Use, failure, and non-compliance of respiratory personal protective equipment and risk of upper respiratory tract infections-A longitudinal repeated measurement study during the COVID-19 pandemic among healthcare workers in Denmark.

INTRODUCTION: Upper respiratory tract infections (URTI) are common and a common cause of sick-leave for healthcare workers, and furthermore pose a threat especially for patients susceptible to other diseases. Sufficient use of respiratory protective equipment (RPE) may protect both the workers and the patients. The COVID-19 pandemic provided a unique opportunity to study the association between use of RPE and URTI in a real-life setting. The aim of this study was to examine if failure of RPE or non-compliance with RPE guidelines increases the risk of non-COVID-19 URTI symptoms among healthcare workers. METHODS: In a longitudinal cohort study, we collected self-reported data daily on work tasks, use of RPE, and URTI symptoms among healthcare workers with patient contact in 2 Danish Regions in 2 time periods during the COVID-19 pandemic. The association between failure of RPE or non-compliance with RPE guidelines and URTI symptoms was analyzed separately by generalized linear models. Persons tested positive for severe acute respiratory syndrome coronavirus 2 were censored from the analyses. The 2 waves of data collection were analyzed separately, as there were differences in recommendations of RPE during the 2 waves. RESULTS: We found that for healthcare workers performing work tasks with a risk of transmission of viruses or bacteria, failure of RPE was associated with an increased risk of URTI symptoms, RR: 1.65[0.53-5.14] in wave 1 and RR: 1.30[0.56-3.03] in wave 2. Also non-compliance with RPE guidelines was associated with an increased risk of URTI symptoms compared to the use of RPE in wave 1, RR: 1.28[0.87-1.87] and wave 2, RR: 1.39[1.01-1.91]. Stratifying on high- versus low-risk tasks showed that the risk related to failure and non-compliance was primarily associated with high-risk tasks, although not statistically significant. DISCUSSION: The study was conducted during the COVID-19 pandemic and thus may be affected by other preventive measures in society. However, this gave the opportunity to study the use of RPE in a real-life setting, also in departments that did not previously use RPE. The circumstances in the 2 time periods of data collection differed and were analyzed separately and thus the sample size was limited and affected the precision of the estimates. CONCLUSION: Failures of RPE and non-compliance with RPE guidelines may increase the risk of URTI, compared to those who reported use of RPE as recommended. The implications of these findings are that the use of RPE to prevent URTI could be considered, especially while performing high-risk tasks where other prevention strategies are not achievable.

Understanding Filtering Facepiece Respirators.

How to ensure adequate protection.

Discrepancy of particle passage in 101 mask batches during the first year of the Covid-19 pandemic in Germany.

During the first wave of Covid-19 infections in Germany in April 2020, clinics reported a shortage of filtering face masks with aerosol retention> 94% (FFP2 & 3, KN95, N95). Companies all over the world increased their production capacities, but quality control of once-certified materials and masks came up short. To help identify falsely labeled masks and ensure safe protection equipment, we tested 101 different batches of masks in 993 measurements with a self-made setup based on DIN standards. An aerosol generator provided a NaCl test aerosol which was applied to the mask. A laser aerosol spectrometer measured the aerosol concentration in a range from 90 to 500 nm to quantify the masks' retention. Of 101 tested mask batches, only 31 batches kept what their label promised. Especially in the initial phase of the pandemic in Germany, we observed fluctuating mask qualities. Many batches show very high variability in aerosol retention. In addition, by measuring with a laser aerosol spectrometer, we were able to show that not all masks filter small and large particles equally well. In this study we demonstrate how important internal and independent quality controls are, especially in times of need and shortage of personal protection equipment.

Homemade facemasks: particle filtration, breathability, fit, and other performance characteristics.

