Distilled water

Distilled water is water that has had virtually all of its impurities removed through distillation (boiling the water and re-condensing the steam into liquid water in a clean container, thus leaving contaminants behind).

Purported benefits

Many people believe that distilled water protects them from less-than-perfect water treatment and trace contaminants, which although scientifically believed to be unharmful to humans, people think can be improved upon. Some people ask why should any quantity of a poison be drunk? The truth is poisons are a naturally occurring part of our environments and only a concern above certain thresholds, which are far higher than what is allowed in government-controlled water supplies. People who still hold this view have one more point: They can afford better water than the city provides, and science has never been performed that would determine health effects; and besides that, pure water just seems more natural and good, so why not use it?

A much bigger reason for some people to drink distilled water is that it may taste much better than local tap water. Water, itself, is the health benefit, and by enjoying the water more, these people find it easier to drink the recommended amount of 3 liters (11 glasses) per day for men or 2.5 liters (8 glasses) per day for women.

When a choice is offered between distilled water and "drinking water" in water filtration and dispening machines for self-bottling, the distinction is meant to suggest that pure water is good for car batteries and irons and other uses, but not always the best drinking water (the other choice has enough contaminants removed to create a cleaner tasting--and presumably more healthy--water, but leaves many of the minerals). The truth is both are acceptable as drinking water, and it is a matter of preference.

The drinking of distilled water has been both advocated and discouraged for the purported effect of drinking water in its pure form is a 'more powerful solvent' that helps cleanse toxins from the body. Detractors argue that it robs the body of essential minerals in this way and also deprives it of minerals normally acquired from drinking water. While there is no evidence to suggest that drinking distilled water is harmful or leaches minerals from the body, the World Health Organization has assembled considerable research which shows a relationship between drinking water containing naturally occurring minerals and lower rates of certain diseases. See Sweetwater's Water Resource Library below.

Many people use distilled water in their irons for pressing clothes to reduce mineral build-up and make the iron last longer. However, many iron manufacturers say that distilled water is no longer necessary in their irons, partly due to a perception that the water is more likely to sputter into the user's face, and primarily because of advanced materials that resist mineral build-up. For example, the General Electric Walmart-branded model "Type 163 Iron" (2005) includes in its directions: Please do not use distilled water in this iron.

Distilled water for drinking, bought in bottles from trusted sources, protects health when living in an environment where common water sources are not proven trustworthy. Doctors advise keeping the lips pressed tight when showering in such locals, and using the bottled water for brushing teeth, cooking, washing of food, and all drinking.

Many people use distilled water for household aquariums because it lacks the chemicals that would build up in and kill most storebought fish.

Distilling and water purification

Unfortunately, the cost of distilling water (about 0.04 to 0.10 Euro or USD per liter in 2005), whatever its perceived benefits, is prohibitive for most households worldwide. Boiling water is a common treatment method that does not require the distilling apparatus, but the fuel is the biggest part of the cost. Boiling kills many harmful bacteria, but it is not the same as distilling, because it leaves particulates sitting in the water; however, some combination of filtering, boiling, and distilling, or other form of purifying or testing (such as purchasing from a trusted source) is necessary to the reliably safe taking of any water into the human body. In many cases, governments take care of these needs, but in any situation where the water could be unsafe (for example, when drinking from untested natural water sources, or in unproven water supplies, such as in remote areas of developing countries) these practices are recommended. The Boy Scout Manual (1978) gives a rudimentary method of distillation as a device to get water for safe emergency drinking in a desert survival situation. A World Health Organization study in 2000 has shown that improving clean water supplies is the most efficient of a wide-range of studied improvements (including everything from education to highway safety) that governments can make in every country studied, including--surprisingly--the USA, which is not usually expected to be like developing countries on such fundamental margins.

