Respiratory Protective Devices Research Articles

Determination of activated carbon fiber adsorption capacity for several common organic vapors: applications for respiratory protection

ABSTRACT In the context of workplace safety, activated carbon in the fiber form (i.e., activated carbon fiber, ACF) represents an alternative adsorbent to granular activated carbon (GAC) for use in organic vapor respiratory protection devices. ACFs are high surface area carbonaceous materials that are often available in a self-supporting non-woven form. The physical form of ACF suggests the potential for a filtration medium that is capable of supporting both organic vapor adsorption and particulate filtration. To study the application of these materials in respiratory protection devices, ACFs (ACFF 1200 m2/g, ACFF 1800 m2/g, and ACFF 2000 m2/g) were challenged with representative organic vapors (toluene, hexane, and methyl ethyl ketone (MEK)) at an occupationally relevant concentration (200 ppm). Breakthrough curves were generated for at least three different bed weights of adsorbent. Pressure drop (i.e., the resistance across the filtration media) was also measured to determine maximum ACF bed depths for use in respiratory protection devices. Breakthrough experiments indicate that ACFF 2000 has the highest adsorption capacity for toluene (381 mg/g), followed by ACFF 1800 and ACFF 1200 (344 mg/g and 239 mg/g, respectively). A similar trend was observed for hexane: 221 mg/g, 196 mg/g, and 146 mg/g for ACFF 2000, ACFF 1800, and ACFF 1200, respectively. ACFF 1200 showed the highest adsorption capacity for the polar adsorbate MEK (168 mg/g), followed by ACFF 1800 and ACFF 2000 (166 mg/g and 147 mg/g, respectively). Based on the constraints of pressure drop, it seems unlikely the exclusive use of ACF in a filtering facepiece respirator can provide an adsorbent mass sufficient for full shift protection against organic vapor contaminants at or above the legally enforceable permissible exposure level (PEL). Nevertheless, the incorporation of ACF into a facepiece respirator appears promising for “nuisance odor” applications; i.e., the further reduction of organic vapor concentrations when workplace exposures are already below PEL concentrations. Implications: This research brings innovation to the field of occupational health and air pollution control technology by investigating the adsorption performance of activated carbon fiber (ACF) media in the context of worker respiratory protection. ACF properties such as high specific surface area (m2/g), high permeability to airflow, and rapid adsorption kinetics make it ideal for use in thin, N95-style respirators for organic vapors. Respiratory protection is an exciting and relevant application for ACF media. A lightweight adsorbent such as ACF, if incorporated into an N95-style respirator, could potentially provide nuisance-level VOC protection in a physical form that is accessible to workers and consistent with OSHA’s voluntary use provisions for facepiece respirators. The research presented in this manuscript represents one of several steps planned in the characterization of ACF media for this particular application.

The use of the respiratory protective devices by the population during the COVID-19 pandemic

Introduction. Wearing a face mask is an important measure against spread of infection during the COVID-19 pandemic. The purpose of the study was to analyze various aspects of the face masks use by the population during the pandemic. The questioner was used. Results. Almost all respondents (96.4%) wore respiratory protective devices during the pandemic; 91.4% respondents worn face masks visiting grocery stores, pharmacies and medical organizations; 64.0% - visiting non-food trade facilities; 76.9% - travelling by surface transport, and 76.1% - being on the subway. Different types of face masks were used, 93.3% of respondents used disposable medical mask, 25.4% - reusable cloth masks. However, only 44.8% of respondents indicated that their protective equipment was made of non-woven material; 26.1% did not know how many layers their protective equipment contained; about a third of respondents (20.1% - 30.21%) were not able to assess the effectiveness of different types of respiratory protection. A third of the respondents (33.6%) wore a disposable medical mask for 2 hours, 35.2% - more than 2 hours in one day, 28.0% - for several days. Conclusions. Most of the respondents wore the face mask. Disposable medical masks were most commonly used. Requirements for the duration of wearing of face masks were met by about third of the respondents, for the handling - half of the respondents. Spontaneous choice of face mask by respondents confirms the importance of the development of hygiene guideline for choosing the most effective respiratory protection.

