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Abstract Filtering facepiece respirators (FFRs) provide effective protection against diseases spread through airborne infectious droplets and particles. The widespread use of FFRs during the COVID-19 pandemic has not only led to supply shortages, but the disposal of single-use facemasks also threatens the environment with a new kind of plastic pollution. While limited reuse of filtering facepiece respirators has been permitted as a crisis capacity strategy, there are currently no standard test methods available for decontamination before their repeated use. The decontamination of respirators can compromise the structural and functional integrity by reducing the filtration efficiency and breathability. Digital segmentation of X-ray microcomputed tomography (microCT) scans of the meltblown nonwoven layers of a specific N95 respirator model (Venus-4400) after treatment with one and five cycles of liquid hydrogen peroxide, ultraviolet radiation, moist heat, and aqueous soap solution enabled us to perform filtration simulations of decontaminated respirators. The computed filtration efficiencies for 0.3 µm particles agreed well with experimental measurements, and the distribution of particle penetration depths was correlated with the structural changes resulting from decontamination. The combination of X-ray microCT imaging with numerical simulations thus provides a strategy for quantitative evaluation of the effectiveness of decontamination treatments for a specific respirator model.
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Addressing decontaminated respirators: Some methods appear to damage mask integrity and protective function
Abstract Decontamination of N95 respirators is being used by clinicians in the face of a global shortage of these devices. Some treatments for decontamination, such as some vaporized hydrogen peroxide methods or ultraviolet methods, had no impact on respiratory performance, while other treatments resulted in substantial damage to masks.
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- Award ID(s):
- 2028589
- PAR ID:
- 10229032
- Date Published:
- Journal Name:
- Infection Control & Hospital Epidemiology
- Volume:
- 41
- Issue:
- 12
- ISSN:
- 0899-823X
- Page Range / eLocation ID:
- 1446 to 1448
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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The rapid progression of the COVID‐19 pandemic revealed an inability to meet increased demand for N95 respirators. These respirators are designed to be used once and disposed, but throughout the pandemic, there was a need for their decontamination and reuse. This research investigates the effect of various decontamination methods on the chemical and mechanical properties of N95 mask straps made of natural rubber to explore how these straps change after decontamination and what materials characterization techniques are well‐suited to evaluate these changes. Using results from ozone decontamination, tensile testing of mask strap assemblies is identified as the most reliable way to quantify changes in strap properties with decontamination and reuse when compared to other analytical techniques. Additionally, visible strap degradation often precedes both strap failure and material property changes and can be a reasonable indicator to discontinue use. Aside from ozone, decontamination with other methods such as heat and UV light appears to be less damaging to the tested materials. Beyond the specific results presented, this study provides insight on testing strategies that can be employed to move forward with evaluating new materials and decontamination methods for use in future pandemics or in more resource‐limited regions.more » « less
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- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1017/ice.2020.332
