Elastomeric half-mask respirator disinfection practices among healthcare personnel.

BACKGROUND: Disposable N95 respirator shortages during the COVID-19 and 2009 H1N1 influenza pandemics highlighted the need for reusable alternatives, such as elastomeric half-mask respirators (EHMRs). Two US medical organizations deployed reusable EHMRs during the COVID-19 response. In addition to wipe-based disinfection following patient care episodes expected per local policies at both organizations, postshift centralized cleaning and disinfection (C&D) was expected at one site (A), permitting shared-pool EHMR use, and optional at the other (Site B), where EHMRs were issued to individuals. Using a survey, we evaluated disinfection practices reported by EHMR users and predictors of disinfection behaviors and perceptions. METHODS: Surveys assessed EHMR disinfection practices, occupational characteristics, EHMR use frequency, training, and individual-issue versus shared-pool EHMR use. RESULTS: Of 1080 EHMR users completing the survey, 76% reported that they disinfect the EHMR after each patient encounter, which was the expected practice at both sites. Increasing EHMR use, recall of disinfection training, and work in intensive care or emergency settings significantly influenced higher reporting of this practice. 36% of respondents reported using centralized C&D, although reporting was higher at the site (A) where this was expected (53%). Confidence in cleanliness of the EHMR following centralized C&D was not influenced by individual versus shared-pool EHMR issue. CONCLUSIONS: Most EHMR users reported adherence with expected post-care individual-based disinfection of EHMRs but did not necessarily use standardized, centralized C&D. Future efforts to limit reliance on behavior related to respirator disinfection may improve EHMR implementation in healthcare to avert dependence on single-use, disposable N95 respirators.

Simulated workplace protection factor study of a quarter-facepiece elastomeric respirator.

The assigned protection factor (APF) for quarter-facepiece respirators is currently 5, based on fit test data from the 1970s with models no longer commercially available. The goal of this project was to evaluate the respirator fit capability of a NIOSH-approved N95 quarter-facepiece elastomeric respirator with a gel-based facial seal design (Envo Mask by Sleepnet Corporation). Human subjects were recruited from healthcare and the general population to satisfy a 25-member NIOSH bivariate panel. Subjects were fit tested with a fast fit protocol using a TSI Portacount Model 8038 in the N95 mode. Second-by-second measures of fit were then collected while subjects performed a 30-min series of simulated healthcare activities. Subjects completed a short comfort questionnaire. The median (5th, 95th percentile) fit factor was 188 (48, 201). Simulated workplace protection factors (SWPFs) had a median (5th, 95th percentile) of 181 (94, 199) (data truncated at 200) and 570 (153, 1508) (non-truncated data). Subjects ranked inhalation and exhalation as "easy" with average scores of 5.0/6.0 and 5.2/6.0, respectively. The facepiece was ranked between slightly comfortable and comfortable (4.8/6.0) and the harness as comfortable (5.0/6.0). Most users agreed (5.2/6.0) that the mask was stable on their faces. The 5th percentile SWPF of 95 supports an APF of at least 10 for this quarter-facepiece elastomeric respirator, similar to the APF for half-facepiece respirators. This study supports increasing the APF for quarter-facepiece respirators, a class that has been largely ignored by manufacturers for the past 40 years. A lightweight, low profile, reusable quarter-facepiece respirator is an effective option for healthcare and other worker protection during a pandemic and similar situations.

Comparing respirator laboratory protection factors measured with novel personal instruments to those from the PortaCount.

