In this article, we’re going to answer all the questions that might confuse you when talking about distilled and purified water:
- Is distillation a method of water purification?
- Does distilled water have detoxification properties for the human body?
- Which one is the healthier choice? Distilled water or purified water?
The Main Differences Between Distilled Water and Purified Water
The main difference between distilled and purified water is the filtration process the water goes through. Distilled water goes through the distillation process, while purified water goes through different filtration and treatment processes such as reverse osmosis, distillation, and deionization.
As distillation is one of the most effective water treatment procedures, despite being one of the most conventional, it’s capable of removing most impurities found in water. Because of this, there’s not much difference between distilled and purified water when it comes to the number of contaminants removed.
Furthermore, since both the distillation and purification processes can remove all the contaminants from water, the source of the water is kind of inconsequential for both water types. The water source can be surface water like a lake or river, an underground aquifer, or tap water.
However, since distillation requires bottled water producers to boil the water until it’s all vapor (just hydrogen and oxygen) and return it to its liquid state afterward, its taste might become a bit flatter than the original taste of the sourced water. Also, since the process of distillation removes the minerals that give tap water or spring water its taste, distilled water tastes quite bland when compared to both.
That said, many websites on the internet make claims regarding both distilled and purified water, saying that the former is mineral-free and the latter is not. While it’s true that distilled water is completely stripped of minerals, the same applies to purified water.
The water treatment techniques like reverse osmosis or deionization via ion-exchange, typically used in water purification, also removes mineral molecules from water. So, purified water is usually as mineral-free as distilled water.
Lastly, the United States Food and Drugs Administration (FDA) and Environmental Protection Agency hold both types of water to their regulations and standards. While the FDA ensures that they’re what the brand that sells them says they are (type), contaminant-free (quality), and bottled safely (packaging), the EPA regulates them under the National Primary and Secondary Drinking Water Regulations.
Distilled Water vs Purified Water Comparison Table
In the table below, we summarized the differences and similarities between distilled and purified water based on collection processes, treatment methods, contaminants, mineral count, taste, and standards and regulations.
|Water Types/Characteristics||Purified Water||Distilled Water|
|Collection process||Collected from any surface or underground water source, including tap||Collected from any surface or underground water source, including tap|
|Treatment Methods||Human-made filtration processes like reverse osmosis, flocculation, distillation, disinfection, etc.||Distillation, in which the water is boiled until it’s vapor and then cooled down to return to its liquid state|
|Contaminants||Contaminant-free thanks to the rigorous filtration processes the water goes through||Distillation removes all impurities since impure elements can’t find any solid molecules to cling to when the water is vapor|
|Mineral content||Filtration technologies like reverse osmosis remove all minerals from water||Completely devoid of minerals since mineral ions can’t find anything to cling to when the water is turned to vapor|
|Taste||Tasteless (or has a neutral, bland, flat taste)||Tasteless (or has a neutral, bland, flat taste)|
|Regulations/Standards||Regulated under guidelines set by the EPA and FDA||Regulated under guidelines set by the EPA and FDA|
What is Distilled Water?
Simply put, distilled water is water that is treated through distillation. Since distillation is one of the easiest, most conventional, and most affordable water filtration techniques (it doesn’t require expensive water filters), it’s widely used on an industrial scale.
During the process of distillation at an industrial scale, water is boiled until it’s all gas, i.e., until it becomes just hydrogen and oxygen, in a giant water tank with transfer tubes. Then, the water vapor is transferred to another tank via the tubes.
While the water is in its gas state, the dissolved impurities that would normally roam freely in its liquid state can no longer find any atoms to stick to, so they’re separated from the gas. These dissolved impurities include hazardous drinking water contaminants like lead and arsenic, as well as healthy minerals like calcium and magnesium.
Once the impurities are separated, the gas is moved into another tank to be cooled down. While cooling down, the water returns to its liquid state – free from all contaminants and minerals.
If you have ever boiled water and then cooled it down to drink it, you might have noticed that it had an unpleasantly bland taste. That’s the case for distilled water, too.
