U.S. Code of Federal Regulations
Regulations most recently checked for updates: Aug 28, 2025
(a) Identification. A urea nitrogen test system is a device intended to measure urea nitrogen (an end-product of nitrogen metabolism) in whole blood, serum, plasma, and urine. Measurements obtained by this device are used in the diagnosis and treatment of certain renal and metabolic diseases.
(b) Classification. Class II.