Challenge test

What is a test challenge?

A challenge test is a microbiological resistance test designed to assess the effectiveness of a preservative system or finished product when faced with simulated contamination. It involves introducing a specific microbial strain (bacteria, yeasts, molds) into the sample and then measuring the reduction in the population over time.

This test can be customized according to the sector of activity (cosmetics, food, pharmaceutical, veterinary) and the applicable regulatory constraints. It constitutes a key requirement in marketing or reformulation processes.

Why carry out a test challenge?

The test challenge allows you to:

• Check the microbiological robustness of a product throughout its lifespan
• Validate the effectiveness of a preservative or antimicrobial system
• Meet regulatory or normative requirements (e.g.: ISO 11930, European Pharmacopoeia, USP, etc.)
• Optimizing formulations containing natural or synthetic preservatives
• Document quality/safety/compliance records during a recording or inspection

It is a fundamental element of the HACCP plan, the cosmetic regulatory dossier (PIF), or the safety assessment of care, nutritional or phytosanitary products.

Test methodology

The protocol can be adapted according to:

• Target microorganisms: Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, Aspergillus brasiliensis, Escherichia coli, etc.
• Applicable regulations: ISO 11930 (cosmetics), USP <51>, agri-food or veterinary standards
• The product tested: aqueous formula, emulsion, powder, plant extract, food supplement, etc.
• Internal objectives: in-house criteria, specific tolerances, testing in extreme conditions

The decay kinetics are measured at different times (e.g.: 0h, 7d, 14d, 28d) and compared to acceptable thresholds defined by the reference systems.

Affected matrices

• Cosmetic products (creams, gels, lotions, oils)
• Liquid, powder or capsule food supplements
• Plant extracts and phytotechnical formulations
• Hygiene or care products for human or veterinary use
• Technical products sensitive to microbiological contamination

Standards and requirements covered

Our partner laboratories carry out challenge tests according to the main international references:

• ISO 11930 (preservation assessment in cosmetic products)
• USP <51> (Antimicrobial Effectiveness Testing)
• European Pharmacopoeia
• Internal customer protocols (custom testing)

Why choose YesWeLab?

YesWeLab relies on a network of laboratories specializing in microbiology applied to the food, cosmetics, and healthcare industries. Our partners are ISO 17025, COFRAC, or GLP accredited and adapt their methods to the specific needs of each project.

With our digital platform, you:

• Centralize your analysis requests
• Easily access quotes, sample tracking and reports
• Benefit from the expertise of our scientific team to adapt standards, microorganisms or experimental conditions

Need a test challenge that complies with current standards?

Add this analysis to your quote request or contact our team directly to be assisted in setting up the protocol adapted to your product.