According to the SCCP opinion on Challenge Testing for Cosmetics, "the manufacturer must guarantee the efficacy of the preservation of his cosmetic products experimentally by Challenge Testing. However, as no legal nor universal Challenge Testing method is available today, it is up to the manufacturer to decide on the details of the test to be used."
The Challenge Testing Laboratory
Our laboratory is specialized in preservation efficacy testing, commonly known as "Challenge Testing". We test cosmetics, personal care and pharmaceutical products, offering high-quality services at competitive prices. The Challenge Testing for Cosmetics is included in the scope of the laboratory's ISO 17025 accreditation.
Challenge Testing for Cosmetics is an essential test, related to the product robustness against microbiological contamination. The results are crucial for the cosmetic product safety assessment, in line with the requirements of the Cosmetics Regulation (EC) No 1223/2009.
The QACS laboratory offers a wide range of protocols on Challenge Testing for Cosmetics. The classic and popular Pharmacopoeia protocols (EP, USP), the recently adopted ISO 11930, the multi strain in-house "Mixed Culture", the wet - wipe related Recontamination protocol. A fast 14 day screening version is available for impatient decision makers.
The evaluation of the preservation efficacy is a milestone of the new cosmetic product development process. Launching new products imposes tight R&D timing. At the QACS lab the Challenge Testing for Cosmetics is scheduled upon receipt, reducing lead time to a minimum. Real time reporting of intermediate results support the R&D decisions.
Real time reporting
Preliminary reports are communicated on intermediate readings.
Challenge Testingprotocols in brief
EP or USP 51 protocol
The Challenge Testingconsists of challenging the preparation, wherever possible in its final container, with a prescribed inoculum of suitable micro-organisms, (Pseudomonas aeruginosa, Staph. aureus, E. coli, Candida albicans, Aspergilus brasiliensis) storing the inoculated preparation at a prescribed temperature, withdrawing samples from the container at specified intervals of time and counting the organisms in the samples so removed. The preservative properties of the preparation are adequate if, in the conditions of the test, there is a significant fall or no increase, as appropriate, in the number of micro-organisms in the inoculated preparation after the times and at the temperatures prescribed. Results are available within 35 days. Min sample quantity is 100g.
Challenge ISO 11930
This Challenge Testingprotocol is a reference method that is to be used to evaluate the preservation of a cosmetic formulation. The test involves, for each test micro-organism, placing the formulation in contact with calibrated inoculums (20g of the test formulation, 0.2 ml of calibrated inoculums) and then measuring the number of surviving micro-organisms at defined intervals during a period of 28 days. The containers of inoculation formulation are stored at (22.5±2.5)°C. The enumeration method used is plate count method by making successive tenfold dilutions. For each time and each strain, the log reduction value is calculated and compared to the minimum values required for evaluation criteria A or B. Min sample quantity is 100g.
Same as the EP Challenge Testingprotocol. Samples are re-inoculated at the 7th day. Observations are repeated after the times prescribed. The test is prolonged by 7 days. Results are available within 42 days. Min sample quantity is 100g.
Mixed culture test
Preservation efficacy screening test (Challenge Testing), designed to provide guidance during the product development stages. Designed to simulate single inoculation followed by a storage period. The test consists of challenging the preparation, with a mixture of several standard strains, divided in categories of bacteria, yeasts and moulds. Readings are reported per strain, results are available within 18 days. The preservative properties of the preparation are adequate if, in the conditions of the test, there is a significant fall or no increase, as indicated by the EP criteria. Min sample quantity is 100g.
On wet wipes, sample preparation is an issue to consider. Wet wipe subsamples are separately contaminated with each of the 5 reconstituted strains. At every interval (0time-2-7-14-28days), individual subsamples are tested for microbial count and the log-reduction is assessed. The rest of the test complies to the EP protocol.
Our experienced scientists are ready to help determine the best and most cost effective cosmetic challenge testing for your needs. We also offer a 24h courier transport service for EU based clients. Request more information or pricing list and see how our team can help you with challenge testing for cosmetics.