Nanomaterials represent the building blocks of nanotechnology-enabled products and applications encompassing a broad range of substances and structures having features in the 1-100 nanometer range. Nanomaterials are of significant interest as they exhibit enhanced physical, chemical and electronic properties in comparison to their bulk counterparts. They can impact a range of applications including energy, electronics, agriculture, transportation, and healthcare, with the potential for pronounced societal and economic benefit. Yet the significant societal benefits offered by nanomaterials are not without possible drawbacks as the impact of exposure on human health and environment is presently unclear. While it is documented that significant and excessive exposure to certain types of nanomaterials can be hazardous to human health1 there are no data linking these exposure levels to realistic exposure conditions for responsible product manufacturing or product life-cycle.
The federal government is tasked with regulatory oversight of nanomaterials through the Environmental Protection Agency (EPA), which is given this authority through several environmental statutes, including the Toxic Substances Control Act (TSCA). At present, the EPA attempts to better understand the effects of environmental and human exposure through gathering toxicological information and using risk assessment models that may not fully apply to the properties of nanomaterials. Regulation of nanomaterials is currently conducted under a voluntary program enacted under TSCA in which companies would provide notice of their intent to produce or utilize specific nanomaterials, and would subsequently sponsor the development of test data regarding toxicological and human exposure properties. These data would be provided to the EPA. A mandatory regulatory framework proposed by the EPA is presently being considered in which any chemical substance in the 1-100 nm range will be subject to the TSCA Significant New Use Rule (SNUR). This regulatory provision treats the nanomaterial as a new chemical substance, requiring companies to submit data to the EPA 90 days prior to commencing manufacturing of the specific materials.
The regulation of engineered nanomaterials (ENMs) presents significant challenges. Each size, formulation, and application of an ENM could potentially represent a unique risk that must be understood and addressed. Additionally, different product applications present different exposure risks, thereby requiring new test data that assesses the complete lifecycle of the product. Furthermore, ENMs potentially represent a dynamic risk as surface properties may change as a nanomaterial encounters biological and ecological systems. At present, the impact to the environment by ENM exposure is much less understood than for exposures to human and biological systems. As these issues are clarified, the federal government and nanotechnology stakeholders are challenged with developing a comprehensive strategy to effectively and proactively understand, address, and manage risk with industry incorporating concise and efficient methodologies. In this context, the federal government is treading lightly in establishing nanomaterial regulatory policy, and is seeking the optimal balance between economic growth and sustainability and public health, safety, and risk assessment.
Managing the risks of nanomaterials is an extremely complex, multidisciplinary problem. A report released this week by the National Research Council (NRC), under sponsorship by the EPA, sanctioned a committee to Develop a Research Strategy for Environmental, Health, and Safety Aspects of Engineered Nanomaterials. Identifying the key issues and challenges to better understand the risks associated with ENMs, the report further emphasized the need to assess realistic exposure scenarios in the complete life-cycle (production, application, and disposal) of products utilizing ENMs, developing the necessary data and models to accurately assess the environmental and human exposure risks. As such the report specified the following four research categories that should be addressed within five years:
- Identify and quantify the nanomaterials being released and the exposed populations and environments;
- Understand processes that affect both potential hazards and exposure;
- Examine nanomaterial interactions in complex systems ranging from subcellular to ecosystems; and
- Support an adaptive research and knowledge infrastructure for accelerating progress and providing rapid feedback to advance research.
Implementation of the NRC’s research strategy would provide improved resources, knowledge, and infrastructure to better manage the risks of ENMs. As similarly recommended in previous reports addressing the risk management of ENMs (PCAST Report to the President and Congress on the Third Annual Assessment of the National Nanotechnology Initiative, National Nanotechnology Initiative Environmental. Health. and Safety Research Strategy), the NRC report recommends developing and establishing a crosscutting, proactive, solution-oriented policy for nanotechnology though a multi-stakeholder approach involving multiple government agencies, academic institutions, and industrial partners. The report further cites the establishment of informatics-based platforms to facilitate these activities. Recent assessment of nanoinformatics has further elucidated critical issues limiting nanomaterials risk assessment, including data collection, testing standardization, consistency of inter-laboratory studies, and minimum data set requirements. The NRC report additionally recommends that present materials studies need to include extended assessment of real world exposure scenarios, and incorporate complete life-cycle analysis assessing all potential means for environmental and human exposure.
While this strategy seems daunting, it should be noted that many of the resources engaging in these activities already exist through a federally funded network of academic institutions and federal laboratories engaged in nanomaterials testing and risk assessment for a range of environment and human health concerns. These include extensive toxicology and exposure analytical capabilities existing at the National Cancer Institute (NCI), and planned for the Food and Drug Administration (FDA). While specific agendas and goals for these agencies may vary, there is significant overlap in materials information dissemination and relevance to broader EHS issues. Furthermore, a grass roots nanoinformatics initiative is being developed by a range of academic, government and industry stakeholders with specific targets to address many of the gaps and limitations in collection, aggregation, and assessment of nanomaterials properties. To this end, the NRC committee has further recommended the funding level by the NNI is appropriate at the presently funded $120 million/year level, roughly 5% of the entire NNI budget.
Nanotechnology stakeholders and the broader community may benefit immensely from the development of collaborative approaches to test, understand, and assess nanomaterials properties and concerns from an exposure standpoint. Information is a key factor that requires consistent and open access platforms and databases for stakeholders to use in their assessments. Working within a collaborative, proactive framework will accelerate the commercialization of nanotechnology-enabled products while providing the necessary assurances for the safety of environment and human health.
1Sourcelist on Chinese Worker Exposure to Nanoparticle Study, Nanomaterials Regulations: Balancing Insight with Oversight, Pilot Study on Mice Reports Asbestos-like Pathogenicity of Carbon Nanotubes, Carbon Nanotubes Introducsed into the Abdominal Cavity of Mice Show Asbestos-like Pathogenicity in a Pilot Study, Study of Chinese Print Workers Claims to Provide the First Human Evidence of the Clinical Toxicity of Long-term Nanoparticle Exposures