In today’s technology market, smaller is better. Nanotechnology is the next space race, and private corporations, universities, and entire nations are jockeying for position. For the technology to meet the high expectations associated with it will require a deliberate understanding not only of how nanoscale materials perform and why, but also the health, safety, and environmental considerations they present. Some of the unique challenges posed to standards developers by nanotechnology are presented here for consideration.
The U.S. National Nanotechnology Initiative defines work in this field as encompassing a scale of engineering of 1 to 100 nanometres. To put this scale in perspective, a nanometre equals one billionth of a metre: a pinhead is colossal in the nanoscale. Because the field’s only common feature is its tiny dimensions, the authors concur with the United Kingdom’s Response to the Royal Society and Royal Academy of Engineering Report that a more apt term for the concept is the plural, “nanotechnologies.” Across unrelated technologies, traditional materials are being optimized for the very different properties they exhibit at the nanoscale due to increased surface area. The gold in Fort Knox may be inert, but at the nanoscale gold becomes a potential catalyst.
So that the standards developing community can focus its attention, it must know the current “lay of the land” from regulatory, policy, and business standpoints. An understanding of current uses, government investment and policy strategies, the environmental and food and drug regulatory framework, and workplace safety considerations provide needed perspective for standards developers.
Nanoscale materials are already employed in numerous industries because product functionality is enhanced by nanostructures’ improved conductivity, ability to transmit light, reactivity, and strength. According to BusinessWeek Online, of the 30 companies listed in the Dow Jones Industrial Index, 19 have launched nanoscale initiatives. These materials are present in sunscreens, stain-resistant fabrics, prescription drugs, computers, chemical reactions, paints and coatings, and sports equipment, to name just a few common products.
In a study published in April by the Canadian Program on Genomics and Global Health, researchers stressed that the advantages in nanotechnologies are not confined to making consumer products better, but could also be instrumental in carrying the developing world toward sustainability. The international panel of 85 experts involved in the study identified the following top five applications for achieving sustainable development with nanotechnologies: energy storage, production, and conversion; agricultural productivity enhancement; water treatment and remediation; disease diagnosis and screening; and drug delivery systems. According to a study from the Freedonia Group, the U.S.-based nanomaterial market is expected to grow from $125 million in 2000 to $1.4 billion by 2008, and in 2020 will exceed $30 billion. Expectations for nanotechnologies are high and growing.
U.S. Government Investment
Since the National Nanotechnology Initiative was established by the Clinton administration in 2001, U.S.-government spending on nanotechnologies has more than doubled. The NNI is instrumental in developing and synchronizing the federal government’s activities. It funds 11 executive agencies while 22 others are involved with the program. Of those 11, fiscal year 2006 budget requests for the National Science Foundation, Department of Defense and Department of Energy were highest at $344, $230 and $207 million, respectively. For the first time since its creation, the NNI budget request divides the federal effort into seven program component areas. The instrumentation research, metrology and standards for the nanotechnology component area, for which $71 million has been requested, lists as a top priority the “standardization of measurement techniques, nomenclature, and testing methodologies to facilitate assurance of quality, safety, and efficacy of nanoproducts, and their effective regulation and productions.” As it approaches the five-year mark, according to the President’s Council of Advisors on Science and Technology in a report published in May, the NNI is turning its attention to societal implications including environmental and health effects and plans to move deliberately to identify, prioritize, and address these concerns.
Indeed, these areas are in need of thoughtful evaluation and attention. There is debate as to whether the current systems for environmental and health protection are robust enough to encourage the growth of nanoscale materials while ensuring that adequate safeguards are in place. These considerations are inherent with any innovation: novel technologies can and do fall nicely into an existing scheme if it is flexible enough. More often, they create new and unique regulatory issues to address. Although existing U.S. program authorities appear sufficient to allow us to begin to explore the health, safety, and environmental considerations associated with nanotechnologies, certain technical tools that are necessary to navigate these waters must be developed through the standards-setting process.
The U.S. Environmental Protection Agency, through the Toxic Substances Control Act, regulates industrial uses of chemical substances. A chemical substance is broadly defined by TSCA as “any organic or inorganic substance of a particular molecular identity.” Notification to EPA is required before manufacturing a “new” chemical substance, that is, one not listed on the TSCA inventory. The immediate question that begs asking is whether nanoscale versions of the existing listings are covered by those listings. Are carbon nanotubes graphite? Are silver nanoparticles silver? Is titanium dioxide the same regardless of scale?
While the chemistry of such materials should not be seriously in doubt, information on the health, safety, and environmental considerations associated with them is less readily available. Although changes in nomenclature to make nanoscale materials “new” might make it easier for the EPA to routinely review them, it has not been demonstrated that creating an entirely new system of nomenclature is a prerequisite for safety. Even without the “automatic” review afforded through premanufacture review, under the current regulatory scheme the EPA has clear authority to require testing or impose limitations on the sale and use of these materials. Admittedly, this type of exercise can require more intensive government effort, via an exposure or risk-based finding that the material may present a significant risk, which requires notice-and-comment rulemaking.
