How to add essential oils and fragrances to cosmetic formulas

Essential oils: safety first!

Just because they are natural, it does not mean essential oils are safe. Almost all essential oils contain allergen ingredients, some can cause skin staining and some are highly irritating and even dangerous when used on the skin. 

Remember: essential oils, hydrosols and floral waters are all different! Learn the difference with this video. 

While fragrances will usually come from a supplier who has already done the safety and regulatory checks, essential oils are available from a wide variety of shops and websites, meaning purchases can be made without you knowing the risks! Make sure you know how to check regulatory and safety databases, including:

• SUSMP – while this is Australia specific, it does provide good safety limits which make sense the world over;
• CosIng – a more extensive regulatory database that is EU specific; it provides a wider range of regulatory limits to help ensure safety; 
• IFRA Database – the official International Fragrance Association database, with comprehensive safety and input data relevant to all types of fragrance compounds and essential oils. 

Watch an overview of essential cosmetic regulations with this video. 

Remember too that cosmetic product ingredient lists must contain the correct names of all essential oils used in a formula, and all allergens present (EU and ASEAN labels). 

Make sure you are up to date with all allergen listing requirements with this blog. 

Formulating for sensitive skin and those with allergen sensitivities? Read how to formulate hypoallergenic products with this blog. 
 

How much essential oil or fragrance to use in cosmetic formulas

In order to reduce the risk of irritancy, yet provide an aroma of intensity which consumers are used to, fragrances and essential oils should be used in products within set amounts. As a general guide, products used on the face should contain less fragrance and essential oils than those used on the body. 

Fragrances and essential oils should be carefully selected to ensure they have low irritancy profiles while also considering the skin coverage and type of person the product will be used on. For example, baby lotions which get applied over most of the baby’s body should contain far less fragrance/essential oils than a product applied to the legs of a normal adult. 

Here is a summary of general formulation inputs – remember to check safety and regulatory limits and adhere to any limits where specified.   
 

How to add essential oils and fragrances to cosmetic formulas

Fragrances and essential oils will almost always be supplied to you in a liquid form. If they are resinous, they will first need to be mixed in a suitable quantity of carrier oil to become more liquid. 

Fragrances and essential oils can be oxidized or destabilized by unsuitable conditions. Before adding fragrances or essential oils ensure:

• the pH of the product is not going to adversely affect the fragrance or essential oil.
• temperature is even throughout the product and is below 40°C.
• mixing of the product ensures there will not be any ‘hot spots’ or uneven distribution of acids or bases which may still be able to react with the fragrance or essential oil. 

Also make sure that on addition, the fragrance or essential oil is evenly dispersed throughout the entire product. To ensure this, you could mix the fragrance or essential oil with: 

• a surfactant (in the case of a foaming product), or 
• solubiliser (in a typically 10:1 ratio polysorbate 20:essential oil, as an example) if being added to water or a gel; or 
• adding after an emulsion has cooled down if adding to a cream, lotion or conditioner. 

Here is an example of how to add essential oils to a body lotion formula:

METHOD

1. Combine ingredients in phase B to form a slurry. Add to phase A under high shear until the gum hydrates and a smooth gel forms.
2. Heat phase A/B to 75°C.
3. Combine ingredients in phase C and heat to 75°C. 
4. Add phase C to phase A/B and stir under high shear until a smooth, glossy emulsion forms. Allow to start cooling.
5. Continue stirring under low shear while cooling. When <40°C, add phase D and stir through until homogenous. 
6. Adjust pH to 5.3 – 5.8
    

Happy formulating!