This review discusses the potential risks of engineered nanomaterials, focusing on their toxicological and environmental impacts. It highlights that nanoparticles can deposit in the respiratory tract, causing oxidative stress and inflammation, and may enter the brain via the olfactory epithelium. Inhalation is a major exposure route, but the extent of nanoparticle translocation into the bloodstream is unclear. Dermal exposure from sunscreen nanoparticles is less well understood, while oral uptake is known and used in food and pharmaceuticals. Few specific nanoparticles have been studied, limiting extrapolation to other materials. Air pollution studies suggest combustion-derived nanoparticles contribute to health effects, while long-term studies on bulk nanoparticles like carbon black and titanium dioxide show adverse effects. Engineered nanomaterials with new properties are being produced, but their toxicity is unknown. Despite existing data, no blanket statements about human toxicity can be made. Ecotoxicological data are limited, preventing a systematic assessment of nanoparticle impacts on ecosystems. Nanotechnology involves manipulating materials at the nanoscale, leading to unique physical and chemical properties. It is used in various applications, including materials, tools, and devices. Nanomaterials are used in products like sunscreens, cosmetics, and drug delivery systems. The market for nanomaterials is growing, with potential applications in electronics, biotechnology, and medicine. However, the production and use of nanomaterials raise concerns about health and environmental risks. Standards and terminology for nanomaterials are needed to support regulation, risk assessment, and communication. The review emphasizes the need for further research to understand the risks of engineered nanomaterials and to develop appropriate safety measures. The potential for nanoparticle exposure through inhalation, dermal contact, and ingestion is significant, and monitoring is necessary to assess environmental and health impacts. The review concludes that a systematic approach is needed to assess nanoparticle exposure and risk, including the development of standardized methods for exposure assessment and risk management.This review discusses the potential risks of engineered nanomaterials, focusing on their toxicological and environmental impacts. It highlights that nanoparticles can deposit in the respiratory tract, causing oxidative stress and inflammation, and may enter the brain via the olfactory epithelium. Inhalation is a major exposure route, but the extent of nanoparticle translocation into the bloodstream is unclear. Dermal exposure from sunscreen nanoparticles is less well understood, while oral uptake is known and used in food and pharmaceuticals. Few specific nanoparticles have been studied, limiting extrapolation to other materials. Air pollution studies suggest combustion-derived nanoparticles contribute to health effects, while long-term studies on bulk nanoparticles like carbon black and titanium dioxide show adverse effects. Engineered nanomaterials with new properties are being produced, but their toxicity is unknown. Despite existing data, no blanket statements about human toxicity can be made. Ecotoxicological data are limited, preventing a systematic assessment of nanoparticle impacts on ecosystems. Nanotechnology involves manipulating materials at the nanoscale, leading to unique physical and chemical properties. It is used in various applications, including materials, tools, and devices. Nanomaterials are used in products like sunscreens, cosmetics, and drug delivery systems. The market for nanomaterials is growing, with potential applications in electronics, biotechnology, and medicine. However, the production and use of nanomaterials raise concerns about health and environmental risks. Standards and terminology for nanomaterials are needed to support regulation, risk assessment, and communication. The review emphasizes the need for further research to understand the risks of engineered nanomaterials and to develop appropriate safety measures. The potential for nanoparticle exposure through inhalation, dermal contact, and ingestion is significant, and monitoring is necessary to assess environmental and health impacts. The review concludes that a systematic approach is needed to assess nanoparticle exposure and risk, including the development of standardized methods for exposure assessment and risk management.