Earlier this year, the U.S. Environmental Protection Agency (EPA) issued a final rule under the Toxic Substances Control Act (TSCA) establishing reporting and recordkeeping requirements for nanomaterials. This new rule affects companies that manufacture, import, or process chemical substances at the nanoscale, requiring them to report information and maintain records about their materials. Companies must now report additional information on the material including specific chemical identity, production volume, manufacturing and processing methods, exposure and release, and human and environmental health effects. EPA will enact the final rule on August 14, 2017.
When EPA delayed the enactment of this new rule on May 16, 2017, the Agency also issued Draft Guidance on its Section 8(a) Information Gathering Rule on Nanomaterials in Commerce and is seeking comments on the draft guidance. This draft guidance is intended to provide answers to questions received from manufactures (including importers) and processors of certain chemical substances when they are manufactured or processed at the nanoscale.
Today, nanomaterials can be found in numerous industrial and consumer products, from manufacturing components in catalysts, semi-conductor materials, EPA-approved remediation for groundwater, electronics and optics to household goods such as personal care products, sporting goods, and clothing. The new reporting rule for such products presents challenges for businesses across numerous commercial sectors, challenges concerning proprietary information about their nanomaterials and properly classifying their materials given the inconsistencies the definition of nanomaterials. With some analysts predicting the nanotechnology market to grow to over $170 billion dollars a year by 2025, reporting concerns, particularly on proprietary information, are likely to spread to new sectors over the next decade.
Determining whether the rule applies to a particular material will require evaluation against a broad definition for nanomaterials; complying with the new rule will require testing materials for unique properties and relaying the necessary information to EPA. Leveraging the right combination of expertise in science and engineering needed for evaluation and testing and experience managing regulatory relationships will be vital for companies whose materials fall under this new rule.
The Challenge of Defining “Nanomaterial”
The new EPA TSCA rule—“Chemical Substances When Manufactured or Processed as Nanoscale Materials; TSCA Reporting and Recordkeeping Requirements”—marks a significant shift in the regulatory environment for nanomaterials. To date, nanoscale materials have been regulated similar to their bulk material versions.
The Occupational Safety and Health Administration (OSHA) and the National Institute for Occupational Safety and Health (NIOSH) have implemented worker safety standards for nanomaterials; however, environmental health and safety standards for nanomaterials are limited. At the state level, nanomaterials went unregulated until 2016, when the Minnesota Department of Health updated its chemicals of high concern list to include a specific multi-walled carbon nanotube (MWCNT-7) based on the International Agency for Review on Cancer’s classification of these materials as possibly carcinogenic to humans.
“Nano” is defined as 10-9 meters, the equivalent of 1/100,000th the diameter of a strand of human hair. Nanomaterials are classified as their own material due to these particles having a high surface area to volume ratio that makes them more reactive (i.e., producing more reactive oxygen species leading to increased toxicity) than the non-nano form of the material. The new TSCA rule defines nanomaterials as 1–100 nm in size with unique properties when compared to the non-nano form of the material. However, academia, industry, and even other government agencies currently use different definitions. Two leading research centers on environmental nanomaterial fate, the University of California Center for Environmental Implications of Nanotechnology (UC-CEIN) and Duke University CEINT, define nanoparticles as having one dimension <1–100 nm in size.
The U.S. National Nanotechnology Initiative, a government-run organization, defines a nanoparticle as having “dimensions between approximately 1 and 100 nanometers, where unique phenomena enable novel applications,” while OSHA defines nanotechnology as “the understanding, manipulation, and control of matter at dimensions of roughly 1 to 100 nanometers…to produce new materials, devices, and structures” and does not define nanoparticle. However, when reviewing nanotechnologies used in the food industry, the European Commission suggests there is no scientific support for using 100 nm as the upper cut-off for the nanomaterial definition.1
The use of different and contradictory definitions of a material at the nanoscale, and the use of multiple terms such as nanoparticle, nanotube, nanomaterial, and nanotechnology, makes forming a cohesive understanding of all the terminology a unique and important regulatory challenge at federal agencies. Because nanomaterials include a variety of materials, shapes, and sizes, keeping the definition broad to include many different functionalities is necessary. Yet without a consistent definition, the materials themselves may be assessed using testing methods more appropriate to the bulk material rather than the use of methods more appropriate to the nanoscale. Though challenging, developing a consistent definition for nanomaterial, including a definition of a novel or unique property, will make testing standards and regulation uniform and easier to document.
Characterization and Toxicity Testing Methodologies for Nanomaterials
Characterization and toxicity testing methods for particles with a size of <1,000 nm have been developed for some endpoints but are still under development for other toxicity endpoints. Novel properties of nanomaterials may result in new exposure pathways and result in new toxicities when compared to the bulk version of the substance in parallel with standard testing methodologies.
