Establishes labeling requirements, safety and performance requirements, and tests for hemodialyzers, an extracorporeal device used in the purification of the blood by diffusion and convection between the blood and a solution of chemicals through a semipermeable membrane. Furthermore, a hemodialyzer functions within clinically acceptable rates of water and solute transport. Use of the device is indicated in the treatment of severe renal insufficiency and in the removal of certain toxic substances. For purposes of this standard, hemodialyzers are limited to those of parallel plate and hollow fiber design, and ready for use upon manufacture; the responsibility of the manufacturer is limited to the use of the hemodialyzer as labeled.