Now, more than a year into the COVID-19 pandemic, there are still many questions around wearing face masks. While the research is clear that wearing a mask can be effective in preventing the spread of coronavirus, one new question that many are asking is whether wearing two masks is better than one.

Erica S. Shenoy, MD, PhD, associate chief of the Infection Control Unit at Massachusetts General Hospital, answers common questions on masking outside of health care settings, and discusses the best type of mask to wear when out and about in your community.

What are the characteristics of a good-quality face mask?

The Centers for Disease Control and Prevention (CDC) is clear on its guidance that mask quality and fit are the most important features to consider. When there are gaps in the fit, droplets can leak out or in. Quality and fit can be achieved with:

  • A single mask with multiple layers that fits snugly against your face, or
  • A cloth mask over a disposable mask to push the disposable mask (which is a layer) closer to your face to achieve the snug fit
Review the features that make a good mask

What about wearing two disposable masks?

It is important to note that the CDC does not recommend wearing two disposable masks or using a disposable mask over a cloth mask. Neither of these approaches improves the function of the mask in a meaningful way.

What’s the benefit of choosing a well-fitting quality mask in preventing the spread of COVID-19?

Studies have shown that well-fitting masks are very effective at both containing the spread of infection if the wearer is sick and protecting the wearer from other infected people. A second mask may be needed to ensure fit, but there are simple options that you can consider to make sure that a single high-quality mask fits well:

  • Choose a mask with a nose wire so that you can bend the wire over your nose to fit your face
  • Use a mask fitter or brace over a disposable or cloth mask to close any side gaps
  • Make sure your mask has multiple layers
  • Knot and tuck” the ear loops of a single multi-layered mask so that it fits snugly on your face

However, not all of these are required simultaneously. For example, if you choose a multi-layered cloth mask with a nose wire that ensures a snug fit, then that is a high-quality, well-fitting mask. In this scenario, you may not need to use the “knot and tuck” strategy nor products such as mask fitters or braces.

Are there any risks to wearing multiple masks at once?

The only time that you should wear two masks is if you need to improve the fit of a disposable mask. In this instance, use a cloth mask over it to press it against your face.

The CDC does not recommend wearing two disposable masks, as that does not improve fit. They also stress not wearing more than one KN95 mask, or a mask over a KN95. KN95 masks have a filtering facepiece respirator and are similar to N95 masks, which are more commonly used in the U.S. in health care settings. It is important to note that 60% of KN95 masks in the U.S. are counterfeit and do not meet the National Institute for Occupational Safety and Health requirements. The CDC has an overview of the various types of masks available and when to use them.

Are cloth masks okay to wear, or should people be investing in N95 masks instead?

Cloth masks are not only okay, but they are also recommended! Follow the simple guidance from CDC when choosing a cloth mask.

Once I have received the vaccine, is it still important to wear a mask and/or practice physical distancing outside of my household?

For now, wearing a mask and social distancing are still important even when we are fully vaccinated. This is because:

  1. Most Americans are not vaccinated yet
  2. While we know that the vaccine protects you from getting sick, we don’t know yet if vaccines prevent vaccinated individuals from passing on the virus. This means that they could be a risk to others who are not vaccinated or immune
  3. Most locations still have widespread community transmission. Eventually, we will start moving towards our pre-pandemic lives, but we need to continue to do what we have been doing for now
Read Mass General Brigham’s answers to commonly asked questions about the COVID vaccine

When I come to Mass General, what type of mask will I be asked to wear?

Patients and visitors to Mass General will be issued a single, hospital-grade medical mask. This mask has multiple layers and meets hospital standards. Non-hospital issued masks are not permitted on our premises.

Are two masks better than one?

Ultimately, wearing one well-fitting mask will provide plenty of protection. And the most protection is when you and the person you are interacting with are both wearing a high quality, well-fitting mask. If your current mask still leaves gaps, then consider some of the options described above.

Read the CDC’s updated mask recommendations to learn how to improve the fit of your mask so that it is as effective as possible.