The expiration date of distilled water is often brought into question, with many claiming it has an indefinite shelf life but does distilled water go bad?
Distilled water does not technically go bad or expire. However, distilled water can potentially become contaminated by toxins and bacteria from either the air, the packaging material of the water, or some other pollutant in the environment.
After extensively researching water purification standards and food storage techniques, I have gathered enough information to determine if distilled water goes bad. In this article, we’ll be taking a closer look at the shelf life of distilled water and how to store it to improve its lifespan.
How Long Can Distilled Water Last?
When you buy distilled water at the store, you will likely see the packaging features an expiration date. The expiration date on most distilled water bottles will say the water is good for around 4 to 5 years. While this date can be useful to determine the quality of distilled water, it does not actually tell you whether it's bad or good.
Distilled water does not actually go bad. Unlike most of the food items in your home, distilled water has an indefinite expiration date and will likely never expire. Given that there are no nutrients or perishable contents in the water, it cannot spoil in the same way as most food and drinks.
That being said, distilled water can potentially become contaminated with toxins and bacteria. If the distilled water has been stored and handled properly, this should not be an issue, and the water will last for years. However, if distilled water is exposed to contamination such as air or toxins, it will be compromised.
Is Expired Distilled Water Safe to Use?
The distillation process of water involves boiling and then capturing the steam collected from the boiling process. This in turn results in one of the purest forms of water purification possible.
Minerals and metals are removed from the water and it becomes very soft, making distilled water particularly useful for cleaning medical supplies, ironing clothes, and humidifying rooms - among other things.
If you are using distilled water for these purposes and are sure that it has not been exposed to any kind of contamination, it will be 100% safe to use. On the other hand, if the distilled water has become contaminated, using it in certain situations can pose serious health risks.
Risks of Using Contaminated Distilled Water
Using contaminated distilled water to humidify a room or household is not recommended. You ultimately need to consider how the distilled water was contaminated to determine how serious of a health risk it is to use it in a humidifier.
Heavily contaminated distilled water that is moldy is not safe to use. The mold particles in the water will be transmitted into the air, which you will likely be breathing in. This can cause respiratory illness, as well as cause other negative effects on your health.
Is Expired Distilled Water Safe to Drink?
Whenever dealing with distilled water that is past its expiration date, you want to be certain that it’s safe to consume before you commit to drinking it. Although distilled water should be safe to drink after it has expired, any form of contamination can pose health risks.
If it was exposed to toxins or bacteria, do not drink distilled water as it may not be safe to consume. That said, distilled water that has been stored properly will be safe to drink years past its written expiration date.
It’s very important to take measures to prevent any form of contamination when storing your distilled water. Implementing the right storage methods can significantly extend the lifespan, making it safe to drink for years or even decades.
Risks of Drinking Contaminated Distilled Water
Much like with any contaminated water source, distilled water that has bacteria or toxins can be very dangerous to consume.
There are various forms of contamination that can sabotage your distilled water. Whether it's from the packaging material, exposure to chemicals, or bacteria, drinking distilled water that has been compromised should be avoided at all costs.
Drinking contaminated water has led to many severe illnesses and health issues around the world. However, what’s more than likely to happen is that you may experience unpleasant side effects from drinking contaminated distilled water such as:
- Stomach Aches
Does Distilled Water Last Longer than Bottled Water?
Based on the expiration dates found on bottle packages, distilled water apparently lasts longer than bottled water.
Most distilled water bottles feature an expiration date of roughly 4 to 5 years. Whereas standard bottled water normally shows an expiration date of just 2 years.
While distilled water may have properties that result in an extended lifespan, purified water that has been bottled should also be safe to drink long after its expiration date. An important factor to keep in mind is that both distilled water and standard water bottles should have an indefinite lifespan. With proper storage implemented, bottled water can last for years.
The key thing that may make bottled water unsafe to consume after the expiration date is if the contents were exposed to any kind of toxins or contaminants. This commonly happens due to the low-grade plastic materials used to package water bottles. Cheap water bottles often contain BPA, a toxic chemical that can damage your health, especially for children and infants.
