The European Union's Scientific Committee on Consumer Safety (SCCS) has issued its final opinion on the safety of using tea tree oil (TTO) in cosmetic products.
The SCCS considers the use of TTO as an anti-seborrheic and anti-microbial agent safe in four product types: up to 2% concentration in shampoo (rinse-off); 1% in shower gel/body wash (rinse-off), 1% in face wash (rinse-off) and 0.1% in face cream (leave-on).
Tea tree oil (INCI: Melaleuca Alternifolia Leaf Oil) is one of the most widely used natural antimicrobials in cosmetics.
The new SCCS limits apply only when TTO is used for the two defended functions assessed, namely antimicrobial and anti-seborrheic.
Personal Care Magazine contributor Barbara Olioso, also known as The Green Chemist, said the SCCS emphasised two important safety points; firstly, oxidation increases sensitisation risk – TTO oxidises readily when exposed to heat, light, air, or moisture, forming peroxides and other degradation products that can increase skin sensitisation.
Secondly, the stability of the finished product must be demonstrated.
It is 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.
Olioso said formulators 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; and whether appropriate stability measures are in place.
“For formulators focused on mild preservation systems, tea tree oil may still be useful — but only within the SCCS framework,” she added.
