A common question arises regarding the interchangeability of boiled water and distilled water, particularly when seeking a purer form. While both processes involve heat, they differ significantly in their outcomes regarding water purity. Boiled water and distilled water serve distinct purposes due to the specific impurities each process removes, leading to different applications.
How Boiling Water Changes It
Boiling water involves heating it to its boiling point. This process effectively eliminates most microorganisms, including bacteria, viruses, and parasites, making water microbiologically safe for consumption, particularly in emergency situations.
However, boiling water does not remove dissolved inorganic contaminants such as minerals, salts, and heavy metals. Chemical pollutants, including pesticides and industrial chemicals, also largely remain. As water evaporates during boiling, the concentration of these non-volatile impurities can increase in the remaining water.
How Distillation Works
Distillation is a purification method that begins by heating water to its boiling point, transforming it into steam. This vaporization leaves behind most impurities.
The steam is then collected and cooled in a separate condenser, where it reverts to its liquid state. This condensed liquid is distilled water. This method effectively removes almost all dissolved solids, minerals, heavy metals, bacteria, and viruses.
Purity Differences Between Boiled and Distilled Water
Boiled water, while microbiologically safe due to pathogen elimination, retains its original chemical composition, including dissolved minerals. The taste of boiled water reflects the minerals present.
Distilled water, conversely, is nearly pure water (H2O), separated from almost all impurities, both biological and chemical. It possesses a very low Total Dissolved Solids (TDS) content, indicating minimal mineral presence. This comprehensive removal of impurities means distilled water often has a flat or bland taste. The fundamental difference in impurity removal makes these two types of water non-interchangeable for many specific applications.
When to Use Each Type of Water
Boiled water is suitable for immediate consumption where microbial contamination is the primary concern, such as during emergencies or when traveling. It is also commonly used for general cooking and cleaning tasks where mineral residue is not an issue. In some instances, boiled tap water can be used as a short-term alternative in home medical devices or for nasal rinses if distilled water is unavailable, provided it is boiled for at least one to five minutes to address potential pathogens.
Distilled water is essential for applications demanding high purity, where minerals or other contaminants could cause damage or interfere with processes. For medical devices like CPAP machines and nebulizers, using distilled water prevents mineral buildup and avoids the aerosolization of pathogens. In scientific laboratories and for sensitive electronic cleaning, distilled water is crucial for accurate results and to prevent corrosive reactions or residue. Automotive applications, such as car batteries and cooling systems, require distilled water because minerals can cause corrosion and shorten the lifespan of components. Humidifiers also benefit from distilled water to prevent mineral “white dust” and inhibit microbial growth.