Another challenging unknown with nanomaterials is predicting an environmentally relevant concentration when released into an environmental setting, such as in wastewater effluent, biosolids, or sediment. For example, predicting the location and amount of a nanomaterial in an environmental “hot spot” is complicated, since many products contain nanomaterials though their (un)intended use or end-of-life-cycle disposal location may be unknown.
The small amount of the nanomaterial relative to the environmental matrix (soil, water, sediment, or tissue) makes detection with traditional techniques difficult.2 As an example, the partitioning of copper nanomaterials, the active ingredient in antimicrobial-based paints used to prevent biofouling on ship hulls, into sediment can be detected using inductively coupled plasma mass spectrometry (ICP-MS).3
This method is a popular tool for assessing any metal content in the environment; however, ICP-MS cannot detect a specific size of the metal. Therefore, additional parallel measurements of the physicochemical properties such as size, hydrophobicity/aggregation, and surface charge of the particles found in both the sediment and the particles found in the original product can confirm a specific size range. To date, parallel testing methods are not a standard method for nanomaterial toxicity or characterization testing.
In developing parallel testing methods, the following should be considered. Once a sampling location is chosen or a representative test chamber is designed, selecting testing techniques that identify the nanomaterial and quantify a toxicity response are important. For example, with nanomaterials in personal care products, their release into household drains and then wastewater treatment plants is likely.4 Many standard water quality tests including pH, alkalinity, biological oxygen demand, and total organic carbon are indirect methods for monitoring the wastewater treatment system and therefore the effects of nanomaterials in the system. Water quality monitoring encompasses an alternative to classic toxicity assays in this system and serves as the standardized test method that can be used in parallel with other testing methods specific to nanomaterials.
Regulatory Agency Use of Newly Generated Data
Use and review of data by regulatory bodies, such as the new nanomaterial regulation under TSCA, will provide regulatory agencies with information on the identity, the use, and the potential exposure to humans and the environment.
As knowledge of the commercial uses of nanomaterials expands, this may result in additional regulation of the nanomaterial industry. Additional regulation may focus on mitigating human health and potential environmental exposures and hazards or on the generation of additional data to inform regulators of the potential for human health or environmental hazards.
Nanotechnology regulation and research has maintained a proactive approach to the exceptional problems created by these new materials. Numerous conferences and events highlight communication among government regulatory bodies, industry, and academia about using cutting-edge research tools to develop new methodologies. These tools have been essential for identifying the unique properties and toxicities of nanomaterials. Moving forward, these communication channels must remain open between various stakeholders so that the policies and regulatory guidelines developed fit within best practices.
With expanding use of nanomaterials in industry in the United States and worldwide, regulation of nanomaterials is crucial for protecting human and environmental health and safety. Potential exposure pathways and risks need to be assessed in the product life cycle as part of current and future regulations of these materials.
How Exponent Can Assist
It is important to remain aware of the global regulatory landscape concerning nanomaterials and to be prepared for regulatory action. Proactive chemical analysis of nanomaterials, documentation of their uses, and evaluation of any data gaps in human and environmental safety should be evaluated. Pairing emerging toxicity tests with standardized methods will also serve as new types of toxicity testing methods.
Exponent provides expertise on nanomaterial characterization, development of toxicity assays using relevant environmental matrices and nanomaterial concentrations, regulatory guidance, and is familiar with current ASTM and OECD testing guidelines for materials. Industries using nanomaterials need to begin internal standard operating procedures for using nanomaterial characterization, toxicity assays, and record keeping for future state and federal regulations. More information on Exponent’s expertise in nanomaterials can be found on our Nanotechnology practices page.
- Som, C., Berges, M., Chaudhry, Q., Dusinska, M., Fernandes, T.F., Olsen, S.I., et al. (2010). The importance of life cycle concepts for the development of safe nanoproducts. Toxicology, 269(2-3), 160e169. As cited in Cushen, M., et al. Nanotechnologies in the food industry–Recent developments, risks and regulation. Trends in Food Science & Technology 24.1 (2012): 30–46.
- Zanker H., Schierz A. Engineered nanoparticles and their identification among natural nanoparticles. Annual Review of Analytical Chemistry 2012; 5:107–132.
- Adeleye, A.S., et al. Release and detection of nanosized copper from a commercial antifouling paint. Water Research 102 (2016): 374–382.
- Taylor, A. A., and S. L. Walker. Effects of copper particles on a model septic system's function and microbial community. Water Research 91 (2016): 350–360.