UPDATED: Version 3.0, Updated November 9, 2020
There is general acceptance that use of face covering (non-medical masks) can limit the spread of COVID-19, not primarily as personal protective equipment but protecting the spread from an individual who is pre-symptomatic, has minimal symptoms or may be asymptomatic1-3
. There are multiple types of masks3-4
. This is now a standard recommendation from CDC1-5
and is required by many localities or employers and the issue of those who “cannot tolerate” a face covering has become an issue. Some do not wear the mask properly, covering only the mouth (or nose) or worse and a chin covering. Another concern is that some are now using face coverings which have one-way exhalation valves. The goal of the face covering is to minimize the spread of respiratory droplets from one individual to another, especially in those situations where physical distancing cannot be assured. CDC offers guidance on how to select, clean and wear a non-medical mask or face covering.3
Attempting to address the discomfort from wearing a face covering by using one with an exhalation valve is not acceptable5
. N95s respirators with an exhalation valve may be used in health care setting where the concern is to protect the wearer. The valve does not filter the air when the wearer breathes and therefore does not prevent the wearer from spreading may allow viral particles to be transmitted through the exhalation valve. In the community situation, where it is as important to prevent the virus from spreading from the wearer to others, a face covering with an exhalation valve should not be used. If an individual only has a face covering or mask with a valve or wishes to use that type of mask when others are not nearby, they can cover the exhalation valve with a surgical mask or a cloth face covering that does not interfere with the respirator fit2, 7
. Many businesses8
are now prohibiting the use of face coverings with a valve to meet a face covering requirement. There is also some question of whether a “gaiter” type of face covering is an acceptable alternative, with the evaluation of gaiter material and structure under investigation3
The first consideration is whether the individual who reports that they cannot tolerate the face covering has tried the various styles available. There are differences in material, how they are secured (around the ears or behind the head) and whether they cover just the nose and mouth or extend to the neck as well. The important factor is that they do cover the nose and mouth (wearing a face covering below the nose is not effective)2,3,5,6
Transparent physical barriers, such as plexiglass help provide protection from respiratory particles and can provide an alternative for individuals who cannot tolerate face coverings. They are often used for additional protection along with face coverings in jobs such as retail cashiers, meat packers, or office workers when it is difficult to maintain proper physical distances. Some states with face covering requirements permit these barriers for certain jobs in lieu of face coverings. Although they can mitigate the spray of droplets, they are unlikely to capture fine particles (aerosols)9
. If a workplace chooses to utilize these as physical barriers, factors for selection should include; scratch and impact resistance, cleaning and ventilation requirements and dimensions of the barrier. These should also be considered potentially contaminated and should be cleaned as any high touch area but being careful to not use products which might damage the surface. Ventilation requirements must be considered to avoid interference with HVAC systems. The dimensions of the barrier should be sufficient to block the breathing zone of those on all sides, both sitting and standing (should extend above the head of the tallest user). It should be as wide as possible, ideally at least 6 feet to provide sufficient work space. Any necessary openings should be as small as possible and not directly in front of any user and out of all breathing zones.
Another option would be to have that individual work in an area where there is no, or limited exposure to others where duration of face covering use could be minimized.
While the CDC suggested the use of face shields as PPE in health care settings when face masks are not available10
, some have advocated for their use as a replacement for face coverings in non-healthcare settings. In the health care setting, a face shield, is often used as PPE as an adjunct to a face mask. The face shield is used to protect the eyes and in conjunction with the mask, the nose and mouth from splashes and other droplets11-12
. They also add protection of the face skin from contamination by aerosol droplets and block touching a face mask or N 95 worn under a face shield. Given that they do not reliably fit close to nose and mouth, they will not provide as much protection to others from droplets emitted from the nose or mouth as would a face covering. Some are designed to protect only the face, while others may extend to the neck or sides of the head. Some are designed to protect against splashes and others may provide both splash and impact protection. A face shield should fit snugly, without gaps between forehead and shield, many will not achieve this and if tight, may lead to headache which would limit their prolonged use. Although there is limited evidence for the use of face shield those that wrap around the sides of the wearer’s face and extend below the chin or are hooded face shields may be better than others2
Many of the face shields are designed for single use and prolonged use or use of cleaning products may affect fit or surface integrity. The type of material use could affect sturdiness leading to crimping, bending or tearing and affect air flow. Individuals who do not tolerate face coverings may also be unable to tolerate face shields due to claustrophobia or other concerns. They will be difficult to wear with corrective lenses, may interfere with vision and may fog. CDC now indicates that face shields should not be used as a replacement for a face covering2
but may be considered in limited circumstances.
Other challenges which may affect the effectiveness of a face shield:
Distance of the shield from the nose and the angle of the shield, and how far they should extend from top to bottom or side to side. Airflow and flow of respiratory droplets around the face shield is unknown and may vary depending on design. There are currently no universal standards for face and eye protection from biological hazards10,13
. The various models that have been used during the pandemic have not been evaluated by NIOSH or FDA. When used, face shields would need to be considered as potentially contaminated and should be handled, cared for and cleaned appropriately. Given the above concerns, face shields as an adjunct to face coverings may still have value in non-health care settings, especially in those positions where physical distance cannot be maintained where there is high community spread as they would cover the eyes and could provide some additional personal protection to the individual. Recently the CDC has indicated that it “does not recommend use of face shields for normal everyday activities or as a substitute for cloth face coverings because of a lack of evidence of their effectiveness for source control 2
And while not part of the question, I did want to address the situation where the person is truly unable to wear a face covering due to an actual disability
and alternative solutions are not readily available. It is considered that requiring an individual to wear PPE or a face covering during the pandemic, is a legitimate business requirement 14
and may be mandated by some local or state governments. In this situation, if the individual makes a request for an accommodation due to disability, (not wanting to wear a mask would not be a disability, chronic respiratory problems might be) the employer would need to engage in an interactive process under the Americans with Disabilities Act and evaluate whether a reasonable means to accommodate exists.
Possible accommodations might include:
- Use of alternate types of face covering
- Physical barriers or working in more isolated area
- Remote working
- If all else fails, providing the employee and leave of absence until face covering are no longer required.
While employers may be required to accommodate an employee who reports and inability to wear a face covering, physicians15-16
or other “public accommodation businesses such as lodging, dining, shopping, or other medical services may be able refuse to allow guest who refuse to wear a face covering 15-17
. Local requirements or limitation on requiring a face covering should be considered.