Strategies for Optimizing the Supply of N95 Respirators
Once personal protective equipment (PPE) supplies and availability return to normal, healthcare facilities should promptly resume conventional practices. The supply and availability of NIOSH-approved respirators have increased significantly over the last several months. Check the NIOSH Certified Equipment List to identify all NIOSH approved respirators and approval holders.
Summary of Recent Changes
As of April 9, 2021
- Acknowledged that the supply and availability of NIOSH-approved respirators have increased significantly over the last several months
- For conventional capacity strategies
- Added language on extended use of N95 respirators as source control
- Added language on use of respirators with exhalation valves
- For contingency capacity strategies
- Added a strategy to prioritize respirators for HCP who are using them as PPE over those HCP who are only using them for source control
- For extended use of N95 respirators as PPE, clarified that N95 respirators should be discarded immediately after being removed
- For crisis capacity strategies
- Removed the strategy of using non-NIOSH approved respirators developed by manufacturers who are not NIOSH-approval holders
- Highlighted that the number of reuses should be limited to no more than five uses (five donnings) per device by the same HCP to ensure an adequate respirator performance
- Removed decontamination of respirators as a strategy with limited re-use
- Emphasized that facemasks for caring for a patient with suspected or confirmed SARS-CoV-2 infection should only be used for certain scenarios as a last resort if respirators are severely limited
- Removed the table “Suggested well-fitting facemask or respirator use, based upon distance from a patient with suspected or confirmed SARS-CoV-2 infection and use of source control”
Audience: These considerations are intended for use by federal, state, and local public health officials, respiratory protection program managers, leaders in occupational health services and infection prevention and control programs, and other leaders in healthcare settings who are responsible for developing and implementing policies and procedures for preventing pathogen transmission in healthcare settings.
Purpose: This document offers a series of strategies or options to optimize supplies of disposable N95 filtering facepiece respirators (commonly called “N95 respirators”) in healthcare settings when there is limited supply. It does not address other aspects of pandemic planning; for those, healthcare facilities can refer to COVID-19 preparedness plans. The strategies are also listed in order of priority and preference in the Summary for Healthcare Facilities: Strategies for Optimizing the Supply of N95 Respirators during the COVID-19 Response in an easy-to-use format for healthcare facilities.
Controlling exposures to occupational hazards is a fundamental way to protect personnel. Conventionally, a hierarchy has been used to achieve feasible and effective controls. Multiple control strategies can be implemented concurrently or sequentially. This hierarchy can be represented as follows:
- Engineering controls
- Administrative controls
- Personal protective equipment (PPE)
To prevent infectious disease transmission, elimination (physically removing the hazard) and substitution (replacing the hazard) are not typically options for healthcare settings. However, exposures to transmissible respiratory pathogens in healthcare facilities can often be reduced or possibly avoided through engineering and administrative controls and PPE. Prompt detection and effective triage and isolation of potentially infectious patients are essential to prevent unnecessary exposures among patients, healthcare personnel (HCP), and visitors at the facility.
N95 respirators are the PPE most often used to control exposures to infectious pathogens transmitted via the airborne route, though their effectiveness is highly dependent upon proper fit and use. N95 respirators are intended to be used once and then properly disposed of and replaced with a new N95 respirator. The optimal way to prevent airborne transmission is to use a combination of interventions from across the hierarchy of controls, not just PPE alone. Applying a combination of controls can provide an additional degree of protection, even if one intervention fails or is not available.
Respirators, when required to protect HCP from airborne contaminants such as some infectious agents, must be used in the context of a comprehensive, written respiratory protection program that meets the requirements of Occupational Safety and Health Administration (OSHA) Respiratory Protection standardexternal icon. The program should include medical evaluations, training, and fit testing.
Surge capacity refers to the ability to manage a sudden increase in patient volume that would severely challenge or exceed the present capacity of a facility. While there are no commonly accepted measurements or triggers to distinguish surge capacity from daily patient care capacity, surge capacity is a useful framework to approach a decreased supply of N95 respirators during the COVID-19 response. To help healthcare facilities plan and optimize the use of respiratory protection in response to COVID-19, CDC has developed a Personal Protective Equipment (PPE) Burn Rate Calculator. Three general strata have been used to describe surge capacity and can be used to prioritize measures to conserve N95 respirator supplies along the continuum of care.1
- Conventional capacity: measures consisting of engineering, administrative, and PPE controls should already be implemented in general infection prevention and control plans in healthcare settings.
