ACMT COVID-19 Web Series FAQs

A respirator excludes unfiltered air, thus increasing the protection for the wearer against airborne particles. A face covering or mask that does not seal against the face decreases the amount of viral particles exhaled by the individual wearing it and should prevent coughs, sneezes, and spit from escaping – however these shielding mechanisms do not eliminate exhaled viral particles and do not completely prevent inhalation of aerosol or particles suspended in air.

REFERENCE:

Understanding the difference: Surgical Mask and N95 Respirator. CDC. Accessed on May 6, 2020 at: https://www.cdc.gov/niosh/npptl/pdfs/UnderstandDifferenceInfographic-508.pdf

Experimental studies have indicated that SARS-CoV-2 can remain viable for hours in the air, up to 24 hours on cardboard, and for 2-3 days on plastic and stainless steel. While the rapidity of drying of the mucous particles carrying the virus seems to be the major factor in viability, this quantitative data is not directly applicable to real-life situations where variations in temperature, humidity, and UV radiation can significantly decrease viral viability. 

The recommendation to store respirators for 5 days between use (if no disinfectants are used) is a precautionary recommendation allowing for maximum safety in re-use of masks that may have had significant viral contamination. Storage in a paper bag (as opposed to plastic) will allow for better drying conditions, and prevent moisture-facilitated mold overgrowth.

REFERENCE:

van Doremalen N, Morris DH, Holbrook MG, Gamble A, Williamson BN, et al. Aerosol and surface stability of HCoV-19 (SARS-CoV-2) compared to SARS-CoV-1. NEJM 2020;383:1564-1567. Accessed May 6, 2020 at: https://www.nejm.org/doi/full/10.1056/NEJMc2004973

No. Surgical masks (which are a form of partial face shield and not a respirator) are not of sufficiently durable construction to clean and reuse.

N95 respirators can be decontaminated effectively and maintain functional integrity for up to three uses, according to National Institutes of Health scientists. Decontamination methods tested included vaporized hydrogen peroxide (VHP), 70-degree Celsius dry heat, ultraviolet light, and 70% ethanol spray. In this study, VHP was the most effective decontamination method, because no virus could be detected after only a 10-minute treatment. UV and dry heat were acceptable decontamination procedures as long as the methods are applied for at least 60 minutes. Ethanol spray damaged the integrity of the respirator's fit and seal after two sessions. The authors urge anyone decontaminating an N95 respirator to check the face fit and seal before each re-use.

The CDC provides additional information on these and other decontamination processes, and practical alternatives, including using a limited supply of N95s signed out to clinical staff and rotated across days – being stored in a paper bag labeled with the individual’s name for 5 days to ensure viral dessication before re-use.

FEMA has published information regarding a number of sterilization systems including a Battelle-delivered service called Critical Care Decontamination System™ . Existing hospital sterilization systems that have been granted FDA Emergency Use Authorization (EUA) and the CCDS™ use vaporous hydrogen peroxide.    

REFERENCES: 

Fischer R, Morris DH, van  Doremalen N, Sarchette S, Matson J, et al. Assessment of N95 respirator decontamination and re-use for SARS-CoV-2. BMJ medRxiv 2020April preprint. Accessed May 3, 2020 at: https://www.medrxiv.org/content/10.1101/2020.04.11.20062018v2.full.pdf 

U.S. Centers for Disease Control and Prevention: Coronavirus Disease 2019 (COVID-19): N95 Respirators. Accessed April 28, 2020 at: https://www.cdc.gov/coronavirus/2019-ncov/hcp/respirators-strategy/index.html

FEMA Fact Sheet: Using the Critical Care Decontamination System™ April 30, 2020. Available at: https://www.fema.gov/news-release/2020/04/30/using-critical-care-decontamination-systemtm

Any personal protective equipment can be cleaned in usual fashion and then left for a period of 3-5 days before use again. However, maintaining such a rotating inventory for individuals or frequent shift work may not be practical, and there is theoretical concern regarding the safety of some workers handling large volumes of contaminated materiel. In addition, some equipment such as disposable isolation gowns are designed for single use – their integrity may deteriorate and they may not repel liquid on multiple re-use or laundering/sanitizing. Re-useable isolation gowns often tolerate up to 50 laundry cycles, although this may vary by manufacturer and fabric.