Homemade cloth masks and other improvised face coverings have become widespread during the COVID-19 pandemic driven by severe shortages of personal protective equipment. In this study, various alternative (mostly common household) materials, which have not traditionally been used in respiratory protective devices, were tested for particle filtration performance and breathability. Most of these materials were found of some-but rather limited-utility in facemasks. At a breathing flow rate of 30 L min-1, 17 out of 19 tested materials demonstrated collection efficiency below 50%; at 85 L min-1, only one material featured particle collection efficiency above 50%. Pressure drop values were mostly below 4 mm w.g. (observed in 89% of cases for the two flow rates), which provides comfortable breathing. Only for one fabric material (silk) tested at 85 L min-1 did the pressure drop reach 11 mm w.g. Based on these results, a three-layer facemask prototype was designed and fabricated comprised of the best performing materials. Additional tests were conducted to examine possible particle detachment/shedding from the materials used in the newly developed facemask, but no such phenomenon was observed. The prototype was evaluated on 10 human subjects using the standard OSHA-approved quantitative fit testing protocol. The mask protection level, determined as an adopted fit factor, was found to lie between that of the two commercial surgical/medical masks tested for comparison. A 10-cycle washing of the mask prototype lowered its collection efficiency across the particle size range; however, washing did not substantially affect mask breathability. The study revealed that although homemade masks offer a certain level of protection to a wearer, one should not expect them to provide the same respiratory protection as high-end commercial surgical/medical masks or-by any means-NIOSH-certified N95 filtering facepieces.

The protective effect of tight-fitting powered air-purifying respirators during chest compressions.

BACKGROUND: Airborne personal protective equipment is required for healthcare workers when performing aerosol-generating procedures on patients with infectious diseases. Chest compressions, one of the main components of cardiopulmonary resuscitation, require intense and dynamic movements of the upper body. We aimed to investigate the protective effect of tight-fitting powered air-purifying respirators (PAPRs) during chest compressions. METHODS: This single-center simulation study was performed from February 2021 to March 2021. The simulated workplace protection factor (SWPF) is the concentration ratio of ambient particles and particles inside the PAPR mask; this value indicates the level of protection provided by a respirator when subjected to a simulated work environment. Participants performed continuous chest compressions three times for 2 min each time, with a 4-min break between each session. We measured the SWPF of the tight-fitting PAPR during chest compression in real-time mode. The primary outcome was the ratio of any failure of protection (SWPF <500) during the chest compression sessions. RESULTS: Fifty-four participants completed the simulation. Overall, 78% (n = 42) of the participants failed (the measured SWPF value was less than 500) at least one of the three sessions of chest compressions. The median value and interquartile range of the SWPF was 4304 (685-16,191). There were no reports of slipping down of the respirator or mechanical failure during chest compressions. CONCLUSIONS: Although the median SWPF value was high during chest compressions, the tight-fitting PAPR did not provide adequate protection.

Fit-testing of respiratory protective equipment in the UK during the initial response to the COVID-19 pandemic.

BACKGROUND: Public Health England guidance stipulates the use of filtering facepiece (FFP3) masks for healthcare workers engaged in aerosol-generating procedures. Mask fit-testing of respiratory protective equipment is essential to protect healthcare workers from aerosolized particles. AIM: To analyse the outcome of mask fit-testing across National Health Service (NHS) hospitals in the UK during the first wave of the coronavirus disease 2019 (COVID-19) pandemic. METHODS: Using the Freedom of Information Act, 137 NHS hospitals were approached on May 26th, 2020 by an independent researcher to provide data on the outcome of fit-testing at each site. FINDINGS: Ninety-six hospitals responded to the request between May 26th, 2020 to October 29th, 2020. There was a total of 86 mask types used across 56 hospitals, 13 of which were used in at least 10% of these hospitals; the most frequently used was the FFP3M1863, used by 92.86% of hospitals. Overall fit-testing pass rates were provided by 32 hospitals with mean pass rate of 80.74%. The most successful masks, in terms of fit-test failure rates, were the Alpha Solway 3030V and the Alpha Solway S-3V (both reporting mean fit-test failures of 2%). Male- and female-specific pass and failure rates were provided by seven hospitals. Across the seven hospitals, 20.1% of men tested failed the fit-test for all masks used, whereas 19.9% of women tested failed the fit-test for all masks used. Failure rates were significantly higher in staff from Black, Asian, and Minority Ethnic (BAME) backgrounds 644/2507 (25.69%) across four hospitals. CONCLUSION: Twenty percent of healthcare workers tested during the first response to the pandemic failed fit-testing for masks. A small sample revealed that this was most prominent in staff from BAME backgrounds.

