Vol. 4, Issue 2, Part E (2022)

Photoprotection has become pivotal in the prevention of keratinocyte cancer and photoaging. Organic ultraviolet (UV) filters such as oxybenzone and octinoxate have become controversial due to their possible impact on the environment and their potential human health risks. As such, inorganic UV filter, zinc oxide (ZnO), has become paramount in discussions about photoprotection. ZnO is used in sunscreens as nanoparticles, which denote a size <100 nm. The smaller size of these mineral particles surges their cosmetic acceptability by users as they are much less visible after application. ZnO has a broad UVA-UVB absorption curve. Overall, the human health risks with inorganic filters are extremely low given a lack of percutaneous absorption; however, there is a possibility of risk when exposed via inhalation, prompting recommendations against spray sunscreen products with nanoparticles. At this time, the known risk to the environment is low though the risk may evolve with increasing usage of these filters and higher environmental concentrations. The continued practice of photoprotection is critical. The public should be counseled to seek shade, use photoprotective clothing including hats and glasses in addition to sunscreens on sun-exposed skin. For those concerned about emerging evidence of environmental impact of organic UV filters, based on current evidence, ZnO-containing sunscreens are safe alternatives. Recently ZnO nanoparticles (NPs) have attracted attention owing to their unique features. There can be numerous applications of ZnO NPs due to their antibacterial, antineoplastic, wound healing, ultraviolet scattering and angiogenic properties. These have also been used to promote tissue repair, as a food preservative and as feed additive. This paper reviews the recent developments in ZnO NPs research and its potential for application in animal health and production.