Respiratory Protective Devices Research Articles

Reusable Respiratory and Skin Protective Devices Will Help Russian NBC Protection Troops to Avoid Pathogenic Biological Agents

Reusable Respiratory and Skin Protective Devices Will Help Russian NBC Protection Troops to Avoid Pathogenic Biological Agents

Modern Approaches to the Development of Head and Respiratory Protective Devices for Military Men

Modern Approaches to the Development of Head and Respiratory Protective Devices for Military Men

Impact of ageing factors on the performance of novel viscoelastic polyurethane foams utilized as seals in respiratory protective devices

This study explores the impact of ageing factors – i.e., perspiration, disinfection procedures and ultraviolet radiation – on the structural and performance characteristics of novel viscoelastic polyurethane foams specifically developed for use in seals for respiratory protective devices (RPDs). The investigation includes an analysis of resilience, compression set and recovery time to ascertain the influence of the chosen factors on the foam’s mechanical properties. Furthermore, an in-depth exploration of the foams’ thermal properties and chemical structure was carried out using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR), respectively. The influence of the ageing factors on the foams’ microstructure was scrutinized via scanning electron microscopy (SEM), supplemented by assessments of colour change and contact angle alterations. The experimental results were contextualized within the existing literature, with particular attention to the desired attributes of RPD seals composed of these newly engineered materials. Recommendations for use were then formulated.

Assessment of the microbial contamination in "Do It Yourself" (DIY) stores - a holistic approach to protect workers' and consumers' health.

In "Do-It-Yourself" (DIY) stores, workers from the wood department are considered woodworkers. Given the health risks associated with woodworking, particularly from fungi and their metabolites, this study aims to assess microbial contamination and health risks for both workers and customers. The study was developed in 13 DIY stores in Lisbon Metropolitan Area, Portugal. It employed a comprehensive sampling approach combining active (MAS-100, Andersen six-stage, Coriolis μ, and SKC Button Aerosol Sampler) and passive (electrostatic dust collectors, surface swabs, e-cloths, settled dust, filters from vacuumed dust, filtering respiratory protection devices, and mechanical protection gloves) methods to assess microbial contamination. A Lighthouse Handheld Particle Counter HH3016- IAQ was used to monitor the particulate matter size, temperature, and humidity. The wood exhibition area presented the highest fungal load, while the payment area exhibited the highest bacterial load. MAS-100 detected the highest fungal load, and surface swabs had the highest bacterial load. Penicillium sp. was the most frequently observed fungal species, followed by Aspergillus sp. Mycotoxins, namely mycophenolic acid, griseofulvin, and aflatoxin G1, were detected in settled dust samples and one filter from the vacuum cleaner from the wood exhibition area. Cytotoxicity evaluation indicates the wood-cutting area has the highest cytotoxic potential. Correlation analysis highlights relationships between fungal contamination and particle size and biodiversity differences among sampling methods. The comprehensive approach applied, integrating numerous sampling methods and laboratory assays, facilitated a thorough holistic analysis of this specific environment, enabling Occupational and Public Health Services to prioritize interventions for accurate exposure assessment and detailed risk management.

Measurement of inward leakage of full-face masks in EN and ISO standards: comparison of gas and aerosol test agents.