Comparative Performance Testing of Respirator versus Surgical Mask Using a Water Droplet Spray Model.

BACKGROUND: During the SARS-CoV-2 pandemic, there was shortage of the standard respiratory protective equipment (RPE). The aim of this study was to develop a procedure to test the performance of alternative RPEs used in the care of COVID-19 patients. METHODS: A laboratory-based test was developed to compare RPEs by total inward leakage (TIL). We used a crossflow nebulizer to produce a jet spray of 1-100 µm water droplets with a fluorescent marker. The RPEs were placed on a dummy head and sprayed at distances of 30 and 60 cm. The outcome was determined as the recovery of the fluorescent marker on a membrane filter placed on the mouth of the dummy head. RESULTS: At 30 cm, a type IIR surgical mask gave a 17.7% lower TIL compared with an FFP2 respirator. At 60 cm, this difference was similar, with a 21.7% lower TIL for the surgical mask compared to the respirator. When adding a face shield, the TIL at 30 cm was further reduced by 9.5% for the respirator and 16.6% in the case of the surgical mask. CONCLUSIONS: A safe, fast and very sensitive test method was developed to assess the effectiveness of RPE by comparison under controlled conditions.

The critical importance of mask seals on respirator performance: An analytical and simulation approach.

Filtering facepiece respirators (FFRs) and medical masks are widely used to reduce the inhalation exposure of airborne particulates and biohazardous aerosols. Their protective capacity largely depends on the fraction of these that are filtered from the incoming air volume. While the performance and physics of different filter materials have been the topic of intensive study, less well understood are the effects of mask sealing. To address this, we introduce an approach to calculate the influence of face-seal leakage on filtration ratio and fit factor based on an analytical model and a finite element method (FEM) model, both of which take into account time-dependent human respiration velocities. Using these, we calculate the filtration ratio and fit factor for a range of ventilation resistance values relevant to filter materials, 500-2500 Pa∙s∙m-1, where the filtration ratio and fit factor are calculated as a function of the mask gap dimensions, with good agreement between analytical and numerical models. The results show that the filtration ratio and fit factor are decrease markedly with even small increases in gap area. We also calculate particle filtration rates for N95 FFRs with various ventilation resistances and two commercial FFRs exemplars. Taken together, this work underscores the critical importance of forming a tight seal around the face as a factor in mask performance, where our straightforward analytical model can be readily applied to obtain estimates of mask performance.

Distribution of low quality filtering facepiece respirators during the COVID-19 pandemic: an independent analysis of the situation in Switzerland.

BACKGROUND: SARS-CoV-2 is a respiratory virus. Transmission occurs by droplets, contact and aerosols. In medical settings, filtering facepiece (FFP) respirators are recommended for use by personnel exposed to aerosol-generating procedures. During the COVID-19 pandemic, the demand for FFP respirators exceeded their supply worldwide and low-quality products appeared on the market, potentially putting healthcare workers at risk. AIMS: To raise awareness about variations in quality of imported FFP respirators in Switzerland during the COVID-19 pandemic, to draw attention to the current directives regulating the market launch of FFP respirators in Switzerland, to provide practical support in identifying suspicious products or documents and, finally, to offer strategies aimed at reducing the distribution of low-quality FFP respirators in the future. METHODS: Three Swiss laboratories, Spiez Laboratory and Unisanté in partnership with TOXpro SA individually set up testing procedures to evaluate aerosol penetration and fit testing of FFP respirators imported into Switzerland during COVID-19 pandemic. Additionally, Spiez Laboratory visually inspected the products, examined the certification documents and crosschecked the product information with international databases. RESULTS: Between 31 March and 15 June 2020, 151 FFP respirators were analysed. The initial assessment performed before testing allowed a reduction of up to 35% in the number of FFP respirators sent to Spiez Laboratory for evaluation, for which product information found to be faulty. After filtration efficiency evaluation and fit testing, 52% and 60% of all products tested by Spiez Laboratory and Unisanté-TOXpro SA, respectively, did not meet the minimum performance requirements established independently by the three Swiss laboratories. CONCLUSION: The demand for FFP respirators exceeded the supply capacity from established suppliers of the Swiss market. New production and import channels emerged, as did the number of poor-quality FFP respirators. FFP respirators remaining in stocks should be checked for conformity before being used, or eliminated and replaced if quality does not meet standards.

