N95 masks are a type of respiratory protective device designed to filter out at least 95% of airborne particles, including dust, smoke, and viruses. They are commonly used in healthcare settings and during public health emergencies, such as the COVID-19 pandemic, to help prevent the spread of infectious diseases. These masks fit tightly to the face, creating a seal that minimizes the amount of unfiltered air that can enter. N95 masks are regulated by the National Institute for Occupational Safety and Health (NIOSH) in the United States, ensuring they meet specific safety standards for effective filtration and fit.