- Contingency capacity: measures that may be used temporarily during periods of expected N95 respirator shortages. Contingency capacity strategies should only be implemented after considering and implementing conventional capacity strategies. While current supply may meet the facility’s current or anticipated utilization rate, there may be uncertainty if future supply will be adequate and therefore, contingency capacity strategies may be needed.
- Crisis capacity: strategies that are not commensurate with U.S. standards of care but may need to be considered during periods of known N95 respirator shortages. Crisis capacity strategies should only be implemented after considering and implementing conventional and contingency capacity strategies. Facilities can consider crisis capacity when the supply is not able to meet the facility’s current or anticipated utilization rate.
CDC’s optimization strategies for N95 respirator supply offer a continuum of options for use when PPE supplies are stressed, running low, or exhausted. Contingency and then crisis capacity measures augment conventional capacity measures and are meant to be considered and implemented sequentially. Once N95 respirator availability returns to normal, healthcare facilities should promptly resume conventional practices.
Decisions to implement contingency and crisis strategies are based upon these assumptions:
- Facilities understand their NIOSH-approved respirator inventory and supply chain
- Facilities understand their NIOSH-approved respirator utilization rate
- Facilities are in communication with local healthcare coalitions and federal, state, and local public health partners (e.g., public health emergency preparedness and response staff) to identify additional supplies
- Facilities have already implemented other engineering and administrative control measures including:
- Use physical barriers and other engineering controls
- Limit number of patients going to hospital or outpatient settings
- Use telemedicine whenever possible
- Limit all HCP not directly involved in patient care
- Limit face-to-face HCP encounters with patients
- Limit visitors to the facility to those essential for the patient’s physical or emotional well-being and care (e.g., care partner, parent)
- Cohort patients and/or HCP
- Facilities have provided HCP with required education and training, including having them demonstrate competency with donning and doffing, with any PPE ensemble that is used to perform job responsibilities, such as provision of patient care
Once availability of NIOSH-approved respirators returns to normal, healthcare facilities should promptly resume conventional practices. Determining the appropriate time to return to conventional strategies can be challenging. Considerations affecting this decision include:
- The number of patients for whom respirator use is recommended for their care (e.g., number of patients with suspected or confirmed SARS-CoV-2 infection)
- Whether there is evidence of ongoing SARS-CoV-2 transmission in the facility
- The incidence of COVID-19 in the community
- The number of days’ supply of respirators currently remaining at the facility
- Whether or not the facility is receiving regular resupply with its full allotment
Engineering controls reduce exposures for HCP by placing a barrier between the hazard and the HCP. Engineering controls can be very effective as part of a suite of strategies to protect HCP without placing primary responsibility of implementation on them (i.e., they function without HCP having to take an action).
Selective use of airborne infection isolation rooms
Aerosol-generating procedures performed on patients with suspected or confirmed SARS-CoV-2 infection should take place in an airborne infection isolation room (AIIR), if possible. The AIIR should be constructed and maintained in accordance with current guidelines, as recommended in CDC’s COVID-19 interim prevention and control recommendations in healthcare settings. Air from these rooms should be exhausted directly to the outside or be filtered through a high-efficiency particulate air (HEPA) filter directly before recirculation.
Use of physical barriers
Barriers such as glass or plastic windows can be an effective solution for reducing exposures among HCP to potentially infectious patients. This approach can be effective in reception areas (e.g., intake desk at emergency department, triage station, information booth, pharmacy drop-off/pick-up windows) where patients may first report upon arrival to a healthcare facility. Other examples include the use of curtains between patients in shared areas and closed suctioning systems for airway suctioning for intubated patients.
Another cornerstone of engineering controls are ventilation systems that provide air movement from a clean (HCP workstation or area) to contaminated (sick patient) flow direction (along with appropriate filtration, exchange rate) that are installed and properly maintained.
