One common question regarding drinking water is whether it’s safe to drink distilled water. The short answer is yes, consuming distilled water generally is safe. While it lacks some minerals found in other types of water, it’s free of many impurities. However, there are risks associated with drinking distilled water long term or in certain situations.
What is Distilled Water?
Distilled water is a type of purified water that has gone through a process called distillation. Distillation involves boiling the water and then condensing the steam back into a liquid. This process removes many impurities and contaminants, leaving almost pure H2O.
What Does Distillation Remove?
Distillation effectively removes a wide range of contaminants, including:
- Bacteria and viruses: The boiling phase of distillation kills these biological contaminants.
- Heavy metals: Distillation removes heavy metals like lead, arsenic, and mercury, which can be harmful when consumed.
- Salts: Distillation also eliminates salts, helping desalinate water.
- Chemicals: Most organic and inorganic chemicals, including pesticides and herbicides, are removed through distillation.
However, some volatile organic compounds (VOCs) and certain other chemicals that have a lower boiling point than water can still be present in distilled water.
Distilled vs. Tap, Filtered, and Reverse Osmosis Water
Comparing distilled water to other types of water provides valuable insights:
- Tap Water: Unlike distilled water, tap water contains minerals such as calcium and magnesium. However, it may also contain contaminants like lead, depending on the source and treatment process. Whether your tap water is better or worse than distilled water depends on where you live.
- Filtered Water: Filtered water has been passed through one or more filters to remove contaminants. The effectiveness depends on the filter type, but generally, filters don’t remove as many contaminants as distillation or reverse osmosis.
- Reverse Osmosis Water: Similar to distilled water, reverse osmosis water is highly purified. Reverse osmosis removes some contaminants, like certain VOCs, that distillation cannot.
Pros and Cons of Drinking Distilled Water
Distilled water is safe to drink, but it’s essential to understand its pros and cons:
Pros
- Purity: Distilled water is one of the purest forms of water, free from many contaminants found in other types of water.
- Taste: Some people prefer the taste of distilled water as it doesn’t have the “hard” taste that comes with minerals.
Cons
- Lack of minerals: Distilled water doesn’t contain minerals like calcium and magnesium, which are beneficial to health. Also, minerals aid in hydration.
- Taste: Conversely, some people might find distilled water flat or tasteless due to the absence of minerals.
When is Distilled Water Preferable and Not Preferable?
Preferable Situations
- Medical and scientific use: Due to its high purity, distilled water is preferable in medical and scientific contexts, such as for diluting solutions, in autoclaves, and in experiments.
- In areas with contaminated water supplies: In regions where the local water supply is heavily contaminated, distilled water is a safe option for drinking and cooking.
- When scale or build-up is an issue: CPAP machines and humidifiers use distilled water so the equipment last longer.
- When purity is key: Infant formula sometimes recommends distilled water because it does not alter the nutritional composition of the mixture. Neti pots and saline solution also start with either distilled or reverse osmosis water.
Non-Preferable Situations
- Daily hydration: For everyday drinking, mineral water or filtered tap water might be healthier due to the presence of necessary minerals.
- People with specific dietary needs: Those who rely on water as a significant source of their mineral intake might need to seek other water types.
Risks of Using Distilled Water
Drinking distilled water occasionally does not cause any harm, but relying on it as your sole source of hydration could potentially lead to mineral deficiencies over time since it lacks minerals like calcium and magnesium.
- Electrolyte Imbalance: Water naturally contains electrolytes such as sodium, potassium, and chloride, which help regulate many bodily functions. Drinking distilled water, which has these electrolytes removed, potentially contributes to an electrolyte imbalance, especially when combined with excessive sweating, illness, or other factors.
- Mineral Deficiency: Distilled water doesn’t contain minerals like calcium and magnesium. While water is not the primary source of these minerals for most people, those who rely on it potentially face deficiencies.
- Tooth Decay: The lack of fluoride, which is often added to tap water to promote dental health, means distilled water might not protect against tooth decay as effectively. This is controversial, as fluoridation has negative health effects, as well.
- Taste: Some people find the taste of distilled water flat or tasteless, which potentially leads to reduced water consumption and dehydration, particularly in people who don’t have other appealing hydration options available.
- Potential Leaching: Distilled water can leach chemicals from its container into the water, as it’s a more aggressive solvent when devoid of minerals.
Storing Distilled Water and Shelf Life
Distilled water has a shelf life, even though it does not go bad in the traditional sense. It absorbs carbon dioxide over time, slightly lowering its pH and altering its taste. Store distilled water in a tightly sealed container to prevent it from absorbing gases from the air. Ideally, keep it in a cool, dark place. This minimizes the risk of growing algae or mold.
How to Make Distilled Water at Home
Making distilled water at home is easy:
- Fill a large pot halfway with tap water.
- Place a heat-resistant bowl in the pot, ensuring its edge is above the water level.
- Turn the stove on high and cover the pot with its lid inverted, so the top (handle side) faces downwards.
- Put ice on top of the lid to create a cold surface.
- As the water boils, it forms steam that condenses on the lid and drops into the bowl – this is your distilled water.
References
- Anjaneyulu, L.; Kumar, E. Arun; Sankannavar, Ravi; Rao, K. Kesava (2012). “Defluoridation of Drinking Water and Rainwater Harvesting Using a Solar Still”. Industrial & Engineering Chemistry Research. 51 (23): 8040–8048. doi:10.1021/ie201692q
- Azoulay A.; Garzon P.; Eisenberg M. J. (2001). “Comparison of the mineral content of tap water and bottled waters”. J. Gen. Intern. Med. 16 (3): 168–175. doi:10.1111/j.1525-1497.2001.04189.x
- Kozisek, F. (1980). “Health risks from drinking demineralised water”. Nutrients in Drinking Water. World Health Organization. ISBN 92-4-159398-9.
- Voors, A. W. (1971). “Mineral in the municipal water and atherosclerotic heart death”. American Journal of Epidemiology. 93 (4): 259–266.