Alternatively, the EPA may consider voluntary initiatives by industry. The focus of an EPA-sponsored public meeting on June 2 was to explore the formation of a voluntary pilot program, with industry cooperation, to obtain data on nanoscale materials to assess in more detail the health, safety, and environmental considerations associated with the technologies.
In the environment, particulate limits are enforced by geographic region. Currently, they are not manufacturer-based, nor do the limits reach the nanoscale. With respect to limits on hazardous air pollutant emissions in manufacturing, limited health and environmental data, coupled with the need for more sensitive monitoring, currently present challenges for assessing whether nanoscale materials are “known to cause or may reasonably be anticipated to cause adverse effects to human health or the environment,” the prerequisite legal finding for the EPA to add substances to the HAPs list.
Permits and pretreatment standards are required to discharge pollutants to navigable waters and state rules govern discharges to groundwater. Although a “pollutant” is broadly interpreted in this setting, once again, the availability of measurement tools presents a challenge. A solid waste is broadly defined so as to encompass liquids and therefore is certainly in concept able to potentially capture nanowaste materials. A solid waste is considered hazardous and subject to stringent and costly disposal requirements if it is listed through a notice-and-comment rulemaking or bears one of the following defined characteristics ignitability, corrosivity, toxicity, or reactivity. Little is known about whether nanoscale solid waste presents a hazard to the environment.
Drug and Medical Applications
An area of great promise lies in uses that effectively and efficiently deliver prescription drugs to specific targets in the human body. Nanotechnologies for therapeutic applications, when used in or as a drug delivery system, must receive approval from the U.S. Food and Drug Administration through an extensive review, including clinical trials to establish their safety and effectiveness. A common misconception is that FDA clearance can be obtained for a specific component independent of the drug. Nowhere does FDA clear or list standalone components that may be generically used in any type of drug application.
The needs for measurement and characterization of nanoscale materials is perhaps most acutely felt by professionals in the field of industrial hygiene. The U.S. Occupational Safety and Health Administration’s hazard communication standard requires hazard determinations for materials in the workplace. Reliable sources of information are being identified for this purpose as we learn that size and safety do not necessarily share a linear relationship. Employers who use hazardous chemicals must generate proper labeling, material safety data sheets, and training for exposed workers. The current lack of standard terminology presents something of a barrier to effective communication of potential hazards through these means.
OSHA expects an employer to act on the basis of what it knows. The duty to be a knowledgeable expert, including an obligation to test products to the extent and in a manner commensurate with its intended use, arises out of holdings in cases involving product liability. Standards for toxicological characterization and measurement tools are still under development to guide such determinations for nanoscale materials. For example, should nanoparticles be measured based upon surface area versus the mass of the nanoparticle in the air? What technologies should be used to routinely measure nanoparticles in the workplace? Can information on ultrafine particles be used to predict the toxicity of nanoparticles?
In a hazard determination, one must look at all possible avenues for workplace exposure inhalation, absorption through the skin, and oral ingestion. Based on limited data, one cannot assume in the context of nanoscale materials that the body’s normal protective filter/ clearance mechanisms will apply. Because they are generally more reactive, dust formation and reaction with incompatible materials warrants evaluation to identify potential fire or explosion hazards. In some cases, nanoproducts may be considered hazardous simply as a function of size.
Employers should assess whether current personal protective equipment technology is adequate for work on the nanoscale. Examples of knowledge-based, precautionary measures in the public domain include corporate development of data matrixes, voluntary occupational exposure limits, and working under hoods. Laboratories owned by DuPont and Rice University that handle nanoparticles use worker protection and waste disposal methods similar to those employed for hazardous waste. Corporations are exchanging information formally with each other and with organizations and developing best practices guidance. Such voluntary stakeholder measures exemplify the product stewardship and attention to worker safety that one wants to see associated with these promising technologies. The National Institute of Occupational Safety and Health provides its recommendations in DHHS (NIOSH) Publication No. 2004-175 and at www.cdc.gov/niosh/ topics/nanotech/faq.html.
ASTM Committee E56 on Nanotechnology
ASTM Committee E56 on Nanotechnology has been established to assess the issues discussed in this article and to develop consensus standards that will aid in improved product performance, reliability, and accountability. The committee met most recently on May 23-25 and will meet again in November. The subcommittees formed are intended to address many of the information needs identified in this article and have begun standards development.
The committee membership is representative of the international scope of its efforts, and these members have committed to an international meeting schedule to foster broad consensus. An evaluation of the health, safety, and environmental considerations and the need to fine-tune the current regulatory systems can only proceed as fast as our ability to develop standard terminology, measurement tools, and recommendations for characterization and risk assessment will allow. The current toolbox is not fully informative of the new properties that engineering at the nanoscale is revealing, and this state of affairs presents an opportunity for private, consensus standards developing organizations, such as ASTM International, to serve as an essential resource. //