Water bottles have become the most commonly purchased well nowadays. People end up purchasing dozens of water bottles through their journey, for a family journey the number goes countless. People, in general, prefer bottled water for the taste, flavour and the quality added to it.

Despite all these factors, you must be shocked to see the expiry date on the water bottle, does water really expire just like everything? In general, the expiry date on any product indicates the life span of the product packed inside the good, but in this case of water bottles, the situation is a reverse.

Coming to the details, according to the sources, technically, there are two reasons for mentioning an expiry date on bottles:

Firstly, most government regulations make it compulsory for food items and consumable good to have an expiry date. The compulsion forces the vendors to select an expiry date based on their findings.

but this second reason is scientifically more convincing and rightful,

When Plastic based water bottles are exposed to sunlight for a very long time; algae or fungal depositions start taking place. You can find such depositions by a light green tint on the bottle surface. Such plastic bottles are considered unhealthy for liquid consumption. The average time of such micro-bacterial decomposition based on average storage conditions is taken as expiry date.

And remember, also try not to drink from a bottle which was opened more than a week ago. Water stored in water bottles is best consumed within two days from opening the bottle for the first time.