Glycolic Acid Dilution and FDA Regulations

Regarding your questions about Glycolic acid dilution and FDA regulations:

Calculating Glycolic Acid Concentration and Dilution

• Making a 5% Glycolic Acid Solution: Your calculation "Glycolic 5 : Water 95" is correct. It means mixing 5 parts of Glycolic Acid (e.g., 5 grams) with 95 parts of water (e.g., 95 grams) to obtain a Glycolic Acid solution with a concentration of 5% by weight (or by volume, if using the same units).
• Using the 5% Solution in a Formula: If you take the 5% Glycolic Acid solution you prepared and "drop it into the formula at 0.05%" as you understood, this will not result in a final Glycolic Acid concentration of 5% in the product. The concentration would only be 5% * 0.05% = 0.0025%, which is very low.
  • If you want the final product to have a specific concentration of Glycolic Acid (e.g., 5%), you need to calculate the amount of Glycolic Acid (or the concentrated solution you have) that must be added to the total formula to achieve the desired final concentration.

FDA Regulations for AHA (Including Glycolic Acid)

• The FDA regulation stating "For consumer use, no more than 5% and product pH not lower than 3.5" refers to the final concentration of AHA (such as Glycolic Acid) in the finished product sold to consumers.
• Therefore, cosmetic products containing Glycolic Acid that are sold to consumers must have a total amount of Glycolic Acid in the formula not exceeding 5%, and the pH value of that product must be not lower than 3.5 for safe use.

Since the initial search did not yield specific Glycolic acid products, I cannot provide product-specific details, but the general formulation principles and regulations explained above should help clarify your questions.