By Jeffrey and Grace Stull
PPE has received considerable attention during the COVID-19 pandemic in the media almost as much, if not more, than during the Ebola outbreak in late-2014 and early-2015.
During the Ebola outbreak, the debate centered around the level of preparedness and the correct PPE to wear. This time around, the focus is on what to wear when the expected PPE becomes in short supply or, in some cases, runs out altogether.
Fire departments and other public safety agencies now face serious decisions for how to protect their personnel, as serving the public does not allow social distancing.
Historically, EMS calls for the fire service have generally entailed the use of examination gloves by firefighters and other responders on nearly all responses. Where there may have been trauma, such as during a vehicle extrication event, face shields may have been worn. Tuberculosis and other aggressive respiratory illnesses generally have prompted emergency medical personnel to wear surgical masks and sometimes N95 filtering facepiece respirators. Rarely do firefighters wear specific barrier clothing during EMS unless it is their turnout pants or some disposable cover, such as an apron or isolation gown.
Our current situation in the United States demands otherwise.
Defining adequate protection
On March 10, 2020, The U.S. Centers for Disease Control and Prevention (CDC) released the “Interim Guidance for Emergency Medical Services (EMS) Systems and 911 Public Safety Answering Points (PSAPs) for COVID-19 in the United States.”
This guidance recommends that EMS clinicians, which can also include firefighters, wear:
- N95 or higher-level respirators and only wear a face mask, if a respirator is not available
- Goggles or disposable face shields, which fully cover the front and sides of the face
- Examination gloves
- Isolation gowns
While wearing eyewear and gloves is relatively straightforward, there has been considerable confusion about respirators versus masks and protective apparel. In particular, the public confuses and often interchangeably refers to masks and respirators.
Disposable N95 filtering facepieces are, in fact, respirators that provide protection against the inhalation of environmental contaminants, which in this case are bioaerosols created by individuals coughing, sneezing and even just generally breathing in close vicinity to the wearer.
Medical face masks, sometimes referred to as surgical masks, can look fairly similar, but they lack the capability for sealing against the wearer’s face that is essential for providing respiratory protection. Surgical masks provide minimal protection and originally were intended for infection control (from healthcare provider to patient) rather than as a form of PPE.
There are other options for protecting against the inhalation of bioaerosols:
- Higher-rated filtering facepiece respirators with designations of N99, N100, R95, R99, R100, P95, P99 and P100 designations as part of their certification. These respirators are typically used in industrial situations against various types of particulate contamination, such as harmful dusts asbestos. These designations refer to the filtration effectiveness as determined by NIOSH and the ability to deal with oily particulates where N = not resistant to oil, R = resistant to oil, and P = oil proof. For COVID-19 instances, the exposure is not oily, so any of these respirator types can be used. However, the most common types are N95 and P100 where P100 respirators have characteristics for better sealing onto the wearer’s face and much higher efficiency in filtering bioaerosols than N95 respirators (99.97% versus 95%).
- Elastomeric facepieces in the form of either a half-mask or full facepiece (with clear visors and thus eye and face protection) that are outfitted with filters or cartridges that provide P100 levels of protection. Some other types of filters may be used that have ratings similar to those above.
- A powered air-purifying respirator, which may take the form of a full facepiece or a full hood with clear visor, which is then connected to a battery-powered and rechargeable blower via a connecting hose that pulls air through a HE (High Efficiency) filter for removing any particulate contamination.
- An SCBA facepiece that uses an adaptor provided and approved by the manufacturer that can convert the SCBA to an air-purifying respirator (APR) which then uses P100 filters or cartridges.
- For reusable facepieces, it is possible to use other types of cartridges or canisters provided that these items are rated for P100 filtration. However, often these cartridges or canisters include chemical-based absorption capabilities, which increase their weight, decrease their service life and are relatively expensive.
Protective apparel is generally used as a contamination shield for the wearer because, according to the National Academies of Medicine, bioareosols that deposit onto clothing can re-aerosolize following exposure to COVID-19 patients, causing transmission of the virus through inhalation along with another route of transmission via hand contact with contaminated surfaces where virus contaminated liquid is transferred to the wearer by touching their nose, mouth and eyes.