In Europe, respiratory protective devices must be certified before they can be marketed. Among the parameters of interest, inward leakage (IL) characterizes the tightness between the face seal and the face, to verify that the device is well-designed. European standard EN 13274-1 (2001) and International Organization for Standardization (ISO) standard ISO 16900-1 (2019) specify that IL should be measured using sodium chloride (NaCl) aerosol or sulfur hexafluoride (SF6) gas. For reusable masks made of nonporous materials, both test agents are considered equally acceptable. However, the few studies that have compared IL values measured with various aerosols and gases have come to divergent conclusions. This work then aimed to measure IL with the test agents recommended by the standards to determine whether they are really equivalent. Since krypton (Kr) is an interesting candidate for replacing SF6 in standard tests, IL was assessed with SF6 and Kr simultaneously, and with NaCl aerosol using various calculation methods. Tests were carried out on 5 models of full-face masks donned on a headform connected to a breathing machine simulating 3 sinusoidal breathing rates of various intensities. The respirator fit on the headform was evaluated using a controlled negative pressure method to determine a manikin fit factor. Four scenarios were then tested to represent very poor, bad, good, and excellent fit. Gas concentration was measured using a mass spectrometer, and IL was calculated for SF6 and Kr. A combination of 3 devices allowed the determination of the number-based concentration of particles with diameters between 20 nm and 2 µm, and IL was calculated for each of the 33 channels, as well as using a cumulative number concentration. In addition, to comply with standards, a conversion was carried out to calculate IL using a cumulative mass concentration. The results of this work evidenced that the IL values measured with NaCl were systematically lower than those determined with gases. IL was also shown to vary with particle size, with a maximum value exceeding that calculated with cumulative concentrations (in number or mass). As part of the revision of the standards, protocols for measuring inward leakage should be redefined. On the one hand, acceptability thresholds should be re-evaluated according to the nature of the test agent (gas or aerosol), as it is clear that the 2 options do not give the same results for a given configuration. On the other hand, the aerosol leakage measurement protocol needs to be reworked to enable the measurement of a well-defined, robust, and reproducible inward leakage value.

Improvement of the model for calculating the protection coefficient of filtering respirators from harmful aerosol

Research objective. Improvement of the model for calculating the protection coefficient of filtering respirators from harmful solid aerosol. Materials and methods. For the experimental determination of the protection coefficient of the filtering respirator according to the standard DSTU EN 149:2017 «Personal respiratory protective devices. Filtering half masks to protect against aerosols. Requirements, testing, marking» and the application of the method DSTU EN 13274-1:2005 «Personal respiratory protective devices. Methods of testing. Part 1. Determination of the penetration coefficient and the overall penetration coefficient», lightweight filtering half masks of «Standard» FFP2 type were used on volunteers. Results. The protection coefficient of the filtering respirators used on volunteers in laboratory conditions was calculated at the specified concentration of test aerosol in the ambient air by the standard testing method described in DSTU EN 13274-1:2005 «Personal respiratory protective devices. Methods of testing. Part 1. Determination of the penetration coefficient and the overall penetration coefficient» and takes into account the measurement error from the instruments not exceeding 10%. A comparison of the obtained indicators of the protection coefficient of filtering respirators in laboratory conditions and with the developed theoretical model, taking into account particle deposition in the sampling probe and submask space during the exhalation process, showed a good agreement of the indicators by the Student's t-test criterion. Scientific novelty. The scientific novelty lies in the development of a model for calculating the protection coefficient of filtering respirators based on the assessed mass distribution function of aerosol particles in the breathing zone; penetration function through the gap between the face and the half mask, taking into account the inhalation and exhalation process, as well as particle deposition in the sampling probe. Practical significance of the work lies in the development of a formula for the theoretical determination of the protection coefficient of filtering respirators, which is used to calculate the professional risk of pneumoconiosis among users

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

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. 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. 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. 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.

Prevalence of chronic respiratory symptoms and associated factors among woodwork workers in Bahir Dar City, Ethiopia; a comparative cross-sectional study

BackgroundExposure to wood dust can cause respiratory symptoms, like cough, phlegm, breathlessness, and chest pain, reduce lung function.ObjectiveThe objective of the study was to assess the prevalence of respiratory symptoms and associated factors among woodwork workers in Bahir-Dar city, Ethiopia.MethodsA comparative cross-sectional study was employed among 229 exposed and 228 unexposed groups. Participants for the study were selected using simple random sampling technique. The chronic respiratory symptoms were assessed using a questionnaire adopted from the American Thoracic Society. The data was entered using Epi-Data version 4.6 and export to SPSS version 22 for analysis. Poisson regression, Multivariate linear regression and multivariable logistic regression analysis were used to identify factors associated with woodworkers, general population and in pooled analysis.ResultThe prevalence of having at least one chronic respiratory symptom was higher among exposed group (59.4%) than unexposed group (18.0%) with PR = 3.03(95%CI: 2.45, 4.45). In woodworker; Not taking health and safety training(5.15,95%(CI:1.93–13.76),primary educational(3.85,95%,CI:(1.1,13.47), not using Mask(6.38, 95%CI:(2.69–15.76) & number of families(3.05,95%,CI:1.04–9.028), In general population; Number of family members(2.75, 95%CI:1.1–7.19)& lower monthly income (3.3, 95%CI: (1.49–7.4), and In pooled analysis; wood dust exposure status 14.36 95%, CI:(7.6–27.00),primary education(2.93,95%CI:1.24–6.92), number of families(3.46,95%CI:1.8–6.64), lower monthly income(2.13,95%CI:1.19–3.81), & smoking (6.65, 95%CI:1.19–36.9) were associated with respiratory symptom.ConclusionPrevalence of respiratory symptoms was higher among exposed group than unexposed group. Reduced wood dust exposure status, Provision of occupational safety and health training, use of respiratory protective devices is recommended to reduce respiratory symptoms among woodwork workers.