Administrative controls are employer-dictated work practices and policies that reduce or prevent hazardous exposures. Their effectiveness depends on employer commitment and HCP acceptance and consistent use of the strategies.
Develop mechanisms to screen patients for acute respiratory illness or prolonged close contact with someone with SARS-CoV-2 infection prior to their healthcare visits, such as through the appointment reminder system. Postpone and reschedule those with signs and symptoms or exposures presenting for non-acute visits.
Nurse advice lines and telemedicine can screen and manage patients with suspected or confirmed SARS-CoV-2 infection or prolonged close contact with someone with SARS-CoV-2 infection without the need for a face-to-face visit. Promoting the use of these technologies and referral networks can help triage persons to the appropriate level of care, potentially reducing the influx of patients to healthcare facilities and reserving personal protective equipment for when it is needed.
CDC guidance recommends that, for patients with SARS-CoV-2 infection, only essential personnel enter the patient care area, and that facilities consider caring for these patients with dedicated HCP. Further limiting the numbers of HCP and patient contacts to those that are medically essential (e.g., excluding dietary personnel, environmental services) could limit the number of respirators used. The medically essential personnel would assume food delivery and environmental services.
Measures can be explored to limit face-to-face contact encounters between HCP and patients with confirmed or suspected SARS-CoV-2 infection. HCP may consider bundling care activities to minimize room entries, and bundling may occur across HCP types (e.g., food trays are delivered by HCP performing other care). Alternative mechanisms for HCP and patient interactions include telephones, video monitoring, and video-call applications on cell phones or tablets.
Encourage use of alternative mechanisms for patient and visitor interactions, such as video-call applications on cell phones or tablets.
Everyone entering the healthcare facility should practice source control. Source control refers to use of well-fitting cloth face coverings, facemasks, or respirators to cover a person’s mouth and nose to prevent spread of respiratory secretions when they are talking, sneezing, or coughing. Because of the potential for asymptomatic and pre-symptomatic transmission, source control measures are recommended for everyone in a healthcare facility, even if they do not have symptoms of COVID-19. Additional information about source control is available in the Interim Infection Prevention and Control Recommendations for Healthcare Personnel During the Coronavirus Disease 2019 (COVID-19) Pandemic.
Extended use of N95 respirators can be considered for source control while HCP are in the healthcare facility, to cover one’s mouth and nose to prevent spread of respiratory secretions when they are talking, sneezing, or coughing. When used for this purpose, N95s may be used until they become soiled, damaged, or hard to breathe through. They should be immediately discarded after removal. Extended use of N95 respirators as PPE is a contingency capacity strategy.
Cohorting is the practice of grouping together patients who are infected with the same organism to confine their care to one area and prevent contact with other patients. Cohorts are created based on clinical diagnosis, microbiologic confirmation when available, epidemiology, and mode of transmission of the infectious agent. Cohorting has been used extensively for managing outbreaks of multidrug resistant organisms including MRSA, VRE, MDR-ESBLs, Pseudomonas aeruginosa; methicillin-susceptible Staphylococcus aureus, RSV, adenovirus keratoconjunctivitis, rotavirus, and SARS. When single patient rooms are not available, patients with confirmed SARS-CoV-2 infection may be placed in the same room. Cohorting patients could minimize respirator use when extended wear of respirators is implemented. For more information on cohorting of patients, refer to 2007 Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settingspdf icon.
Assigning designated teams of HCP to provide care for all patients with suspected or confirmed SARS-CoV-2 infection could minimize respirator use when extended wear of respirators is implemented. This strategy can also limit the number of exposed HCP who need to be fit tested.
It is important that HCP be trained 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.
Proper use of respirators, including putting on and removing them, 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 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 such as tuberculosis. If healthcare facilities are expecting to receive patients with SARS-CoV-2 infection, they should begin training and start to plan for fit testing now. It is essential to have HCP trained and fit tested 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.
In order 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 limited 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 passed a user seal check. The respirator might also be saved and then used for patient care.
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 Standardexternal icon. A qualitative fit test is a pass/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, considerations can be made to use 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. In March 2020, OSHA recommendedexternal icon healthcare employers consider changing from a quantitative fit testing method to a qualitative fit testing method. 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.