Current Issues in the Assessment of Respiratory Protective Devices for Occupational and Non-occupational Uses: Proceedings of a Workshop.

Current Issues in the Assessment of Respiratory Protective Devices for Occupational and Non-occupational Uses: Proceedings of a Workshop.

Viscoelastic Polyurethane Foams with Reduced Flammability and Cytotoxicity.

Consistent and proper use of respiratory protective devices (RPD) is one of the essential actions that can be taken to reduce the risk of exposure to airborne hazards, i.e., biological and nonbiological aerosols, vapours, and gases. Proper fit of the facepiece and comfort properties of RPDs play a crucial role in effective protection and acceptance of RPDs by workers. The objective of the present paper was to develop viscoelastic polyurethane foams for use in RPD seals characterised by proper elasticity, allowing for the enhancement of the device fit to the face and the capability of removing moisture from the skin in order to improve the comfort of RPD use. Moreover, it was pivotal to ensure the non-flammability of the foams, as well as a simultaneous reduction in their cytotoxicity. The obtained foams were characterised using scanning electron microscopy, infrared spectroscopy, thermogravimetry, and differential scanning calorimetry. Measurements also involved gel fraction, apparent density, compression set, rebound resilience, wettability, flammability, and cytotoxicity. The results are discussed in the context of the impact of modifications to the foam formulation (i.e., flame-retardant type and content) on the desired foam properties. The test results set directions for future works aimed to develop viscoelastic polyurethane foams that could be applied in the design of respiratory protective devices.

Microbiological and toxicological hazard assessment in a waste sorting plant and proper respiratory protection

Even though biological hazards in the work environments related to waste management were the subject of many scientific works, the knowledge of the topic is not extensive. This study aimed to conduct a comprehensive assessment of microbiological and toxicological hazards at the workstations in a waste sorting plant and develop guidelines for selecting filtering respiratory protective devices that would consider specific workplace conditions. The research included the assessment of quantity (culture method), diversity (high-throughput sequencing), and metabolites (endotoxin - gas chromatography-mass spectrometry; secondary metabolites - liquid chromatography tandem-mass spectrometry) of microorganisms occurring in the air and settled dust. Moreover, cytotoxicity of settled dust against a human epithelial lung cell line was determined with an MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The research was performed in a waste sorting plant (Poland; 240,000 tons waste/year) at six workstations: two feeders, two pre-sorting cabins, secondary raw material press and organic fraction waste feeder for composting.The total dust concentration at tested workstations varied from 0.128 mg m−3 to 5.443 mg m−3. The number of microorganisms was between 9.23 × 104 CFU m−3 and 1.38 × 105 CFU m−3 for bacteria and between 1.43 × 105 CFU m−3 and 1.65 × 105 CFU m−3 for fungi, which suggests high microbial contamination of the sorting facility. The numbers of microorganisms in the air correlated very strongly (R2 from 0.70 to 0.94) with those observed in settled dust. Microorganisms representing Group 2 biological agents (acc. to Directive, 2000/54/EC), including Corynebacterium spp., Pseudomonas aeruginosa, Staphylococcus aureus, and others potentially hazardous to human health, were identified. The endotoxins concentration in settled dust ranged from 0.013 nmol LPS mg−1 to 0.048 nmol LPS mg−1. Seventeen (air) and 91 (settled dust) secondary metabolites characteristic, e.g., for moulds, bacteria, lichens, and plants were identified. All dust samples were cytotoxic (IC50 values of 8.66 and 56.15 mg ml−1 after 72 h). A flowchart of respiratory protective devices selection for biological hazards at the workstations in the waste sorting plant was proposed based on the completed tests to help determine the right type and use duration of the equipment.

The health and economic impact of constructing temporary field hospitals to meet the COVID-19 pandemic surge: Wuhan Leishenshan Hospital in China as a case study.

