Distillation is one method of water purification. Is distilled water safe to drink or as good for you as other types of water? The answer depends on a few different factors.
In order to understand whether distilled water is safe or desirable to drink, let's take a look at how distilled water is made:
What Is Distilled Water?
Distilled water is any water that has been purified using distillation. There are multiple types of distillation, but all of them depend on separating components of a mixture based on their different boiling points. In a nutshell, water is heated to its boiling point. Chemicals that boil off at a lower temperature are collected and discarded; substances that remain in a container after the water evaporates also are discarded. The water that is collected thus has a higher purity than the initial liquid. As pure water becomes increasingly harder to find, industrial scale distillation continues to evolve.
Key Takeaways: Drinking Distilled Water
- Distilled water is water purified using distillation. In this process, different boiling points are used to separate components in the water.
- Generally, distilled water is safe to drink. However, it is not the best choice for drinking water.
- Distilled water contains fewer metals and minerals than its source water. Since some minerals are essential for human health, drinking distilled water may not be a healthy option.
- In some cases, distilled water is contaminated by chemicals from the still. This is more common in home distillation set-ups.
- Distilled water, like other bottled water, is susceptible to leaching from its container.
- Distilled water is a good choice for drinking water if the source water is contaminated by metals, volatile organic compounds, or fluoride.
Can You Drink Distilled Water?
Usually, the answer is yes, you can drink distilled water. If drinking water is purified using distillation, the resulting water is cleaner and more pure than before. The water is safe to drink. The disadvantage to drinking this water is that most of the natural minerals in the water are gone. Minerals are not volatile, so when the water boils off, they are left behind. If these minerals are desirable (e.g., calcium, magnesium, iron), the distilled water might be considered inferior to mineral water or spring water. On the other hand, if the initial water contained trace amounts of toxic organic compounds or heavy metals, you might want to drink distilled water rather than the source water.
Generally, distilled water that you would find at a grocery store was made from drinking water, so it is fine to drink. However, distilled water from other sources may not be safe to drink. For example, if you take nonpotable water from an industrial source and then distill it, the distilled water may still contain enough impurities that it remains unsafe for human consumption.
Another situation that could lead to impure distilled water results from using contaminated equipment. Contaminants could leach out of the glassware or tubing at any point of the distillation process, introducing unwanted chemicals. This is not a concern for commercial distillation of drinking water, but it could apply to home distillation (or moonshine distillation). Also, there may be unwanted chemicals in the container used to collect the water. Plastic monomers or leaching from glass are a concern for any form of bottled water.
History of Water Distillation
People have been distilling drinking water from sea water since at least 200 AD. Alexander of Aphodisias described the process. However, historians believe water distillation predates this, since Aristotle refers to water distillation in Meteorologica.
In the modern era, it's common for distillers to add back minerals to distilled water for drinking to improve flavor and confer health benefits. Regular distilled water is important for laboratory experiment to control the composition of the solvent. Distilled water is commonly used for aquarium water to avoid introducing contaminants and microorganisms from tap water. Humidifiers and evaporators benefit from using distilled water because it doesn't lead to mineral buildup or scale. Ocean vessels routinely distilled sea water to make drinking water.
- Kozisek, F. (2005). "Health risks from drinking demineralised water." World Health Organization Report: Nutrients in Drinking Water.
- Taylor, F. Sherwood (1945). "The Evolution of the Still". Annals of Science. 5 (3): 186. doi:10.1080/00033794500201451
- Voors, A. W. (April 1, 1971). "Mineral in the municipal water and atherosclerotic heart death". American Journal of Epidemiology. 93 (4). pp. 259-266.