Furthermore, although we have plenty of food sources that allow us to get the minerals required in our diet, drinking mineral-free water is not recommended. On the contrary, mineral intake through water is still vital for our health, as many Americans already suffer from calcium and magnesium deficiencies.
All things considered, it’s no surprise that distilled water is not used for drinking as much as it is in different industries, predominantly in these contexts:
- Medical: Kidney dialysis machines that cleanse our blood and CPAP machines that help with sleep issues, such as sleep apnea, employ distilled water. Additionally, distilled water is the most common water type used for disinfecting medical tools.
- Laboratory: If water needs to be used in lab experiments, the main preference of chemists is distilled water since it only contains hydrogen and oxygen.
- Ironing: As we said, the distillation process removes minerals that give water its hardness. Since these minerals might cause stains on laundry and wear them out, mineral-free, distilled water is commonly used in ironing.
- Cosmetics: Water, often referred to as aqua in this context, is an essential ingredient of many cosmetic products like perfumes, moisturizers, and shampoos. The water that’s used in these products is typically distilled water.
- Automotive: Because all dissolved solids and minerals are removed from the water during the distillation process, distilled water poses no threat to sensitive automobile parts and paint.
Benefits and Drawbacks of Drinking Distilled Water
From everything that we now know about distilled water, let’s summarize the benefits of drinking it:
- It’s completely contaminant-free, so it’s perfectly safe to consume
- Bottled distilled water is regulated by the FDA and EPA, so you can be sure that it’s always up to the health standards set by these authorities
- It’s completely mineral-free character makes it ideal for use in many areas and industries like medicine, laboratories, cosmetics, and automotive
- It’s certainly safer than tap water which mostly has chemicals like chlorine and fluoride. Municipal authorities pump these into the water supply system for disinfection purposes and to promote teeth health in children and young adults.
That being established, drinking distilled water has some major disadvantages, too:
- During the distillation process, many healthy minerals like calcium, magnesium, potassium, and electrolytes are removed alongside hazardous contaminants. Since, as we said before, most Americans already lack such minerals both in their bodies and diets, and since these minerals play important roles in bone structure, muscle function, and blood pressure, their absence in drinking water might be cause for concern. Especially if you’re an athlete who loses minerals (electrolytes) from your body through sweating, drinking distilled water won’t replace those minerals.
- Compared to other kinds of water, distilled water tastes rather bland
To summarize, distilled water doesn’t make great drinking water, despite its other uses.
What is Purified Water?
Purified water is water that’s been subjected to a variety of treatment techniques in order to eliminate all the contaminants and mineral content from the water.
Similar to distilled water, the water source of purified water can be anything from a municipal tap to huge water wells that draw water from underground aquifers. The water is then subjected to many filtration and treatment techniques to remove impurities and total dissolved solids.
According to the EPA, purified water should be completely free of all the contaminants mentioned in the National Primary and Secondary Drinking Water Regulations set by the agency. Furthermore, it should contain no more than ten parts per million of total dissolved solids.
To that end, many bottled water brands and local water suppliers employ a 5-stage water treatment process:
- Coagulation: As the first step of large-scale water treatment processes, the water is stored inside a large tank. Then, a positively charged chemical coagulant like aluminum sulfate, ferric sulfate, or ferric chloride is put inside the water tank. The positive charge of these coagulants neutralizes negatively-charged contaminant molecules and binds them together.
- Flocculation: Once the negatively-charged contaminants stick together, they form larger clumps, often referred to as flocs. This process of enlarging impure particles is known as flocculation.
- Sedimentation: The reason behind coagulation and flocculation is that contaminant particles float freely inside the body of water due to their minute weight. However, when they form flocs, they become heavier, so they sink to the bottom of the storage tank. That way, they’re easily separable from the water. That said, not all chemicals and heavy metals are big enough for sedimentation at this stage. What sedimentation mainly handles are dirt, clay, and sand.
- Filtration: Another reason behind coagulation and flocculation is that the contaminant particles are too little in size to pass through the filters utilized in the filtration stage of water treatment. However, after flocculation, even if some particles haven’t flocculated enough to sink to the bottom of the tank, they’re now big enough for filters to block their passage. So, the water travels through filters that can eliminate the non-sediments like chemicals and heavy metals. The filter types employed in this process vary depending on the impurity of the water source, bottled water brand, or municipal authority. We’ll explain all the different filtration types used to purify water later.
