Efficacy of preservative system is to be used in the overall evaluation of the antimicrobial protection of a cosmetic product.
The antimicrobial protection of a product can come from many sources:
- chemical preservation
- inherent characteristics of the formulation
- package design
- manufacturing process
The evaluation of the preservation of a cosmetic formulation is based on inoculation of the formulation with calibrated inocula (prepared from relevant strains of microorganisms). The number of surviving microorganisms is measured at defined intervals during a period of 28 days. For each time and each strain, the log reduction value is calculated and compared to the minimum values required.
International Standard ISO 11930:2012 efficacy of Preservative System according to: Evaluation of the antimicrobial protection of a cosmetic product according to ISO 11930:2012