What is deionized water?

Deionized water is characterized as water that has had impurities removed, specifically the ions that can contribute to electrical conductivity. This purification process involves passing water through ion exchange resins that replace positively charged ions, such as sodium, calcium, and magnesium, with hydrogen ions, and negatively charged ions, such as chloride and sulfate, with hydroxide ions. The result is water that is free from dissolved salts and other ionic contaminants.

In hair services, deionized water is often preferred because it does not leave behind mineral deposits that can interfere with hair treatment products or lead to build-up, ensuring that the hair can be treated effectively without unwanted reactions from impurities present in regular tap water. This quality makes deionized water an essential component for many beauty and grooming applications.

Other options involve processes or products that do not specifically define deionized water. For instance, boiling water does purify it, but it does not specifically remove ions in the way that deionization does. Adding minerals might enhance hydration but is not relevant to the characterization of deionized water. Similarly, mixing water with essential oils alters its properties for fragrance or other benefits, but it does not pertain to the process of deionization.