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.

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.

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.