Do Purified Waters Have Salt In It?

December 12, 2025 •

3 min read

According to the EPA, purified water is defined as water that has been treated to remove contaminants to a level of 10 parts per million of total dissolved solids or less. So, do purified waters have salt in it? The answer is more complex than a simple 'yes' or 'no', as it depends entirely on the specific purification method used and whether minerals are added back later.

Quick Summary

Purified water, especially through processes like reverse osmosis and distillation, is nearly salt-free. However, some bottled brands add minerals and salts back for taste. Salt content depends on the purification method and post-processing, with variations between purified, distilled, spring, and tap water.

Key Points

Purification Removes Salt: Water purification methods like reverse osmosis and distillation effectively remove virtually all dissolved salts, including sodium.
Remineralization Adds Salt Back: Many bottled water companies add a small amount of minerals and salts back into purified water to enhance the taste, which would otherwise be described as 'flat'.
Check the Label: To know the exact salt content of a specific brand, you must read the product label, as 'purified' doesn't guarantee a salt-free final product.
Variable Salt Content: Natural spring, mineral, and tap waters have highly variable salt concentrations depending on their geographical source and treatment.
Distilled Water is Salt-Free: Distilled water, which is a form of purified water created by boiling and condensing, is a reliable source of water that is free of salts.

Understanding the Water Purification Process

Water purification involves several methods to remove impurities, including dissolved salts. The primary goal is to achieve a very low concentration of total dissolved solids (TDS), which includes inorganic salts like sodium chloride.

Reverse Osmosis (RO)

Reverse osmosis is one of the most effective purification methods for removing dissolved salts. This process forces water through a semipermeable membrane with incredibly small pores, leaving behind a wide range of contaminants, including sodium. This results in water with minimal to no salt content. RO systems are commonly used for both residential water purification and commercial bottled water production.

Distillation

Distillation involves boiling water and then collecting the condensed steam, leaving solid contaminants and minerals, including salt, behind. This process produces very pure, almost salt-free water. Distilled water is often used in laboratory settings or for specific applications, as its lack of minerals gives it a 'flat' taste that some find unappealing for drinking.

Deionization

Deionization, or demineralization, uses ion-exchange resins to remove mineral ions, such as sodium, calcium, and magnesium, from water. It is a highly effective method for producing pure water, but it doesn't remove uncharged molecules, viruses, or bacteria as effectively as other methods.

The Role of Remineralization

Since truly purified water can taste flat due to the absence of minerals, many bottled water companies add a controlled blend of minerals and salts back into the water for taste. This process is known as remineralization. While this reintroduces some level of saltiness, the concentration is carefully controlled to be much lower than that found in tap or many spring waters. For example, ingredients such as magnesium chloride, potassium bicarbonate, or potassium chloride might be added. The key is that the company intentionally adds these back, which is different from a natural source containing these minerals.

Comparison: Purified Water vs. Other Water Types

To better understand the salt content, it is helpful to compare purified water with other common water types.


Water Type	Purification Method	Typical Salt Content (Sodium)	Notes
Purified Water (RO/Distilled)	Reverse Osmosis, Distillation	Very low to zero	Initially has virtually no salt; some brands remineralize for taste.
Spring Water	Sourced from underground spring, minimal filtration	Varies widely	Minerals and salts depend on the geological source; some can be naturally high in sodium.
Mineral Water	Sourced from a mineral spring	Varies widely	Contains naturally occurring minerals and salts; levels vary significantly between brands.
Tap Water	Municipal water treatment	Varies widely	Content depends on the source and treatment process; can be naturally salty in some areas.

The Importance of Checking Labels

For consumers concerned about sodium intake, especially those on low-sodium diets, it is crucial to read the labels on bottled water. A bottle labeled "purified" may have started as salt-free water, but could have added salts and minerals afterward for flavor. Some brands are transparent about their remineralization process and will list the specific minerals added. The FDA and EPA have guidelines for sodium in drinking water, with lower levels recommended for those on restricted diets.

Conclusion

In summary, whether purified waters contain salt depends on the exact water and its processing. Water that is truly purified via methods like reverse osmosis or distillation contains negligible amounts of salt. However, many commercial brands remineralize this pure water by adding salts back to improve taste. Natural spring or mineral waters contain salts that are naturally present in their underground sources, and tap water's salt content is highly variable. Always check the product label to be certain of its specific mineral and salt content. The purification process itself is designed to remove, not add, salts. Source.

Frequently Asked Questions

Purified water is safe to drink, but since it lacks essential minerals like calcium and magnesium, some people prefer water with minerals. The human body primarily gets these minerals from food, so drinking purified water is not generally harmful for most individuals with a balanced diet.

Bottled water companies sometimes list salts like magnesium sulfate and potassium chloride as added ingredients because they are intentionally added back to purified water to enhance the flavor, as pure water can taste flat.

Water purified through a reverse osmosis system is nearly salt-free because the process forces water through a very fine membrane that effectively traps and removes dissolved salts.

No, distilled water does not contain salt. The process of distillation involves boiling water and collecting the steam, which leaves all solid impurities and dissolved salts behind.

Purified water, especially without remineralization, tends to have a 'flat' or neutral taste because the minerals that contribute to flavor have been removed. Tap water's taste varies depending on its source and the minerals it contains.

No, not all bottled waters are purified. Some are sourced from natural springs or mineral springs, which means their mineral and salt content is naturally occurring and not necessarily removed.

For individuals with a normal, balanced diet, drinking purified water is unlikely to cause a mineral deficiency, as the vast majority of our mineral intake comes from food, not water.