The pH value tells us something about the acidity of our body, but also of our hair. How often have you not seen cosmetic products that the product is pH neutral? But what does it mean? And what does the use of different products (shampoos, conditioners, relaxers, etc.) mean for the pH of your hair?
The abbreviation pH is derived from the Latin "Potential Hydrogenii" and refers to the number of hydrogen ions found in a particular substance. The values are expressed on a logarithmic scale which varies from 0 to 14. A value close to 0 is called an acidic substance. A value close to the 14 is referred to as an alkaline or basic material. A pH value of 7 is neutral (water has a neutral pH value). The pH value of the logarithmic scale means that each whole number in the scale determines an increase or decrease of the acidity by a factor of ten. A pH value of 8 is ten times more alkaline than a pH value of 7. A pH value of 9 is 100 times more alkaline than a pH value of 7, etc.
The pH value of our skin and hair is between 4.5 and 5.5. Shampoos, conditioners and other chemical hair products use acidic and alkaline substances to make hair changes. For example, acids will harden and densify the hair while alkaline substances release the hair and soften the hair shaft.
The pH value of shampoos
- Understanding the different PH values helps you find a good shampoo:
- An acid shampoo has a ph value between 0 and 6.9
- An alkaline shampoo has a ph value between 7.1 and 14
- The higher the pH value (more alkaline), the stronger and more damage the shampoo puts on your hair. A high pH shampoo makes the hair dry and fragile.
- The best pH value of shampoo for hair is between 5 and 6.
The pH strips
The pH values of products are often not described on the package. With a pH strip, you can easily test the values of your products. You stop the test (e.g.) your shampoo and discolor it. Compare the color with the strip on the color palette, and you know exactly what pH value your shampoo has!
What is the pH of hair and scalp?
Maintaining the correct pH value of the hair and scalp is essential to the overall health of the hair. Hair products can affect the pH of hair. Healthy, curly hair should have a pH balance of approximately 4.5 – 5.5, making it slightly acidic, while the pH of straight hair is between 4.5 and 5.0.
What is Neutral pH?
A pH of 7 is chemically neutral. Hair care products with a pH value between 3.5 and 5.5 are best for the comparison of the hair.
Variation in pH Value:
The pH value that is less 6.0, then the scales layer pulls together and closes. A mildly acidic conditioner (lower than pH7) promotes the shine of the hair because a smooth surface reflects more light; strong acids, however, damage the hair. Acid conditioners may not be used when red/orange tints are added to the hair, using a care product for colored hair instead. When the pH value is 7.0, the scales layer becomes softer and swells up like a pineapple. This is an essential part of the color process to deposit pigments into the hair structure, but the pH becomes too alkaline, so it does damage. Many transformation products use the effect of alkaline pH values on hair. The hair that is more alkali will hold more color. In that case, the scratch layer will not succeed in retaining new pigments, which ultimately causes the color to be washed out too early.
By setting a thorough diagnosis of hair, a hairdresser is in the unique position to check the pH of the hair and scalp. You can also better understand how to style your curly hair using a hair curler. By recommending care cures that are specifically intended for the hair type of the customer, hairdressers can prevent damage and provide fantastic looking hair with a pH value that is in the balance.