The presence of appropriately selected preservatives in cosmetic products is crucial to ensure the microbiological purity of products with a high microbiological risk. It is maintenance test (also known as load testing) allows us to make sure that the preservation system we have selected is doing its intended job.

What is the maintenance test?

A stress test involves the controlled introduction of suitable strains of micro-organisms into a microbiologically pure sample. There are many methods according to which the preservation test can be performed. There are pharmacopoeial methods to choose from, PCPC (Personal Care Products Council) methods, but it is the ISO methods (PN-EN ISO 11930:2019 and ISO PN-EN 29621:2011 (for products with low microbiological risk) that are most commonly chosen. The micro-organisms used for the test are mainly: S. aureus, E. coli, P. aeruginosa, C. albicans and A. brasiliensis. Each of the strains is placed in separate dishes with the appropriate medium and neutralising substance. The condition of the sample is monitored for 28 days at specified intervals. The results obtained are compared with the limit values.

Why is a maintenance test performed?

According to the FDA, most cases of microbiological contamination of cosmetic products were due to ineffective preservative systems used or a lack of quality control of the products before use. A stress test allows us to make sure during product development that the preservative system we have chosen does its job. And carried out additionally during production, it allows us to make sure that the production process does not affect its performance. It is performed to be sure that any micro-organisms it comes into contact with do not proliferate in the final product. In addition:

Article 10 of Regulation (EC) No. 1223/2009 of the European Parliament and of the Council requires a cosmetic product safety assessment and a cosmetic product safety report, which requires a stress test.

At MPR Labs you will perform maintenance test - Challenge test - according to the latest testing standards. Need to have your cosmetic tested or registered? Write to us!