Is Challenge Testing Mandatory for Cosmetic Products?

Challenge Testing (Preservative Efficacy Testing) is a laboratory test designed to evaluate the effectiveness of a cosmetic product’s preservative system under controlled contamination conditions.

In accordance with ISO 11930, the test begins by inoculating the cosmetic product with standardized concentrations of the following reference microorganisms:

• Pseudomonas aeruginosa
• Staphylococcus aureus
• Escherichia coli
• Candida albicans
• Aspergillus brasiliensis

The preservative system is then evaluated by measuring the logarithmic reduction of these microorganisms at specified intervals, typically on Days 2, 7, 14, and 28.

Is Challenge Testing Mandatory?

Challenge Testing is generally required for cosmetic products that contain a preservative system and are repeatedly opened or exposed during consumer use.

Challenge Testing is not required for finished products that are:

• Single-use products
• Packaged in containers that cannot be opened or contaminated during normal use

Examples include:

• Single-use alcohol wipes
• Sheet masks
• Aerosol sprays
• Deodorant sprays
• Roll-on products

For other cosmetic products, Preservative Efficacy Testing (Challenge Testing) is an essential study to demonstrate that the preservative system provides adequate microbiological protection throughout the product’s intended period of use.

At Bilim Laboratory, Challenge Testing (ISO 11930) is performed within the scope of our ISO/IEC 17025 accreditation, providing reliable and internationally recognized results to support cosmetic product safety and regulatory compliance.