Evaluating layer contributions and salt coating effects on mask performance.

The impact of respiratory diseases is vast and multifaceted, affecting individuals, healthcare systems, and global economies. In response to the spread of respiratory pathogens, masks and respirators have become pivotal, demonstrating their capability to mitigate transmission. However, the limitations of conventional face masks or respirators, such as their single-use nature, environmental impact, and the risk of contact-based transmission, have accelerated the development of antimicrobial masks. Designing effective antimicrobial masks requires a deep understanding of the properties of each layer and the identification of an optimal configuration to enhance their protective efficiency. In this study, we investigated the filtration performance, including filtration efficiency and breathability, of individual layers in conventional 3-ply masks and stacked spunbond (SB) fabrics with and without salt coating, under both dry and wet fabric conditions. We aimed to elucidate the filtration efficiency of each mask layer with respect to particle size and type (NaCl aerosols, DOP aerosols), with particular focus on the impact of salt-coated SB fabric and its application. While bare fabrics showed a decrease in filtration efficiency with increased wetness, salt-coated fabrics exhibited enhanced filtration efficiency. Importantly, evaluating the efficacy of a stack comprised of salt-coated SB fabrics across diverse antimicrobial respiratory devices highlighted its efficacy as both the outermost layer in a 3-ply mask and as a mask covering (i.e., a supplementary layer over a mask or respirator). This investigation not only emphasizes the significance of salt-coated antimicrobial technology in mitigating disease transmission but also offers a practical approach for adeptly implementing this technology in respiratory protection devices.

Re-inventing protection in a post-pandemic world: A new aerodynamic endonasal filtration technology

Is there a “missing device” for respiratory personal protection? Does it exist an easy-to-use device, allowing extensive use in everyday settings by the population, maximizing tolerability and low visual and physical invasiveness protecting from a wide range of threats including airborne pathogens, hence including the particle range of fine and ultrafine particles? Looking at the recent past, in the urgency of finding ready-to-use solutions for the respiratory protection of the population during the outbreak of the SARS-CoV-2 pandemic, devices for occupational safety have been used, such as filtering face masks. These are devices intended for workers operating during work shifts in environments characterized by potential high risk, known a priori, often directly sensible; this makes wearers motivated to tolerate discomfort for a given period to face a localized risk, and safety managers determined to supervise compliance with usage specifications. Their use by general population has implied known shortcomings, such as weak compatibility with relational work and activities, low tolerability during prolonged use, low compliance with the proper use of the device, all of this lessening actual protection. The need for a new perspective has emerged, targeting effectiveness in whole daily life, rather than punctual efficacy. Nasal filters are promising candidates to protect individuals throughout the day during the most varied activities, but they lack a systematic definition as a device and as a product; it follows that the high complexity needed to reach an effective performance envelop is generally underestimated. By reviewing available literature, the present paper draws on the experience from the pandemic and infers systematic product specifications and characterization methods for a new, effective personal respiratory protection device; these specifications are compared with the stringent constraints associated with the endonasal applications and, based on air filtration state of the art, quantifies the need for technology disruption and outlining possible new development paths.

Validation of krypton as a new tracer gas for the standardization tests of collective and individual protection systems.

