While properly sealed bottled water doesn't exactly "go bad" in the sense of spoiling and becoming unsafe to drink due to bacterial growth, it can degrade in quality over time.
The Longevity of Bottled Water
The key takeaway is that water itself has an indefinite shelf life when protected from contaminants. So, why do bottled water containers have expiration dates? It comes down to the plastic bottle itself.
The Plastic Bottle Factor
- Leaching: Over time, the plastic can leach chemicals like antimony and Bisphenol A (BPA, although many bottles are now BPA-free) into the water, especially when exposed to heat or sunlight. This can affect the taste and potentially pose health risks.
- Permeability: Plastic is permeable to some extent, meaning it can allow external odors and flavors to seep into the water.
- Degradation: The plastic itself can degrade, impacting the integrity of the bottle and potentially contaminating the water.
Storage Matters
How you store bottled water significantly affects its quality:
- Avoid Direct Sunlight: Store bottles in a cool, dark place to minimize plastic degradation and leaching.
- Keep Away from Chemicals: Prevent exposure to strong odors or chemicals that can permeate the plastic.
- Temperature Control: High temperatures accelerate plastic degradation.
Understanding Expiration Dates
Expiration dates on bottled water are more about quality than safety. The FDA doesn't require expiration dates for bottled water, but manufacturers often include them to indicate the period during which the water is expected to maintain its optimal taste and purity.
In Summary:
While water itself won't spoil, the plastic bottle it's contained in can degrade over time, affecting the water's taste and potentially its safety. Proper storage is essential to maintaining the quality of bottled water. The expiration date is more about taste and bottle integrity than about the water itself becoming unsafe.
