The article reviews the toxicity of nanomaterials, emphasizing their increasing presence in consumer products and medical applications. It highlights the need for better understanding and protection of workers and end-users from potential health risks associated with nanoparticle exposure. The review discusses the mechanisms of NP toxicity, primarily through the production of reactive oxygen species (ROS), and the impact of ROS on cellular and systemic health. It also covers the challenges in evaluating NP toxicity, including the gap between available data on production and toxicity, and the limitations of in vitro and in vivo testing methods. The article further explores the influence of NP physicochemical properties, such as size, shape, and surface chemistry, on their toxicity and biodistribution. Finally, it emphasizes the importance of comprehensive studies to understand the long-term effects of NP exposure and the development of predictive models for assessing NP toxicity.The article reviews the toxicity of nanomaterials, emphasizing their increasing presence in consumer products and medical applications. It highlights the need for better understanding and protection of workers and end-users from potential health risks associated with nanoparticle exposure. The review discusses the mechanisms of NP toxicity, primarily through the production of reactive oxygen species (ROS), and the impact of ROS on cellular and systemic health. It also covers the challenges in evaluating NP toxicity, including the gap between available data on production and toxicity, and the limitations of in vitro and in vivo testing methods. The article further explores the influence of NP physicochemical properties, such as size, shape, and surface chemistry, on their toxicity and biodistribution. Finally, it emphasizes the importance of comprehensive studies to understand the long-term effects of NP exposure and the development of predictive models for assessing NP toxicity.