Respiratory Protection in a Time of Crisis: NIOSH Testing of International Respiratory Protective Devices for Emergency Use.

National Institute for Occupational Safety and Health (NIOSH)-approved respirators are required by the Occupational Safety and Health Administration (OSHA) when personal respiratory protection is used in US occupational settings. During the COVID-19 pandemic, the demand for NIOSH-approved N95 filtering facepiece respirators overwhelmed the available supply. To supplement the national inventory of N95 respirators, contingency and crisis capacity strategies were implemented and incorporated a component that endorsed the use of non-NIOSH-approved respiratory protective devices that conformed to select international standards. The development and execution of this strategy required the collaborative effort of numerous agencies. The Food and Drug Administration temporarily authorized non-NIOSH-approved international respiratory protective devices through an emergency use authorization, OSHA relaxed their enforcement guidance concerning their use in US workplaces, and NIOSH initiated a supplemental performance assessment process to verify the quality of international devices. NIOSH testing revealed that many of the non-NIOSH-approved respiratory protective devices had filtration efficiencies below 95% and substantial inconsistencies in filtration performance. This article reports the results of the NIOSH testing to date and discusses how it has contributed to continuous improvement of the crisis strategy of temporarily permitting the use of non-NIOSH-approved respirators in US occupational settings during the COVID-19 pandemic.

Are loose-fitting powered air-purifying respirators safe during chest compression? A simulation study.

BACKGROUND: The application of appropriate personal protective equipment for respiratory protection to health care workers is a cornerstone for providing safe healthcare in emergency departments. We investigated the protective effect and usefulness of loose-fitting powered air-purifying respirators (PAPRs) during chest compression. METHODS: This was a single-center simulation study performed from May 2019 to July 2019 in a tertiary hospital. We measured the concentrations of ambient aerosol and particles inside the loose-fitting PAPR during chest compression, and this ratio was set as the simulated workplace protecting factor (SWPF). According to the National Institute for Occupational Safety and Health regulations, the assigned protection factor (APF) of loose-fitting PAPRs is 25. Thus, the loose-fitting PAPRs were assumed to have a protective effect when the SWPF were ≥ 250 (APF × 10). We measured the SWPF of PAPR in real time during chest compression and also investigated the problems encountered during its use. RESULTS: Ninety-one participants (median age 29 [interquartile range (IQR): 26-32] years; 74% female) completed the simulation. None of the participants failed with SWPF below 250 during three sessions of chest compression. The median (IQR) values of SWPF at three cycles were 17,063 (10,145-26,373), 15,683 (9477-32,394), and 16,960 (7695-27,279). There was no disconnection of equipment or mechanical failures during chest compression. In addition, most participants (83%) replied that they rarely or never experienced difficulty in verbal communication and felt that the loose-fitting PAPR was comfortable. CONCLUSIONS: The loose-fitting PAPRs provided sufficient respiratory protection without disturbances during chest compression.

Feasibility and Consistency of Results with Deployment of an In-Line Filter for Exercise-Based Evaluations of Patients With Heart Failure During the Novel Coronavirus Disease-2019 Pandemic.

BACKGROUND: Exercise testing plays an important role in evaluating heart failure prognosis and selecting patients for advanced therapeutic interventions. However, concern for severe acute respiratory syndrome novel coronavirus-2 transmission during exercise testing has markedly curtailed performance of exercise testing during the novel coronavirus disease-2019 pandemic. METHODS AND RESULTS: To examine the feasibility to conducting exercise testing with an in-line filter, 2 healthy volunteer subjects each completed 2 incremental exercise tests, one with discrete stages of increasing resistance and one with a continuous ramp. Each subject performed 1 test with an electrostatic filter in-line with the system measuring gas exchange and air flow, and 1 test without the filter in place. Oxygen uptake and minute ventilation were highly consistent when evaluated with and without use of an electrostatic filter with a >99.9% viral efficiency. CONCLUSIONS: Deployment of a commercially available in-line electrostatic viral filter during cardiopulmonary exercise testing is feasible and provides consistent data compared with testing without a filter.