Personal Protective Equipment: Respiratory Protection
While engineering and administrative controls should be considered first when selecting controls, the use of personal protective equipment (PPE) should also be part of a suite of strategies used to protect personnel. Proper use of respiratory protection by HCP requires a comprehensive program (including medical clearance, training, and fit testing) that complies with OSHA’s Respiratory Protection Standardexternal icon and a high level of HCP involvement and commitment. The program should also include provisions for the cleaning, disinfecting, inspection, repair, and storage of respirators used by HCP on the job according to manufacturer’s instructions. Proper storage conditions can maximize shelf life of respirators. The following strategies in this section are traditionally used by some healthcare systems. If not already implemented, these strategies can be considered by healthcare settings in the face of a potential N95 respirator shortage before implementing the contingency strategies that are listed further below.
N95 respirators include standard and surgical N95 respirators. 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 OSHA standards.
A NIOSH-approved N95 respirator with an exhalation valve offers the same protection to the wearer as one that does not have a valve. As source control, findings from NIOSH research suggest that, even without covering the valve, N95 respirators with exhalation valves perform the same or better than surgical masks, procedure masks, cloth masks, or fabric coverings.
A surgical N95 respirator is a NIOSH-approved N95 respirator that has also been cleared by the FDA as a surgical mask. Surgical N95 respirators (sometimes called medical respirators) are recommended only for use by HCP who need protection from both airborne and fluid hazards, such as splashes or sprays. In times of shortage, only 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 provided these respirators. Other HCP can use standard N95 respirators. If surgical N95 respirators 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 faceshield or surgical facemask should be worn over the standard N95 respirator. Care should be taken not to compromise the fit of the respirator if a facemask is placed over the respirator.
Use NIOSH approved alternatives to N95 respiratorspdf icon 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.
Every other NIOSH approved filtering facepiece respirators is at least as protective as the N95. These include N99, N100, P95, P99, P100, R95, R99, and R100 (with or without an exhalation valve). On March 2, 2020, FDA issued an Emergency Use Authorization (EUA)external icon authorizing the use of certain NIOSH-approved respirator models in healthcare settings.
As source control, findings from NIOSH research suggest that all NIOSH approved filtering facepiece respirators with exhalation valves, even without covering the valve, perform the same or better than surgical masks, procedure masks, cloth masks, or fabric. If there is a risk that the worker may be exposed to splashes, sprays, or splatters of blood or body fluids, then a faceshield or surgical facemask should be worn over the standard N95 respirator. Care should be taken not to compromise the fit of the respirator if a facemask is placed over the respirator.
Elastomeric respirators are half-facepiece or full-facepiece, 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. Similar to N95 respirators, elastomeric respirators require annual fit testing. Elastomeric respirators with unfiltered exhalation valves should not be used in surgical settings due to concerns that air coming out of the exhalation valve may contaminate the sterile field. The NIOSH Certified Equipment List identifies the elastomeric respirators without exhalation valves or with filtered exhalation valves that may be used in surgical settings.
PAPRs are reusable respirators that are typically loose-fitting hoods or helmets. These respirators are battery-powered with blower that pulls air through attached filters or cartridges. The filter is typically a high-efficiency particulate air (HEPA) filter. Loose-fitting PAPRs do not require fit-testing and can be worn by people with facial hair. However, PAPRs should not be used in surgical settings due to concerns that the blower exhaust and exhaled air may contaminate the sterile field.
On March 28, 2020, FDA issued an update to address NIOSH-Approved Air Purifying Respirators for Use in Health Care Settings During Response to the COVID-19 Public Health Emergencyexternal icon. Facilities using elastomeric respirators and PAPRs should have up-to-date cleaning/disinfection procedures, which are an essential part of use for protection against infectious agents.
Currently, CDC recommends discharge of patients with suspected or confirmed SARS-CoV-2 infection when they are medically stable and have an appropriate home environment to which to return. CDC lists considerations for care at home in: Interim Guidance for Implementing Home Care of People Not Requiring Hospitalization for Coronavirus Disease 2019 (COVID-19). If patients cannot be discharged to home for social rather than medical reasons, public health officials might need to identify alternative non-hospital housing where those patients can convalesce.