BackgroundIn response to the COVID-19 pandemic, two new temporary hospitals were constructed in record time in Wuhan, China, to help combat the fast-spreading virus in February 2020. Using the experience of one of the hospitals as a case study, we discuss the health and economic implications of this response strategy and its potential application in other countries.MethodsThis retrospective observational study analyzed health resource utilization and clinical outcomes data for 2011 inpatients diagnosed with COVID-19 and admitted to Leishenshan Hospital during its 67 days of operation from February 8th to April 14th, 2020. We used a top-down costing approach to estimate the total cost of treating patients at the Leishenshan Hospital, including capital cost for hospital construction, health personnel costs, and direct health care costs. We used a multivariate generalized linear model to examine risk factors associated with in-hospital deaths.ResultsDuring the 67 days of hospital operation, 19 medical teams comprising of 933 doctors and 2312 nurses were gradually transferred to Leishenshan Hospital from across China. Of the 2011 admissions, 4.5% used intensive care and 2.0% used ventilators. Overall median length of stay was 19 days, and 21 days for patients in the intensive care unit (ICU). The case fatality rate (CFR) was 2.3% overall, 41.8% in the ICU, and 0.4% in general ward (GW). CFRs were 55% and 50% among patients using non-invasive and invasive ventilators, respectively. The mean total cost and direct health care cost were CNY806 997 (US$114 793) and CNY16 087 (US$2288), respectively. Patients admitted to the ICU had much higher direct health care costs, on average, compared to those in the GW (CNY150 415 vs CNY9720, or US$21 396 vs US$1383). The mean direct health care cost per patient with severe or critical diseases was more than five times higher than those with mild or moderate diseases (CNY45 191 vs CNY8838, or US$6428 vs US$1257). Older age, having comorbidities, and critical disease were associated with higher risks of death from COVID-19. Lower health worker to patient ratio (<2.6) was not associated with in-hospital death.ConclusionAn adequate health workforce were mobilized and deployed to a new temporary hospital. The Leishenshan Hospital increased access to care during the surge in COVID-19 infections, facilitated timely treatment, and transferred COVID-19 patients between GWs and ICUs within the hospital, all of which are potential contributors to lowering the CFR. Patients in the ICU experienced a much higher CFR and a greater burden of health care cost than those in GW. Our results have important implications for other countries interested in constructing temporary emergency hospitals, such as the need for adequate infrastructure capacities and financial support, centralized strategies to mobilize health workforce and to provide respiratory protective devices, and improvement in access to health care.

What We Are Learning from COVID-19 for Respiratory Protection: Contemporary and Emerging Issues.

Infectious respiratory diseases such as the current COVID-19 have caused public health crises and interfered with social activity. Given the complexity of these novel infectious diseases, their dynamic nature, along with rapid changes in social and occupational environments, technology, and means of interpersonal interaction, respiratory protective devices (RPDs) play a crucial role in controlling infection, particularly for viruses like SARS-CoV-2 that have a high transmission rate, strong viability, multiple infection routes and mechanisms, and emerging new variants that could reduce the efficacy of existing vaccines. Evidence of asymptomatic and pre-symptomatic transmissions further highlights the importance of a universal adoption of RPDs. RPDs have substantially improved over the past 100 years due to advances in technology, materials, and medical knowledge. However, several issues still need to be addressed such as engineering performance, comfort, testing standards, compliance monitoring, and regulations, especially considering the recent emergence of pathogens with novel transmission characteristics. In this review, we summarize existing knowledge and understanding on respiratory infectious diseases and their protection, discuss the emerging issues that influence the resulting protective and comfort performance of the RPDs, and provide insights in the identified knowledge gaps and future directions with diverse perspectives.

Using infrared imaging and deep learning in fit-checking of respiratory protective devices among healthcare professionals.

This study aimed to investigate the application of infrared thermal imaging and adopt deep learning to detect air leakage for determining the fitness of respirators during fit-checks. The outbreak of Covid-19 virus constitutes a public health crisis with substantial resultant morbidities and mortalities; has exerted profound impacts. This was a prospective observational study, employing a non-probability sampling method on a convenience sample to recruit the participants and followed the Strengthening the Reporting of Observational Studies in Epidemiology statement guidelines. The use of infrared thermal imaging identified air leakage points as a disruption to the facial thermal pattern distribution at (a) front of face; (b) right lateral of the face; (c) left lateral of the face; (d) top of the facemask with the head facing down; and (e) bottom of the facemask with the head facing up. Results also indicated that artificial intelligence tools and the proliferation of deep learning have the potential to detect the location of air leakage locations. The use of infrared thermal imaging provides evidence of the feasibility and applicability of infrared thermal imaging techniques in detecting air leakage for individuals wearing respirators. The use of infrared thermal technology can serve a potential role in complement fit-checking of respiratory protective devices and offers promising practical utility in determining the fitness of respirators for nurses at the frontline to protect against the air-borne viruses.

