Formulation Questions for Alcohol Hand Spray

Here are the answers to your questions regarding the formulation of an alcohol-based hand spray:

1. Necessity of Food Grade Alcohol: The Ethyl Alcohol (99.9%, 200 Proof, Research/Perfumer Grade) is suitable for cosmetic use and even food-related work where incidental ingestion might occur after evaporation. While not strictly labeled "food grade" in the traditional sense for consumption as a beverage, its purity and denaturing process make it appropriate for applications like hand sprays where contact with skin and potential minor ingestion (e.g., from hands touching the mouth) is possible. You can use this type of alcohol.

2. Preservative with Glycerin or Propylene Glycol: Yes, if you add humectants like Glycerin or Propylene Glycol to your alcohol spray, you will likely need a preservative. While high concentrations of alcohol (typically above 60-70%) are self-preserving and act as disinfectants, adding other ingredients, especially water-attracting humectants, can dilute the alcohol concentration and introduce water into the formula. Water can support microbial growth, so a preservative is necessary to ensure the stability and safety of the product over time, unless the final alcohol concentration remains high enough for preservation.

3. Adding Double Hyaluron for Moisture: Yes, you can add Double Hyaluron Liquid to increase the moisturizing properties of your hand spray. This ingredient is designed to provide hydration. Ensure it is compatible with the high alcohol concentration and the overall pH of your final formulation. The product description indicates it is mixable in the water phase and works within a pH range of 3-9.

4. Using Mild Preserved as a Preservative: Yes, Mild Preserved Eco™ can be used in your formula. It is a blend of Ethylhexylglycerin and 1,3 Propanediol that functions as a preservative and is compatible with alcohol and water-based systems. The recommended usage rate for general cosmetic formulas is 1.0-1.5%, and it works within a pH range of 4-9.

5. Determining Shelf Life: The shelf life of your finished product is not simply determined by the shortest shelf life of the individual ingredients. It depends on the complete formulation, the packaging, storage conditions, and the effectiveness of the preservation system in the final product. To accurately determine the shelf life and ensure product safety and stability, it is recommended to perform stability testing and microbial challenge testing on your specific finished formulation.