Using Lactic Acid Neutralized (AHA) at pH 5.0: Exfoliation vs. Moisturizing Function
Asked by: lkantiyo
On: November 25, 2025
Product Type:
Cosmetics
Question
I would like to inquire about the technical specifications of Lactic Acid (AHA) Neutralized (Deodorized) (Product ID 6376). Specifically:
- Can this ingredient be used effectively and stably in a final product formulated at pH 5.0?
- What are the functional implications (e.g., exfoliation vs. moisturization) of using this AHA at pH 5.0, considering its pKa?
- Are there any additional technical recommendations or considerations for its use at this pH level?
Answer
Yes, Lactic Acid (AHA) Neutralized (Deodorized) (Product ID 6376) can be used in a final product with a pH of 5.0.
Technical Analysis and Recommendations
Compatibility and Stability at pH 5.0:
- This product is specifically designed to be a partially neutralized form of Lactic Acid, containing both Lactic Acid and Potassium Lactate. This adjustment makes it gentler and raises its inherent pH.
- The product description states that a 10% concentration of this raw material in water has a pH of 4.0-4.5. Therefore, formulating a final product at pH 5.0 is perfectly acceptable and stable, as it is within the product's intended range of use for gentleness.
Functional Benefit at pH 5.0:
- The primary function of the product at pH 5.0 will shift significantly towards moisturization and skin conditioning rather than strong chemical exfoliation.
- Lactic Acid has a pKa of approximately 3.86. At pH 5.0, the majority of the Lactic Acid will be in its salt form (Lactate), which acts as a powerful humectant (a component of the skin's Natural Moisturizing Factor or NMF).
- The exfoliation effect will be very mild, making it suitable for sensitive skin or daily use products where the focus is on hydration and gentle softening.
Additional Recommendations:
- Use Rate: The recommended use rate for this raw material is 0.1-10%. Ensure you do not exceed this limit.
- Exfoliation Goal: If your goal is to achieve a more noticeable exfoliation effect, the final product's pH should be adjusted closer to the product's inherent pH, such as pH 4.0-4.5. At this lower pH, a higher percentage of the Lactic Acid will be in its free acid form, maximizing its exfoliating potential while still benefiting from the gentleness of the neutralized form.
- pH Adjustment: If you are formulating at pH 5.0, you may need to use a small amount of an acid (like Citric Acid or Lactic Acid 90%) or a base (like Triethanolamine or Sodium Hydroxide) to fine-tune the final pH after adding all ingredients, although the neutralized nature of this raw material makes pH adjustment less critical than with pure Lactic Acid.