A quantitative fit test is performed using a benchtop instrument (e.g., TSI PortaCount) to assess the fit factor provided by a respirator when assigned to a worker. There are no wearable instruments on the market to measure protection factors while the respirator is in use. The aim of this study is to evaluate two new, wearable, quantitative instruments-a dual-channel optical particle counter (DC OPC) and a dual-channel condensation particle counter (DC CPC)-that would enable in-situ, real-time measurement of respirator workplace protection factor. Respirator laboratory protection factors measured by the new instruments were compared to those measured with the TSI PortaCount on one test subject for three test aerosols (sodium chloride, incense, ambient) at target laboratory protection factors of 100, 300, and 1,000 for sodium chloride and ambient, and 75 and 500 for incense. Three replicates were performed for each test condition. Data were analyzed with a two-sided paired t-test at a significance level of 0.05. Laboratory protection factors measured with the DC CPC agree with those measured with the PortaCount whereas those from the DC OPC generally do not. Mean laboratory protection factors derived from the DC CPC are only statistically significantly different for mean values of a laboratory protection factor at ambient conditions for a target laboratory protection factor of 300 (p = 0.02) and for incense at a target laboratory protection factor of 75 (p = 0.03). Although statistically significant, the difference in laboratory protection factors derived from the DC CPC are not substantial in practice and may be explained by systematic uncertainty. In contrast, the DC OPC reports substantially larger mean laboratory protection factors, differing by about half an order of magnitude in extreme cases, and statistically significantly different mean laboratory protection factors for the sodium chloride aerosol for target laboratory protection factors of 100 and 300 (p = 0.01 and p = 0.01).

Are quantitative fit factors predictive of respirator fit during simulated healthcare activities?

An annual OSHA fit test is required for all U.S. employees required to wear a respirator during work, but there are limited data demonstrating a link between fit test results and respirator fit during work. The goal of this research is to determine if the fit factor (FF) achieved during an abbreviated ambient aerosol condensation particle counter (CPC) quantitative fit test is predictive of fit achieved during a simulated workplace protection factor (SWPF) scenario that includes realistic healthcare activities. Fifteen subjects (7 male; 8 female) were recruited for a range of facial sizes. Each subject donned an N95 filtering facepiece respirator and performed a single 29-min routine consisting of initial and final 2.5 min fast fit tests (five 30-sec exercises: normal breathing, head side to side, head up and down, talking, and bending over) and three repetitions of three 6-min simulated healthcare activities (CPR, ultrasound, and making a hospital bed). Two CPC instruments simultaneously collected second-by-second measures of particle concentration inside and outside of the respirator facepiece. FFs or SWPFs were calculated by dividing outside by inside facepiece concentrations. Overall FFs and SWPFs were highly correlated. Each exercise FF was highly correlated with the overall SWPF. Normal breathing, head up and down, and talking were most predictive of overall SWPF. Normal breathing and talking together were predictive of each of the three simulated healthcare activities. For CPR and bed making activities, head movement exercises were also found to be predictive. A quantitative fit test using a small set of exercises is highly predictive of an individual's fit during simulated work activities. Some exercises (e.g., talking and head movements) are predictive of fit during simulated workplace activities. Limitations include only one respirator model, a small subject pool not representative of the full range of face sizes. This article uses an innovative second-by-second assessment method that collects information about in- and outside-facepiece concentrations throughout the test period.

Impact of time and assisted donning on respirator fit.

The goal of this study was to examine the impact of assistance with donning and time on quantitative fit factors (FF) and pass rates for subjects wearing an N95 filtering facepiece respirator (FFR) and a non-certified adhesive mask. Fit factors were measured using two side-by-side TSI Portacount instruments sampling second-by-second simultaneous inside- and outside-facepiece concentrations. Naïve subjects made two visits at least one week apart. At each visit subjects first donned either the respirator or adhesive mask without assistance and performed a five-exercise fast fit test. They then donned a new respirator or mask with assistance in proper donning (e.g., proper forming of the nosepiece, strap placement, etc.) and performed a second five-exercise fast fit test. The same sequence of unassisted and assisted donning was then repeated with the other facepiece. Fifteen subjects participated in the study; time between visits ranged from 7-29 days (average 12 days). On visit 1 the respirator FFs were significantly higher (GM = 88) than for the adhesive mask (GM = 14); with assistance these FFs showed significant improvements to 116 and 124, respectively. At visit 1 almost half of subjects donning the respirator without assistance achieved a passing FF of 100 or greater, while only one-fifth of subjects were able to pass the fit test wearing an adhesive mask without assistance. Pass rates improved for both groups with assistance, but more so for the adhesive mask wearers. On visit 2 the pass rates for both groups had decreased, with the adhesive mask group showing a greater decrease. With assistance, pass rates improved for both groups, but again more so for those wearing the adhesive mask. Results suggest that wearers would benefit from assistance and re-training every time they don a respirator, even if the time between donnings is as short as one or two weeks.

