Chemical substances with structures that measure approximately 1 – 100 nanometers (nm, 10-9 meters) along at least one dimension are often referred to as nanomaterials, or nanoscale materials, yet some experts contend that this definition is too narrow and propose a definition that is not based on a specific metric. In either case, the nanoscale size of manufactured nanomaterials greatly increases the surface area to volume ratios of the materials relative to their larger, bulk counterparts that result in novel physical phenomena. For example, quantum dots, sometimes referred to as artificial atoms, exhibit unique electronic and optical properties that are not observed in their bulk complements and are dependent on the enhanced surface area to volume ratio wherein electrons become confined. Novel effects that arise from manufactured nanomaterials make them strong candidates to advance products to overcome limitations of current technologies, particularly in relation to enhancing the mechanical properties of materials, providing rapid and accurate medical diagnostics, guiding drug delivery to improve therapeutic efficacy, and going beyond binary computation.
The properties and behaviors of nanomaterials are widely variable, modifiable, and remarkable and have spawned innovations that benefit societies and modern economies. Although nanomaterials are widely utilized in commercial products, nanomaterial reactivity is less widely studied and currently thus remains difficult to predict. Titanium dioxide nanoparticles serve as an excellent example. TiO2 nanomaterials can absorb UV energy, and it is this property that has led to their usage in sunscreen products. Moreover, the resulting spike in chemical reactivity from energy absorption enables their use in self-cleaning products where the reactivity is used to degrade microbes and surface chemicals. However, how the chemical reactivity of TiO2 nanomaterials interact with biological and environmental systems throughout their lifecycles, which are associated with each product’s industrial niche (e.g. beaches or pools, industrial window cleaning products, milk whitening agent, powdered donuts, and solar cells) require much more study as do other manufactured nanomaterials. Thus, there is a need to evaluate effects of manufactured nanomaterials in multiple contexts and through a variety of techniques. For collected data to be applicable, fundamental research is tailored to reflect the complex conditions to which manufactured nanomaterials that are contained within consumer products are exposed and subsequently released. To achieve this, scientists are interested in: collaboration and integration across scientific disciplines, well-developed nanomaterial classifications, advancing characterization techniques to be used in versatile environments, and designing environmentally - and clinically - relevant experiments. By accounting for these factors, members of the scientific community and policymakers can work together to better manage risk and safe use of manufactured nanomaterials.