Preservative Level in Your Formula

Based on the ingredients provided, you are using Phenoxyethanol SA (eq. Optiphen Plus) at 1.25% in your formula.

According to the product information for Phenoxyethanol SA (eq. Optiphen Plus), the recommended usage rate is typically between 0.5% and 1.25%. Specifically:

• For eye products: Use no more than 0.5%
• For closed container products (like bottles): Use no more than 1.0%
• For open container products (like cream jars): Use up to 1.25%

Your formula appears to be a liquid cleansing product, likely intended for a closed container (bottle). While 1.25% is within the overall maximum recommended range and suitable for open containers, the recommended maximum for closed containers is 1.0%. Using 1.25% is at the very upper limit and slightly exceeds the specific recommendation for closed containers.

To ensure adequate preservation and safety, it is highly recommended to perform a challenge test on your final formulation. This test will confirm if the preservative system is effective against microbial growth under real-world conditions, regardless of the percentage used within the recommended range.