Melaleuca alternifolia (Tea Tree Oil) is used extensively in cosmetics and personal care products. Tea Tree Oil is known to have skin conditioning, insecticidal, repellent and anti-bacterial properties and therefore is used in pharmaceutical products for treatment of wounds, acne and insect bites.
Tea Tree Oil is comprised of more than 100 chemicals and is a substance of unknown/variable composition, complex reaction products or of biological materials (UVCB).
ECHA opened an ad hoc consultation on the harmonised classification and labelling proposal for melaleuca alternifolia (Tea Tree Oil) in March 2023 and in November 2023, the Risk Assessment Committee (RAC) adopted an opinion that Tea Tree Oil is a category 1B reproductive toxicant, rather than the category 2 classification proposed by Poland. RAC concluded that classifications were warranted in nine hazard classes, with reproductive toxicity (cat. 1B) being the most stringent.
In its opinion, RAC accepted that in vitro studies showed differences in accumulation of a metabolite of p-cymene between rats and humans. However, it said it was not currently possible to conclude on mode of action or show that results from the animal studies in the dossier are not relevant to humans. It noted that there is no human epidemiological data on tea tree oil’s reproductive toxicity.
The Category 1B (H360) classification of tea tree extract as a reprotoxic substance is one step toward a harmonised classification as a hazard of highest concern in the EU regulations and makes its eventual removal from the European cosmetics marketplace likely.
Any substance classified as a CMR (carcinogenic, mutagenic, and reprotoxic) in the EU Classification, Labelling and Packaging (CLP) regulation, which includes those classified as Category 1B (H360), are banned for use in cosmetics in the EU, unless industry members receive an exemption by demonstrating safe use according to specific criteria as per Article 15 of the EU Cosmetics Regulation (EC) 1223/2009. A total ban will have significant consequences.
All affected brands and products will either need to be removed from the market, or reformulated to remove Tea Tree Oil within 15 months. Household products within the EU are also affected, Tea Tree Oil will be limited to below 0.3% in the final product.
Suppliers of tea tree oil may submit a safety dossier to the EU Scientific Committee on Consumer Safety (SCCS) to apply for this exemption. There is currently no certainty that the ingredient will be defended, and the likelihood that Tea Tree Oil will be banned in cosmetics in the EU and Northern Ireland (where EU rules apply) is high, pending publication of the final legislation.
Industry has funded In vitro mechanistic studies, and these are now being run in an attempt to show that Tea Tree Oil has a different mode of action in humans. A feasibility study is expected to be completed by the end of October 2024 and the comparative metabolism study by the end of February 2025.
Tea Tree Oil was provisionally listed for the 23rd Adaptation to Technical and Scientific Progress (ATP) to CLP. However, Industry requested the suspension of this process until preliminary test results are available. The WTO (World Trade Organisation) notification of 25th September 2024 does not contain the substance, so it appears that the Commission has accepted the request.
If Tea Tree Oil is added to Annex II (prohibited substances) of the EU Cosmetics Regulation, cosmetics already on the market that contain Tea Tree Oil could continue to be sold until the new CMR omnibus took effect, at which point the remining stock would have to be removed from circulation.
A potential Tea Tree Oil ban will not apply to cosmetics sold in Great Britain, as the UK has a separate regulatory framework. This could of course change if the UK regulators follow the EU decision to reclassify Tea Tree Oil as a CMR substance.
For Tea Tree Oil products sold in the U.S., the formally designated responsible person should consider how they will be able to meet the requirement to substantiate safety of products containing Tea Tree Oil under (MoCRA), following the EU reclassification.
Other Essential Oils
Tea Tree Oil contains up to 8% p-cymene which Sweden has proposed should also be classified as a category 1B reproductive toxicant based on effects in male rats. RAC has yet to adopt an opinion on p-cymene.
Any regulations against Tea Tree Oil will likely have a knock-on effect for other essential oils and other naturally complex substances. While there is no activity yet against Lavender oil or Peppermint oil, there is disquiet among the suppliers of essential oils. The designation of these oils as complex natural substances will have to change as the EU moves from risk-based to hazard-based assessment of chemicals.
Published October 17, 2024
Image generated with the assistance of Artificial Intelligence.