SCCS Releases Draft Assessment on Tea Tree Oil, Confirming Safe Usage Scenarios

Melaleuca alternifolia leaf oil, also known as tea tree oil, INCI name Melaleuca alternifolia (Tea Tree) Leaf Oil, CAS No. 68647-73-4, has functions such as antioxidant, skin conditioning, antimicrobial, and fragrance, and is currently not regulated under EU Cosmetic Regulation (EC) No. 1223/2009. Besides cosmetics, tea tree oil is also often used as a fragrance ingredient in household cleaning products.

The EU Scientific Committee on Consumer Products SCCP (predecessor of the EU Scientific Committee on Consumer Safety SCCS) assessed the safety of tea tree oil in 2004 and 2008 respectively, issuing opinions SCCP/0843/04 and SCCP/1155/08, which identified tea tree oil as a skin sensitiser that can cause skin and eye irritation as well as contact allergy.

However, due to the lack of reliable skin absorption study data, SCCP was unable to calculate the Margin of Safety (MoS) for tea tree oil in these two assessments.

In February 2024, the European Risk Assessment Committee (RAC) of ECHA proposed classifying tea tree oil as a Category 1B reproductive toxicant (H360Fd). Once the European Commission adopts RAC's proposal to include tea tree oil in Annex VI of the EU CLP Regulation as a CMR substance for regulation, tea tree oil will automatically trigger the relevant provisions of the EU cosmetics regulation prohibiting CMR substances.

Article 15 of the EU Cosmetics Regulation stipulates that substances classified as CMR of category 1A, 1B or 2 under the EU CLP Regulation (EC) No 1272/2008 are prohibited in cosmetics, except in exempted situations. Exemption for Category 1B CMR substances requires meeting the following four conditions, namely: compliance with food safety requirements, the substance being irreplaceable, the product being intended for a specific use with known exposure levels, and being assessed as safe for use in cosmetics by the SCCS (taking into particular account the substance's exposure from cosmetic products and exposure from other sources, especially for sensitive populations).

In August 2024, the European Commission received a request to assess the safety of tea tree oil as an anti-seborrheic and antibacterial agent in cosmetics and commissioned SCCS to conduct a safety assessment.

On June 6, 2025, the SCCS released the draft of its scientific opinion (SCCS/1681/25) on tea tree oil, providing the following conclusions.

Tea tree oil is safe when used as an anti-seborrheic and antimicrobial agent in rinse-off shampoo, rinse-off shower gel/bubble bath, rinse-off facial cleanser, and leave-on face cream at maximum concentrations of 2.0%, 1.0%, 1.0%, and 0.1%, respectively;

The above safety concentration assessment has taken into account the use of tea tree oil as a Category 1B reproductive toxicant, as well as the aggregate exposure from cosmetic and non-cosmetic sources and exposure of the most vulnerable population;

This opinion only applies to tea tree oil whose chemical composition meets the latest version requirements of the ISO 4730:2017 standard for 'Essential oil of Melaleuca, terpinene-4-ol type (Tea Tree oil)';

This opinion only applies to products applied to the skin, not to aerosol or spray products that may lead to consumer exposure via inhalation;

Tea tree oil is a moderate skin sensitizer;

No data on the stability of tea tree oil under storage and use conditions were provided in the submission.

Due to potential changes caused by exposure to light, heat, air, and/or moisture, tea tree oil must remain stable in cosmetic products to ensure compliance with the specifications in the latest version of ISO 4730:2017 during its shelf life; this assessment does not involve the environmental safety of tea tree oil.

The draft opinion SCCS/1681/25 is now open for comments, with a feedback deadline of 18 August 2025.