Warning of the potential problems of using undiluted essential oils, especially tea tree oil, on the skin.

Essential oils are used widely in the community for medicinal purposes, for massage and in oil burners. Essential oils are also included in many household products including shampoos, hand-washes and cleaning products.  One of the most popular oils used is tea tree oil, used for its antiseptic properties on itches and bites, acne, rashes, and cuts. Even though these oils are ‘natural’, they can still cause problems for some people.

One of the main problems with the use of essential oils, relates to when they are used ‘neat’ or straight from the bottle, without being diluted.  Without dilution, there is potential for people to become sensitised and an allergy to the essential oil may develop. A good example is tea tree oil; its antibacterial properties are active even after being diluted to a concentration of 5%, so there is no need for this oil to be applied neat onto the skin.

Data from our patch testing clinic has found that that allergy to tea tree oil is not uncommon, with more than 40 cases reported, or approximately 1% of all patients tested to tea tree oil being allergic.

An area of action that we believe is necessary, is labelling on bottles of essential oils to include instructions that the oil should be diluted before being applied directly to the skin.

For more information contact the Occupational Dermatology Research and Education Centre, Skin and Cancer Foundation 03 9623 9402 or email admin@occderm.asn.au