File Description: 

This document provides guidance for masking and addresses questions regarding double masking. Below is the content of the document. Uploaded: 1.29.21 


Renewed discussions regarding the potential benefit of double masking on source control and prevention of COVID-19 transmission have prompted many questions about whether changes will be made to the current DUHS masking policy.  Eleven months of experience has demonstrated that the healthcare setting is a well-controlled environment with robust infection prevention protocols in place that help limit the transmission of COVID-19. The healthcare setting is distinctly different than a community setting without these strict controls in place and much of our workforce is now vaccinated.  Furthermore, masks used in healthcare settings are also assessed for filtration efficacy and meet regulatory standards before distribution.  


Unfortunately, no well-designed studies have been conducted to scientifically answer the question “are two masks better at preventing COVID-transmission than one?” One study demonstrates the impact of wearing a well-fitting mask to improve source control and how wearing an overlying mask may improve overall mask fit.1 Logically, having additional layers of barrier protection over the nose and mouth would reduce particle dispersion. 


With the now broadly circulating B1.1.7 (UK) variant and concern over the B1.351 (S. African) variant in the U.S., many are looking for ways to augment the infection prevention strategies in place – double masking is one such strategy. As we strive to continuously update our COVID-19 guidance to keep in step with the scientific community, we updated masking guidance language as follows. We will continue to closely monitor COVID-19 infections among team members and, should we see any concerning trends or signals, will reevaluate our recommendations below:


Double masking is optional for patients, visitors, and Duke team members at this time. However, we do encourage team members to make simple mask modifications to improve fit, and thereby improve source control. More tips to make your mask fit better are available on the Infection Prevention webpage.

  • For patients and visitors: Patients and visitors will be offered a Duke-issued medical mask when entering the healthcare space. If the patient or visitor is wearing their own mask, they may place the Duke-issued mask over the top of their mask if they choose. Patients and visitors may wear their own masks as long as they adequately cover the mouth and nose and have ties or earloops. Patients and visitors may not wear neck gaiters or bandanas. Patients and visitors may not wear any mask with an exhalation valve. Simple mask modifications can be made to help improve fit, if needed. Review a full list of our patient and visitor masking guidelines.
  • For Duke team members: Duke team members are still required to wear a Duke-issued medical mask in the healthcare setting. Should team members choose to wear a second mask, they may place a Duke-issued mask over the top of their own mask. Simple mask modifications can be made to help improve fit, if needed. Wearing the Duke-issued medical mask as the outer layer provides a fluid-resistant barrier. We continue to recommend eye protection during patient care activities. Review a full list of our team member masking guidelines.

Mask modifications:

There are many options to make your mask fit better if it is too loose.

  • This video demonstrates one way to make your mask tighter.
  • A second option is to simply twist the straps of your Duke-issued mask before you put it on so that the elastic is in a crisscross.
  • Another option is to use a plastic clip to pull the straps tighter behind your head.



Mueller et al. Matter 2020 Sep 2;3(3):950-962.

The information on this site is intended solely for the internal use by Duke University Health System, its medical staff, clinicians and staff and any and all content or services available on or through this website is prohibited to be shared with external parties with the exception of those marked as patient communications that would be disclosed to patients.