Is a level 3 mask and face shield equivalent to wearing a N95?

By Olivia Wann, JD
Modern Practice Solutions, LLC

A surgical mask is fluid-resistant and provides protection against large droplets, splashes, or sprays. The N95 respirator is effective against small particle aerosols and large droplets.

The surgical mask is loose-fitting and leakage occurs around the edge of the mask when the user inhales. The N95 respiratory is tight-fitting. When properly fitted and donned, minimal leakage occurs. CDC published the Interim Infection Prevention and Control Recommendations for Healthcare Personnel During the Coronavirus Disease 2019 (COVID-19) Pandemic, updated September 20, 2021. 1 In this guidance, CDC recommends implementing the universal use of personal protective equipment for healthcare personnel.

CDC plainly states that in facilities located in counties with substantial or high transmission risk to COVID, NIOSH-approved N95 or equivalent or high -level respirators should be used for all aerosol-generating procedures. CDC also recommends eye protection to include goggles or a face shield that covers the front and sides of the face for all patient encounters.

This guidance corresponded with federal OSHA’s guidance for dentistry indicating that NIOSH-certified, disposable N95 filtering facepiece respirator (or better) offers more protection to workers who may encounter asymptomatic or pre-symptomatic patients who can spread COVID-19 or other aerosolizable pathogens. 2
OSHA published the Occupational Exposure to COVID-19 Emergency Temporary Standard (known as “ETS”) effective June 21, 2021. Your workplace is exempt from this standard if you are (1) non-ambulatory care setting, (2) all non-employees are screened prior to entry; and (3) people with suspected or confirmed COVID-19 are not permitted to enter. The standard is also exempts if all the workers are vaccinated 3 If the ETS did apply, respirators are encouraged with a mini respiratory protection program.

Tennessee Department of Labor and Workforce Development (TOSHA) published its COVID-19 Emergency Temporary Rule August 23, 2021. The rule does not apply if the facility is a non-hospital ambulatory care setting where all non-employees are screened prior to entry and people with suspected or confirmed COVID-19 are not permitted to enter. 4

Does this mean dental offices are not obligated to wear N95s? Are employees adequately protected with a regular level 3 mask and a face shield? Not necessarily. It is clearly recognized that the N95 filtering facepiece respirator offers greater protection against SARS-CoV-2 (the virus that causes COVID-19) than a regular surgical mask.

Protection against COVID-19 is a multi-layer approach that involves work practice and engineering controls, administrative controls, and the appropriate personal protective equipment. TOSHA compared it to slices of Swiss cheese. If you layer the slices of Swiss cheese adequately, you can close up any holes. A single approach is clearly inadequate.

Let’s evaluate your engineering controls:

  • Have you implemented HEPA filtration?
  • Does your facility have air filters with a Minimum Efficiency Reporting Value (MERV) of 13 or greater? In addition to high volume evacuation, do you use a rubber dam or external suction?
  • Now let’s focus on the administrative controls: Do you have a process to screen all non-employees for COVID-19 symptoms? Do you prohibit from entry anyone with suspected or confirmed COVID-19?
  • Think about asymptomatic patients who may not feel sick and yet have COVID-19 and are capable of transmitting the virus. Also, fully vaccinated persons who become infected with the Delta variant can be infectious and spread the virus to others. Do we have a false sense of security?

If you feel confident in your program and the safety of your team, an option is to make respirators voluntary use providing the state allows this choice. This decision would reflect that you, as the employer, made a determination that respiratory protection is not needed for an airborne hazard—whether that hazard is dust in a factory setting or SARS-CoV-2 in a healthcare setting.

If a dental office only allows voluntary use of filtering facepiece respirators after determining that such use will not in itself create a hazard, the dental office’s only
further obligation under the Respiratory Protection standard is to provide a copy of Appendix D (for voluntary use respirators) of the 1910.134 Respiratory Protection Standard. Medical evaluations and fit tests are not necessary when permitting employees to wear filtering facepiece respirators on a voluntary basis.

However, other respirators, such as a tight-fitting, full or half-face respirator would require a medical evaluation and fit test even if worn voluntarily. The filtering facepiece respirator such as the N95 is the only exception.

This is supported by OSHA where it reads: 1910.134(c)(2)(i)
An employer may provide respirators at the request of employees or permit employees to use their own respirators if the employer determines that such respirator use will not in itself create a hazard. If the employer determines that any voluntary respirator use is permissible, the employer shall provide the respirator users with the information contained in Appendix D to this section

“Information for Employees Using Respirators When Not Required Under the Standard” and 1910.134(c)(2)(ii)

In addition, the employer must establish and implement those elements of a written respiratory protection program necessary to ensure that any employee using a respirator voluntarily is medically able to use that respirator and that the respirator is cleaned, stored, and maintained so that its use does not present a
health hazard to the user. Exception: Employers are not required to include in a written respiratory protection program those employees whose only use of respirators involves the voluntary use of filtering facepieces (dust masks).

Certain states require the use of respirators in dentistry. For example, dental employers must provide respirators to unvaccinated employees under California-OSHA emergency standards which took effect June 17, 2021.

We, at Modern Practice Solutions, are going to recommend the best safety solution in light of the spread of the variants that spread faster than the original SARS-CoV-2 strain. This means for all aerosol-generating procedures, utilize a NIOSH-certified N95 or equivalent in communities whose transmission risk to COVID-19 is substantial to high as recommended by CDC. Use CDC’s COVID-19 tracker to evaluate this risk week to week.

If you need assistance with your OSHA compliance program, please email me at

1 Interim Infection Prevention and Control Recommendations for Healthcare Personnel During the Coronavirus Disease 2019 (COVID-19) Pandemic,

2 Dentistry Workers and Employers,

3 Occupational Exposure to COVID-19; Emergency Temporary Standard,

4 The Tennessee Department of Labor and Workforce Development Division of Occupational Safety and Health, Occupational Safety and Health Standards COVID-19 Emergency Temporary Rule,

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