Strategies for Conserving the Supply of N95® Filtering Facepiece Respirators

N95 filtering facepiece respirators (commonly called N95 respirators) include Surgical N95s, a type of respirator sometimes needed in healthcare settings. Surgical N95s have fluid resistance, flammability, and biocompatibility protections. In the United States, all N95 respirators used in occupational settings are approved by the National Institute for Occupational Safety and Health (NIOSH) and used in accordance with Occupational Safety and Health Administration (OSHA) standards.

Conventional Capacity Strategies

Training on use and indications for use of N95 respirators
It is important to train healthcare personnel (HCP) on indications for use and the proper use of N95 respirators. The OSHA Respiratory Protection standard requires employers to provide respirator training to an employee prior to use in the workplace. For example, HCP should be educated on the use of N95 respirators when caring for patients managed with airborne precautions, and other instances for respirator use, such as when indicated for the performance of aerosol generating procedures.

Understanding proper use of respirators, including donning (putting on) and doffing (taking off), limitations on their use, and maintenance, is essential for effective use of respiratory protection. HCP should be thoroughly trained before they are fit tested to ensure they are comfortable donning the respirator and know how to conduct a user seal check. HCP should be trained on the respirator they are expecting to use at work.

Just-in-time fit testing
Just-in-time fit testing refers to the capacity of healthcare facilities to do larger scale evaluation, training, and fit testing of employees when necessary during a pandemic. Facilities may adopt a plan to use the “just-in-time” method for fit testing, which has been incorporated into pandemic plans for many facilities. For large facilities, it may not be feasible to fit test all employees, especially if their job does not typically place them at risk for exposure to airborne infectious diseases like tuberculosis. Healthcare facilities should begin training and start to plan for fit testing as soon as they expect to receive patients with a respiratory infectious disease requiring respiratory protection. It is essential to train and fit test HCP prior to receiving patients. This just-in-time fit testing approach could also be used when healthcare facilities must expedite fit testing after receiving different respirators than their usual supply because of shortages.

Limiting respirators during training
To conserve the supply of N95 respirators, healthcare facilities should understand which of their HCP need to be in a respiratory protection program and thus medically evaluated, trained, and fit tested. If training and fit testing are conducted during two separate steps, it is possible to allow one-time re-use of N95 respirators used by individual HCP during training and then fit testing. Employees should be fit tested after they are comfortable donning the respirator and have performed a user seal check.

Qualitative fit testing
Preferential use of qualitative fit testing can preserve some respirators for further use in training. Respirator fit test methods are classified as either qualitative or quantitative, and there are multiple protocols of each classification that are NIOSH-recommended or meet the requirements of OSHA’s Respiratory Protection Standard. A qualitative fit test is a pass or fail test to assess the adequacy of respirator fit that relies on the individual’s sensory detection of a test agent. A quantitative fit test numerically measures the effectiveness of the respirator to seal with the wearer’s face, without relying on the wearer’s voluntary or involuntary response to a test agent. Quantitative fit tests involve adaptation of the respirator to the fit testing equipment, which can involve making holes in the respirator.

Many healthcare systems already use qualitative fit test methods for fit testing HCP. For those using quantitative fit test methods, consider using qualitative fit test methods to minimize the destruction of an N95 respirator used in fit testing and allow for the re-use of the same N95 respirator by the HCP for training. Qualitative fit methods may also allow for rapid fit testing of larger numbers of HCP. Any switch in methods should be assessed to ensure proficiency of the fit testers in carrying out the test.

Use of NIOSH Approved® respirator alternatives to N95 respirators
Use NIOSH Approved alternatives to N95 respirators where feasible. These include other classes of filtering facepiece respirators, elastomeric half-mask and full facepiece air-purifying respirators, and powered air purifying respirators (PAPRs). All of these alternatives will provide equivalent or higher protection than N95 respirators when properly worn. NIOSH maintains a searchable, online version of the Certified Equipment List identifying all NIOSH Approved respirators.

Filtering facepiece respirators
Every other NIOSH Approved filtering facepiece respirator is at least as protective as the N95 respirator. These include N99®, N100®, P95®, P99, P100®, R95®, R99, and R100. These respirators require annual fit testing.

