Preservatives are chemical compounds that, when added to a product, protect it from the growth of microorganisms. However, to fulfil this basic function, preservatives should be appropriately selected for a given cosmetic formulation. The article aimed to present the key concepts regarding the preservation of cosmetics and legal regulations in this area. Moreover, cosmetics of low microbiological risk were characterised and the studies verifying the effectiveness of preserving cosmetic products were presented. The key to reduce the likelihood of microbial infections is to identify their origin. Therefore, in order to limit potential primary and secondary contamination in cosmetic products, it is necessary to determine and find a solution to reduce the sources of these infections.

The natural protective mechanisms of the skin indicate the harmful effects of sunlight, by the appearance of erythema and increased sweat secretion. The extremely unfavourable influence of solar radiation on the skin is the phenomenon of immunosuppression, which can lead to the formation of skin cancer foci. Effective sun protection delays skin photoaging, prevents sunburn and the formation of cancer. The available sun-protective preparations show increasing photostability. The aim of the work was to present fundamental issues in the field of sun protection and to explain the essence of the natural protective mechanisms of human skin. The article also explains the classification of sunscreen filters, divided into mineral (physical) and chemical ones.