Comparison of two quantitative fit-test methods using N95 filtering facepiece respirators.

Current regulations require annual fit testing before an employee can wear a respirator during work activities. The goal of this research is to determine whether respirator fit measured with two TSI Portacount instruments simultaneously sampling ambient particle concentrations inside and outside of the respirator facepiece is similar to fit measured during an ambient aerosol condensation nuclei counter quantitative fit test. Sixteen subjects (ten female; six male) were recruited for a range of facial sizes. Each subject donned an N95 filtering facepiece respirator, completed two fit tests in random order (ambient aerosol condensation nuclei counter quantitative fit test and two-instrument real-time fit test) without removing or adjusting the respirator between tests. Fit tests were compared using Spearman's rank correlation coefficients. The real-time two-instrument method fit factors were similar to those measured with the single-instrument quantitative fit test. The first four exercises were highly correlated (r > 0.7) between the two protocols. Respirator fit was altered during the talking or grimace exercise, both of which involve facial movements that could dislodge the facepiece. Our analyses suggest that the new real-time two-instrument methodology can be used in future studies to evaluate fit before and during work activities.

Comparing written programs and self-reported respiratory protection practices in acute care hospitals.

Airborne biological hazards in hospitals require the use of respiratory protection. A well-implemented respiratory protection program can protect health care workers from these exposures. This study examines the relationship between written respiratory programs and reported practices in health care settings. Twenty-eight hospitals in Illinois and Minnesota were recruited to a study of respiratory protection programs and practices in acute care settings. Interviews were conducted with hospital managers, unit managers, and health care workers from departments where respirators are commonly required. Each hospital's written respiratory protection program was scored for the 11 elements required by the Occupational Safety and Health Administration (OSHA), using a standardized tool, for a maximum possible score of 22 (2 pts. per element). Twenty interview questions associated with program practices were also scored by percent correct responses. Written program scores ranged from 2-17 with an average of 9.2. Hospital and unit managers scored on average 82% and 81%, respectively, when compared to the OSHA standard; health care workers scored significantly lower, 71% (p < 0.001). Minnesota written program scores were not significantly higher than Illinois hospitals (p = 0.16), while all Illinois survey respondents scored higher than those in Minnesota (p < 0.001). There was no trend between written programs and interview responses. Written respiratory protection programs in the study sites did not provide the level of detail required OSHA. Interview responses representing hospital practices surrounding respiratory protection indicated that hospitals were aware of and following regulatory guidelines.

Evaluation of Minnesota and Illinois hospital respiratory protection programs and health care worker respirator use.

The objective of this study was to assess respiratory protection programs for aerosol-transmissible diseases in acute care hospitals for conformance with regulatory requirements and public health guidelines. Twenty-eight representative hospitals were selected by size, location, and ownership in Minnesota and Illinois. Interviews were conducted with 363 health care workers and 171 managers from high-risk departments. Written programs from each hospital were reviewed for required elements. Seventy-seven health care workers were observed donning and doffing a FFR. The most serious deficiency in many written programs was failure to identify a program administrator. Most written programs lacked adequate details about medical evaluation, fit-testing, and training and did not include a comprehensive risk assessment for aerosol transmissible diseases; tuberculosis was often the only pathogen addressed. Employees with the highest probability of tuberculosis exposure were most likely to pick a respirator for close contact, but higher levels of respiratory protection were rarely selected for aerosol-generating procedures. Surgical masks were most commonly selected for close contact with droplet disease- or influenza-infected patients; better protection (e.g., respirator) was rarely selected for higher-risk exposures. Most of the observed health care workers had access to a NIOSH-certified N95 FFR, properly positioned the facepiece, and formed the nose clip. The most frequent deficiencies were failure to correctly place straps, perform a user seal check, and remove the respirator using straps.

Experiences when using different EHMR models: Implications for different designs and meeting user expectations.

