Lavender oil has been clinically proven to kill staphylococcus aureus. However, lavender is also known to cause allergies and is phototoxic. Studies were done that showed that lavender lacks natural antioxidant activity and when exposed to air it actually oxidizes and forms allergenic peroxides. These react with the skin and can cause pigmentation.
Lavender is one of the known photo toxic agents. Upon exposure to UV light it causes an increase in burning and also can create pigmentation formation to occur at a later stage.
Lavender contains 44% Linalool as a part of its chemical makeup. Linalool is known as an allergen. There are cosmetic regulations with the use of essential oils that contain allergens and as such they have a maximum limit permitted for use for leave on products and rinse off products. Lavender is permitted in a cosmetic product at maximum 100 parts per million (0.01 %) in a rinse off product and (0.001%) in leave on products.
What is even more interesting is that cosmetics which contained lavender (remember that there is a limit to how much they are permitted to use) were found to be absolutely useless with activity. The concentration that was used was insufficient to actually provide any antibacterial activity.