Review of materials and testing methods for virus filtering performance of face mask and respirator

Respiratory protection devices such as face masks and respirators minimize the transmission of infectious diseases by providing a physical barrier to respiratory virus particles. The level of protection from a face mask and respirator depends on the nature of filter material, the size of infectious particle, breathing and environmental conditions, facial seal, and user compliance. The ongoing COVID‒19 pandemic has resulted in the global shortage of surgical face mask and respirator. In such a situation, significant global populations have either reused the single‒use face mask and respirator or used a substandard face mask fabricated from locally available materials. At the same time, researchers are actively exploring filter materials having novel functionalities such as antimicrobial, enhanced charge holding, and heat regulating properties to design potentially better face mask. In this work, we reviewed research papers and guidelines published primarily in last decade focusing on, (a) virus filtering efficiency, (b) impact of type of filter material on filtering efficiency, (c) emerging technologies in mask design, and (d) decontamination approaches. Finally, we provide future prospective on the need of novel filter materials and improved design.

Improving the performance of filters for personal respiratory protection

Introduction. To adequately protect workers from gaseous air pollution using air purifying respiratory protective devices (RPD), it is necessary to periodically replace filters. The aim of the study was the analyze the methods of monitoring the performance of workers’ RPD. Materials and methods. Nowadays the subjective reaction of smell to an increase in the concentration of gas in the mask is widely used. This practice is compared with the available scientific information on the subjective ability of humans to detect gases. Results. The requirements for filter replacement in the legislation of foreign countries are analyzed. It has been established that for most hazardous substances there is no available information on the thresholds of odor (irritant) perception, and the available data show a high probability of exceeding the odor perception thresholds over the maximum permissible concentrations of hazardous substances in the working area. for getting used to it, distraction of attention, low individual sensitivity, etc. The existing approach in Russia leads to the belated replacement of part of the filters and, as a consequence, to the deterioration of the professional health of workers. Conclusion. Recommendations are formulated on the measures, the implementation of which is necessary to improve the protection of personnel used air purifying RPD.

The association between risk perception and knowledge with the behavior of using respiratory protection devices in the four National Oil Products Distribution Company

Introduction: Having a clear understanding of the relationship between risk perception, knowledge, and protective behaviors could play a significant role in occupational risk management. This study aimed to survey the relationship between risk perception and knowledge on the behavior of using respiratory protection equipment in the four National Oil Products Distribution Company. Materials and Methods: In this descriptive cross-sectional study conducted in 2018, 52 workers from the loading and quality control departments of 4 national companies distributing petroleum products in Sabzevar, Bojnourd, Torbat Heydariyeh, and Shahroud participated. Data were collected through a researcher-made questionnaire whose validity and reliability were assessed (CVI: 0.9 and CVR: 0.92 and Cronbach's alpha coefficient was determined to be 0.73), and data were analyzed using SPSS19 software, and descriptive statistics and linear regression were analyzed. Results: More than half of the participants, who were exposed to the chemicals, use RPDs (Respiratory Protective Devices) all the time and when they are exposed to chemicals. While 75% of them reported using RPDs (Respiratory Protective Devices), reduces the quality of their work. In this study, there was not any significant relationship between RPDs behavior with knowledge and risk perception (P &gt; 0.05). However, the association between work experience and RPDs was negatively significant (p= 0.009). Conclusion: The results of this study suggested that only education and knowledge could not promote individual risk perception, improving protective behavior, therefore other barriers such as uncomfortably of RPDs, or their interference with the worker should be considered. To achieve this goal, the safety and health officials of the companies must pay attention to its quality in addition to the correct choice of these devices.