Wearing protective apparel minimizes the spread of contamination by preventing ordinarily clothing from becoming contaminated, which often cannot be changed between calls. Moreover, emerging research is now showing that SAR-CoV-2, the virus responsible for COVID-19, can have longevity on plastic surfaces longer than two days and on the interior and exterior of masks for four and seven days, respectively, though this data is preliminary and does necessary indicate that the viable viral contamination remaining in these time frames is sufficient to cause infection.
There are limited standards on isolation gowns. Under normal circumstances, isolation gowns intended for healthcare applications are subject to U.S. Food and Drug Administration (FDA) oversight, and their performance can be classified to four levels spanning minimal/low to moderate/high-risk, according to a standard known as AAMI PB70.
Only Level 4 gowns are evaluated for viral penetration resistance and demonstrate barrier performance for the passage of surrogate virus using an industry standard test. In that test, a surrogate for pathogenic virus that measures 27 nanometers (nm) in diameter is used in the evaluation. In contrast, SAR-CoV-2 has a diameter ranging from 60 to 140 nm. Regardless, virus generally moves through materials as very small amounts of liquid. Learn more about protections provided by gowns here.
Clothing typically worn by first responders, including turnout gear for firefighters, EMS clothing, chemical/biological protective gear, and some types of special operations or technical rescue clothing also use the same industry viral penetration resistance test when the clothing items are certified to the respective NFPA standards (NFPA 1971 for structural, NFPA 1999 for EMS, NFPA 1994 for chemical/biological, and NFPA 1951 for technical rescue). These forms of protective clothing (other than certified NFPA 1999 EMS clothing) are not often used for emergency medical calls, which now includes identification, treatment and transport of individuals suspected of COVID-19.
Distinguishing non-PPE and related items
In a pandemic, supplies of available PPE, particularly disposable respirators, gowns and gloves are dwindling, forcing first responder organizations to consider alternative products, some of which are indicated above. Though slated primarily for healthcare organizations, many of the recommended strategies recommended by the CDC can be applied for the fire and emergency services during contingency capacity (when shortages should be anticipated) and crisis capacity (when actual shortages occur). There are also strategies for optimizing the supply of N95 respirators and gowns.
These strategies offer advice for reducing the use to priority protection needs, using PPE certified to standards in different countries or regions, attempting to disinfect disposable products, and switching to reusable products, where new information is emerging at a rapid pace.
It is our recommendation, wherever possible, to use gear and products from known sources for which appropriate standards have been applied (NIOSH for respirators and NFPA for fire and emergency service garments). Care has to be exercised for using other standards, such as AAMI PB70, which is applied to surgical and isolation gowns, as this standard spans several levels of barrier performance where there are significant differences in the ability of materials to hold out contaminated liquids. Again, only Level 4 gowns provide the same barrier performance as required in the NFPA standards that address bloodborne pathogen protection.
Furthermore, with the relaxation of oversight requirements for PPE products used in healthcare by the FDA in these times of a national health emergency, both well intentioned products and those attempting to take advantage of a new market opportunity are flooding the market, many aimed at first responders. Included among these are counterfeit products, products with dubious claims, and many products that simply might not work or, worse, result in unintended disease transmission to a firefighter or other first responder.
There is indeed a thin line between PPE and non-PPE that has been illuminated during the COVID-19 pandemic.
What’s next: Disinfecting/sanitizing processes
Combined with the problems of PPE selection is both an uncertainty and plethora of related cleaning and disinfection or sanitization processes or products being positioned to allow reuse of some disposable products and provide needed care for durable products that are intended for reuse. This in itself is a topic of current concern as the fire service attempts to find ways to stretch PPE and keep members safe.
We plan to provide detailed guidance for cleaning and disinfecting/sanitizing PPE involved in COVID-19 in a forthcoming column.
Note: We work with Dr. Christina Baxter of Emergency Response TIPS, where several white papers and quick reaction guides have been put together to address the current pandemic.
About the Authors
Jeffrey and Grace Stull are president and vice president, respectively, of International Personnel Protection, Inc. They are members of several NFPA committees on PPE as well as the ASTM International committee on protective clothing. Mr. Stull was formerly the convener for international work groups on heat/thermal protection and hazardous materials PPE as well as the lead U.S. delegate for International Standards Organization Technical Committee 94/Subcommittees on Protective Clothing and Firefighter PPE. They participate in the Interagency Board for Equipment Standardization and Interoperability and have authored the book, "PPE Made Easy.”