Scientists have found a way to keep cosmetics fresh without chemicals

But the safety of creams and emulsions - especially in the context of "pure" natural cosmetics - is still an issue: without preservatives, products quickly deteriorate due to bacteria and fungi.

A new study published in the Journal of Dermatologic Science and Cosmetic Technology offers an effective yet all-natural alternative.

A team of scientists led by Dr Maria Trapali (University of Western Attica, Greece) found that the combination of lavender hydrolate (aqueous extract) and essential oil can reliably protect creams from pathogens.

In the course of the experiment, the scientists created classic oil-in-water emulsions and purposely infected them with dangerous microbes: E. coli, Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans. The mixtures were then stored for 12 weeks at 25°C and 40°C, simulating typical cosmetics storage conditions.

The results were impressive: even the lowest concentrations (0.05% hydrolat + 0.05% lavender essential oil) kept bacterial counts below 10 CFU/ml (colony forming units), in full compliance with strict European pharmacopoeial standards. In comparison, unprotected creams without preservatives already contained more than 100,000 bacteria in each millilitre after four weeks.

The study also showed that only the combined use of lavender hydrolat and lavender essential oil provided the maximum preservative effect. Individually, both components worked noticeably weaker, while together they showed a synergistic effect.

In addition, the authors proposed an express method (based on gas chromatography with mass spectrometry) to control the stability of the main active component - linalool - in different batches of lavender raw materials.

The data obtained opens new opportunities for manufacturers of natural cosmetics and personal care products.

Lavender has proven that it can become a full-fledged substitute for synthetic preservatives, preserving the effectiveness and safety of cosmetics even during prolonged storage and elevated temperatures.