Lavender steps up as a natural preservative in skin-care emulsions

Synthetic parabens and formaldehyde releasers are falling out of favor, but keeping creams safe from microbes remains a challenge. The global shift toward “clean-label” cosmetics has left formulators scrambling for milder preservatives. A research paper led by Dr. Maria Trapali (University of West Attica, Greece), now offers a drop-in solution: the simple pairing of Lavandula angustifolia hydrosol with its own essential oil.

The study is published in the Journal of Dermatologic Science and Cosmetic Technology.

Using standard oil-in-water emulsions, the researchers challenged products with high loads of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans. After 12 weeks at 25° C and 40° C, emulsions containing 0.05% hydrosol + 0.05% essential oil kept counts below 10 CFU/mL—well inside European Pharmacopeia limits. In contrast, an unpreserved control passed 10⁵ CFU/mL within four weeks.

Six oil-in-water emulsions were stored at 25° C and 40° C for 12 weeks. Products containing 0.05% lavender essential oil plus 0.05% hydrosol remained below 10² CFU g⁻¹, while an unpreserved control exceeded 10⁴ CFU g⁻¹ by week four. The authors also provide a rapid GC-MS protocol to ensure consistent linalool levels across lavender chemotypes.

The work is the first to document a true synergy between lavender hydrosol and essential oil, outperforming either agent alone.