Does water expire or can water expire? This question pops up more often than you might think, especially when you're staring at a dusty bottle of water in your pantry with a date that passed months ago. The short answer might surprise you: water itself never goes bad, but how it's stored matters for safety, taste, and quality. Bottled water has expiration dates due to packaging and regulations, not because water chemically spoils. Let's explore science, storage tips, and safety concerns so you know how long can you store water and when water is safe to drink.
Does Water Expire? The Quick Answer
People often ask, does water expire in plastic bottles, how long can you store water or whether bottled water can remain safe past the printed date. Here's what you need to know right away:
- Water (H₂O) does not chemically expire - it's one of the most stable compounds on Earth
- Bottled water expiration labels exist due to packaging breakdown, regulations, and taste concerns - not spoilage
- Properly stored tap water or bottled water stays safe to drink well past expiration dates if sealed and kept cool, away from heat and sunlight
- The shelf life of bottled water depends more on the container than the water inside
Why Bottled Water Has Expiration Dates
Can water go bad or does water go out of date? If not, why your water bottle has a date stamped on it when water doesn't expire? The answer lies in legal requirements and practical concerns rather than actual spoilage.
Legal and Regulatory Background
The Food and Drug Administration (FDA) doesn't require expiration dates on bottled water, but many companies include them anyway. This practice started when New Jersey required a two-year expiration date on all food products, including bottled water. Even though this law was later repealed for lacking scientific basis, the practice stuck.
Bottled water companies continue using best-by dates for several reasons:
- Consumer expectations and peace of mind
- Quality assurance for taste and freshness
- Legal protection and standardized practices
- International Bottled Water Association recommendations
How Packaging Affects Water Quality
The real issue isn't whether water goes bad - it's what happens to the container over time. Plastic water bottles are made from polyethylene terephthalate (PET), which can degrade over time under certain conditions.
When plastic bottles are exposed to:
- High temperatures
- Direct sunlight
- Excessive heat
The plastic may leach small amounts of chemicals into the water inside. This doesn't make the water dangerous, but it can affect taste and potentially introduce microplastics into your drink.
Storing Tap Water vs. Bottled Water
When it comes to emergency preparedness or simply ensuring you always have safe drinking water on hand, knowing how long water can be stored is essential. While both tap water and spring water or bottled water's shelf lives are generally safe, their storage requirements differ. Factors like container type, temperature, and exposure to light all play a role in maintaining water’s quality and taste.
How Long Does Tap Water Last?
Tap water can be stored safely for up to 6 months when kept in sanitized containers. Here's what affects its shelf life:
Safe Storage Conditions:
- Clean, sealed containers
- Cool, dark places
- Away from direct sunlight
- Proper labeling with storage dates
Why Tap Water Changes Over Time:
- Chlorine used for disinfection evaporates
- Water may absorb carbon dioxide from air, creating a flat taste
- Open containers can become breeding grounds for bacteria
Storage Tips for Tap Water:
- Use food-grade containers
- Fill containers to the top to minimize air exposure
- Store water in cool areas (below 70°F)
- Rotate your supply every 6 months
- Label containers with fill dates
How Long does Water in a Plastic Bottle Last?
Does bottled water go bad? The simple answer is no - bottled water lasts for years if stored properly. Water in a cool environment or sealed container can maintain quality much longer than many expect.
| Storage Condition | Expected Quality Duration |
| Cool, dark storage | Indefinitely safe, best taste for 2+ years |
| Room temperature | Indefinitely safe, taste changes after 2 years |
| High temperatures | Safe but taste affected within months |
| Direct sunlight | Safe but potential plastic degradation |
Best practices for storing bottled water:
- Keep bottles in a cool, dry place
- Avoid plastic exposure to heat sources
- Store bottled water away from chemicals and cleaning supplies
- Don't store in garages or cars where temperatures fluctuate
Health and Safety Concerns Over Time
Even though stored water may remain drinkable for months or even years, its safety and quality can change over time. Factors like plastic leaching, bacterial growth, or exposure to light can all affect whether the water is still safe for consumption. Understanding these risks helps you spot warning signs early and take simple steps to keep your stored water fresh and healthy.