Sulfur hexafluoride (SF6) is the reference tracer gas in many international standards for characterizing respiratory protective devices (RPD), fume cupboards, building ventilations, and other installations. However, due to its significant impact on global warming, its use is becoming increasingly restrictive. Krypton 84 (Kr) was chosen to be a possible replacement based on theoretical and practical criteria for the properties that a substitute gas should possess. While compliance with these criteria is generally sufficient to guarantee the reliability of the choice, it is essential in the case of widespread use such as a standard to validate experimentally that this tracer has the same behavior as SF6. In this regard, numerous tests have been carried out to characterize the face leakage of RPD and the rupture of containment of fume cupboards performance tests under different operating conditions. The results obtained are identical with both tracers and lead us to propose the use of Kr as a new reference gas in standards for which SF6 was used.

Effective removal of odors from air with polymer nonwoven structures doped by porous materials to use in respiratory protective devices

Effective removal of odors from air with polymer nonwoven structures doped by porous materials to use in respiratory protective devices

Effects of Cement Dusts on Peak Expiratory Flow Rate (PEFR) in Female Cement Dust Exposed Construction Workers

Background: Occupational and environmental lung diseases are the major problems of clinical medicine. The cement dust workers are constantly exposed to high amounts of visible ambient air particulate matter, mostly without any respiratory protective device. Therefore, the inhalation of dust over periods of time leads to impaired lung functions. Objectives: To observe the effects of cement dust exposure on PEFR in female cement dust workers. Methods: This cross-sectional study was conducted in the Department of Physiology, Rangpur Medical College, Rangpur from July 2016 to June 2017. A total of 60 female subjects aged 20–50 years were selected for the study. Among them, 30 were apparently healthy workers exposed to cement dust, and 30 apparently healthy height, weight & BMI-matched subjects not exposed to cement dust were selected as control from the surrounding community. Their pulmonary functions were studied by measuring PEFR. For statistical analysis, an unpaired ‘t’-test was performed by computer-based software SPSS-17.0 version for Windows. Results: The mean measured and mean percentage of the predicted value of PEFR was significantly (p_0.001) lower in cement dust-exposed female workers (CD- EFW) than the non-exposed female workers (CD-NEFW). Conclusion: From the result of this study, it can be concluded that cement dust (CD) may have harmful effects on some pulmonary functions. J Rang Med Col. September 2023; Vol. 8, No. 2: 25-28

Chronic Respiratory Symptoms and Associated Factors among Fruit and Vegetable Workers in Addis Ababa, Ethiopia: A Comparative Cross sectional Study

BackgroundFruit and vegetable market is an abundant source of bioaerosols. Exposure to organic and inorganic waste and long-term inhalation of bioaerosols during working hours leads to chronic respiratory symptoms. Hence, this study aimed to determine the prevalence of chronic respiratory symptoms and related factors among fruit and vegetable workers compared with the control group in Addis Ababa, Ethiopia. Methods and materialsA comparative cross-sectional study was conducted from 2020 to 2021. Data were entered in EpiData 3.1 and exported to Statistical Package for the Social Sciences (SPSS) version 25. Logistic regressions were computed to depict the data and related factors. The culture method was done to count and compare bacterial and fungal concentrations between fruit and vegetable workers and office workers. ResultsIn this study, the prevalence of chronic respiratory symptoms (PR = 2.87, 95% confidence interval [CI]: 1.772–4.66) was significantly higher among fruit and vegetable workers (46.7%) than controls (23.4%). Sex (adjusted odds ratio [AOR] = 2.11, 95% CI = 1.12–3.98), educational status (AOR = 1.34, 95% CI = 0.78–2.32), working hours per day (AOR = 3.91, 95% CI = 1.586–9.65), and working department (AOR = 3.20, 95% CI = 0.90–11.40) were associated with chronic respiratory symptoms. Bacterial and fungal concentrations were significantly higher in the air of the vegetable market (276 colony-forming unit) than the air in the workplace of controls (7 colony-forming unit). ConclusionThe fruit and vegetable market workers (greengrocers) had a higher prevalence of chronic respiratory symptoms relative to office workers. Respiratory protective devices should be given to deliver preventive measures.

Bagasse dust exposure and chronic respiratory symptoms among workers in the Metehara and Wonji sugar factories in Ethiopia: a longitudinal study design

BackgroundEthiopia’s sugar factories are growing by creating job opportunities for thousands of workers with varying educational, professional and socioeconomic backgrounds. These sugar factories are a source of several hazards that...

Respiratory Protection: Lessons Learned from a Global Pandemic.