Elastomeric respirators
Half-mask and full-facepiece elastomeric respirators are tight-fitting respirators that are made of synthetic or rubber material permitting them to be repeatedly disinfected, cleaned, and reused. They are equipped with replaceable filter cartridges. When equipped with a particulate filter (N95, N99, N100, P95, P99, P100, R95, R99, and R100), they are at least as protective as anN95 respirator. Elastomeric respirators require annual fit testing. Elastomeric respirators with unfiltered exhalation valves should not be used when a source control device is required. The NIOSH Certified Equipment List identifies the elastomeric respirators without exhalation valves or with filtered exhalation valves that may act as a source control device. Facilities using elastomeric respirators should have up-to-date cleaning and disinfection procedures, which are an essential part of use for protection against infectious agents.

Powered air-purifying respirators (PAPRs)
PAPRs are reusable respirators that are typically loose-fitting hoods or helmets. These respirators are battery-powered with a blower that pulls air through attached filters or cartridges. When equipped with a particulate filter, they provide a higher level of protection than N95 respirators. Loose-fitting PAPRs do not require fit-testing and can be worn by people with facial hair. PAPRs should not be used in surgical settings due to concerns that the blower exhaust and exhaled air may contaminate the sterile field. Facilities using PAPRs should have up-to-date cleaning and disinfection procedures, which are an essential part of use for protection against infectious agents.

Contingency Capacity Strategies

Prioritize respirators for HCP who use them for respiratory protection
In times of anticipated shortages, prioritize N95 respirators for HCP who are recommended to wear them as respiratory protection when caring for patients. In this scenario, respirators should not be used by HCP who are only using them for source control.

Temporarily suspend annual fit testing
Facilities can consider temporarily suspending annual fit testing of HCP in times of expected shortages; this may require enforcement discretion by OSHA. However, an initial fit test with the same model, style, and size is still necessary. In addition, a seal check should be performed on each use as with any respirator use.

Use of any NIOSH Approved N95 respirator
In times of anticipated shortage, the FDA may issue an emergency use authorization to allow healthcare settings to use N95 respirators without the additional fluid resistance, flammability, and biocompatibility protections. If N95 respirators with these additional protections (i.e., Surgical N95s) are not available, and there is a risk that the worker may be exposed to splashes, sprays, or splatters of blood or body fluids, then a face shield should be worn in addition to the N95 respirator. HCP who are working in a sterile field or who may be exposed to splashes, sprays, or splatters of blood or body fluids should be prioritized to use Surgical N95s.

Use of N95 respirators beyond the designated shelf life for training and fit testing
In times of anticipated shortage, consider using N95 respirators beyond the designated shelf life. However, respirators beyond the designated shelf life might not perform to the requirements for which they were approved. Because of this, use of respirators beyond the designated shelf life could be prioritized for situations where respiratory protection is not recommended, such as training, fit testing, and source control. It is important to check that components such as the straps, nose bridge, and nose foam material did not degrade, which can affect the quality of the fit, and seal and therefore the effectiveness of the respirator. As respirators beyond the designated shelf life can still serve an important purpose, healthcare facilities should retain and reserve all unused N95 respirators during pandemics or epidemics.

Extended use of N95 respirators as respiratory protection
During conventional use in patient care, a disposable respirator should be removed and discarded between patients. However, practices allowing extended use of N95 respirators as respiratory protection, when acceptable, can also be considered as a contingency capacity strategy. Extended use refers to the practice of wearing the same N95 respirator for repeated close contact encounters with several different patients, without removing the respirator between patient encounters. Extended use is well suited to situations wherein multiple patients with the same infectious disease diagnosis, whose care requires use of a respirator, are cohorted (e.g., housed on the same hospital unit). Extended use can also be considered for care of patients with tuberculosis, varicella, measles, and other infectious diseases where use of a NIOSH Approved particulate respirator is recommended.

When practicing extended use of N95 respirators over the course of a shift, consider 1) the ability of the N95 respirator to retain its fit, 2) contamination concerns, 3) practical aspects (e.g., meal breaks), and 4) comfort of the user. N95 respirators should be discarded immediately after being removed. If removed for a meal break, the respirator should be discarded and a new respirator put on after the break.

