Using Phenoxyethanol in Lotion with Milk

Regarding your questions about using Phenoxyethanol in your lotion containing pasteurized goat milk:

1. Adding at Low Temperature in the Final Step: Yes, Phenoxyethanol can generally be added at low temperatures in the final step of your lotion formulation. The specific maximum temperature depends on the type of Phenoxyethanol you are using. Some types can be added below 80°C, while others require the temperature to be below 60°C when adding in the final step. Always check the recommended usage instructions for the specific Phenoxyethanol product you have.

2. Suitability for Lotion with Milk: Phenoxyethanol is a common preservative used in cosmetic formulations. However, formulations containing natural ingredients like milk (even pasteurized) can be more susceptible to microbial growth compared to standard water-based or oil-based products. While Phenoxyethanol is effective against bacteria, some types may have limited effectiveness against fungi and yeast. For a formulation containing milk, it is highly recommended to use a broad-spectrum preservative system or combine Phenoxyethanol with other preservatives to ensure comprehensive protection against various microorganisms.

Given the complexity of a milk-based formula, performing a challenge test is crucial. This test evaluates the effectiveness of your preservative system in your specific formula under controlled conditions to ensure it can prevent microbial contamination throughout the product's shelf life. Relying solely on the natural preservatives in milk or a single preservative like standard Phenoxyethanol might not be sufficient for long-term stability and safety.

Consider using a broad-spectrum variant like Phenoxyethanol SA (eq. Optiphen Plus) or a combination product like Chlorphenesin / Phenoxyethanol (Microcare PHC eq.) if you are not combining standard Phenoxyethanol with other preservatives.