cover story
PPE in the Era
of COVID-19
By Kelly M. Pyrek
B
efore the onset of the COVID-19 pandemic,
personal protective equipment (PPE) was the
unsung hero of healthcare, the medical commodity
so ubiquitous, it blended into the background.
Now, with scarcity comes a newfound respect for
and appreciation of articles of PPE and its status
as an armor against SARS-CoV-2.
The NIH COVID-19 Treatment Guidelines,
issued in late April 2020, indicate that for
healthcare workers who are performing aero-
sol-generating procedures on patients with
COVID-19, the COVID-19 Treatment Guidelines
Panel recommends using fit-tested respirators (N-
95 respirators) or powered air-purifying respirators
(PAPRs) rather than surgical masks, in addition to
other personal protective equipment (i.e., gloves,
gown, and eye protection such as a face shield
or safety goggles).
Supply chain disruption-driven PPE shortages
have caused healthcare professionals to get
creative about reuse of PPE, triggering new
research inroads that strive to better inform these
unchartered, pandemic-era interventions.
In late April, National Institutes of Health
scientists declared that N95 respirators can be de-
contaminated effectively and maintain functional
integrity for up to three uses. As we know, N95
respirators are designed for single-use and are
worn by healthcare providers to reduce exposure
to airborne infectious agents, including the virus
that causes COVID-19. The study was conducted
in a controlled laboratory setting and awaits
translation in a real-world healthcare environment.
The NIH emphasizes that the findings are not yet
peer-reviewed but are being shared to assist the
public health response to COVID-19.
The study investigators are with NIH’s Rocky
Mountain Laboratories (RML) in Hamilton, Mont.,
part of the National Institute of Allergy and
Infectious Diseases (NIAID). With collaborators
from the University of California, Los Angeles,
they tested the decontamination of small sections
of N95 filter fabric that had been exposed to
SARS-CoV-2, the virus that causes COVID-19.
Decontamination methods tested included
12
vaporized hydrogen peroxide (VHP), 70-degree
Celsius dry heat, ultraviolet light, and 70 percent
ethanol spray.
All four methods eliminated detectable
viable virus from the N95 fabric test samples,
the scientists reported. The investigators then
treated fully intact, clean respirators with the
same decontamination methods to test their
reuse durability. Volunteer RML employees wore
the masks for two hours to determine if they
maintained a proper fit and seal over the face;
decontamination was repeated three times with
each mask using the same procedure.
The scientists found that ethanol spray dam-
aged the integrity of the respirator’s fit and seal
after two decontamination sessions and therefore
do not recommend it for decontaminating N95
respirators. UV and heat-treated respirators
began showing fit and seal problems after three
decontaminations — suggesting these respirators
potentially could be re-used twice. The VHP-treat-
ed masks experienced no failures, suggesting they
potentially could be re-used three times.
The scientists concluded that 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. The
scientists urge anyone decontaminating an N95
respirator to check the fit and seal over the face
before each re-use.
Experts emphasize that novel methods of
sanitizing N95 masks to ensure safety of clinicians
is needed, but the construction of respiratory
protection presents unique challenges. Carrillo,
et al. (2020) remind us that, “N95 masks are
composed of thermoplastic elastomer (straps),
aluminum (nose clip), polyurethane (nose foam),
polypropylene (filter), and polyester (shell and
cover web). The polyester shell and cover web
are created from disorganized, thin fibers with an
electrostatic charge. This design, while effective for
reducing infection in clinicians, poses significant
challenges for sanitization. Washing these masks
In late April,
National
Institutes of
Health scientists
declared that
N95 respirators
can be
decontaminated
effectively
and maintain
functional
integrity for up to
three uses.
may 2020 • www.healthcarehygienemagazine.com