Distilled water is used in Constant Positive Airway Pressure (CPAP) machines to humidify the air entering the users nasal cavity, mouth, and throat. Distilled water will not leave any contaminants behind when the humidifier in the CPAP machine evaporates the water.

Distilled water is water that has been boiled into vapor and condensed back into liquid in a separate container. Impurities in the original water that do not boil below or near the boiling point of water remain in the original container. Thus, distilled water is a type of purified water.

Distilled Water V's Purified Water.... What is the difference?

Distilled water is a type of purified water that has had both contaminants and minerals removed. Purified water has had chemicals and contaminants removed, but it may still contain minerals.

Purified water is filtered through one of these processes:

Reverse osmosis filters the water through a special material called a semipermeable membrane. This material allows fluid to go through, but it removes salt and impurities.

Distillation boils the water, and then condenses the steam back into a liquid to remove impurities and minerals.

Deionization removes salt and other mineral ions (molecules) from water.