It is important to remember that disinfectants include chemicals that are irritants, potential sensitizers, or otherwise toxic (e.g., ethylene oxide) – these chemicals should never be applied directly to skin and should never be ingested. In addition, a certain residence time is required in order to kill biological organisms on surfaces. Thus, these products should never be applied and wiped off quickly, or the device immediately placed back on by the worker.

REFERENCES:

Kiline FS. A review of isolation gowns in healthcare: fabric and gown properties. J Engineered Fibers Fabrics 2015;10(3):180-190. Accessed on May 6, 2020 at: http://www.jeffjournal.org/papers/Volume10/V10I3(20)%20F.%20Kilinc.pdf

A “fitted mask” is a respirator (filtering facepiece respirator). The letter designations indicate the durability of the mask filtering material and are primarily important for industrial use where workers may be using oily paints (e.g., auto body repair painting shops) or exposed to an oily mist (e.g., drill press operators exposed to cutting oils and lubricating oils). CDC/NIOSH (National Institute for Occupational Health and Safety) approves various manufacturer’s respirators as: Not resistant to oil, Resistant to oil, or oil-Proof.

For the purposes of healthcare workers responding to the COVID-19 pandemic, the durability of the mask construction means that an “R” or “P” respirator will stand up to decontamination and cleaning longer than an “N” respirator. Traditionally, “N” respirators are single use, “R” were for an 8 hour shift use, and “P” is 30 days use. Under “extended use and limited re-use” situations such as this pandemic, any respirator may continue to be used as long as it still fits, the elastics and seal are adequate as determined by a qualitative check of breathing seal (inhale/exhale against your gloved hand), and work of breathing is OK (indicating the filtering fabric is not clogged). When re-using respirators, avoid touching the inside aspect of the mask. For practical purposes, use of facial cosmetics should be minimized while using the masks and the filtering area should not be written on (identification can be maintained on the exterior of a paper bag used for storage or by an ID on one of the elastic bands).

REFERENCES:

NIOSH-Approved Particulate Respirators. The National Personal Protective Technology Laboratory (NPPTL). CDC/NIOSH. Accessed on May 6, 2020 at: https://www.cdc.gov/niosh/npptl/topics/respirators/disp_part/default.html  

Recommended guidance for extended use and limited reuse of N95 filtering facepiece respirators in healthcare settings. CDC/NIOSH. Accessed on May 6, 2020 at: https://www.cdc.gov/niosh/topics/hcwcontrols/recommendedguidanceextuse.html

Respirators also have a numeric designation (95, 99, 100) that indicate the percent of a standard particle size (0.3 micrometers or 300 nanometers (nm), which is about 1/25 the size of a red blood cell or small lymphocyte) that is excluded. Exclusion occurs from direct impact against the layers of fabric as air transverses the mask and also be electrostatic forces that “attract” particles.

The SARS-CoV-2 virus that causes COVID-19 illness is smaller than 300 nm (approximately 80-100 nm), but is released into the air in droplets or as an aerosol with sneezing, etc. These larger particles are on the order of micrometers in diameter (1 micrometer = 1000 nanometers) and are excluded by a properly fitting respirator.

REFERENCE:

NIOSH-Approved Particulate Respirators. The National Personal Protective Technology Laboratory (NPPTL). CDC/NIOSH. Accessed on May 6, 2020 at: https://www.cdc.gov/niosh/npptl/topics/respirators/disp_part/respsource1quest2.html

All respirators, from an N95 to a P100 to a Powered Air-Purifying Respirator (PAPR) with appropriate cartridge filters, are considered to have good filtering capability in the setting of an aerosolized biological agent. There is some increased protection provided by the higher “protection factor” of the PAPRs with an in-date high efficiency particulate air (HEPA) filter compared to filtering facepiece respirators such as n95s, but this needs to be weighed against the decreased time that can be spent in the former (heat stress, dehydration, battery pack life) as well as the difficulties with their use (e.g., familiarity, lack of ability to use stethoscopes, decreased hearing from fan noise) and more involved cleaning, donning and doffing procedures. Individuals should receive training in use of a PAPR if such respiratory protection is indicated. 