Facilities can consider temporarily suspending annual fit testing of HCP in times of expected shortages. In March 2020, OSHA issued new temporary guidanceexternal icon regarding the enforcement of OSHA’s Respiratory Protection Standard. The guidance gave OSHA field offices enforcement discretion concerning the annual fit testing requirement as long as HCP have undergone an initial fit test with the same model, style, and size. Other conditions include explaining to HCP the importance of conducting a user seal check each time the respirator is put on and conducting a fit test if there are visual changes to the employee’s physical condition.
Personal Protective Equipment: Respiratory Protection
In times of anticipated shortages, N95 respirators should be prioritized for those HCP who are recommended to wear them as PPE when caring for patients. Respirators should not be used by HCP who are only using them for source control.
In times of anticipated shortage, consideration can be made to use N95 respirators beyond the manufacturer-designated shelf life. However, expired respirators might not perform to the requirements for which they were certified. Over time, components such as the strap and material may degrade, which can affect the quality of the fit and seal. Because of this, use of expired respirators could be prioritized for situations where HCP are NOT exposed to pathogens, such as training, fit testing, and source control. As expired respirators can still serve an important purpose, healthcare facilities should retain and reserve all N95 respirators during the pandemic.
Practices allowing extended use of N95 respirators as PPE, when acceptable, can also be considered. The decision to implement policies that permit extended use of N95 respirators should be made by the professionals who manage the institution’s respiratory protection program, in consultation with their occupational health and infection control departments with input from the state/local public health departments.
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 such as a COVID-19 unit). It can also be considered to be used for care of patients with tuberculosis, varicella, measles, and other infectious diseases where use of an N95 respirator or higher respirator is recommended. When practicing extended use of N95 respirators over the course of a shift, considerations should include 1) the ability of the N95 respirator to retain its fit, 2) contamination concerns, 3) practical considerations (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. If it is necessary to re-use N95 respirators in addition to extended use, please see the re-use section under crisis capacity strategies below. 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 or surgical facemask over the respirator to reduce contamination of the respirator, especially during aerosol generating procedures or procedures that might generate splashes and sprays. Care should be taken not to compromise the fit of the respirator if a mask is placed over the respirator.
When N95 Supplies are Running Low
Personal Protective Equipment: Respiratory Protection and Well-Fitting Facemasks
Consideration can be made to use N95 respirators beyond the manufacturer-designated shelf life for care of patients with diseases for which a respirator is recommended during their care (e.g., COVID-19, tuberculosis, measles, and varicella). Many models found in U.S. stockpiles and stockpiles of healthcare facilities have been found to continue to perform in accordance with NIOSH performance standards. However, fluid resistance and flammability were not assessed. Use of the N95 respirators recommended in Release of Stockpiled N95 Filtering Facepiece Respirators Beyond the Manufacturer-Designated Shelf Life: Considerations for the COVID-19 Response can be considered. 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 particularly important that HCP perform the expected seal check, prior to entering a patient care area. CDC does not recommend using N95s beyond the manufacturer-designated shelf life in surgical settings. On March 2, 2020, FDA issued an Emergency Use Authorization (EUA)external icon authorizing the use of certain NIOSH-approved respirator models in healthcare settings. This EUA includes respirator units that are past their designated shelf life.
Other countries approve respirators for occupational use according to country-specific standards. These products are evaluated using some methods that are similar to those used by NIOSH. Some methods are different but are expected to provide protection similar to NIOSH-approved filtering facepiece and elastomeric respirators. Devices supplied by current NIOSH-approval holders producing respirators under the standards authorized in the listed countries below are expected to provide the protection indicated, given that a proper fit is achieved. Therefore, they are considered to be suitable alternatives to provide protection during the COVID-19 response when supplies are short. Within Tables 1 and 2, the country, conformity assessment standards, standards and guidance documents, acceptable product classification, and NIOSH classification are provided in alphabetical order. All of these respirators have protection factors of at least 10 in the countries listed below, as outlined in the standards and guidance documents specified.
