Water activity (aw-value) as a measure for the microbiological risk of cosmetics

Go back

Nov 13, 2018 - Cosmetics

Water activity (aw-value) as a measure for the microbiological risk of cosmetics

Within the framework of the Regulation (EC) 1223/2009 and the associated preparation of a safety report for each cosmetic product placed on the market, analytical data from a preservative efficacy test (PET) is usually indispensable.

For products that are classified as microbiologically low-risk, the test is not required. The lack of water for the growth of microorganisms is an argument to forgo the PET. Do you want to show that your product is low-risk?

The determination of the so-called water activity (aW-value) provides evidence of whether a preservative efficacy test needs to be conducted for a product. If this value is lower than 0.75, the PET is generally not necessary. This is also documented in the ISO 29621 standard.

In addition to water activity, other factors such as the pH-value and ethanol content of a formulation influence the assessment of microbiological risk.

Whether it's microbiological examinations according to ISO 11930, DIN EN ISO 17516, or conducting a water activity determination – get in touch with us! We advise and support you competently, quickly, and reliably.