COVID-19 patients can be safely treated using a face shield or goggles, an appropriately fitting respirator with a good seal, gloves and a gown. Specific recommendations and considerations of high-risk (e.g., intubation or bronchoscopy, cardiopulmonary resuscitation) vs lower-risk procedures (e.g., food or medication delivery, drawing blood), numbers of patients, and frequency of contact may also impact decision making and allocation of limited PPE. Consultation with institutional resources (industrial hygiene, occupational health, infection control) and updated professional society and federal recommendations is encouraged.

REFERENCES:

FEMA has developed fact sheets addressed to both healthcare and non-healthcare settings emphasizing a 3-tier set of actions to Reduce, Reuse, and Repurpose PPE (protection from respiratory and skin/mucous membrane contact). These are available at:

Coronavirus (COVID-19) Pandemic: Addressing PPE Needs in Non-Healthcare Setting

Coronavirus (COVID-19) Pandemic: Personal Protective Equipment Preservation Best Practices

Short Fact Sheet: https://www.fema.gov/media-library-data/1587131519031-6501ee8a0ce72004832fa37141c53bc0/PPE_FACTSHEET.pdf

There is a hierarchy of PPE use and incorporation into exposure reduction practice that may help in time of scarcity. In an institution-wide coordinated system, PPE is only one component of exposure reduction.

A number of very important administrative, engineering, and work practice controls are as important as PPE and continuous efforts to improve these should be made. Some examples include:

1. Avoiding and reducing exposure by limiting the number of personnel with direct patient contact
2. Robust PCR testing of patients and staff initially by triage criteria
3. Cohorting patients with probable or documented COVID-19
4. Ensuring good room air exchanges by air handling units, use of fans, negative pressure rooms
5. Consideration of other technologies (e.g., UV lights, ion generators) if and where appropriate
6. Use of shielding when performing procedures
7. Attention to hand hygiene
8. Cleaning of “high-contact” surfaces
9. Avoiding hand to face behaviors

If trained and available, the highest level of PPE protection (e.g., PAPR with HEPA filters) should be reserved for those with the highest risk of exposure (e.g., emergency physician performing frequent endotracheal intubations, pulmonologist performing bronchoscopy on COVID-19 patients in ICU). When masks and respirators are in short supply, the following considerations are reasonable steps in decreasing order of preference:

1. Good (in-date) respirator (N-95) with fit testing in past for size/style/brand, and no physical changes
2. Respirators from other countries with fit testing
3. Expired N-95 respirator with fit testing
4. Respirator without a formal fit test (qualitative seal demonstrated by exhaling against gloved hand; “user seal check”)
5. Respirators from other countries without a fit test
6. Expired respirators from other countries without a fit test
7. Surgical masks
8. Home-made devices (e.g., scarves)

REFERENCES:

FEMA has developed fact sheets addressed to both healthcare and non-healthcare settings emphasizing a 3-tier set of actions to Reduce, Reuse, and Repurpose PPE (protection from respiratory and skin/mucous membrane contact). These are available at:

Coronavirus (COVID-19) Pandemic: Addressing PPE Needs in Non-Healthcare Setting

Coronavirus (COVID-19) Pandemic: Personal Protective Equipment Preservation Best Practices

            Short Fact Sheet: https://www.fema.gov/media-library-data/1587131519031-6501ee8a0ce72004832fa37141c53bc0/PPE_FACTSHEET.pdf

Medical Advisory Secretariat. Air cleaning technologies: an evidence-based analysis. Ontario Health Technology Assessment Series 2005;5(17). [Developed in response to 2003 SARS epidemic] Accessed May 7, 2020 at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3382390/pdf/ohtas-05-52.pdf

If the employee or healthcare worker has not had any significant weight changes (+/- 20 pounds) or facial changes (e.g., reconstructive surgery, beard) and the manufacturer is the same as when previously fit-tested, OSHA has waived annual fit-testing because of the pandemic. Every respirator user should make sure that they perform a seal check (breathing in and out against a clean gloved hand while wearing the mask) each time they use a filtering facepiece respirator.

If there has been a change in the manufacturer or type of mask, note that size designations are not transferable. At a minimum, a qualitative user seal check should be done to make sure the respirator provides a seal. Ideally, at least a formal qualitative (i.e., non-destructive) fit test should be done when possible to provide further instruction on use and to ensure proper fit for anticipated activities. If an exhalation valve mask is being used, there is the possibility that a SARS-CoV-2 infected user could exhale viral particles. A paper procedure mask or surgical mask placed over the respirator should reduce or eliminate this concern, although it will increase the work of breathing some.

