Manufactured nanomaterials are in more than 1,300 commercial products including medical equipment, textiles, fuel additives, cosmetics, plastics and more. EPA scientists research the most prevalent nanomaterials that may have human and environmental health implications. The research is developing a scientific foundation to better understand, predict and manage the challenges of nanomaterials.
Why is EPA studying nanomaterials?
Knowledge of the unique features of nanomaterials that influence their behavior in environmental and biological systems is inadequate for predicting potential human and environmental health impacts. Models and data are needed to support the development of more efficient and comprehensive nanomaterials (ENM) testing procedures.
What are the unique characteristics of nanomaterials?
Due to the rapid and diverse growth of engineered nanomaterials, it is a challenge for regulators and risk assessors to understand the potential for exposure and whether methods used for assessing conventional chemicals can be used for nanomaterials. EPA researchers are identifying and characterizing the unique chemical and physical features of nanomaterials to be able to develop predictive models to determine which nanomaterials may pose a higher probability of risk and those expected to have little impact.
What nanomaterials are EPA studying?
- Nano Silver: Because silver nanomaterials 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 nanosilver 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: These nanomaterials 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 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 evaluates the physical and chemical properties of carbon nanotubes to determine which ones 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 nanomaterials 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 used in many products. It can be found in sunscreens, cosmetics, paints and coatings, and electronic devices. Titanium dioxide may be 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 nanomaterials to be released from consumer products and enter the environment, be transformed in the environment, and to become toxic to sensitive environmental species or to humans.
- Iron: 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 found 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 hazardous environmental pollutants. EPA research is being conducted to assure that this beneficial use of nanomaterials is not associated with unwanted or unexpected adverse side effects on human health or the environment.
- Micronized Copper: Micro and nanometer sized copper particles are used as preservatives in pressure treated lumber and in some paints and coatings. EPA is working with the Consumer Product Safety Commission to evaluate the potential for release of copper particles or copper ions from such products under normal use and wear. If copper is released into the environment, additional research will assess the potential for exposure and adverse effects on human and environmental health.
How will EPA use this research?
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.