Probabilistic model of penetration of biological agents through filtering devices

The human protection issue from biological agents with the help of filtering devices is studied in this article. This issue is actual for all the countries of the world due to the current coronavirus situation. Considering the hypothesis of the ordinariness of the biological agents’ flow and the absence of aftereffects in the filter, the probabilistic model of the penetration of biological agents through filtering respiratory protection devices is designed based on the Kolmogorov differential equation system applied for the adequate protection of medical personnel.

Application of Olfactometry to Assess the Anti-Odor Properties of Filtering Facepiece Respirators Containing Activated Carbon Nonwovens.

Filtering facepiece respirators (FFR) with anti-odor properties are used to reduce odor nuisance occurring both in everyday life and at workplaces. Unfortunately, there are no standardized methods to measure the efficiency of odor reduction of such personal protective devices. This paper aims to determine whether olfactometric-based methods, commonly used in environmental studies, can be employed for this purpose. The proposed procedure is based on the detection of n-butanol by study participants, and it consists of three subsequent stages: (i) defining the individual levels of odor sensitivity of each study participant; (ii) determining THE odor detection level while using FFRs with varying anti-odor properties; and (iii) completing a questionnaire concerning the subjective perceptions of study participants. As a measure of odor reduction efficiency, a coefficient W, defined as a quotient of the degree of odor reduction by the FFR, and the individual odor sensitivity of the subject, was proposed. The experimental results showed the ability of our measure to differentiate the effectiveness of odor reduction of tested FFRs. This indicates that it can be potentially employed as the assessment tool to confirm the effectiveness of such respiratory protective devices as a control measure mitigating the adverse effects of malodors on workers’ health, cognition, and behavior.

An increase in respiratory protection device injuries associated with the COVID-19 pandemic

To the Editor: The COVID-19 pandemic abruptly changed many people's lives. While social distancing, quarantining, and personal protective equipment (PPE) have positively impacted the pandemic's progression, ancillary consequences have occurred.1,2 Prior to the COVID-19 pandemic, the use of respiratory protection equipment was largely limited to health care and industrial settings. However, as PPE use by the general population increased, reports of dermatologic reactions have also increased.3 This study reports on the epidemiology of respiratory protection equipment-related injuries in the United States associated with the COVID-19 pandemic.