The role of fit testing N95/FFP2/FFP3 masks: a narrative review.

For healthcare workers performing aerosol-generating procedures during the COVID-19 pandemic, well fitted filtering facepiece respirators, for example, N95/FFP2 or N99/FFP3 masks, are recommended as part of personal protective equipment. In this review, we evaluate the role of fit checking and fit testing of respirators, in addition to airborne protection provided by respirators. Filtering facepiece respirators are made of material with sufficient high filter capacity to protect against airborne respiratory viruses. Adequate viral protection can only be provided by respirators that properly fit the wearer's facial characteristics. Initial fit pass rates vary between 40% and 90% and are especially low in female and in Asian healthcare workers. Fit testing is recommended to ensure a proper fit of respirators for the individual healthcare worker so that alternative respirators can be selected if required. Although fit testing is required to comply with respirator standards, it is not performed consistently within all healthcare settings. Fit checking (a self-test) is recommended every time a healthcare worker dons a respirator, but is unreliable in detecting proper fit or leak. Additionally, fit testing has a high educational value and as such is best performed as part of a hospital respiratory protection programme. Whether fit checking alone, as opposed to fit tested and fit checked respirators, provides adequate airborne protection against aerosols containing the SARS-CoV-2 virus and other respiratory viruses remains unknown. While fit testing undoubtedly incurs additional costs, it is still recommended, not only to protect healthcare workers but also as it may reduce overall healthcare cost when considering the potential costs of sickness leave and the associated legal costs of compensation.

Safety code blue! Assessing the use of blue surgical sterilization wrap for homemade respirator masks during the COVID-19 crisis.

The use of surgical sterilization wrap for respirator masks during the COVID-19 crisis has become a popularized personal protective equipment alternative option due to claims supporting its ability to meet N95 standards. This study sought to assess these claims using standardized filter testing. The tested material failed to meet N95 standards and suggests its use may place medical personnel at increased risk of harm when managing COVID-19 patients.

Speech intelligibility test methodology applied to powered air-purifying respirators used in healthcare.

Powered air-purifying respirators (PAPRs) are worn to protect workers from hazardous respiratory exposures in a wide range of workplaces, including healthcare. However, PAPRs may diminish the ability of wearers to correctly hear words spoken by others, potentially interfering with safe performance of healthcare duties. Accordingly, the impact of PAPRs during healthcare use on speech intelligibility (SI) and consequently on user safety, usability, and patient care is not well studied. The objectives of this study were to (1) determine a listener's ability to comprehend single-syllable words spoken by a PAPR wearer; (2) determine a PAPR wearer's ability to intelligibly hear and identify single-syllable words spoken by a PAPR wearer; (3) to assess the variability between speakers, listeners, and PAPR models; (4) to investigate the effects of PAPR design features on SI; and (5) inform a SI requirement for certifying future PAPRs for use in healthcare. This study utilized a Modified Rhyme Test to assess SI for PAPRs. The current National Institute for Occupational Safety and Health (NIOSH) methods for assessing SI are limited to the recently introduced PAPR100 respirator class and the class of respirators claiming chemical, biological, radiological, and nuclear (CBRN) protections. Four NIOSH-approved PAPRs were evaluated using four human subjects. Four experimental conditions were examined:(1) Speaker and Listener with no PAPR; (2) Speaker and Listener both wearing PAPRs; (3) Speaker with a PAPR, Listener without a PAPR; and (4) Speaker without a PAPR, Listener with a PAPR resulted in a total of 144 experiments. Statistical analysis showed that the SI performance ratings were not significantly different among the PAPR models, but experimental conditions had significant impact on SI. The pattern of SI across the conditions of the experiment also showed a significant difference depending on PAPR model. The SI performance rating for all PAPRs could meet the current NIOSH CBRN certification requirement for speech intelligibility.