Non-NIOSH approved products developed by manufacturers who are not NIOSH approval holders are expected to meet the performance requirements if they have been issued a certificate of approval by an authorized test laboratory indicating they conform to the standards below. Non-NIOSH-approved products developed by manufacturers who are not NIOSH approval holders should not be used when an N95 respirator is recommended to be worn. FDA issued updates to its emergency use authorizations concerning non-NIOSH-approved respirators that have been approved in other countries on October 15, 2020 (Non-NIOSH Approved Disposable FFRs Manufactured in Chinaexternal icon) and March 24, 2021 (Imported, Non-NIOSH Approved Disposable FFRsexternal icon). Visit Factors to Consider When Planning to Purchase Respirators from Another Country and the NIOSH Science Blog for additional information on understanding the use of imported Non-NIOSH-approved respirators.
Table 1. Respirators Approved Under Standards Used in Other Countries That Are Similar to NIOSH-Approved N95 Filtering Facepiece Respirators
|Country||Performance Standard||Acceptable Product Classification||May Be Used in Lieu of NIOSH-Certified Products Classified as|
|P3||N99 or lower|
|PFF3||N99 or lower|
|People’s Republic of China||GB 2626-2006
|P3||N99 or lower|
|DS/DL3||N99 or lower|
|R95||R95 or lower|
|P95||P95 or lower|
|N99||N99 or lower|
|R99||R99 or lower|
|P99||P99 or lower|
|N100||N100 or lower|
|R100||R100 or lower|
|P100||P100 or lower|
|Country||Performance Standard||Acceptable Product Classification||May Be Used in Lieu of NIOSH-Certified Products Classified as|
|P3||N99 or lower|
|Brazil||ABNT/NBR 13694:1996; ABNT/NBR 13697:1996||P2||N95|
|P3||N99 or lower|
|People’s Republic of China||GB 2626-2006;
|P3||N99 or lower|
|RS/RL3||N99 or lower|
|R95||R95 or lower|
|P95||P95 or lower|
|N99||N99 or lower|
|R99||R99 or lower|
|P99||P99 or lower|
|N100||N100 or lower|
|R100||R100 or lower|
|P100||P100 or lower|
Re-use refers to the practice of using the same N95 respirator by one HCP for multiple encounters with different patients but removing it (i.e. 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.2
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 SARS-CoV-2 infection might also become necessary. However, it is unknown what the potential contribution of contact transmission is for SARS-CoV-2, and caution should be used.
It is important to consult with the respirator manufacturer regarding the maximum number of donnings or uses they recommend for the N95 respirator model. If no manufacturer guidance is available, data suggest limiting the number of reuses to no more than five uses (five donnings) per device by the same HCP to ensure an adequate respirator performance.3 HCP should always inspect the respirator and perform a seal check upon donning a re-used respirator. N95 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.
N95 respirators should not be re-used when caring for patients with varicella or measles, 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 facemask over the respirator to reduce/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.
The surfaces of a properly donned and functioning NIOSH-approved N95 respirator will become contaminated with pathogens while filtering the inhalation air of the wearer during exposures to pathogen laden aerosols. The pathogens on the filter materials of the respirator may be transferred to the wearer upon contact with the respirator during activities such as adjusting the respirator, improper doffing of the respirator, or when performing a user-seal check when redonning a previously worn respirator. One potentially effective strategy to mitigate the contact transfer of pathogens from the respirator to the wearer could be to issue each HCP who may be exposed to patients with SARS-CoV-2 infection a minimum of five respirators. Each respirator will be used on a particular day and stored in a breathable paper bag until the next week. This will result in each worker requiring a minimum of five N95 respirators if they put on, take off, care for them, and store them properly each day. This amount of time in between uses should exceed the 72 hour expected survival time for SARS-CoV-2 (the virus that causes COVID-19).4 If this strategy is used, the total number of donnings should still not exceed five times before discarding the respirator, when no manufacturer instructions are provided to indicate otherwise. Decontamination or bioeburden reduction of NIOSH-approved N95 respirators is no longer a strategy to conserve supplies as the availability to NIOSH-approved respirators has significantly increased.
