The presence of a date printed on bottles of water often leads to the misinterpretation that the water itself expires. Water, in its pure form, does not degrade or become unsafe over time. However, the expiration date relates to the integrity of the plastic bottle and the potential for chemical leaching into the water. Plastics are susceptible to breakdown when exposed to temperature fluctuations and prolonged storage. This breakdown can result in the release of chemicals, such as antimony and bisphenol A (BPA) in some types of plastic, into the water, potentially affecting its taste and safety.
The practice of assigning these dates serves as a quality control measure implemented by bottling companies. It ensures that the water retains its intended flavor and purity, and that the bottle maintains its structural integrity over a specified period. Furthermore, many jurisdictions have regulations requiring expiration dates on all consumable products, including bottled water. This ensures consumer protection and facilitates inventory management for retailers, helping to prevent the sale of products in compromised containers. While historically the emphasis was solely on freshness, current labeling practices are primarily focused on the quality and safety of the packaging.