BACKGROUND: New elastomeric half-mask respirator (EHMR) models without exhalation valves (EVs) or with exhalation valve filters (EVFs) are facilitating expanded use in health settings to reduce workers' exposure to airborne hazards while acting as source control to prevent pathogen spread. The physical comfort of new models has not been assessed in comparison to previously used EHMRs with EVs. METHODS: Researchers assessed 1,962 health care and emergency medical service personnels' self-reported adverse experiences from 2 cohorts while wearing EHMR models with EVs (cohort 1, n = 1,080) and without EVs or with EVFs (cohort 2, n = 882). Fisher exact test identified differences between the cohorts accounting for organizational factors when possible. RESULTS: Cohort 1 respondents experienced communication challenges and discomfort when wearing the EHMR > 1 hour statistically significantly more often than cohort 2. Cohort 2 respondents reported statistically significantly more instances of difficulty breathing, moisture buildup, being uncomfortable to wear < 1 hour, and being uncomfortably warm. CONCLUSIONS: Discomfort is prevalent among end users and more often among those wearing EHMRs without an EV/with an EVF. As EHMR research and development advances, prevalence in use may increase for emergency and routine situations. Organizations may not only need guidance about respirator selection but also model-specific selection.

Provider experiences with daily use of elastomeric half-mask respirators in health care.

BACKGROUND: During public health emergencies, demand for N95 filtering facepiece respirators (N95 FFRs) can outpace supply. Elastomeric half-mask respirators (EHMRs) are a potential alternative that are reusable and provide the same or higher levels of protection. This study sought to examine the practical aspects of EHMR use among health care personnel (HCP). METHODS: Between September and December 2021, 183 HCPs at 2 tertiary referral centers participated in this 3-month EHMR deployment, wearing the EHMR whenever respiratory protection was required according to hospital protocols (ie, when an N95 FFR would typically be worn) and responding to surveys about their experience. RESULTS: Participants wore EHMRs typically 1 to 3 hours per shift, reported disinfecting the respirator after 85% of the removals, and reported high confidence in using the EHMR following the study. EHMRs caused minimal interference with patient care tasks, though they did inhibit communication. DISCUSSION: HCP who had not previously worn an EHMR were able to wear it as an alternative to an N95 FFR without much-reported interference with their job tasks and with high disinfection compliance. CONCLUSIONS: This study highlights the feasibility of the deployment of EHMRs during a public health emergency when an alternative respirator option is necessary.

Wipe Disinfection of Reusable Elastomeric Half-Mask Respirators for Health Care Use.

BACKGROUND: During shortages, elastomeric half-mask respirators (EHMRs) are an alternative to reusing N95 filtering facepiece respirators but require between-use disinfection. The objectives of this study were to (a) measure microbial reductions on EHMR surfaces under laboratory conditions by a standardized procedure using wipes impregnated with health care disinfectants and to (b) measure microbial reductions on EHMRs disinfected by volunteer health care providers. METHOD: We inoculated EHMR (Honeywell model RU8500) surfaces with Pseudomonas aeruginosa, Bacillus atrophaeus spores, and bacteriophages MS2 and Φ6, and disinfected them using two wipes with hydrogen peroxide (HP), alcohols, and quaternary ammonium compounds (QACs). Then, we randomized 54 volunteer subjects into three groups (Group 1: two wipes with instructions, Group 2: five wipes with instructions, Group 3: no instructions or set number of wipes) and used 0.5% HP wipes without precleaning on EHMRs inoculated with Raoultella terrigena and MS2. FINDINGS: The laboratory study demonstrated that all organisms achieved at least 4 log10 median reductions (HP>QAC/alcohol>QAC>QAC/saline). Pseudomonas was highly susceptible to HP and QAC/alcohol and Φ6 to all disinfectants. MS2 reduction was highest using HP and lowest using QAC/saline. Bacillus was least susceptible. The volunteer study showed a 3 to 4 log10 average reductions of bacteria and virus; Raoultella reductions were greater than MS2, with variability within and between subjects. Conclusions: HP disinfectant wipes used in laboratory and by volunteers reduce bacteria and viruses on EHMRs by 3 to 4 log10 on average. IMPLICATIONS FOR PRACTICE: Commercially available hospital disinfectant wipes reduce bacteria and viruses on EHMRs and can fill the need for between-use disinfection. HP and combination QAC/alcohol have the greatest efficacy under our test conditions.

