Many households have a water dispenser for cool, boiled water that can be drunk at any time. However, this convenience can pose health risks. If not finished on the same day, it must be discarded.
This is because the nitrogen-containing organic compounds in the boiled water will continuously decompose into nitrites over time. Meanwhile, the inevitable presence of microorganisms will accelerate this decomposition. The harm of nitrites to the body is well-known; they have a strong ability to bind with hemoglobin in the body, which can interfere with the blood's normal oxygen transport function. Therefore, boiled water is best consumed on the day it is made.
In addition, many families now habitually drink bottled water. Even bottled water, which appears to be well-sealed, should be finished within three to four days. This is because after the bottle is opened for a long time, bacteria can enter through the water inlet. Furthermore, when water is dispensed, a negative pressure is created in the dispenser, which inevitably draws in some air. Bacteria and microorganisms in the air can also take advantage of this opportunity to enter. If not finished within a short period, the bacteria count will exceed the standard, and the purified water will no longer be pure.