Development of a standardized method for the evaluation of the microbial protective efficiency of cosmetic packaging

Abstract

The doubt regarding adverse effects of antimicrobial preservative, has modified the demand by the consumers which impose more and more the production of low-level and even preservative free cosmetics. In these products, protection against microbial contamination is therefore devoted to the packaging. This have prompted the emergence of a great diversity of so called “protective”, “overprotective” and “barrier” packaging, but this designation is not normalized and the choice of the right packaging adapted to each cosmetic product remains essentially empirical, hazardous and time consuming. The cluster Cosmetic Valleys decided to launch a commission aimed at defining a complete and experimentally validated method allowing to classify the microbiological protection level of cosmetic packaging. As reported herein, this was requiring the development a specific bacteriostatic medium usable over 7 days and an in vitro procedure reproducing in-use contamination and consumer gesture. On the basis of tests realized over 800 packs of different origins and performances, a classification in six grades was proposed in order to distinguish the protective efficiency of cosmetic packaging. This work can be considered is a first step towards a regulatory text.