You just moved to a new state and you can’t seem to figure out why your hair (or skin) is acting and feeling so weird now? Did you check the water hardness level? Hard water is certainly not the first thing that comes to mind when we face hair issues. Unfortunately, it does have a real impact on hair. Let’s discuss how we get hard water and why people with chemically treated hair face bigger issues than others.
What is hard water and how is it formed?
Hard water is a term used to describe water that is rich in mineral ions, particularly calcium and magnesium. The higher the content of calcium and magnesium the harder is the water. Rain water itself is not hard but it is slightly acidic (pH 5.6) because it dissolves some carbon dioxide in the atmosphere to form carbonic acid. When it hits the ground, it it passes through the rocks, soil, limestone, and chalk and will dissolve the calcium and magnesium salts present. The purification process from your local water plant does not remove these ions. Only impurities and bacteria are dealt with. Depending on where you are located the hardness level will be different. The map below can give you an idea of the water hardness in your area.
Note: The unit used is gpg which stands for grain per gallon of water. 1 grain per gallon is equivalent to 17.11 ppm of calcium carbonate.
The impact of hard water on chemically treated hair
The calcium and magnesium ions in hard water have strong positive charges (2+) and are referred to as cations. When the water hits your hair, those cations will quickly find the negative charges on the hair and bind to them.
In this study, the authors concluded that the more damaged the hair, the more ion uptake occurs by the hair. Caucasian hair was used in their experiments. Chemical treatments such as bleaching and oxidative hair dyes are known to damage hair. They produce more negative sites on hair due to the formation of significant amounts of cysteic acid. Cysteic acid results from the breaking the disulfide bonds in cystine, followed by oxidation.
Additional research studies demonstrated that coloring hair can increase the ion uptake significantly. Most of these ions have been found in the cuticle layers of hair.
3 important findings worth mentioning:
- The pH of your water can affect the extent of the ion deposition in your hair. A high pH will convert the carboxylic groups in the hair into negatively charged residues. Even if your water hardness is low in the area, a higher pH will increase the ion uptake into hair. (positive attracted to negative).
- Regardless of the water hardness level, the hair will reach a saturation point. It doesn’t keep ‘soaking’ up the ions forever. (see graph above).
- Calcium deposits more than magnesium. Magnesium ions have a higher charge density. They will get hydrated by the water molecules more easily and thus prefer the water phase better than hair.
Next: Let’s discuss the reasons why hard water impacts the hair and what we can do about it.