It's strange why water has not expired for billions of years on Earth, but as soon as it is placed in a sealed bottle, it is marked with an expiration date? As a chemical compound, water is composed of oxygen and hydrogen, which is recycled on the earth, almost most of the water has been biologically used, it is not too much to say that it is urine, and there is a more terrifying carbon cycle than this, it can be said that all the carbon elements metabolized by our bodies are almost all metabolized by previous organisms, decomposed, or from the corpse.
Therefore, theoretically speaking, there is no concept of shelf life for water, and in fact, as long as it is not industrially produced food, there is basically no shelf life. However, because of this, since no one in nature has "guaranteed" water for you, you must have serious consequences if you drink it yourself. The shelf life of water, such as bottled water, is very strict, and 0.1% of the bacteria content exceeds the strict standard after one year, and the shelf life is set at one year. In fact, even if the water is left out of its shelf life for many years, it is still safer than taking water from most natural water bodies.
And the meaning of "expired" water is that microorganisms exceed the standard. Expiration means that the organic matter runs in, the bacteria eat the organic matter, multiply, and the water is undrinkable. Or harmful substances get into the water and cannot be drunk.
In addition, the expiration time of sealed water is usually the shelf life of the container, and the water can be stored for a long time, but the plastic and other substances are not. This explains why water can last that long while bottled water has such a short shelf life. Most of the water is PET bottles, and PET plastic will be denatured and release harmful substances after a long time, so the shelf life of water is a few years, which is actually the shelf life of the bottle.
In fact, it is very simple, water just refers to a general category, and there are a bunch of water with various names. And not expiring is a narrowed qualifier. When the question points to something specific, it is inaccurate because our linguistic habits omit the narrowing step. Theoretically, adjustments should be made accordingly.
Therefore, the standard of "expiration" is set by people, our human water must have a shelf life, for hygiene, in order to drink water without diarrhea, that's all, in addition to sealing water, the current urban water supply plants are basically sterilized with ozone, chlorination to curb pipeline bacteria. In fact, if this water is put in nature, what can happen, the animals will still drink it, and there will be nothing.
Wild animals are naturally eliminated, weak physique, low immunity have been abandoned, leaving behind are extremely strong immunity and physical fitness, people are relying on wisdom to develop to the top of nature, but immunity has been pulled down, a little virus of animals, can exterminate human beings.
After tens of thousands of years of development, human beings have learned to use fire, changed their eating habits, and promoted the development of the brain. The longer the microorganisms remain in the body, the more they multiply. The result of evolution. If animals also learned to make a fire and eat cooked food, they would be just as sick if they drank dirty water and ate dirty food.
There is also immunity caused by the living environment, beggars on the street pick up food in the garbage can all year round and do not get sick, and ordinary people go to the hospital early, just because their digestive system has adapted to the germs. The older generation of poor people are the same, even if the living conditions are good, they are thrifty, and they are reluctant to throw away the meat or anything that has deteriorated, and they all eat it directly, but they still don't have diarrhea.
Of course, water in nature also has self-purifying functions, such as precipitation, filtration, distillation, etc., and animals also give priority to drinking clean running water until there is no other choice. One of the big selling points of pet water dispensers is that the water can flow, and pets are more willing to drink it.