N95 respirator is one of nine kinds of particle respirators certified by NIOSH (National Institute of occupational safety and health). "N" means the particles that are not suitable for oil (the oil smoke produced by cooking is the oil particles, while the droplets produced by people's talking or coughing are not oil particles); "95" means that under the detection conditions specified in NIOSH standard, the filtration efficiency reaches 95%. N95 is not a specific product name. As long as the product meets the N95 standard and passes the NIOSH review, it can be called "N95 mask".
Among the nine standards formulated by NIOSH, N95 is the minimum standard for infection prevention, which is cheap and easy to be adopted by medical institutions. N95 respirator is used for occupational respiratory protection, including some microbial particles (such as virus, bacteria, mold, anthrax, tuberculosis, etc.).
The N95 mask is characterized by its ability to prevent droplet infection caused by splashing of body fluids or blood. The size of the droplets is 1 to 5 microns in diameter. OSHA requires medical workers exposed to TB bacteria to wear masks above N95 standard.
N95 respirator is a respirator with a breathing valve. The function of the breathing valve is to work in a hot and humid environment with poor ventilation or a large amount of labor. Using the respirator with a breathing valve can help you feel more comfortable when exhaling. Wearing hours: it depends on personal use and environment, but it shall be replaced immediately when users feel dyspnea or discomfort,when masks are contaminated by blood stains or droplets and other foreign matters,when the user feels that the respiratory resistance increases,or when the mask is damaged and so on.
The N95 mask, which is popular on the Internet, can achieve 95% filtering effect after testing, and the effect of PM2.5 protection should be the best. But for N95 masks, doctors do not recommend ordinary people to wear: "in theory, the more airtight the mask's protective materials are, the better the effect of blocking particles is. Conversely, the more airtight the mask is, the more difficult it is to breathe. If it is not worn properly, it may cause dizziness due to lack of oxygen. Wearing N95, a professional protective mask, is easy to cause dyspnea, especially for patients with cardiovascular disease and other diseases.