by PureNature July 06, 2018
When manufacturing skin care products, it’s all too easy to forget about pH levels. However, if you want your products to succeed (and of course you do!) correct pH is vital.
Basically, if the pH of a product isn’t just right, the formula won’t work. If a solution is too acidic or too alkaline, serums can collapse or moisturisers will lose their consistency. Certain products - especially those with AHAs or BHAs (salicylic acid) - or other cosmeceuticals need to be a specific pH in order to function properly. Some preservatives will only work within certain pH ranges. Check your ingredients before starting!
The pH of a formula will change according to what you’ve used in the formulation. Ingredients such as Alpha-Hydroxy Acids (glycolic, lactic, tartaric, malic, and citric acids) will decrease your pH, while using a higher pH surfactant (for example, decyl glucoside or disodium cocoamphidiacetate) will increase the pH. So it’s important to be prepared to measure and adjust pH at the end.
Most skin care manufacturers recommend a pH of between 4.5 - 7. To achieve this, some recipes call for the addition of citric acid or sodium hydroxide at the end in order to alter the pH of the product. Citric acid decreases the pH, making it more acidic, while the sodium hydroxide increases the pH, making it more alkaline.
In hair products, pH is even more important. Our hair prefers products that are pH 6.2 or lower (acidic).
This is one of the reasons that cold-press soap doesn’t make a good shampoo: the pH is in the alkaline or over pH 8 range.
So too, the pH of our skin is incredibly important.
Typically healthy skin has a slight acidic pH average of 5.5. Increased pH values reduce the antibacterial and antimycotic properties of the skin surface, decreasing hydration, and increasing the risk of bacterial and yeast infections.
Measuring pH is easily done with a pH Testing Strips Kit. Our kit includes easy-to-use strips which give a basic indicative pH for soaps, cosmetics and other solutions. Each booklet comes with its own colour chart.
Adjusting pH simply requires the right ingredients. Citric Acid Solution 25% will reduce pH, while Sodium Hydroxide Solution 10% will increase it.
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