UVabsorbereihin

UV absorbers are chemical compounds that absorb ultraviolet radiation and dissipate the energy as heat, protecting biological tissue or materials from UV-related damage. In cosmetics, they function as UV filters in sunscreen products, blocking or reducing exposure to UVA and UVB rays. They are also added to plastics, coatings, and textiles to slow photodegradation and preserve appearance and mechanical properties.

UV absorbers can be categorized into organic (chemical) filters and inorganic (physical) filters. Organic filters, such as avobenzone, octocrylene, octisalate, octinoxate, and homosalate, absorb UV photons and re-emit energy as heat. Inorganic filters include zinc oxide and titanium dioxide, which mainly scatter and reflect UV light but can also absorb. Hybrid formulations combine organic and inorganic components to improve broad-spectrum coverage and cosmetic feel. Formulations may be optimized for photostability, water resistance, and minimal skin penetration.

In sunscreens, UV absorbers contribute to a broad-spectrum shield, with performance described by metrics such as SPF for UVB protection and UVA protection factors, as well as the critical wavelength. For materials, the aim is to limit photodegradation, color fading, and loss of mechanical strength under UV exposure.

Safety and regulation vary by region and product type. Most cosmetic UV filters undergo safety assessment before market approval, with labeling requirements and permitted concentration ranges. Some filters have raised safety or environmental concerns, leading to regulatory restrictions or bans in certain jurisdictions. Ongoing research evaluates environmental fate, bioaccumulation, and ecotoxicology of UV absorbers in water bodies.

See also: ultraviolet radiation, sunscreen, photostability, photoprotection.