Distilled water vs. government-treated water

It has been suggested that because distilled water (like reverse osmosis produced water) lacks fluoride ions that are added by many governments (such as most municipalities in the United States) at a water treatment plant for its effect on the inhibition of cavity formation, the drinking of distilled water may conceivably increase the risk of tooth decay due to a lack of this element.^* Regardless, most people continue to cook with tap water as treated and delivered by their government, and in cases of flouridized water this is thought to potentially provide sufficient fluoride to maintain normal prophylaxis in many cases. Studies funded by the World Health Organization and others seem to show a clear relationship between minerals in tap water such as calcium and magnesium and a decreased rate in certain diseases. In many other developing countries, government water treatment is necessary for health, but distilled water, if affordable, can be even safer by eliminating risks caused by variations from standards. An argument against shunning distilled water for displacing government-treated water is that governments treat water because it is much more economical than individual households treating it. Therefore, people who can afford it may choose distilled water for their drinking, and that does not deprive them of an overall health and caries plan, nor does it deprive governments of making changes informed by new knowledge (such as providing a caries prevention plan that includes distilled drinking water).

Myths about distilled water

A popular myth about distilled water is that it has the dangerous property of being more easily heated above its boiling point without showing the normal characteristics of boiling. This is called superheating. When the superheated water is disturbed or has impurities added to it, a sudden, explosive boil occurs, possibly causing serious injury to anyone near it. In fact, superheating of plain tap water, for instance in the microwave, is just as great a danger as when heating distilled water. In the popular Discovery Channel show Mythbusters, an experiment was conducted where distilled water was placed in a microwave oven for several minutes long enough to boil, but no convection (boiling bubbles) took place. When a contaminant (a sugar cube) was added to the superheated water, it had an explosive effect. However, this effect also occurs with normal tap water, as macroscopic impurities (especially those which carry air bubbles) are needed for boiling to start. The dissolved impurities in tap water are not enough to inhibit the superheating.

Unproven cleanliness of bottled distilled water

A second criticism of distilled water supplies as used around the world (in 2006) is that individual bottling is often used for economic distribution. Some distributors sanitize and seal the bottle with each filling; however, many households and companies (who keep water dispensers for employees and customers to drink) re-use their bottles. While municipalities and government-organized water services treat and measure contaminants in water, bottled distilled water, while assumed to be contaminant-free (as with piped government supplies where the pipes are not tested), is not necessarily proven to be as safe as assumed, or--at least--safer. For example, even though instructions like the ones below are often given by bottled distilled water suppliers, few standards are available for knowing the effect of using a bottle a long time between washings, for knowing how many people follow the instructions correctly, what happens when they do not follow them at all, or for knowing that the washing is not leaving soap or bleach, or that cracks in the bottle are not harboring bacteria. Although this risk is small enough to be thought negligible, studies are needed to prove it and measure the effect in individual households, and to compare this supply with government-delivered water supplies.

Instructions for keeping water bottles and dispensers clean, as given to public consumers:

Every 2-4 months, empty the bottle (through normal use).
Fill it with 2-4 liters of distilled water.
Add 1-3 ml of household bleach.
Close the bottle and shake vigorously for 30 seconds to cover all inside surfaces.
Let the bottle sit closed for 10 minutes.
Empty the bottle and rinse it twice with 2-4 liters of distilled water.
Re-fill the bottle with distilled water for use.
Routinely wipe all surfaces of the water storage tank and dispenser above the water without introducing soaps or bleach that cannot be thoroughly rinsed.
Clean the dispenser by running 2-4 liters of distilled water with 1-3 ml of household bleach completely through the dispenser.
Rinse the dispenser by running 2-4 liters of distilled water through all portions.
At all times, keep stored water bottles sealed closed in a cool, dry storage room, out of direct sunlight (Leave water in the hot trunk of a car for no more than 20 minutes for delivery), because heat from sunlight over time promotes bacterial growth.
Dust off bottles before inverting into a dispenser, and wipe them without introducing chemicals to the water supply.
Discard bottles after 2-5 years of use, and never use water or a bottle that develops any detectable smell.
Re-cap empty bottles while being stored (other sources say leave them open to air dry).
When re-filling empty bottles, pour in a liter of distilled water and swish it around to rinse the inside of the bottle, then pour it out before filling the bottle.

External links

Liquid water | Distillation | Drinking water