- Disinfection: The last stage of the water treatment process for purified water is disinfection. Municipal authorities pump chlorine and chloramines into their water supply system to clear the water from organic pathogens like bacteria and viruses. Bottled water producers, on the other hand, prefer ozonation because its odor and taste are less distinct than that of chlorine, and it’s more effective at killing pathogens. That being established, chlorine, chloramines, or ozone in bottled or municipal water never exceed levels established by the EPA.
The Different Filtration Techniques Used When Producing Purified Water
We already mentioned how different brands and water suppliers might utilize different filtration technologies depending on the contaminants found in the water source and their preferences. Distillation, which we already covered in detail above, can be one of those techniques.
Besides distillation, the most common filtration techniques used to produce purified water are:
- Activated carbon filters: Activated carbon technology removes aesthetic impurities regulated by the EPA under its National Secondary Drinking Water Regulations. These include taste, color, odor, and sometimes, chemicals like chlorine.
- Reverse osmosis: Being one of the most effective technologies to eliminate contaminants from water, reverse osmosis is quite common everywhere, be it industrial-scale water treatment plants or home water treatment units. The effectiveness of this tech is thanks to its utilization of a semipermeable membrane with a microscopic pore size (more often than not, 0.0001-micron). This membrane prevents many contaminants from making their way to the end product, including dangerous heavy metals like lead and healthy minerals like calcium and magnesium.
- Ion exchange: You might have already heard of ion-exchange because it’s the working principle behind traditional, salt-based water softening units that remove hard water minerals (mainly calcium and magnesium, and sometimes iron to an extent). Since these minerals also give water a slightly bitter taste, some bottled water brands opt to remove them as well.
Benefits & Drawbacks of Drinking Purified Water
The main benefits of drinking purified water revolve around safety. For instance:
- Thanks to the rigorous filtration process, there are no contaminants left inside the water before it’s bottled
- Similar to distilled water, bottled purified water is strictly regulated by the FDA, and it’s always in line with the standards set by the EPA under the National Primary Drinking Water Regulations. So, it’s safer to consume than tap water.
- Unlike distilled water, which has uses in medicine, the automotive industry, and cosmetics, purified water is produced only for drinking
However, purified water has one major drawback as well:
- Since reverse osmosis and ion exchange remove minerals, purified water contains no minerals either. That said, water is not our only dietary source of minerals, and we can still consume these healthy minerals through a calcium and magnesium-rich diet.
Is Distilled Water Better Than Purified Water?
The simple answer to this question is no, distilled water is not better than purified water for the reasons below:
- Safety (or health hazard): Both distilled and purified water are contaminant-free, and both are regulated by the FDA and EPA. Although there are some claims that distilled water reduces minerals from living human tissues, these claims have no scientific backing, so both types of water are equally safe.
- Treatment process: Distilled water is just distilled. Depending on the water source, purified water might be distilled, pushed through reverse osmosis membranes, nano-filtered, and deionized at the same time. So, it’s safe to say that the treatment process of purified water is more rigorous than that of distilled water.
- Taste: Both types of water taste bland. Distilled water might be more unpleasant since it’s boiled and cooled.
- Mineral content: Neither type of water has healthy minerals
- Purpose: Purified water is treated and produced specifically for drinking. Distilled water is treated mostly for industrial use.
All that considered, there is no aspect that makes distilled water better than purified water.
Distilled water is treated through a distillation process in which the water is boiled until it’s all vapor and then cooled down to its liquid state. In the end, there are no contaminants or minerals left inside the water.
Purified water, depending on the impurity of the water source, can be subjected to different filtration techniques that may include distillation as well as reverse osmosis and deionization. Similar to distillation, no contaminants or minerals remain inside the water at the end of purification either.
While distilled water is commonly used in areas like medicine, automotive, and cosmetics, the only reason for producing purified water is for human consumption. That said, both types of water are tasteless.
In terms of preference, there’s not much to differentiate between them, so there’s no base to claim that distilled water is any better than purified water.