The COVID-19 pandemic exposed the limitations of global health systems' abilities to manage the rapid spread of a novel infectious disease, which was exacerbated by shortages of respiratory protective devices and other critical personal protective equipment (PPE). An advisory panel of experienced health-care professionals with backgrounds in Occupational and Environmental Health and Safety (OEHS), Infection Prevention, Nursing, and Clinical Application Specialists convened to discuss challenges and strategies associated with the selection and use of respiratory protective devices as experienced during the first year of the COVID-19 pandemic. This discussion led to the following recommendations: 1) the need for clear communication of alternative respiratory protection selection and use recommendations in accordance with US regulatory and agency guidance; 2) the need for collaboration between Infection Prevention, OEHS, clinical staff, supply chain/materials management, emergency preparedness, executive leadership, and finance; 3) the need for adequate stockpiling, inventory rotation, and diverse respiratory protection options to accommodate the majority of health-care workers; 4) the need for efficient and innovative strategies to communicate evolving regulatory, agency, and facility recommendations and to deliver appropriate training on respiratory protection; and 5) the need for additional research on respiratory protection use - involving filtering facepiece respirators (FFRs) as well as other respirator types designed to be reused - to balance infection prevention best practices with a sustainable process. In conclusion, these considerations may offer guidance and identify areas for research on preparedness, communication, education, and training to enhance the preparation of health-care facilities including community-based health-care organizations for unexpected public health events.

Oregon Project Firstline: A needs assessment of healthcare personnel infection prevention knowledge and training preferences

Background: Infection prevention and control (IPC) competency is critical for healthcare personnel (HCP) and patient safety. In collaboration with the CDC new national IPC training collaborative called Project Firstline, the Oregon Health Authority’s (OHA) Healthcare Associated Infection (HAI) Program established a state-level program in 2021. The goal of Oregon Project Firstline is to provide relevant, accessible, and engaging IPC training materials for our state’s HCP. We assessed the IPC learning needs of Oregon’s healthcare workforce, and to understand the preferred methods and formats of training across the various HCP roles. Methods: OHA’s HAI program recruited HCP by distributing electronic surveys through multiple healthcare, regulatory, and public health partners’ email listservs and HCP-targeted newsletters. Survey responses were recorded from September 23 to December 10, 2021. The HAI program assessed respondents’ IPC knowledge, online and in-person job training preferences, frequently used training devices, and trusted sources for IPC information. An individual’s understanding of an IPC topic was categorized based on their self-assessed confidence in their knowledge and ability to teach the topic to others. In total, 6,382 surveyed responses were analyzed. Results: The average understanding among HCP was lowest in IPC topics relating to triage and isolation of contagious patients and fit testing of respiratory protection devices. For these topics, 3,208 HCP (66.21%) and 3,657 HCP (75.48%) HCP, respectively, did not understand the topic well enough to teach others (Fig. 1). The highest number of HCP (n = 2,512, 39.36%) requested additional training in methods on how to educate others about IPC topics (ie, “train the trainer”). Surveyed respondents most frequently used personal computers for job trainings in both work and at-home settings (n = 4,603, 72.12%) and 3,437 HCP (53.85%) were open to either in-person or remote formats for job education. The CDC and OHA were the most frequented and trusted IPC sources among surveyed HCP: 4,124 HCP (64.62%) and 3,584 HCP (56.16%), respectively. Conclusions: IPC is a critical topic in HCP training across all healthcare facility types and employee roles. Effective educational planning includes understanding the learners’ knowledge needs and preferred methods of learning. Our learning needs assessment identified important IPC knowledge gaps and will help ensure that our training courses will be offered in effective educational formats for Oregon’s diverse HCP. Future training will include appropriate triage of potentially infectious patients, respiratory fit testing, and general IPC “train the trainer” sessions. Additionally, we will offer both in-person and remote options.Disclosures: None

Respiratory protective device: One size to fit them all?