How to Improve the Lifespan of Distilled Water
Distilled water generally has a labeled expiration date of roughly 4 to 5 years. However, it can technically last forever if it’s not exposed to contamination or toxins.
By implementing storage techniques and handling your distilled water properly, you can drastically improve its lifespan and potentially make it last indefinitely. Consider the following methods to improve the lifespan of your distilled water.
1. Avoid Single-Use Plastics
One of the primary reasons that distilled water becomes contaminated is due to toxins seeping into the water from plastic packaging. Distilled water that has been packaged in a single-use plastic container like most store-bought distilled water can often become contaminated with BPA.
As mentioned, BPA is a toxic chemical that is often used to make most single-use plastic bottles that we see sold in stores. When these cheap plastics are exposed to the sun and heat or become noticeably damaged or scratched, they will leak BPA into the water.
The best way to prevent this from happening is to simply avoid single-use plastics entirely. Alternatively, if you end up using single-use plastic bottles for your distilled water, make sure you store the containers properly and keep them away from direct sunlight, in a cool, dry, and dark environment.
2. Keep Bottles Sealed
Any bottle that you open essentially becomes compromised to potential contaminants. Air in particular has been known to cause water and other food items to expire early.
You should only be opening your distilled water once you are ready to use it. Be sure to keep the container completely sealed so that you do not increase the risk of contamination.
3. Buy Quality Water Containers
Whether you are storing a small amount of distilled water at home for humidifying and ironing, or stockpiling a massive quantity for a food storage system, choosing the right containers is essential to maximizing the lifespan of your distilled water.
One of the most common ways that distilled water becomes sabotaged is due to low-end containers that are easily damaged and are made with harmful chemicals. A quality water container will ensure that your distilled water has an indefinite shelf-life.
There are plenty of container options worth mentioning, but most importantly, you should prioritize choosing a material that suits your storage needs. Consider one of the following types of water containers for storing your distilled water:
- Glass Storage Containers
- Metal Storage Containers (stainless steel/non-toxic)
- Plastic Storage Containers (BPA-free)
4. Refrigerate Opened Distilled Water
If you end up opening and using your distilled water, it’s important that you take extra precautions to prevent it from becoming contaminated. The best way to do this is to close the container and place it in the fridge.
Much like with food, refrigeration greatly improves the shelf life of most goods in your home. Distilled water should still be safe to use and drink after it is opened, but if you want to secure its lifespan and prevent any risk of contamination, I highly recommend refrigerating opened containers.
5. Choose the Right Storage Location
Picking a suitable place in your home to store your water can often be as important as the containers that you choose.
You want to find a stable environment to store distilled water that will not result in it becoming contaminated. In general, parts of your home that are cool, dry, and away from direct sunlight are the best for storing distilled water, with the following locations normally being ideal:
This is particularly important if you are using low-end single-use plastic containers. Alternatively, if you are using glass containers, keeping the water near periodic direct sunlight can actually have some benefits, resulting in safer drinking water that is less likely to become contaminated.
How to Sterilize Contaminated Distilled Water
Although drinking distilled water that has expired should be safe in most cases, you don’t want to take any chances when it comes to your health and safety. That’s why it's important to know how to sterilize distilled water once it's been contaminated.
The most reliable way to sterilize distilled water is to boil it. You need to boil any contaminated water for 20 minutes until it’s safe to consume. This will kill just about any bacteria and most contaminants. Alternatively, you can use water purification tablets, which will also kill harmful bacteria in your water.
With that being said, while both of these methods are great for removing bacteria, they will not get rid of toxins or chemicals such as lead. In general, clean and safe distilled water should look clear and have a very neutral scent and taste. Signs such as cloudiness, bad taste, or odor may indicate that the distilled water is contaminated with chemicals or pathogens.
About THE AUTHOR
I have over a decade of experience in food and beverage management, including a ServSafe food safety qualification. As part of this qualification, I have been professionally trained in safe food storage.Read More About Mark Walker