1. Introduction to Respiratory Protection and Overall Structure of the Book 2. The Past and the Future of Infectious Diseases 3. Introduction to the Human Respiratory System and the Mechanisms of How People get Infected by Contagious Viruses 4. Respiratory Protective Devices (RPD) History, Category, and Classification for Protection in a Pandemic Environment 5. Respiratory Protective Devices (RPD) Performance and Key Issues 6. Respiratory Protective Devices (RPD) Performance Testing Methods and Associated Standards in Different Countries, Comparison and Issues 7. Laboratory simulations: Respiratory Protective Device (RPD) Performance Studies for Hazards and Human Physiology 8. Human Subjective Evaluation of Respiratory Protective Device (RPD) Wearability, Usability, Function, and Comfort 9. Respiratory Protective Device (RPD) Protection Mechanisms, Filtration Efficiency, and Associated Modelling and Predictions 10. Healthcare workers and special populations 11. Respiratory Protective Device (RPD) Challenges: Decontamination and Reuse 12. Policies and regulations for Respiratory Protective Device (RPD) Conformity Assessment Around the World 13. Political, Social, and Psychological Impact on Respiratory Protective Device (RPD) Adoption 14. Sustainability and Environmental Impact of Respiratory Protective Device (RPD) Usage and Disposal 15. Material Perspectives on Respiratory Protection Revolution 16. Pandemic and development of novel Respiratory Protective Devices (RPD) 17. Applications of Sensing and Wearable Technology for Enhanced Performance of Respiratory Protective Devices (RPD) 18. Incorporation of Advanced Technology into Respiratory Protective Devices (RPD)