Nanotechnology & Nanomaterials Research
Nanotechnology relies on the ability to design, manipulate, and manufacture particles at the nanoscale. These particles are called nanoparticles or nanomaterials. Manufactured nanoparticles are now in more than 1,300 commercial products including medical equipment, textiles, fuel additives, cosmetics, plastics and more. EPA scientists are researching the most prevalent nanomaterials that have implications toward human and environmental health. That research is presently focused on developing a scientific foundation to better understand, predict and manage the challenges of engineered nanomaterials.
Currently, knowledge of the unique features of nanomaterials that influence their behavior in environmental and biological systems is inadequate for predicting potential impacts across the materials’ lifecycle. We need new models and data to support the development of more efficient and comprehensive engineered nanomaterials (ENM) testing procedures.
The rapid and diverse growth of engineered nanomaterials presents a challenge for regulators and risk assessors to understand potential for exposure causing adverse health effects and whether methods used for assessing conventional chemicals can be applied for these novel materials. Identification and characterization of the role that key chemical and physical features of nanomaterials play in the behavior of engineered nanomaterials will enable the development of predictive models that can be used to differentiate between the nanomaterials that may pose a higher probability of risk and those expected to have little impact.
Nanoparticles are produced from a variety of materials including metals such as copper, silver, and iron, metal oxides including titanium dioxide, cerium dioxide,, and carbon-based materials such as carbon nanotubes and graphene. Materials are selected for study based on their prevalence in the marketplace, and the ability to reveal the role of physical and chemical properties of nanomaterials in determining their behavior in environment.
- Nano Silver: Because silver nanoparticles have antibacterial, antifungal and antiviral properties, they are used in medical equipment, textiles and cosmetics, fabrics, plastics and other consumer products. EPA is researching the fate and transport of silver nanoparticles and how they interact with the environment. EPA is developing methods to measure nanosilver concentration and characteristics such as size, shape, surface charge, and surface chemistry to better understand the role of these physical and chemical properties.
- Carbon Nanotubes: Are one of the most abundant classes of nanomaterials, and come in a variety of shapes and sizes. Carbon materials have a wide range of uses, including structural composites for vehicles or sports equipment, coatings, textiles, polymers, plastics and integrated circuits for electronic components. The interactions between carbon nanotubes and natural organic matter strongly affect their transport, transformation and exposure in aquatic environments. EPA research will evaluate the physical and chemical properties of carbon nanotubes that influence their behavior in the environment and in biological systems.
- Cerium dioxide: Nanoscale cerium dioxide is used in electronics, plastics, biomedical supplies, energy, fuel additives, and other consumer products. One application of cerium dioxide nanoparticles, in particular, leads to dispersion in the environment, which is the use as a fuel-borne catalyst in diesel engines. There is ongoing research to evaluate exposure to cerium dioxide from diesel emissions and the potential for environmental and public health impacts.
- Titanium dioxide: Nano titanium dioxide is currently used in many products. Depending on the type of particle, it may be found in sunscreens, cosmetics, paints and coatings, photo-voltaics and other electronic devices. Titanium dioxide may become activated by ultraviolet radiation, a normal component of sunlight, to catalyze reactions that can be toxic to fish and other aquatic species under certain conditions. EPA is researching the potential for titanium dioxide nanoparticles to be released from consumer products and enter the environment, to be transformed in the environment, and to become toxic to sensitive environmental species or to humans.
- Iron: Nano-scale iron is being investigated for many uses, including “smart fluids” for uses such as optics polishing and as a better-absorbed iron nutrient supplement. One important use of nano zero-valent iron particles is to catalyze the breakdown of chlorinated hydrocarbon compounds that are among the most common toxic contaminants in hazardous waste sites. The injection of zerovalent iron into such sites is a relatively inexpensive and rapid way to reduce the presence of these otherwise persistent hazardous environmental pollutants. EPA research is being conducted to assure that this beneficial use of nanotechnology is not associated with unwanted or unexpected adverse side effects on human health or the environment. This research will help assure the safe and beneficial use of nanotechnology for environmental remediation.
- Micronized Copper: Micron sized and nanometer sized copper particles are used as preservatives in pressure treated lumber and in anti-fouling paints and coatings. EPA is working with the Consumer Product Safety Commission to evaluate if there is a potential for release of copper particles or copper ions from such products under normal use and wear. If copper is released into the environment, research will assess the potential for exposure and adverse effects on human or the ecosystem.
EPA will use this research to develop research protocols for characterizing engineered nanomaterials (ENMs) and for evaluating exposure and toxicity in complex biological or environmental systems. This research will allow EPA scientists to evaluate the relationships between the physical and chemical properties of ENMs and their fate, transport, and effects which could lead to safer and more sustainable ENMs.