RESPIRATOR THAT INCLUDES AN INTEGRAL FILTER ELEMENT, AN EXHALATION VALVE, AND IMPACTOR ELEMENT

摘要

A negative pressure respirator 20' that has an integrally-disposed filter element 28 and that covers at least the nose and mouth of a wearer. The respirator 20' includes an exhalation valve 22 and an impactor element 50 that covers the exhalation valve 22. The exhalation valve 22 has a diaphragm and an orifice and opens in response to increased pressure when the wearer exhales to allow exhaled air to be rapidly purged from the mask interior. The impactor element 50 is positioned in the exhale flow stream to remove particles and other contaminants from the exhaled air. The exhalation valve and impactor element have a ratio of Zn:Dj of less than about 5. The respirator 20' is beneficial because it provides comfort to the wearer by allowing warm, moist, high-CO2-content air to be rapidly-evacuated from the mask interior through the valve 22 and also protects the wearer from splash-fluids and from polluted air while at the same time protecting other persons or items from being exposed to particles and other contaminants exhaled by the wearer.