In brief: Distilled water is produced by evaporating water and then condensing the vapour. Many dissolved salts and nonvolatile substances remain behind. The result is not automatically sterile or suitable for every technical, medical or food-related use.
How distillation works
| Step | What happens? |
|---|---|
| Heating | Water enters the gas phase |
| Separation | Many nonvolatile substances remain behind |
| Condensation | Water vapour becomes liquid again |
| Collection | Distillate is collected in a clean container |
What distillation does not guarantee
Some volatile organic compounds can carry over with vapour, and pipes or collection vessels can re-contaminate water after distillation.
WHO laboratory guidance uses distilled water for defined purposes while also stressing quality control and clean storage.[1]
Purity is purpose-specific
Laboratory water, battery water, ironing water and pharmaceutical-grade water follow different standards. The word “distilled” alone does not establish suitability for drinking, inhalation, wounds, contact lenses or medicines.
Drinking distilled water?
Distilled water contains very few dissolved minerals. Most mineral intake comes from food. For everyday use, regulated drinking water is the usual choice; technical distilled products should not be consumed simply because they are labelled distilled.
FAQ
Is distilled water sterile?
Not automatically. It can become contaminated after production.
Is distilled water the same as demineralised water?
No. Demineralised water is commonly produced using ion exchange.
Can battery water be consumed?
No. Technical products are not intended as drinking water.
Can distilled water be used in medical devices?
Only when the device or product instructions specify that exact water quality.
Conclusion
Distillation is effective for removing many dissolved substances, but suitability always depends on quality control, storage and intended use.
