The Scientific Committee on Consumer Safety (SCCS) has released its final opinion on Tea Tree Oil (Melaleuca alternifolia Leaf Oil) SCCS/1681/25, bringing long-awaited clarity to formulators, safety assessors and brands using this popular natural active.
Tea Tree Oil has been widely used in cosmetics for its antimicrobial, purifying and anti-seborrheic benefits. But concerns about sensitisation, oxidation by-products, and potential reprotoxic classification prompted a detailed scientific review. The final opinion, adopted in October 2025, sets specific concentration limits and strict conditions for safe use in cosmetics.
In this article, we break down the key points you need to know.
1. Tea Tree Oil Is Considered Safe — Under Strict Conditions
The SCCS concluded that Tea Tree Oil can be considered safe for consumers when used:
- Only for antimicrobial or anti-seborrheic functions
- Only in dermally applied cosmetics
- Only at or below the recommended concentration limits
- Only when the Tea Tree Oil in the final product complies with ISO 4730 specifications
This means brands must ensure not only the raw material, but the Tea Tree Oil inside the finished formulation matches the ISO profile (major constituents, impurities, and oxidation markers).
2. Maximum Concentrations Allowed
The SCCS established the following safe use levels:
| Product Type | Maximum Tea Tree Oil (%) |
|---|---|
| Shampoo (rinse-off) | 2.0% |
| Shower gel / body wash (rinse-off) | 1.0% |
| Face wash (rinse-off) | 1.0% |
| Leave-on face cream | 0.1% |
These limits apply only when Tea Tree Oil is used for the two defended functions assessed (antimicrobial and anti-seborrheic). Using TTO for other functions — such as fragrance or soothing claims — requires additional safety justification in the CPSR.
3. Sensitisation Risk and Stability Matter
Tea Tree Oil is recognised as a moderate skin sensitiser, and the SCCS emphasises two important safety points:
a) Oxidation increases sensitisation risk
Tea Tree Oil oxidises readily when exposed to heat, light, air, or moisture, forming peroxides and other degradation products that can increase skin sensitisation.
b) Stability of the finished product must be demonstrated
It’s not enough to show that the raw material is stable. Brands must provide evidence that TTO remains within the safe compositional profile throughout the product’s shelf life.
This is essential for PIF compliance.
4. Aerosols and Sprays Are Not Allowed
The SCCS opinion explicitly excludes aerosols and spray formats due to the lack of inhalation safety data.
For any product with airborne droplets or vapour (mists, room sprays, hair sprays), Tea Tree Oil is not considered safe under this opinion.
5. ISO 4730 Specification Is Mandatory
To comply with the SCCS opinion, the Tea Tree Oil in your cosmetic must match ISO 4730, which defines:
- Major constituents (e.g., terpinen-4-ol, γ-terpinene)
- Acceptable ranges for minor components
- Limits for impurities and oxidation by-products
This applies to the oil as present in the finished cosmetic, not only the raw material as supplied.
6. Implications for Natural and “Clean Beauty” Brands
Brands working with natural preservation or multifunctional actives should consider:
- Whether TTO is being used primarily as an antimicrobial booster
- Whether the function matches the SCCS assessment
- Whether sensitisation risk is compatible with the target consumer group
- Whether lower levels could deliver the same benefit when paired with other multifunctional ingredients
- Whether appropriate stability measures are in place (antioxidants, airless packaging, proper chelators, etc.)
For formulators focused on mild preservation systems, Tea Tree Oil may still be useful — but only within the SCCS framework.