Bilgiye hızlı erişim:
The microbiological safety of cosmetic products is not solely dependent on the quality of raw materials but is also directly related to the product's resistance to contamination. In this context, the adequacy of preservative systems is crucial, especially in formulations containing water, to prevent microbial spoilage.
One internationally recognized method for evaluating preservative efficacy is the Challenge Test, a standardized protocol conducted to ensure the microbiological safety of cosmetic products. This test is performed in accordance with the ISO 11930 standard and objectively assesses the effectiveness of a cosmetic product's preservative system against microorganisms.
How Does the Challenge Test Work?
The Challenge Test is a simulation test applied under controlled conditions to measure the microbiological stability of cosmetic formulations. The process involves the following stages:
Pre-Evaluation and Preparation:
Before the product undergoes the Challenge Test, it is ensured that there is no microbiological contamination (either sterile or within acceptable limits). The sample to be tested is prepared appropriately for the laboratory environment.
Controlled Contamination:
Specific quantities of test microorganisms are introduced into the product. These microorganisms represent species that should not be present in cosmetic products and pose a risk of contamination. The standard test organisms include:
Staphylococcus aureus
Pseudomonas aeruginosa
Escherichia coli
Candida albicans
Aspergillus brasiliensis
Monitoring and Sampling Over Time:
The product is analyzed at specified intervals (e.g., day 0, day 7, day 14, and day 28) to monitor changes in the number of microorganisms.
Efficacy Assessment:
If the microbial load decreases over time or is completely eliminated, and these reductions meet the acceptance criteria specified in ISO 11930, the product's preservative system is considered effective.
Inadequacy Scenario:
If the presence of microorganisms remains above the accepted limits during the specified periods, it indicates that the product's preservative system is inadequate. In such cases, the formulation should be reviewed, and the types or concentrations of preservatives should be revised.
Why Should a Challenge Test Be Conducted?
To ensure consumer safety
To predict product shelf life
To scientifically demonstrate the effectiveness of the preservative system in the formulation
To strengthen technical documentation during export processes and regulatory inspections
The Challenge Test is particularly critical for products with high water content, such as emulsions, shampoos, gels, creams, wet wipes, and similar items.
Challenge Test Applications at Cosming
At Cosming Laboratory, Challenge Tests are conducted in accordance with the ISO 11930 standard, under appropriate microbiological conditions and validated methods. The test process includes the following stages:
The microbiological suitability of the products is determined through a pre-evaluation conducted before the test.
Controlled contamination is performed on the product using standard test microorganisms.
Changes in microbial load over time are monitored and calculated on a logarithmic basis (log₁₀ cfu/g or ml).
The obtained data are statistically evaluated, and the test results are presented to the manufacturer in a detailed report.
The Challenge Test is not just an analysis process; it is also a critical quality control method that documents the microbiological safety of the product throughout its shelf life.
To request a Challenge Test or obtain detailed information, please contact us.
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