N95 respirators should be discarded when contaminated with blood, respiratory or nasal secretions, or other bodily fluids from patients. HCP can consider using a face shield over the respirator to reduce contamination of the respirator, especially during aerosol generating procedures or procedures that might generate splashes and sprays. A medical mask should not be placed over a respirator because it may compromise the fit of the respirator. For re-use of N95 respirators in addition to extended use, please see the re-use section under crisis capacity strategies below.

Crisis Capacity Strategies

Use of respirators beyond the designated shelf life for healthcare delivery
Consider using NIOSH Approved N95 respirators beyond the designated shelf life for care of patients with diseases for which a respirator is recommended during their care (e.g., COVID-19, tuberculosis, measles, varicella). Many models found in U.S. stockpiles and stockpiles of healthcare facilities were found to continue to perform in accordance with NIOSH performance standards. However, fluid resistance and flammability were not assessed. Decisions to implement this strategy would require authorization by the FDA or enforcement discretion by OSHA.

It is optimal to use these respirators in the context of a respiratory protection program that includes medical evaluation, training, and fit testing. If used in healthcare delivery, it is important to check that components such as the straps, nose bridge, and nose foam material did not degrade, which can affect the quality of the fit, and seal and therefore the effectiveness of the respirator. It is also particularly important that HCP perform the seal check prior to entering a patient care area. CDC does not recommend using N95 respirators beyond the designated shelf life in surgical settings.

Use of respirators conforming to international standards with similar filtration efficiencies to NIOSH Approved respirators (International Respirators)
In the United States, OSHA mandates that workplaces must use respirators approved by NIOSH to assure that these devices provide sufficient protection. Other countries have standards for respirators with similar filtration efficiencies to NIOSH Approved respirators. However, some evaluation methods are different such as approaches to ensure the ongoing quality of the respirators. To better ensure that international respirators will provide the protections claimed, purchasing respirators supplied by entities that are also NIOSH approval holders for other respirator products is recommended. Therefore, they may be suitable alternatives to provide protection in healthcare facilities during pandemics when supplies are short. Decisions to implement this strategy would require authorization by FDA or enforcement discretion by OSHA.

When purchasing international respirators supplied by entities that are NIOSH approval holders for other respirator products is not possible, verify that the respirators were tested to the standards by a third-party accredited test laboratory to increase confidence that these products will perform as indicated. International respirators supplied by entities that are not NIOSH approval holders should not be used when an N95 respirator is recommended to be worn.

Limited re-use of N95 and other disposable respirators
Re-use refers to the practice of using the same disposable respirator by one HCP for multiple encounters with different patients but removing it (doffing) after each encounter. This practice is often referred to as “limited reuse” because restrictions are in place to limit the number of times the same respirator is reused.

For pathogens for which contact transmission is not a concern, routine limited re-use of single-use disposable respirators has been practiced for decades. For example, for tuberculosis prevention, a respirator classified as disposable can be reused by the same provider as long as the respirator maintains its structural and functional integrity. If reuse must be implemented in times of shortages, HCP could be encouraged to reuse their N95 respirators when caring for patients with tuberculosis disease first. Limited re-use of N95 respirators when caring for patients with other infections where respiratory protection is recommended might also become necessary. However, it is unknown what the potential contribution of contact transmission is for some respiratory pathogens, and caution should be used.

It is important to consult with the respirator approval holder regarding the maximum number of donnings or uses they recommend for the N95 respirator model. If no approval holder guidance is available, data suggest limiting the number of reuses to no more than five total uses (five total donnings) per device by the same HCP to ensure an adequate respirator performance. An example of this scenario is: an HCP wears an N95 respirator to care for a patient, removes it after exiting the room, and then later returns to care for the patient and puts the same respirator on again. This would count as two uses or donnings. HCP should always inspect the respirator and perform a seal check upon donning a re-used respirator. N95 respirators and other disposable respirators should not be shared by multiple HCP.

