What is a Challenge Test for Cosmetic Products and Why is it Important?

The Challenge Test is an essential microbiological analysis to ensure the safety of a cosmetic product throughout its shelf life. According to ISO 11930:2019, this procedure involves exposing the cosmetic formula to a series of specific microorganisms to evaluate the effectiveness of its preservative system.

Table of contents

1. Why is a Challenge Test conducted?

2. Challenge Test: How is it carried out?

3. Get a Challenge Test

What is a Challenge Test for Cosmetic Products and Why is it Important?

Why is a Challenge Test conducted?

According to the Technical Guidelines published by the European Commission on the assessment of cosmetic safety, every manufacturer must demonstrate that their product remains stable and safe during normal use. A cosmetic contaminated with microorganisms can cause skin irritation, infections, or adverse reactions.

The Challenge Test allows

1. Verify the effectiveness of preservatives : Confirm whether the preservative system stops the growth of microorganisms.

2. Ensure microbiological stability : Ensures that the product remains free from contamination throughout its life cycle.

3. Comply with legal regulations : This is an essential requirement within the product information file (PIF), as indicated in Regulation (EC) 1223/2009 .

   
   

Challenge Test: How is it carried out?

Although details may vary depending on the type of product and the exact methodology applied, ISO 11930:2019 describes the procedure in a standardized manner:

1. Selection of microorganisms : Reference strains recommended by official organizations are usually used (e.g., Staphylococcus aureus , Pseudomonas aeruginosa , Escherichia coli , Candida albicans and Aspergillus brasiliensis ).

2. Product inoculation : A known quantity of each microorganism is intentionally introduced into the cosmetic sample.

3. Incubation period : The product is stored under controlled conditions (temperature and humidity) for 28 days to allow for possible proliferation of microbes.

4. Periodic measurement : At established intervals, a sample is taken and it is determined whether the population of microorganisms has effectively decreased or has remained within safe levels.

5. Interpretation of results : Final microorganism counts are compared with the reduction thresholds required by ISO 11930 to confirm the suitability of the preservative system.

   
   

Ultimately, the Challenge Test is not just a regulatory requirement, but a key tool for delivering high-quality, safe cosmetic products that remain stable throughout their shelf life. Ensuring this is done correctly, following the guidelines of ISO 11930 and current European legislation, is essential to guaranteeing consumer trust and the brand's reputation.

Contact a cosmetic regulatory expert today.