Chemical Leaching from Plastic
When plastic water bottles are exposed to heat or sunlight, they may release small amounts of chemicals. The most common concerns include:
Microplastics: Tiny plastic particles that can enter the water over time. While research on health effects continues, minimizing exposure is generally recommended.
Chemical Migration: Bottles are made from polyethylene terephthalate, which is generally safe but can leach trace amounts of chemicals under extreme conditions.
Biological Contamination Risks
Bottled water, when sealed and stored in cool conditions, remains more stable and safer than water in reusable tumbler water bottles because it minimizes exposure to air, microbes, and potential chemical migration.
Water that has been stored in opened containers faces different risks:
- Bacterial growth in non-sterile environments
- Algae development in clear containers exposed to light
- Cross-contamination from dirty hands or cups
Signs that water has gone bad:
- Cloudy appearance
- Strange odors
- Unusual taste
- Visible particles or growth
Testing and Treatment Methods
If you're unsure about water quality, several options can help:
- Boiling for 1 minute kills most bacteria and viruses
- Water filtration systems remove many contaminants
- Home testing kits check for specific issues
- Professional water safety testing for comprehensive analysis
Understanding Water Regulations and Standards
Safe drinking water doesn’t just depend on storage—it’s also shaped by the regulations that govern its quality. In the U.S., tap water and bottled water fall under different agencies, each with its own rules and testing requirements. Knowing how the FDA and EPA set and enforce these standards helps clarify common misconceptions about which type of water is “safer.”
FDA vs. EPA Oversight
The Food and Drug Administration regulates bottled water as a food product, while the Environmental Protection Agency oversees tap water quality. Both agencies maintain strict safety standards, but their approaches differ:
FDA Bottled Water Standards:
- Must meet same safety standards as tap water
- Additional quality requirements for taste and odor
- Regular testing for contaminants
- Facility inspections and record-keeping requirements
Key Facts About Regulations:
- Bottled water is not required to be safer than tap water
- Expiration dates are not federally mandated
- State regulations may vary
- Import/export rules affect international brands
Environmental Impact and Sustainability
Beyond health and safety, storing water also raises important environmental questions. The widespread use of plastic bottles contributes to pollution, resource waste, and a growing carbon footprint. By understanding these impacts and exploring more sustainable storage alternatives like glass, stainless steel, or BPA-free options, we can make choices that are better for both our health and the planet.
The Plastic Problem
Americans consume massive amounts of bottled water annually, creating significant environmental challenges. Each major brand generates over $1 billion in annual sales, representing billions of plastic bottles.
Environmental considerations:
- Plastic bottles take hundreds of years to decompose
- Manufacturing requires significant energy and resources
- Transportation adds to carbon footprint
- Recycling rates remain below optimal levels
Eco-Friendly Storage Alternatives
For long-term water storage, consider these sustainable options:
Glass Containers:
- No chemical leaching concerns
- Indefinite shelf life when properly sealed
- Easy to clean and sterilize
- Higher upfront cost but long-term value
Stainless Steel Options:
- Durable and long-lasting
- No plastic concerns
- Good for both storage and daily use
- Resistant to temperature changes
BPA-Free Plastic:
- Safer than traditional plastic
- More affordable than glass or steel
- Still requires proper storage conditions
- Should be replaced periodically
Practical Storage Guide for Different Scenarios
Having safe water on hand isn’t just about how long it lasts—it’s also about planning for different situations. Whether you’re preparing for natural disasters, setting up long-term reserves, or simply keeping a steady supply at home or the office, storage strategies will vary. By tailoring your approach to each scenario, you can ensure that clean water is always available when you need it most.
Emergency Preparedness
Storing bottled water for emergencies requires special planning. Emergency management experts recommend one gallon per person per day, with at least a three-day supply.
