Drinking water doesn’t technically expire in the way perishable foods do, but its quality and safety can degrade over time, especially if stored improperly. The U.S. Food and Drug Administration (FDA) doesn’t require bottled water to have an expiration date, but manufacturers often add a "best by" or "use by" date to indicate peak quality.
Understanding "Expiration" for Bottled Drinking Water
While pure water itself doesn’t spoil, the containers it’s stored in can impact its safety and taste. Over extended periods, plastic bottles can leach chemicals into the water, and seals can degrade, allowing contaminants to enter. This is why understanding the "best by" date is crucial for ensuring you’re drinking the safest and best-tasting water.
Why Does Bottled Water Have a "Best By" Date?
Manufacturers typically add a "best by" date, often around two years from the bottling date. This date is primarily about quality, not safety. After this date, the plastic bottle may begin to degrade.
- Chemical Leaching: Over time, chemicals from the plastic can migrate into the water. While generally considered safe in small amounts, prolonged storage can increase this migration.
- Seal Degradation: The seal on the bottle can weaken. This might allow airborne contaminants or bacteria to enter, compromising the water’s purity.
- Taste Alteration: The plastic itself can impart a slight taste to the water, which might become more noticeable over time.
Is It Safe to Drink Expired Bottled Water?
Drinking bottled water past its "best by" date is generally considered safe, but it’s not ideal. The primary concern shifts from the water itself to the integrity of the container. If the bottle has been stored properly, the water is unlikely to make you sick.
However, if the bottle has been exposed to extreme temperatures, direct sunlight, or has a compromised seal, the risk increases. It’s always best to err on the side of caution, especially if you’re unsure about the storage conditions.
Factors Affecting Drinking Water Shelf Life
Several factors influence how long your drinking water remains at its best quality. Proper storage is key to maximizing its shelf life and maintaining its safety.
Storage Conditions Matter
Where and how you store your bottled water significantly impacts its longevity. Avoid conditions that can accelerate degradation.
- Temperature: Store water in a cool, dry place, away from direct sunlight and extreme heat. High temperatures can speed up the leaching of chemicals from plastic.
- Sunlight: UV rays from sunlight can degrade plastic over time and potentially promote the growth of algae or bacteria if the water is exposed.
- Contamination: Keep bottles sealed and away from potential contaminants like chemicals, cleaning supplies, or strong odors, which can be absorbed through the plastic.
The Role of the Container
The type of container plays a role in the water’s shelf life. While most bottled water comes in plastic, other options exist.
- Plastic Bottles (PET): The most common type. While safe for typical storage, prolonged exposure to heat or light can cause issues.
- Glass Bottles: Offer better protection against chemical leaching and taste transfer. However, they are more fragile and expensive.
- Metal Containers: Often used for reusable water bottles. Ensure they are food-grade stainless steel and free from BPA.
How to Tell if Your Water Has Gone Bad
While water doesn’t develop a "rotten" smell or taste like food, there are signs that indicate it’s no longer at its best. Trust your senses, but also consider the storage history.
Visual and Olfactory Clues
Before drinking, take a moment to inspect the water and its container.
- Cloudiness: If the water appears cloudy or has visible particles, it’s best to discard it. This could indicate bacterial growth or container degradation.
- Unusual Odor: While pure water is odorless, a strange smell emanating from the bottle might suggest contamination or a reaction with the plastic.
- Damaged Container: Check for any cracks, leaks, or signs of tampering with the bottle or its seal.
Taste Test (with Caution)
If the water looks and smells fine, a small sip can help determine its quality. If it tastes off, metallic, or plasticky, it’s probably time to replace it.
Emergency Preparedness and Water Storage
For emergency preparedness, storing water is vital. While the "best by" date is a quality indicator, properly stored water can last much longer for survival purposes.
Long-Term Water Storage Guidelines
When storing water for emergencies, focus on maintaining its purity and safety for an extended period.
- Use Food-Grade Containers: Opt for new, food-grade plastic containers specifically designed for water storage.
- Sanitize Containers: Thoroughly clean and sanitize any containers before filling them.
- Add a Preservative (Optional): For very long-term storage (over six months), a small amount of unscented household bleach (about 2 drops per quart) can be added to help kill bacteria. However, this is generally not recommended for everyday drinking water.
- Rotate Stock: Even with proper storage, it’s wise to rotate your emergency water supply every 6-12 months to ensure freshness.
How Long Can Stored Water Be Kept?
Commercially bottled water, stored correctly, can remain safe to drink for years beyond its "best by" date. However, its quality might decline. For emergency preparedness, water stored in clean, food-grade containers can be safe for up to a year or even longer if kept in ideal conditions.
Frequently Asked Questions About Drinking Water Expiration
Here are answers to some common questions people have about the shelf life of drinking water.
### Does tap water expire if stored in a jug?
Tap water, when stored in a clean, sealed jug, doesn’t technically expire. However, the quality can degrade over time. Bacteria can grow in the water, and the plastic jug might leach chemicals. It’s best to consume tap water stored in a jug within a few days to a week for optimal safety and taste.
### Can you get sick from drinking old bottled water?
You are unlikely to get seriously sick from drinking old bottled water, especially if it has been stored properly. The main risks involve a slight increase in chemical leaching from the plastic or potential contamination if the seal has been compromised. If the water looks, smells, or tastes unusual, it’s best to avoid drinking it.
### How should I store bottled water long-term?
For long-term storage, keep bottled water in a cool, dark, and dry place, away from direct sunlight and extreme temperatures. Ensure the bottles remain sealed and are not stored near chemicals or strong odors. This helps prevent the plastic from degrading and maintains the water’s quality.