Bioterrorism

Terrorism that involves the deliberate release or distribution of biological agents is called bioterrorism. These pathogens are bacteria, viruses, fungi, other microorganisms and their related toxins, insects, and they can be natural or human-modified forms, which are roughly the same way as in biological warfare that can sicken or kill people, livestock, or crops.&#x0D; These high-priority means include organisms or toxins that pose the greatest risk to the public and national security: Anthrax (Bacillus anthracis) Botulism (Clostridium botulinum toxin) Plague (Yersinia pestis). They have the ability to have harmful effects on human health in many ways, from relatively mild allergic reactions to serious medical conditions and even death. Bacillus anthracis, the bacterium that produces anthrax, and is one of the pathogens most likely to be used for biological attacks.Bioterrorism cancausemass deaths, epidemics, medical staff illness, environmental pollution, legal issues, and cause anxiety in the medical community and the wider community (1).&#x0D; Unfortunately, bioterrorism agents are difficult to control and affect military personnel and civilian men, women and children. In the past 100 years, the United States and the international community have experienced various acts of bioterrorism against civilians. The model shows that the economic impact of bioterrorism attacks ranges from an estimated US$477.7 million per 100,000 people exposed (brucellosis scenario) to US$26.2 billion per 100,000 people exposed (anthrax scenario). The possibility of bioterrorism is particularly worrying because it causes disease, death and panic, disproportionate to the resources consumed (2).&#x0D; The purpose of bioterrorism is usually to create fear and / or threaten the government or society in order to obtain political, religious or ideological objectives. Compared to weapons like explosives, it can have a unique impact on society. Depending on the situation, wear a mask to reduce inhalation or spread of bacteria. If you have been in contact with biological agents, remove and store your clothing and personal things. Follow official instructions for disposing of contaminated items. Wash with soap and water and put on clean clothes.&#x0D; Bioterrorism agents can be spread through the air or into food or water, and are extremely difficult to detect. The outbreak of biological weapons’ diseases may lead to the extinction of endangered wild animal species, the erosion of genetic diversity of domesticated animals and plants, and the destruction of traditional human livelihoods (3). Symptoms of exposure to biological agents may include sore throat, fever, blurred vision or diplopia, rash or blistering, exhaustion, slurred speech, confusion, muscle weakness, nausea, abdominal pain, vomiting, diarrhoea, and cough. The occurrence of a weapon attack may be impossible, but planning and preparation can greatly reduce the death and suffering caused by it.&#x0D; Only 16 countries plus Taiwan possess or presumably possess biological weapons programs: Canada, China, Cuba, France, Germany, Iran, Iraq, Israel, Japan, Libya, North Korea, Russia, South Africa, Syria, and the United States. Britain and the United States. The way to deal with such threats is through international law and carefully negotiated treaties and verification mechanisms. An important protection measure against biological weapons is currently being negotiated in Geneva. Available protective equipment includes respiratory protection devices, full-face protective masks and surgical masks for respiratory protection, combat suits, protective gloves, and skin-protecting boots. Full protection is required when the agent is not recognized. The inherent characteristics of biological agents that affect their potential for use as weapons include: virulence; toxicity; pathogenicity; incubation period; transmissibility; lethality and stability.&#x0D; Now regarding the COVID19 pandemic, there is a game of blame between the two superpowers, the United States and China. It is not clear whether the spread of COVID19 is intentional or unintentional, whether it is a natural virus threatening the world or an artificial virus. Two conspiracy theories about the origin of COVID19 are widely circulated in China and the West, one accusing the United States and the other accusing the higher-level biological containment laboratory in Wuhan, the epicentre of the pandemic (4).&#x0D; However, this has caused pain, death, mental distress, depression, and billions of dollars in treatment and vaccine costs all over the world. This whole process reminds us of Frankenstein's sci-fi monster. The moral lesson learned from this is that people need to blend in and feel connected to others in order to survive. In addition, humans must carefully consider the cost of scientific progress.

Comparison of ISO work of breathing and NIOSH breathing resistance measurements for air-purifying respirators

The National Institute for Occupational Safety and Health’s methods and requirements for air-purifying respirator breathing resistance in 42 CFR Part 84 do not include work of breathing. The International Organization for Standardization Technical Committee 94, Subcommittee 15 utilized work of breathing to evaluate airflow resistance for all classes of respiratory protective devices as part of their development of performance standards regarding respiratory protective devices. The objectives of this study were: (1) to evaluate the relationship between the International Organization for Standardization’s work of breathing measurements and the National Institute for Occupational Safety and Health’s breathing resistance test results; (2) to provide scientific bases for standard development organizations to decide if work of breathing should be adopted; and (3) to establish regression equations for manufacturers and test laboratories to estimate work of breathing measurements using breathing resistance data. A total of 43 respirators were tested for work of breathing at minute ventilation rates of 10, 35, 65, 105, and 135 liters per minute. Breathing resistance obtained at a constant flow rate of 85 liters per minute per National Institute of Occupational Safety and Health protocol was correlated to each of the parameters (total work of breathing, inhalation, and exhalation) obtained from the work of breathing tests. The ratio of work of breathing exhalation to work of breathing inhalation for all air-purifying respirators is similar to the ratio of exhalation to inhalation resistance when tested individually. The ratios were about 0.8 for filtering facepiece respirators, 0.5 for half-masks, and 0.25 for full-facepiece respirators. The National Institute for Occupational Safety and Health’s breathing resistance is close to work of breathing’s minute ventilation of 35 liters per minute, which represents the common walking/working pace in most workplaces. The work of breathing and the National Institute of Occupational Safety and Health’s breathing resistance were found to be strongly and positively correlated (r values of 0.7–0.9) at each work rate for inhalation and exhalation. In addition, linear and multiple regression models (R-squared values of 0.5–0.8) were also established to estimate work of breathing using breathing resistance. Work of breathing was correlated higher to breathing resistance for full-facepiece and half-mask elastomeric respirators than filtering facepiece respirators for inhalation. For exhalation, filtering facepiece respirators were correlated much better than full-facepiece and half-mask elastomeric respirators. Therefore, the National Institute for Occupational Safety and Health’s breathing resistance may reasonably be used to predict work of breathing for air-purifying respirators. The results could also be used by manufacturers for product development and evaluation.

