In damp or poorly ventilated or heavy work environments, using a respirator with a breathing valve can help you feel more comfortable when you exhale. The breathing valve mask cover is a one-way valve. The exhaled air can expel gas. There is no filter layer in the exhaust process. If the patient wears this mask, the virus may be excreted. Patients diagnosed with or suspected of having a new crown should not wear such masks.
When exhaling, the positive pressure of the exhaust blows open the valve to quickly exhaust the gas in the mask, reducing the stuffiness when using the mask, and the negative pressure when inhaling is automatically closed to avoid inhaling pollutants from the external environment.