet for germs

Live bacteria and viruses can live on the surface of masks. To be clear — contagious bacteria and viruses.

This means that every single time you reach up to adjust that mask, go to take it off, or even pick it up to toss it in the wash, you’re could be coming in contact with the exact germs you’re trying to avoid.

You could transfer these germs to your eyes, nose or mouth, swipe them onto your phone screen, pass them to your child or spouse, or drop them onto your kitchen countertop. Anywhere you touch after touching the germ-ridden surface of that mask is fair game.

And sadly, while the advice to wear a mask has been clear, procedures for disinfecting those masks have not always received the same attention.

This cotton disinfects in the light

That’s because researchers reporting in ACS Applied Materials & Interfaces have developed a special type of cotton face mask that kills up to 99.9999% of bacteria and viruses within just 60 minutes of exposure to good old sunlight.

Yup, with these new masks, you can simply slip it off by the straps before walking into your house, drop it outside on a table or chair in the sun and leave it for an hour.

And it’s disinfected. Pretty cool, right?

Even more amazing, the scientists say that it’s not only sunlight that works to kill off viruses and bacteria on a mask’s surface but also lights inside offices and buildings too — although since they’re less intense than sunlight, they do take longer.

However, this means that as you’re wearing your mask, the lights around you are actually disinfecting it!

The secret’s in the photosensitive dye

The team found that a fabric made with a dye called rose Bengal, which is a photosensitizer (makes the cloth sensitive to light) killed 99.9999% of bacteria added to the fabric within 60 minutes of daylight exposure.

And it inactivated 99.9999% of T7 bacteriophage — a virus thought to be more resistant than some coronaviruses — within 30 minutes.

Yup, you read that right…

Just 30 minutes to kill off a virus that’s harder to destroy than some coronaviruses, like the one raging across our country right now.

Further testing showed that the material could be hand-washed at least 10 times and constantly exposed to daylight for at least seven days without losing its antimicrobial activity.

In fact, the fabric was so impressive that the team is now looking at how they can make it into protective suits as well as face masks.

So, remember, if you want to find these masks when they become available, look for ones made from fabric dyed with rose Bengal to solve your mask disinfection issues and stay safer.

Unfortunately, the science on whether sunlight can kill germs on masks made from other materials seems to be inconclusive. Right now, the best way to sanitize your regular cloth masks is by washing them with laundry detergent.


Cloth face masks that can be disinfected by the sun — EurekAlert!

Dr. Adria Schmedthorst

By Dr. Adria Schmedthorst

Dr. Adria Schmedthorst is a board-certified Doctor of Chiropractic, with more than 20 years of experience. She has dedicated herself to helping others enjoy life at every age through the use of alternative medicine and natural wellness options. Dr. Schmedthorst enjoys sharing her knowledge with the alternative healthcare community, providing solutions for men and women who are ready to take control of their health the natural way.