Pharmaceutical and biotechnology product manufacturers use varying grades of purified water for manufacturing, research and development, and testing activities. The grade of water used depends on the requirements of the product being produced. The primary categories of purified water designated by the U. S. Pharmacopeia organization (USP) are USP Purified Water (PW) and USP Water for Injection (WFI).

The key concerns for pharmaceutical-grade waters are chemical and microbiological purity. It is essential that a producer defines correctly the water quality specification for its intended use and demonstrates (through proper testing and validation activities) that the water quality is in compliance with the specification. (return)