Green Toxicology Meets Nanotoxicology: The Process of Sustainable Nanomaterial Development and Use

Green Toxicology: Connecting Green Chemistry and Modern Toxicology

“…In vitro systems are particularly relevant for the toxicity testing of nanomaterials because classic QSARs fail to predict toxicity due to nano-specific features . In contrast, in vitro systems help address concerns of nanoparticle uptake through models for pathways such as the air–blood barrier (lungs), the blood–brain barrier, or the skin. , These models are likely to give a more realistic estimate of bioavailability and therefore of hazard compared to extrapolation of results from animal studies to humans. Thus, most emerging in silico tools for predicting nanotoxicity are based on data gained from in vitro toxicological data .…”

“…In contrast, the classic toxicology perspective typically focuses in depth on the exposure to the product, while ignoring the process. Therefore, we and others propose that chemists and toxicologists need to better collaborate to design a holistic production process, where exposure throughout the entire lifecycle of a product is considered. ,, Indeed, toxicity of a product can be caused by the reagents, solvents, or catalysts used in the production or by impurities and degradation products . To mitigate this, green chemists use strategies such as a one-pot synthesis to reduce occupational exposure to reactants, increasing the efficacy of a reaction with a non-toxic catalyst to reduce residual side products, or altering the workflow to minimize waste and environmental spillage.…”

“…Similarly, green toxicology calls for more sustainable practices in toxicity testing, specifically to reduce resources, chemicals, and biohazard waste produced. This really means reducing animal studies since these require large doses of a substance (up to 0.5 kg of a small molecule), the assays take months or years before generating results, and because the animal assays are performed late in the development of new substances. , Therefore, the use of alternative in vitro and in silico testing methods and strategies, in line with the 3Rs to replace, reduce, and refine in vivo tests, is critical. , Skin sensitization testing is one of the best examples where much progress has been made in the development, validation, and regulatory acceptance and implementation of non-animal predictive approaches. − In particular, modern skin sensitization tests include a variety of in silico modeling, in vitro assays, and improved animal models. − As such, by focusing on the development and validation of further in silico assays in particular, or in vitro assays for relevant end points applicable to different organs, the sustainability of toxicology testing will improve.…”

“…New or updated regulatory mandates such as REACH in Europe or the Toxic Substances Control Act (TSCA) in the United States have created an additional need for toxicology testing over this past decade. − Toxicologists and risk assessors have responded by developing and relying on novel predictive approaches. However, validating new tools and methods can be a tedious and lengthy process, and traditional validation studies can take up to 10 years . Indeed, regulatory mechanisms can slow down science and make it difficult to move away from traditional approaches.…”

“…3,6,54 Indeed, toxicity of a product can be caused by the reagents, solvents, or catalysts used in the production or by impurities and degradation products. 54 To mitigate this, green chemists use strategies such as a one-pot synthesis to reduce occupational exposure to reactants, 7 increasing the efficacy of a reaction with a non-toxic catalyst to reduce residual side products, or altering the workflow to minimize waste and environmental spillage. These are a few existing examples, but by systematically merging green chemistry and green toxicology through this guiding principle, transformative innovations in designing a more sustainable society may be possible.…”