Emergency Water Storage Checklist:
- Calculate family needs (1 gallon/person/day minimum)
- Choose appropriate containers (food-grade plastic or glass)
- Label all containers with fill dates
- Store water in cool, dark locations
- Rotate supply every 6-12 months
- Include water purification tablets as backup
- Keep manual can opener for canned goods
Long-Term Storage Solutions
For families preparing for extended emergencies or living in areas with unreliable water supplies:
55-Gallon Drum Storage:
- Use food-grade containers only
- Add water preservative for extended storage
- Position drums for easy access and rotation
- Check seals regularly for integrity
Water Rotation Schedule:
- Mark calendars for rotation reminders
- Use "first in, first out" principles
- Test stored water periodically
- Replace containers showing wear or damage
Daily Use and Office Storage
Bottled water is convenient for offices, schools, and daily hydration needs. Here's how to manage smaller quantities:
- Always keep bottled water in climate-controlled areas
- Avoid plastic exposure to heat sources like radiators
- Use water coolers for shared office spaces
- Monitor best-by dates for quality assurance
Myths and Facts About Water Expiration
When it comes to stored or bottled water, many people are misled by expiration dates and common myths. In reality, water itself doesn’t expire—the real concerns lie in container quality and storage conditions. By separating fact from fiction, we can better understand what truly affects water’s safety and taste over time.
Common Misconceptions
Myth: Expired water is dangerous to drink.
Fact: Water doesn't go bad chemically. Drink expired water is generally safe if the container wasn't damaged.
Myth: Bottled water becomes toxic after its expiration date.
Fact: Bottled water can last indefinitely when stored properly. Dates indicate peak quality, not safety.
Myth: All plastic containers are equally safe for water storage.
Fact: Food-grade containers designed for water storage are much safer than repurposed containers.
Scientific Facts About Water Stability
Water is one of the most chemically stable compounds on Earth. Pure H₂O doesn't break down or spoil under normal storage conditions. The type of plastic used in containers affects water quality more than time itself.
What actually happens over time:
- Container materials may degrade over time
- Taste changes due to chemical absorption
- Microplastics may increase in heated plastic containers
- Sealed water remains microbiologically stable
Special Cases: Sparkling Water and Flavored Options
Not all bottled water is the same—sparkling and flavored varieties come with their own storage rules and shelf-life concerns. Unlike still water, carbonation and added ingredients can impact both taste and freshness over time. Understanding these differences helps you know when your favorite fizzy or flavored drink is still enjoyable, and when it’s past its prime.
Does Sparkling Water Expire?
Sparkling water presents unique considerations compared to still water. The carbonation can affect both taste and container integrity over time.
How long does sparkling water last?
- Unopened: 12-18 months past best-by date
- Opened: 2-4 days in refrigerator
- Sparkling water loses carbonation faster than still water
- Aluminum cans maintain carbonation better than plastic bottles
Signs sparkling water has deteriorated:
- Loss of fizz or carbonation
- Flat taste
- Off-flavors from container interaction
- Plastic bottle deformation from pressure loss
Key Takeaways
Water is one of nature's most stable compounds and doesn't expire under normal conditions. The confusion around water expiration dates comes from packaging requirements and quality considerations, not actual spoilage.
Essential points to remember:
- Water itself never goes bad chemically
- Packaging breakdown and storage conditions affect taste and safety
- Expiration dates are regulatory guidelines, not safety deadlines
- Properly stored bottled water remains safe to drink for years past printed dates
- Best practice: Store sealed containers in cool, dark places and rotate every 6-12 months for optimal taste
The bottom line? You need water to survive, and understanding proper storage helps ensure you always have safe, good-tasting water available. Whether you're preparing for emergencies or just managing your daily hydration needs, focus on proper storage conditions rather than worrying about expiration dates.
Frequently Asked Questions
1. Can you drink 20 year old bottled water?
Technically, it is true that bottled water itself does not expire. Pure water does not allow microorganisms to survive and grow. If the bottle is well sealed, not exposed to direct sunlight, and the temperature is stable, even if it is kept for 20 years, the water is still safe to drink. However, whether the water is drinkable or not, and what the quality is like, depends very much on the container in which the water is stored. Over time, plastic bottles will slowly deteriorate, and chemicals such as bisphenol A and microplastics will run into the water. This is not necessarily harmful, but the taste and purity of the water will certainly be affected. Before drinking bottled water that's been sitting around for a long time, be sure to look out for things that aren't quite right. Take a close look at the bottle to see if it's cracked, changed shape, or the color is off. Open the bottle and smell the water. If it smells funny or smells like plastic, it's likely that chemicals have seeped in. If the water tastes funny or has a strange aftertaste, it's best not to drink it. Although the risk of harmful bacteria is low if the bottle is properly sealed, it's the contamination from the packaging itself that's the biggest concern. Simply put, even if bottled water that has been sitting around for 20 years is well preserved and may not be harmful, it is generally not recommended to drink it because of the declining quality of the water. At best, it can be used as an emergency water source. If you drink it on a regular basis, it's better to drink fresh bottled water, or filtered tap water, which is safer.