Applied Biosafety's Themed Issue on Methods for Testing, Decontaminating, and Reducing Bioburden on Respiratory Protective Devices and Filters

<i>Applied Biosafety's</i> Themed Issue on Methods for Testing, Decontaminating, and Reducing Bioburden on Respiratory Protective Devices and Filters

Use of Respiratory Protection Devices by Medical Students during the COVID-19 Pandemic.

The use of face masks has assumed a leading spot among nonspecific prevention measures during the coronavirus pandemic. The effectiveness of this protective measure depends on the specifics of individual use. The purpose of our study was to analyze the use of respiratory protective equipment (RPE) by medical students during the COVID-19 pandemic. The evaluation of face mask use was based on the results of a survey of medical students at Sechenov University. There were 988 participants in the study: 97.5% used RPE during the pandemic, 89.1% used disposable medical and hygienic face masks, 27.4% used reusable cloth face masks, and 13.2% used respirators. The majority of respondents (75.2%) were found to wear face masks correctly. However, 17.0% of the respondents were found to cover only their mouths with a face mask, while 7.8% reported often shifting their face mask under the chin due to perceived discomfort. Only 25.1% of respondents changed their disposable face mask after 2–3 h of wearing, while 13.0% decontaminated and used it several times. Most cloth face mask users (93.7%) decontaminated their marks, but only 55.7% of respondents did so daily. Face masks were most often worn in medical organizations (91.5%), and 1.4% of respondents did not use respiratory protection anywhere. In conclusion, we consider it necessary to introduce a special module on nonspecific prevention in the discipline of hygiene.

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.

NSF Response Case Study: Hazardous Materials Release at Intercontinental Terminal Company, Deer Park, Texas

ABSTRACT On March 17th, 2019 the Intercontinental Terminal Company (ITC) Deer Park, Texas river terminal and storage facility, comprised of 242 above ground storage tanks with a site capacity of 13.1 million barrels of hazardous products, experienced a tank fire. This incident would also become known as the “2nd 80s Fire” based on the identification of tanks impacted. The fire was contained to a single grouping of 15 tanks, with stored products including Naphtha, Toluene, Xylene, Benzene, Pyrolysis Gasoline, and Gasoline Blend stocks. Extended firefighting efforts resulted in volumes of water and firefighting foam that exceeded the capacity of the containment systems, resulting in the subsequent containment failure on March 22nd, which enabled the hazardous chemicals and mixture of various products to eventually reach the Houston Ship Channel. The surrounding industrial and residential communities experienced shelter-in-place orders due to the air quality concerns, and the vital waterway was shut down to commercial traffic. On-water benzene levels exceeded 20 parts per million (ppm) during the initial phases of the response near the facility while many areas within five miles exceeded the Occupational Safety Health Agency (OSHA) Permissible Exposure Limit (PEL) for benzene exposures. Benzene remained the primary chemical hazard to response crews seeking to contain, remove, and reopen the waterways for more than two weeks past the initial chemical release events. An interagency agreement was developed between the Environmental Protection Agency (EPA) and the U.S. Coast Guard (USCG) to assist in response activities, which included containing, collecting, recovering and disposing of the released materials from the shoreline and the surface water. The National Strike Force (NSF) deployed 52 personnel from each of the three Strike Teams, Public Information Assist Team (PIAT) and CG-Incident Management and Assistance Team (CG-IMAT). Due to the elevated presence of benzene, the NSF was the only USCG trained, experienced and qualified organic response resource prepared to respond to environmental threats with elevated concentrations of products that represented an inhalation hazard requiring respiratory protection devices. This paper demonstrates the significance of NSF's respiratory protection program, and how their capabilities can be used for both technical operations support, and also for site safety management, especially during complex spills or releases.