The test of potassium permanganate-reducing substances is retained in the specifications of pharmaceutical water in containers, not as the most suitable method for the test of organic impurities present in the water in containers, but as a counter measure for performing the test of the water in containers with the same test method despite of the material (glass, polyethylene or polypropylene, etc) and the size (0.5 - 2000 mL) of the containers, and the duration of storage.〔【出典】第十六改正日本薬局方(平成23年3月24日 厚生労働省告示第65号)〕