Health Care Workers' Comfort Ratings for Elastomeric Half-Mask Respirators Versus N95® Filtering Facepiece Respirators During the COVID-19 Pandemic.

BACKGROUND: Reusable elastomeric half-mask respirators (EHMR) are an alternative to address shortages of disposable respirators. While respirator discomfort has been noted as a barrier to adherence to wearing an N95 filtering facepiece respirator (FFR) among health care personnel (HCP), few have examined EHMR comfort while providing patient care, which was the purpose of this study. METHOD: Among a cohort of 183 HCP, we prospectively examined how HCP rated EHMR tolerability using the Respirator Comfort, Wearing Experience, and Function Instrument (R-COMFI) questionnaire at Study Week 2 and Week 10. At the completion of the study (Week-12), HCP compared EHMR comfort with their prior N95 FFR use. Overall R-COMFI scores and three subscales (comfort, wear experience, and function) were examined as well as individual item scores. FINDINGS: The HCP reported an improved overall R-COMFI score (lower score more favorable, 30.0 vs. 28.7/47, respectively) from Week 2 to Week 10. Many individual item scores improved or remained low over this period, except difficulty communicating with patients and coworkers. The overall R-COMFI scores for the EHMR were more favorable than for the N95 FFR (33.7 vs. 37.4, respectively), with a large proportion of workers indicating their perception that EHMR fit better, provided better protection, and they preferred to wear it in pandemic conditions compared with the N95 FFR. CONCLUSION/APPLICATION TO PRACTICE: Findings suggest that the EHMR is a feasible respiratory protection device with respect to tolerance. EHMRs can be considered as a possible alternative to the N95 FFR in the health care setting. Future work is needed in the EHMR design to improve communication.

Examining the Impact of Elastomeric Half Mask Respirator Knowledge and User Barriers on Safety Climate Perceptions in Health Care Settings.

BACKGROUND: Availability of personal protective equipment (PPE) and its effective use may influence safety climate perceptions among health care personnel (HCP). It is unclear how health care organizations can leverage the effective use of respiratory protection to engage in continuous improvement of their safety climate, which can inform opportunities for employee education and engagement. METHODS: After using an elastomeric half mask respirator (EHMR) as their primary form of respiratory protection for several months, 1,080 HCP provided feedback in an electronic survey about respiratory protection training, confidence in EHMR use, barriers during use, and perceived safety climate. Ordinal logistic regressions were used as nonlinear models to test relationships between these variables. FINDINGS: We observed that an increase in user confidence (p < .013), training content (p < .001), training formats (p < .001), and a decrease in EHMR barriers (p < .001) were associated with a statistically significant increase in proactive safety climate. In the second model, an increase in user confidence (p < .006) and training content (p < .001), and a decrease in barriers (p < .001), was associated with a statistically significant increase in compliant safety climate. CONCLUSIONS/APPLICATION TO PRACTICE: HCP EHMR confidence was positively associated with safety climate perceptions, underscoring the value of competency building by respiratory protection leaders prior to implementation. Because fewer barriers experienced while using an EHMR were associated with a more positive perception of safety climate, it is important to first communicate with end users about potential barriers and, second, to continue research with end users and manufacturers to improve the design of EHMRs moving forward.

Characteristics Associated With Health Care Worker Knowledge and Confidence in Elastomeric Half-Mask Respirator Use.

OBJECTIVE: This study evaluated health care workers' (HCWs') knowledge and confidence in using elastomeric half-mask respirator (EHMR) attributes known to influence usage. METHODS: Health care workers were surveyed regarding their EHMR donning and doffing experience. Respondents were categorized into competency categories based on their scores. Category differences were analyzed using χ 2 and multiple logistic regression. RESULTS: Seventy-two percent showed high levels of EHMR donning and doffing knowledge and confidence (mastery); however, 21% had greater confidence than knowledge (misinformed). Respiratory therapists had greater odds of mastery than other HCWs ( P < 0.05), whereas those working in medical/surgical and pediatric units had greater odds of doubt than other HCWs ( P < 0.01). CONCLUSIONS: Although most HCWs show high knowledge and confidence with EHMR use, strategies to confirm respirator use competency may ensure greater HCWs protection.

