pH of hair: what it is and what it means by Aaron Dorn
pH refers to whether a product is alkaline or acidic and is as important to a hairstylist as pounds & ounces are to a chef. The scale ranges from 0.0 having the highest concentration of acid, to 14.0 having the least. Pure water is at the middle of the pH scale. 7.0 (acid/alkaline are equal) So it is neutral. The hair itself has no pH since it is solid, but the protective mantle of the hair has a pH that ranges from 4.5 to 5.5 on the scale.
Anything that you apply to the hair that is below 4.5 will act as an acid; it will harden, constrict and shrink the hair. Anything that you apply to the hair above 5.5 will act as an alkali; soften, swell and expand the hair and change the interior. Therefore, always ensure that the protective pH 4.5 to 5.5 has been returned.
The measurement of pH is very important because the largest external organs on the human body, the skin, hair and nails are mildly acidic. Human hair is at its greatest strength, luster and flexibility when the average acid mantle is between pH 4.5 to 5.5. Likewise, our skin is softer and more resilient when it falls within a pH range of 4.5 to 5.5.
Scientifically formulated shampoos, conditioners and treatments, can give hair the beautiful shine, body and resilience of healthy hair, and dramatically improve its outer appearance. Look for hair care products that are acid balanced. Redken hair care products are formulated with a mildly acidic pH of 4.5 to 5.5 to be compatible with the acid mantle of hair and skin. Your knowledge of pH will enable you to select products that will leave your hair and skin in as natural and healthy environment as possible.
The term alkaline refers to the ammonium hydroxide or sodium hydroxide (lye) present in a product. Its purpose is to raise the pH of a product so the chemical reaction will process rapidly. Because of its alkalinity it tends to strip the hair and scalp from its natural oils, this could be drying or even irritating to your hair and skin. Alkali is found in soaps, most shampoos, and in general household cleaners.
It is important to remember that pH is logarithmic; each number multiplies itself by ten (x10). Example: pH 8 is ten (10x) times more alkali than pH 7. pH 14 is ten million (x10,000,000) times more alkali than pH 7. On the acidic side of the scale, pH 6 is ten (x10) times more acidic than pH 7.