21 C.F.R. § 868.5870Download PDFCurrent through September 30, 2024Section 868.5870 - Nonrebreathing valve(a)Identification. A nonrebreathing valve is a one-way valve that directs breathing gas flow to the patient and vents exhaled gases into the atmosphere.(b)Classification. Class II (performance standards). 21 C.F.R. § 868.5870