REFERENCES:

Enforcement Memos/Temporary Enforcement Guidance – Healthcare Respiratory Protection Annual Fit Testing for N95 Filtering Facepieces During the COVID-19 Outbreak. United States Department of Labor/Occupational Safety and Health Administration. March 14, 2020. Accessed on May 6, 2020 at: https://www.osha.gov/memos/2020-03-14/temporary-enforcement-guidance-healthcare-respiratory-protection-annual-fit

All personnel using respirators (including N95s) should be medically cleared for use (assessing cardiac and pulmonary risk factors) and undergo fit testing. Individuals should receive training in use of a PAPR if such respiratory protection is indicated.

As the use of respirators expands beyond traditional acute care health providers during this pandemic with its associated uncertainty and anxiety, changes in use patterns and duration have raised a number of concerns. These include: comfort, fogging of eyewear, “closed in” sensations, skin integrity (irritation, abrasions, allergic reactions, exposure to cleaning chemical residue), work of breathing, and the impact of existing health conditions, such as obesity, heart or lung conditions.

Pregnant workers can use respirators safely. There is no clinically important difference in the quality of air breathed in and out with a properly fitting respirator. The filtering material is not a respiratory hazard. Work of breathing can be increased in pregnant workers using respirators, but studies have shown this to be an effect of the activity itself or resistance of the mask, without a significant difference between small groups of pregnant and non-pregnant workers. These studies have also shown no evidence of fetal distress (as measured by fetal heart rate monitoring).

REFERENCES:

Appendix A to ¶ 1910.134 – Fit Testing Procedures (Mandatory) Part I. OSHA-Accepted Fit Test Protocols. United States Department of Labor/Occupational Safety and Health Administration. . Accessed on May 6, 2020 at: https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.134AppA

Appendix C to ¶ 1910.134 – OSHA Respirator Medical Evaluation Questionnaire (Mandatory). United States Department of Labor/Occupational Safety and Health Administration. Accessed on May 6, 2020 at: https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.134AppC

Roberge RJ, Kim J-H, Powell JB. N95 respirator use during advanced pregnancy. Am J Infect Control 2014;42(10):1097-1100. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4469179/pdf/nihms-698453.pdf

Kim J-H, Roberge RJ, Powell JB. Effect of external airflow resistive load on postural and exercise-associated cardiovascular and pulmonary responses in pregnancy: a case control study. Pregnancy Childbirth 2015;15:45. Accessed on May 6, 2020 at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4357216/pdf/12884_2015_Article_474.pdf

Although designated as “single use”, N95 respirators can be used continuously for an entire shift as long as there is no gross soiling of the mask and fit and ease of breathing are unimpaired. Paper procedure masks or surgical masks (FDA-approved for the OR environment) have been used over the top of an N95 to decrease soiling. This does increase the workload, but is fine as long as the work of breathing is tolerated.  

REFERENCES:

Recommended guidance for extended use and limited reuse of N95 filtering facepiece respirators in healthcare settings. CDC/NIOSH. Accessed on May 6, 2020 at: https://www.cdc.gov/niosh/topics/hcwcontrols/recommendedguidanceextuse.html

Traditionally, “N” respirators are single use, “R” daily 8 hour shift use, and “P” is 30 days use. Under approved “extended use” situations such as this pandemic, any respirator may continue to be used as long as it still fits, the elastics and seal are adequate as determined by a qualitative check of breathing seal (inhale/exhale against your gloved hand), and work of breathing is OK (indicative of filtering mesh not clogged). Avoid touching the inside aspect of the mask. For practical purposes, use of facial cosmetics should be minimized while using the masks and the filtering area should not be written on (identification can be maintained on the exterior of a paper bag used for storage or by an ID on one of the elastic bands).

REFERENCES:

Recommended guidance for extended use and limited reuse of N95 filtering facepiece respirators in healthcare settings. CDC/NIOSH. Accessed on May 6, 2020 at: https://www.cdc.gov/niosh/topics/hcwcontrols/recommendedguidanceextuse.html