2. Is it okay to drink water past the expiration date?
That's right, most of the time it's perfectly fine. Unlike food, water itself doesn't go bad and doesn't harbor bacteria. So, bottled water can theoretically be drunk all the time if it's properly sealed and stored. The expiration date printed on the bottle, more for regulatory or marketing needs, it is only the manufacturer's estimate of the best taste time, not that after this time can not drink, become unsafe. The U.S. Food and Drug Administration has also said that there is no mandatory shelf life for bottled water, even after the date on the package, it is still safe to drink. However, over time, the quality of the water will slowly decline. Plastic bottles may leach chemicals into the water a little bit, especially when it's hot, in direct sunlight, or when storage conditions are unstable. This can change the taste of the water to a plastic flavor, and on rare occasions, it can also bring in trace amounts of harmful substances, such as microplastics. To minimize the risk, be sure to check the bottle for cracks, turning cloudy or bulging, and also take a quick sniff and taste before drinking. Overall, it's usually safe to drink expired bottled water as long as it's properly sealed and stored in good condition. If you're not sure how the water is doing, treat it with a home water purifier or replace it with new bottled water, which is both safer and tastes better, so how reassuring.
3. How long can I keep bottled water for?
Bottled water itself doesn't go bad because pure water doesn't have sugars and proteins in it, which are the breeding grounds for bacteria. If bottled water is kept sealed, in a cool, dry place, away from chemicals and sunlight, it can theoretically last for a long, long time, and you don't even have to think about expiration. However, manufacturers generally recommend that you drink it within two years of buying it. This ensures that the water tastes the best and freshest. Over time, plastic bottles will slowly age and decompose, which not only affects the flavor of the water, but may also allow some trace chemicals to seep into the water. For those who store water for emergencies, it's a good idea to change out your stored water every 6 to 12 months. This ensures that you have fresh water available at all times and reduces the risk of bottles becoming brittle, leaking or even cracking. If bottled water is left in a hot environment, such as a car or garage, the quality of the water will deteriorate more quickly, even if it's still safe to drink.
4. How do I know if water has gone bad?
The water itself doesn't expire, but once it's contaminated, or the chemicals in the container leach into the water, it's undrinkable. The most obvious problems can be seen at a glance. For example, the water becomes cloudy, there is something floating in it, or the color changes. Don't drink water that smells funny, whether it's metallic, plastic, sulfurous, or musty. Taste can also tell you the answer. Bitter, acidic water is likely to have absorbed something from the surrounding environment, or a substance produced by bad packaging. If bottled water is left in a hot place for a long time, or kept in the sun, the plastic will break down, releasing chemicals that affect the odor and taste. Tap water or stored water can also go bad if microorganisms grow in it or if it is chemically contaminated. If you are not sure if the water is drinkable, handle it carefully. Boil water for at least a minute, longer at higher altitudes, or use a certified water filter to remove possible contaminants.
5. How long until sparkling water goes bad?
Unopened sparkling water, as long as it is kept in a cool, dark place, out of the sun, and not in a high-temperature environment, it usually retains its freshness for 12 to 18 months after its shelf life, and the bubbles will not run out. Even after the expiration date, the water itself will not really go bad, but the air bubbles may slowly leak out from the sealed area, and the taste will fade. Therefore, the main problem is that it affects the taste, not that it will be unsafe to drink. Once sparkling water is opened, the bubbles will be gone very quickly. If you want to get the best taste and full of bubbles, it is best to drink it within 2 to 4 days if you keep it in the refrigerator and keep it covered. After a week, sparkling water usually tastes like plain water, but it is safe to drink as long as it is not spoiled. In short, sparkling water doesn't become harmful to your health over time, but the taste and the buzz get worse. If you want to enjoy the bubbles, drink it as soon as you open it. Unopened bottles or cans of sparkling water can be kept in the pantry for a long time.