From the moment of the first step on the recipe of the cosmetic, to its production is a long way. The process of creating the dream cosmetic product has already been described in the previous post “Cosmetics production – step by step”. However, before the cosmetic is produced and goes on store shelves, it must undergo a series of tests.
During introducing a cosmetic to the market, the responsible person must guarantee that within the specified period of validity, the product will be safe to use for the consumer. To be able to guarantee this, many tests are performed. One of them is the stability test – test during which the cosmetic mass is subjected to extreme conditions compared to normal storage conditions. The purpose of the test is to assess whether the cosmetic recipe will be stable over time. Stability assessment is related to determining if there are any undesirable changes in the cosmetic mass (including the appearance of lumps or drops of water or oil, change in color or smell). During stability tests, the cosmetic mass undergoes accelerated aging under the influence of temperature and light. The test is performed at both elevated and reduced temperatures. It is assumed that 12 weeks at 45 ° C corresponds to the stability of the cosmetic product over a period of 24 months.
The stability of the cosmetic product is also affected by the light and packaging of the cosmetic. The impact of light is determined by subjecting the sample of cosmetic mass to UV rays, and then comparing this sample with the cosmetic mass stored in a darkened place. The impact of packaging is determined during compatibility tests conducted in the final packaging. Incorrectly selected packaging can cause deterioration of the quality of the cosmetic over time, as well as cosmetic mass can affect the deterioration of the quality of the packaging (e.g. its deformation).
The stability test is one of the basic test that is carried out during the assessment of cosmetic products. It is also the most time-consuming test, it lasts up to 12 weeks. Their implementation is required by applicable legal acts, according to which the Cosmetic Product Safety Report must include information on the performance of stability tests and a report on the performance of these tests. To make sure that the cosmetic marketed is safe, in addition to the described stability and compatibility tests, a lot of other tests are performed, including microbiological purity test or effectiveness of the preservative system, but about these tests in the next entry.