Use of additional N95 respirators beyond the manufacturer-designated shelf life for care of patients for whom a respirator is recommended during their care (e.g., SARS-CoV-2 infection, tuberculosis, measles, varicella) can be considered. Some models have been found NOT to perform in accordance with NIOSH performances standards, and consideration may be given to use these respirators as identified in Release of Stockpiled N95 Filtering Facepiece Respirators Beyond the Manufacturer-Designated Shelf Life: Considerations for the COVID-19 Response. In addition, consideration can be given to use N95 respirators that have not been evaluated by NIOSH beyond the manufacturer-designated shelf life. These respirators should ideally be used in the context of a respiratory protection program that includes medical evaluation, training, and fit testing. It is particularly important that HCP perform the expected seal check, prior to entering a patient care area.
The number of infectious particles required to cause an infection (infectious dose) is often uncertain or unknown for respiratory pathogens. Further, there is often uncertainty about the influence of factors such as exposure duration and nature of clinical symptoms on the likelihood of infection transmission from person-to-person.
Source control (i.e., masking of patients) and maintaining physical distance from the patient are particularly important to reduce the risk of transmission. This prioritization approach to conservation is intended to be used when N95 respirators are so limited that routinely practiced standards of care for all HCP wearing N95 respirators when caring for a patient with SARS-CoV-2 infection are no longer possible. N95 respirators beyond their manufacture-designated shelf life, when available, are preferable to use of well-fitting facemasks. The use of N95s or elastomeric respirators or PAPRs should be prioritized for HCP with the highest potential exposures including being present in the room during aerosol generating procedures performed on persons with SARS-CoV-2 infection.
When facemasks must be used by HCP entering a patient care area, improving the fit of a facemask can reduce exposure to infectious particles. Options to improve the fit of a facemask are discussed in Improve How Your Mask Protects You, and include, but are not limited to selection of a facemask with ties rather than ear loops, use of a mask fitter, tying the facemask’s ear loops and tucking in the side pleats, fastening the facemask’s ear loops behind the wearer’s head, and using a cloth layer over the facemask to help it conform to the wearer’s face. Use of facemasks to care for a patient with suspected or confirmed SARS-CoV-2 infection should only be used as a last resort if respirators are severely limited.
When No Respirators are Left
During severe resource limitations, consider excluding HCP who may be at increased risk for severe illness from SARS-CoV-2 infection, such as those of older age, those with chronic medical conditions, or those who may be pregnant, from caring for patients with confirmed or suspected SARS-CoV-2 infection. Any HCP who are assigned to care for patients with suspected or confirmed SARS-CoV-2 infection should wear a well-fitting facemask.
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 has 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 well-fitting facemasks.
NIOSH has 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/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/or patients wearing well-fitting facemasks.
As of February 10, 2021
- Added clarifications on use of facemasks as a crisis capacity strategy.
As of November 23, 2020
- Added considerations for returning to conventional capacity practices
- Conventional capacity strategies
- Combined the sections on training on indications for use and proper use of respirators
- Contingency capacity strategies
- Added clarifications on extended use
- Crisis capacity strategies
- Added clarifications on limited re-use and decontamination, including clarification on a recommendation to limit the number of reuses to no more than five uses (five donnings) per device to ensure adequate respirator performance if no manufacturer guidance is available
- Removed the strategy of designating convalescent HCP for provision of care to confirmed or suspected COVID-19 patients
- 1 Hick JL, Barbera JA, Kelen GD. Refining surge capacity: conventional, contingency, and crisis capacity. Disaster Med Public Health Prep. 2009;3(2 Suppl): S59-67.
- 2 Fisher EM and Shaffer RE. Considerations for recommending extended use and limited reuse of filtering facepiece respirators in health care settings. J Occup Env Hygiene. 2014; 11(8): D115-D128.
- 3 Bergman, MS, Viscusi DJ, Zhuang Z, Palmiero AJ, Powell JB, Shaffer RE. Impact of multiple consecutive donnings on filtering facepiece respirator fit. Am J Infect Control. 2012;40(4): 375-380.
- 4 van Doremalen N, Bushmaker T, Morris DH. Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1. N Engl J Med. 2020 Mar 17.