Homemade and commercial sunscreens: a comparative analysis of their efficiency in uv protection

Abstract

Daily, many people are exposed to solar radiation that reaches the Earth's surface, including ultraviolet radiation (UVR), which is part of the electromagnetic spectrum. It can be subdivided according to its wavelength into UV-A (315 nm - 400 nm), UV-B (280 nm - 315 nm), and UV-C (100 nm - 280 nm). UVR can pose risks to human health, such as erythema, photoaging, and photocarcinogenesis, but it also provides benefits, such as sterilization and vitamin D synthesis. To protect against UVR exposure, the use of sunscreens is recommended, as they act as a protective barrier for the skin. However, due to their high cost, many people choose to produce their own sunscreens, which are not subjected to tests to verify their effectiveness. This study aimed to compare the efficacy of commercial and homemade sunscreens (made with zinc oxide paste, zinc oxide, annatto, and clay). Although all formulations reduced UV intensity, commercial sunscreens proved to be more effective. Among the homemade options, the annatto-based sunscreen showed the best performance.