The European Union has recently re-evaluated the safety of tea tree oil concerning its potential impact on human fertility, concluding that it poses no risk when used in cosmetics and toiletries at specified concentrations. This follows an initial proposal in November 2023 to classify tea tree oil as a presumed human reproductive toxicant, based on rat studies that showed lower sperm counts in male rats after high oral doses. However, those studies used doses far exceeding typical human exposure, and rats metabolise tea tree oil differently, producing a toxic byproduct not found in humans.
EU Scientific Committee Findings
In a November 2025 update, the Scientific Committee on Consumer Safety (SCCS) reviewed the data, including human pharmacovigilance reports, and found no evidence of reproductive toxicity from existing products. The committee determined that tea tree oil is safe for use in cosmetics and toiletries up to specified maximum concentrations.
UK Regulatory Position
The UK's Health and Safety Executive has not classified tea tree oil as a reproductive toxicant, aligning with the EU's updated assessment. The re-evaluation considered the differences in metabolism between rats and humans, as well as the lack of adverse effects in human studies.
Pharmacologist Ian Musgrave, who reported on the issue, notes that while high doses in rats caused effects, typical human exposure through topical application is minimal and safe. The EU's initial classification was precautionary, but further research has alleviated those concerns.
Related concerns about fertility have also been raised for other essential oils, but tea tree oil now appears to be cleared of any significant risk. Consumers can continue to use tea tree oil products as directed without worry about reproductive health.