During times of crisis, practicing limited re-use while also implementing extended use can be considered.
If limited re-use is practiced on top of extended use, caution should be used to minimize self-contamination and degradation of the respirator. If no manufacturer guidance is available, a reasonable limitation should continue to be five total donnings regardless of the number of hours the respirator is worn. An example of this scenario is: An HCP wears a respirator during the first 3 hours of their shift, removes the respirator to eat lunch, and puts it back on after lunch. This would count as two uses or donnings. Some N95 respirators might be worn after more than five donnings, but the structural and functional integrity may be compromised.

N95 respirators should not be re-used when caring for patients with varicella or other pathogens that can also be transmitted via contact routes, as contact transmission poses a risk to HCP who implement this practice.

Respirators soiled or grossly contaminated with blood, respiratory or nasal secretions, or other bodily fluids from patients should be discarded. HCP can consider using a face shield or medical mask over the respirator to reduce and prevent contamination of the N95 respirator, especially during aerosol generating procedures or procedures anticipated to generate splashes and sprays. It is important to perform hand hygiene before and after the previously worn N95 respirator is donned or adjusted.

Use Enhanced Performance and Enhanced Performance Plus barrier face coverings
Enhanced Performance and Enhanced Performance Plus barrier face coverings (BFCs) are disposable or reusable BFCs that achieve a minimum of 50% filtration efficiency against particulates. They are intended to cover the nose and mouth. These BFCs meet the ASTM F3502-21 consensus standard and are tested by a laboratory. The manufacturer must specify how to wear it properly to reduce gaps and, if reusable, the number of times you can wash the BFC. They are intended primarily for source control and to provide a degree of particulate filtration to reduce the amount of inhaled particulate matter. However, they are not meant to replace respiratory protection, and they may not offer fluid resistance.

Prioritize the use of N95 respirators by activity type
Medical masks may need to be used when NIOSH Approved respirators and Enhanced Performance and Enhanced Performance Plus BFCs are so limited that it is no longer possible to have HCP wear respiratory protection when entering the room or care area of a patient for whom respirator use is recommended for their care. The use of N95 respirators, elastomeric respirators, or PAPRs should be prioritized for HCP with the highest potential for exposures including being present in the room during aerosol generating procedures performed on persons with transmissible infectious diseases. If medical masks are used instead of an N95 respirator, this strategy should be combined whenever possible with other recommended actions to reduce the risk for transmission including properly maintained ventilation systems, use of airborne infection isolation rooms, source control (i.e., masking of individuals who may be contagious), and maintaining physical distance from the patient.

Expedient patient isolation rooms for exposure risk-reduction
Portable fan devices with high-efficiency particulate air (HEPA) filtration that are carefully placed can increase the effective air changes per hour of clean air to the patient room, reducing risk to individuals entering the room without respiratory protection. NIOSH developed guidance for using portable HEPA filtration systems to create expedient patient isolation rooms. The expedient patient isolation room approach involves establishing a high-ventilation-rate, negative pressure, inner isolation zone that sits within a “clean” larger ventilated zone. In the absence of any remaining supply of N95 respirators, it may be possible to use this technology in conjunction with HCP wearing Enhanced Performance and Enhanced Performance Plus BFCs or well-fitting medical masks.

Ventilated headboards for exposure risk-reduction
NIOSH developed the ventilated headboard that draws exhaled air from a patient in bed into a HEPA filter, decreasing risk of HCP exposure to patient-generated aerosol. This technology consists of lightweight, sturdy, and adjustable aluminum framing with a retractable plastic canopy. The ventilated headboard can be deployed in combination with HEPA fan and filter units to provide surge isolation capacity within a variety of environments, from traditional patient rooms to triage stations, and emergency medical shelters. In the absence of any remaining supply of N95 respirators, it may be possible to use this technology in conjunction with HCP and patients wearing Enhanced Performance and Enhanced Performance Plus masks or well-fitting medical masks.

N95 and NIOSH Approved are certification marks of the U.S. Department of Health and Human Services (HHS) registered in the United States and several international jurisdictions.

N99, N100, R95, P95, P100, PAPR100-N, PAPR100-P, and HE are certification marks of the U.S. Department of Health and Human Services (HHS) registered in the United States.