REDECA: A Novel Framework to Review Artificial Intelligence and Its Applications in Occupational Safety and Health.

INTRODUCTION: The field of artificial intelligence (AI) is rapidly expanding, with many applications seen routinely in health care, industry, and education, and increasingly in workplaces. Although there is growing evidence of applications of AI in workplaces across all industries to simplify and/or automate tasks there is a limited understanding of the role that AI contributes in addressing occupational safety and health (OSH) concerns. METHODS: This paper introduces a new framework called Risk Evolution, Detection, Evaluation, and Control of Accidents (REDECA) that highlights the role that AI plays in the anticipation and control of exposure risks in a worker's immediate environment. Two hundred and sixty AI papers across five sectors (oil and gas, mining, transportation, construction, and agriculture) were reviewed using the REDECA framework to highlight current applications and gaps in OSH and AI fields. RESULTS: The REDECA framework highlighted the unique attributes and research focus of each of the five industrial sectors. The majority of evidence of AI in OSH research within the oil/gas and transportation sectors focused on the development of sensors to detect hazardous situations. In construction the focus was on the use of sensors to detect incidents. The research in the agriculture sector focused on sensors and actuators that removed workers from hazardous conditions. Application of the REDECA framework highlighted AI/OSH strengths and opportunities in various industries and potential areas for collaboration. CONCLUSIONS: As AI applications across industries continue to increase, further exploration of the benefits and challenges of AI applications in OSH is needed to optimally protect worker health, safety and well-being.

A Control Banding Framework for Protecting the US Workforce from Aerosol Transmissible Infectious Disease Outbreaks with High Public Health Consequences.

Recent high-profile infectious disease outbreaks illustrate the importance of selecting appropriate control measures to protect a wider range of employees, other than those in healthcare settings. In such settings, where routine exposure risks are often high, control measures may be more available, routinely implemented, and studied for effectiveness. In the absence of evidence-based guidelines or established best practices for selecting appropriate control measures, employers may unduly rely on personal protective equipment (PPE) because of its wide availability and pervasiveness as a control measure, circumventing other effective options for protection. Control banding is one approach that may be used to assign job tasks into risk categories and prioritize the application of controls. This article proposes an initial control banding framework for workers at all levels of risk and incorporates a range of control options, including PPE. Using the National Institutes of Health (NIH) risk groups as a surrogate for toxicity and combining the exposure duration with the exposure likelihood, we can generate the risk of a job task to the worker.

Work of Breathing for Respiratory Protective Devices: Method Implementation, Intra-, Inter-Laboratory Variability and Repeatability.

As part of development of performance standards, the International Organization for Standardization (ISO) technical committee, ISO/TC 94/SC 15 Respiratory protective devices (RPD), adopted work of breathing (WOB) to evaluate airflow resistance for all designs (classes) of respiratory protective devices. The interests of the National Institute for Occupational Safety and Health's (NIOSH) National Personal Protective Technology Laboratory (NPPTL) are to compare the proposed WOB method and results for current RPD with those for present resistance methods. The objectives here were to assemble a method to meet the ISO SC15 standards, validate operation and conformance, and assess repeatability of WOB measurements for RPD. WOB method implementation and use followed standards ISO 16900-5:2016 and ISO 16900-12:2016. Volume-averaged total work of breathing (WOBT/VT where VT is tidal volume) determined for standard orifices was analyzed for variation and bias. After fabrication and assembly, the method gave preliminary verification orifice results that met ISO requirements and were equivalent to those from other laboratories. Evaluation of additional results from RPD testing showed tidal volume and frequency determined compliance. Appropriate adjustments reduced average absolute bias to 1.7%. Average coefficient of variation for WOBT/VT was 2.3%. Over 97% of results obtained during significant use over time met specifications. WOBT/VT for as-received air-purifying and supplied-air RPD were repeatable (p<0.05). WOBT/VT for unsealed half mask air-purifying RPD was an average of 31% lower compared to sealed. When experimental parameters were appropriately adjusted, the ISO WOB method implemented by NIOSH NPPTL consistently provided ISO-compliant verification WOBT/VT. Results for appropriately sealed RPD were reproducible.