When exposed to hazardous or toxic substances, workers may be required to wear respiratory protective devices, selected in accordance with the pollutant, required protection level, individual characteristics, and work conditions. To emphasize the importance of the selection procedure, this study aimed to investigate the effects of the facial dimensions and breathing rate on the fit and the protection efficiency provided by full-face respirators. Manikin total efficiency measurements (mTEs) were then conducted on five head forms of various facial dimensions equipped with nine respirators of different models and sizes. A breathing machine simulating sinusoidal breathing rates was used to represent seven work rates, from rest to maximal intensity. For each experiment, the manikin fit factor (mFF), characterizing the respirator fit on the head form, was measured by a controlled negative pressure method. By varying the head form, respirator, breathing rate, and mFF, a total of 485 values of mTE were measured. Findings indicate that even if the respirator was equipped with a high-efficiency filter, mTE strongly decreases if the respirator does not fit the face of the wearer. In particular, it was highlighted that one given respirator cannot fit all facial dimensions and that the best match between the respirator size and facial dimensions is difficult to predict because respirator sizes are not standardized. Moreover, although the total efficiency of a well-fitted respirator naturally decreases when increasing the breathing rate due to filtration mechanisms, the reduction is more significant if the respirator does not fit well. To consider both the mTE and the breathing resistance, a quality factor value was determined for each tested combination of head form, respirator, and breathing rate. The maximum manikin fit factor mFFmax measured for each combination of head form and respirator was compared to that measured on nine human subjects with similar facial dimensions, providing encouraging results concerning the use of head forms during respirator testing.

Determining the filtration effectiveness of non-standard respiratory protective devices by an ad-hoc laboratory methodology

The recent pandemic caused by COVID-19 profoundly changed people's habits. Wearing a face mask has become usual in everyday life to reduce the risk of infection from airborne diseases. At the beginning of the pandemic, the massive request of surgical or filtering face piece (FFP) masks resulted in a global shortage of these devices for the most exposed people, such as healthcare workers. Due to this high demand for respiratory protective devices, many industrial plants have partly converted to the production of face masks using adapted materials and not complying with any specific regulation (non-standard respiratory protective devices or community masks). In this work, an ad-hoc laboratory methodology has been developed to evaluate the filtration efficiency of the materials that compose the community masks using specific instrumentation. The instrumentation consists of three main tools: an aerosol generator, a specifically designed measuring chamber, and an optical particle sizer (OPS) for the measurement of aerosol concentration. The generated aerosol was sent into the measuring chamber, divided into two separate sections by the respiratory mask. The OPS measured the aerosol mass concentration upstream and downstream of the respiratory mask, and from the concentration difference the filtration efficiency was evaluated. The proposed methodology has been validated by evaluating the particle filtration efficiency (PFE) of certified respiratory masks and was then applied for the evaluation of the filtration efficiency of different types of non-standard or community masks to analyze their effectiveness in protecting from the risk of infection of airborne diseases.

Face mask performance related to potentially infectious aerosol particles, breathing mode and facial leakage.

During the COVID 19 pandemic, wearing certified Respiratory Protective Devices (RPDs) provided important means of protection against direct and indirect infections caused by virus-laden aerosols. Assessing the RPD performance associated with infection prevention in standardised certification tests, however, faces drawbacks, such as the representativeness of the test aerosols used, the protection of third parties during exhalation or the effect of facial leaks. To address these drawbacks, we designed a novel test bench to measure RPD performance, namely the number based total efficiency, size-segregated fractional filtration efficiency and net pressure loss, for 11 types of certified surgical masks and Filtering Face Pieces dependent on breathing mode and facial fit. To be representative for the context of potentially infectious particles, we use a test aerosol based on artificial saliva that is in its size distribution similar to exhaled aerosols. In inhalation mode excluding facial leaks, all investigated samples deposit by count more than 85% of artificial saliva particles, which suggests a high efficiency of certified RPD filter media related to these particles. In exhalation mode most RPDs tend to have similar efficiencies but lower pressure losses. This deviation tends to be significant primarily for the RPDs with thin filter layers like surgical masks or Filtering Face Pieces containing nanofibers and may depend on the RPDs shape. Both the filtration efficiency and pressure loss are strongly inter-dependent and significantly lower when RPDs are naturally fitted including facial leaks, leading to a wide efficiency range of approximately 30-85%. The results indicate a much greater influence of the facial fit than the filter material itself. Furthermore, RPDs tend be more effective in self-protection than in third-party protection, which is inversely correlated to pressure loss. Comparing different types of RPDs, the pressure loss partially differs at similar filtration efficiencies, which points out the influence of the material and the filter area on pressure loss.