Room Spray Formulation Questions

Question

I have questions regarding the ratios for making Room spray as follows:

What should be the ratio of water to Alcohol?
Are there many types of Alcohol used in Room spray? Some brands use PEG40, some use PPG-1-PEG-9. I'm not sure how they are similar or different.
Will the mixture of water, Alcohol, and Essential Oil separate? Is there a substance that needs to be added to prevent the separation between water and oil?
There are many types of fixatives and air disinfectants. Can you recommend or suggest which ones to use? Or can multiple substances be added, such as Benzyl Alcohol, Anice Alc, Benzyl Benzoate, Polysorbate 80, Benzyl Alc, etc.?

Thank you very much.

MySkinRecipes Expert · Accepted Answer

Room Spray Formulation Questions

Here are the answers to your questions about making room spray:

Water to Alcohol Ratio:
- A typical room spray formulation uses a high percentage of alcohol, often around 70-90%, with the remainder being water and fragrance/other additives.
- The exact ratio depends on the desired strength, evaporation rate, and flammability. Higher alcohol content leads to faster evaporation and better fragrance throw.
- Using purified or distilled water is recommended.
Different Alcohols and Solvents:
- Yes, various types of alcohols and glycol-based compounds are used in room sprays.
- Ethanol or Isopropyl Alcohol are common primary solvents.
- Ingredients like PEG-40 Hydrogenated Castor Oil or PEG/PPG derivatives (such as PEG/PPG-20/15 Dimethicone) are often included. These are not primary alcohols in the same sense as ethanol, but rather function as solubilizers or emulsifiers to help blend the fragrance oil with the water/alcohol mixture and improve stability. They differ in their chemical structure and properties, affecting solubility and feel.
Separation of Layers and Solubilizers:
- Yes, essential oils and fragrance oils are generally not soluble in water and will separate, even with alcohol present, especially if the alcohol concentration is not high enough or if water is included.
- To prevent separation and create a clear, stable solution, you need to add a solubilizer.
- Polysorbate 80 is a common and effective solubilizer for this purpose. PEG-40 Hydrogenated Castor Oil is another option that can help emulsify oils into water.
- The amount of solubilizer needed depends on the specific fragrance oil and the water/alcohol ratio, but it is typically used at a ratio of 1:1 or 2:1 (solubilizer to fragrance oil) or even higher. You will need to test to find the right amount for your specific formula to achieve clarity.
Fixatives and Disinfectants:
- You can use various ingredients to enhance your room spray formulation, but their primary roles might differ from being strict fixatives or air disinfectants.
- Benzyl Alcohol can act as a solvent and a preservative.
- Anisyl Alcohol and Benzyl Benzoate are often used as fragrance ingredients or solvents, and Benzyl Benzoate can sometimes function as a fixative to help the scent last longer.
- Polysorbate 80, as mentioned, is a solubilizer; while it helps incorporate the fragrance, its primary role isn't fixation or disinfection.
- While some ingredients might have mild antimicrobial properties, dedicated air disinfectants are formulated specifically for that purpose. The ingredients you listed are primarily related to dissolving, dispersing, and stabilizing the fragrance.
- You can include multiple ingredients in your formula, but ensure they are compatible and used at appropriate concentrations for safety and effectiveness.