Buffer solutions play an important role in many industrial processes such as electroplating, food processing, manufacture of medicines, dyes and photographic materials, etc.
Many biological fluids such as blood, urine, etc., have definite pH which is maintained by buffer action of many substances. For example, blood pH is maintained between 7.35 and 7.45 by a buffer system whose principal acid-base pair is H2CO3/HCO3 -. Besides protein buffers also regulate the pH of blood.
The pH of tears is maintained at 7.4 by protein buffers.
The pH of beer is maintained between 4 and 5 by the buffer action of dissolved C02 and proteins.