Challenge Testing, PET challenge cosmetics, cosmetics testing, usp 51 challenge test, iso 11930 challenge testing, Preservation Efficacy test for Cosmetics

EU No1223/2009 states that cosmetics & personal care products should demonstrate preservation efficacy, as cosmetic preservative systems should ensure product robustness and consumer safety throughout product life cycles. Preservative Efficacy Testing (PET) also known as Challenge Testing is the appropriate tool to substantiate antimicrobial preservation efficacy against microbial contamination. At QACS, The Challenge Test Laboratory, we apply several challenge test protocols.

Methodology may follow Pharmacopoeias, International Standards, Industry or in house developed protocols. QACS is  ISO17025 accredited to perform cosmetic challenge testing.

Inoculates 5 microorganisms (Pseudomonas aeruginosa, Staphylococcus aureus, E. coli, Candida albicans, Aspergilus brasiliensi). We store the inoculated preparation at a prescribed temperature then withdraw samples from the container at specified time intervals and count the organisms.  Minimum sample quantity is 100g and results are available within 35 days.

ISO 11930, a reference method to evaluate the preservation of a cosmetic formulation inoculates 5 microorganisms (Pseudomonas aeruginosa, Staphylococcus aureus, E. coli, Candida albicans, Aspergilus brasiliensi). Surviving micro-organisms that remain are measured at defined time intervals within a 28 day period.  Minimum sample quantity is 100g and results are available within 35 days.

Similar to the EP reference standard, the re-inoculation protocol, re-inoculates samples on the 7th day.  The tests is prolonged by 7 days and observations are repeated following the times prescribed.  Minimum sample quantity is 100g and results are available within 42 days.

The multi strain in-house mixed culture test is designed to simulate single inoculation followed by a storage period. We divide several standard strains into categories of bacteria, yeasts and moulds & challenge the preparation with a mixture of strains. Readings are reported per strain. Results are available within 42 days. Minimum sample quantity 100g.

Cosmetic Challenge testing involves separately contaminating wet-wipe sub-samples with each one of 5 reconstituted strains. We then test individual sub-samples for microbial count at every interval (0 time, 2 days, 7 days, 14 days, 28 days) and assess log-reduction. The rest of the test complies with the EP reference standard. Results are available within 35 days. Minimum sample quantity 100g.

Reporting

QACS, Challenge Testing services assist cosmetic RnD decisions with:

→ Competitive market prices

→ Real-time reporting

→ Intermediate results at specific time intervals

→ option for urgent delivery reporting at 14 days

→ EU carriage policy

→ 24h courier service for sample collection

If you need your test results urgently, we can perform a fast screening process within 14 days.