Tea Tree Oil (TTO; INCI: Melaleuca alternifolia Leaf Oil) is a natural ingredient widely used in cosmetics for its antimicrobial, purifying, and soothing properties. Commonly incorporated into facial care products, shampoos, shower gels, and acne-prone skin formulations, it has become a staple in formulations targeting skin balance and hygiene.
However, in recent years, Tea Tree Oil has come under intense scientific and regulatory scrutiny due to potential concerns related to skin sensitization, reproductive toxicity, and systemic exposure at certain concentrations.
The Scientific Committee on Consumer Safety (SCCS) issued its preliminary opinion in May 2025, establishing safe use concentrations and specific conditions for Tea Tree Oil in cosmetic products placed on the European market. This represents a significant regulatory milestone for formulators and responsible persons across the cosmetics industry.
Tea Tree Oil: Regulatory Classification and Mandate
In November 2023, the Risk Assessment Committee (RAC) of the European Chemicals Agency (ECHA) proposed the harmonized classification of Tea Tree Oil as toxic to reproduction (Repr. 1B) under the CLP Regulation (EC) No 1272/2008.
If confirmed, this classification would categorize Tea Tree Oil as a CMR substance (carcinogenic, mutagenic, or toxic for reproduction – categories 1A/1B), whose use in cosmetics is prohibited under Regulation (EC) No 1223/2009, unless safety can be scientifically demonstrated under Article 15.2(d).
In response, the European Commission mandated the SCCS to perform a comprehensive safety assessment of Tea Tree Oil to determine whether it could still be safely used in cosmetics and, if so, under specific conditions.
The industry dossier was submitted in August 2024, and the preliminary SCCS opinion (SCCS/1681/25) was published on 28 May 2025.
Tea Tree Oil: Scope and Evaluation Criteria
The SCCS reviewed the industry’s technical dossier supporting Tea Tree Oil’s use for its anti-seborrheic and antimicrobial properties in both rinse-off and leave-on formulations.
The Committee’s scientific mandate focused on three key questions:
- Can Tea Tree Oil be considered safe for use in cosmetics despite its proposed Repr. 1B classification?
- If not, what are the maximum safe concentrations for different product categories?
- Are there additional risks related to sensitization, stability, combined exposure, or inhalation that must be addressed?
SCCS Conclusions: Safe Use Concentrations And Conditions
The SCCS concluded that Tea Tree Oil may be considered safe for use in cosmetics only under strict conditions related to concentration, product type, and ingredient quality.
Maximum concentrations considered safe:
- 2.0% in shampoos.
- 1.0% in shower gels or facial cleansers.
- 0.1% in facial creams (leave-on).
Additional conditions:
- Tea Tree Oil must comply with ISO 4730:2017, which specifies its chemical profile and impurity limits (including methyl eugenol).
- Spray and aerosol formulations are not permitted, due to inhalation exposure risks.
- The stability of Tea Tree Oil in the final formulation must be verified to prevent oxidation or the formation of toxic by-products.
- Cumulative exposure from all sources must remain below the calculated Margin of Safety (MoS).
- The risk of skin sensitization must remain within acceptable limits, supported by Quantitative Risk Assessment (QRA) data.
In summary, the SCCS confirmed that Tea Tree Oil is not banned, but its safe use is conditional upon compliance with specific purity, formulation, and exposure requirements.
Regulatory Implications For The Cosmetics Industry
The SCCS preliminary opinion carries immediate implications for manufacturers, safety assessors, and regulatory compliance teams across the cosmetics supply chain.
- Technical obligations for formulators:
- Reassess existing formulations to ensure Tea Tree Oil concentrations comply with the 2.0%, 1.0%, and 0.1% thresholds.
- Source certified raw materials compliant with ISO 4730:2017, including impurity and stability controls.
- Perform oxidation and stability studies, documented within the Cosmetic Product Safety Report (CPSR).
- Evaluate aggregate exposure considering all product categories containing TTO.
- Update labeling and consumer warnings, particularly for sensitive or allergic skin types.
- Eliminate aerosol products until inhalation safety data becomes available.
- Commercial and strategic impacts:
- Reformulation costs for product lines exceeding concentration limits.
- Increased dependency on suppliers with verified traceability and analytical controls.
- Market opportunities for brands prioritizing compliance and ingredient transparency.
- Potential product withdrawals if the final SCCS opinion further lowers the permitted limits.
- Alignment pressure for non-EU markets that mirror European regulatory updates.
Tea Tree Oil: Strategic Implications for Formulators
The re-evaluation of Tea Tree Oil reflects a broader shift in European cosmetic regulation—natural origin no longer implies automatic safety.
Even naturally derived substances are now subject to comprehensive toxicological assessment under modern risk-based frameworks.
This case highlights the importance of:
- Strengthening ingredient traceability and documentation.
- Ensuring alignment between formulation practices and SCCS scientific opinions.
- Adopting a proactive approach to risk management and regulatory surveillance.
For the cosmetics industry, this presents not only a challenge but also an opportunity to differentiate through safety, scientific transparency, and compliance leadership.
Practical Recommendations For Manufacturers And Laboratories
To ensure conformity with the SCCS opinion and maintain product safety, SHAPYPRO recommends that cosmetic companies:
- Audit all current formulations containing Tea Tree Oil and adjust concentrations as required.
- Request ISO 4730:2017 compliance certificates and independently verify the oil’s chemical purity.
- Conduct accelerated stability and oxidation tests throughout the product’s shelf life.
- Include aggregate exposure and MoS calculations in every CPSR.
- Avoid aerosol applications or temporarily suspend their sale until additional inhalation data becomes available.
- Develop alternative formulations using safer essential oils or bioactive plant extracts with favorable toxicological profiles.
By implementing these actions, brands can ensure both regulatory compliance and consumer confidence in their natural ingredient portfolios.
Analytical And Toxicological Relevance
Tea Tree Oil is a complex mixture of over 100 compounds, including terpinen-4-ol, γ-terpinene, α-terpinene, and p-cymene, whose proportions and oxidation levels determine its biological and toxicological behavior.
The SCCS emphasizes that oxidized fractions may contribute significantly to sensitization potential. Therefore, proper storage, antioxidant use, and packaging stability studies are essential to ensure safe product performance.
The standardization under ISO 4730:2017 plays a crucial role in guaranteeing chemical consistency and reproducibility among different batches and suppliers.
Conclusion: Tea Tree Oil and SCCS Regulation
The SCCS preliminary opinion on Tea Tree Oil marks a turning point in the regulation of natural cosmetic ingredients. While the oil is not prohibited, its use is now subject to well-defined limits and technical requirements to ensure consumer safety.
Manufacturers must adapt their formulations, documentation, and supplier management systems accordingly to maintain compliance under the EU Cosmetics Regulation.
Ultimately, this case exemplifies the direction of the cosmetics sector: a shift toward evidence-based safety, traceable ingredient sourcing, and scientifically driven transparency.
At SHAPYPRO, we closely monitor regulatory updates and assist laboratories and cosmetic brands in:
- Interpreting SCCS scientific opinions.
- Performing safety assessments (CPSR).
- Ensuring ingredient conformity and regulatory compliance with the latest European frameworks.