The Importance of pH Balance in Skincare
pH balance is such an important aspect in cosmetic formulation, let me explain why.
First of all we must dive into some science about pH.
pH or Potential Hydrogen is a scale from 0 to 14 which represents the concentration of Hydrogen molecules in a solution. The scale is divided up into 3 sections: Acidic, Neutral and Alkaline (base).
Acidic solutions range from 0 to 7, with the lower numbers being stronger acids and the higher numbers being weaker acids. On the opposite side of the scale is the alkaline solution which ranges from 7 to 14, with the lower numbers being weaker alkaline and the higher numbers being stronger alkaline.
The value of 7 is called Neutral – this also happens to be the pH of water.
Now that we understand the basics of pH, let’s look at why is it so important in cosmetics formulation.
The pH of a cosmetic product is imperative in cosmetic formulation because of two reasons.
- The natural acidic pH of the skin.
- Certain ingredients require specific pH environment to be active.
As a formulator I have to account for both of these, and also how they fit into the desired intention of the product.
The skin is naturally acidic in nature, and this acidity plays an important role in the skins defence mechanisms and overall skin health. The exact pH of the skin is widely debated; however a pH range of 4 – 6 is generally accepted, although in cosmetics the ideal range is 5.3 – 5.7 for products without acids.
The PH of the skin can be altered due to internal factors or external factors like cosmetics and harsh soaps. The topical application of any cosmetic can temporally change the pH of the skin causing an imbalance, which can then lead to sensitivity and irritation.
As a formulator appease the natural balance of the skin, unless the product has a desired purpose to disrupt. This leads us into the number two: Ingredient activity.
Ingredients, just like your skin, also have a pH range that they require to perform their intended task. In some cases their activity is dependent on the pH regardless of their concentration. A really great example of this is Glycolic Acid, which as an acid requires an acidic environment for it to be effective on the skin. So, if you have Glycolic Acid in a solution at the pH of 7 you render the functionality of the acid to be pretty much useless. This is a great example of how specific ingredients require certain pH environments.
The pH of cosmetics is not limited to just products containing acids; all ingredients in cosmetics have a pH range in which they perform their best at. As the formulator you have to juggle ingredients, pH ranges, final pH and the desired intention of the product to have the most active product to produce the best results on the skin.
Louise Hoban – Biotechnologist & Cosmetic Formulator @ David Deans Skincare