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Nanotechnology

Chemical Information Call-in: Carbon Nanotubes

This notice serves to announce that the Department of Toxic Substances Control (DTSC) intends to request information regarding analytical test methods, fate and transport in the environment, and other relevant information from manufacturers of carbon nanotubes.  The term "manufacturers” includes persons and businesses that produce Carbon nanotubes in California or import carbon nanotubes into California for sale.  The purpose of this information request will be to identify information gaps and to develop information about carbon nanotubes, an important emerging nanomaterial.

DTSC will exercise its authority under Health and Safety Code, Chapter 699, sections 57018-57020.  These sections were added as a result of the adoption of Assembly Bill (AB) 289 (2006).  They are intended to make relevant information on the fate and transport, analysis, and other information on chemicals more available.  The law places the responsibility to provide this information to the Department on those who manufacture or import the chemicals.

Carbon nanotubes (CNTs) are of interest to DTSC because they are in use commercially and because data on analytical methods, toxicity, physicochemical properties, and fate and transport are largely unavailable.  Recent research on the potential impacts to the environment, workers and the public have highlighted some potential areas in manufacturing issues and fate and transport that DTSC should consider.  One study by Massachusetts Institute of Technology (MIT) detected 15 different aromatic hydrocarbons including 4 different polyaromatic hydrocarbons (PAHs) when they manufactured CNTs from a carbon vapor source using chemical vapor deposition.  Another study by researchers at the Georgia Institute of Technology found that the fate of CNTs spilled into groundwater and the ability of municipal filtration systems to remove CNTs from drinking water is dependent on the characteristics of the water such as pH, natural organic content, etc.  The chemical call-in program will help develop the existing body of information on carbon nanotubes and will identify gaps in the existing information that could be filled to better protect human health and the environment.

On October 31st, 2008, the U.S. EPA issued a Federal Register notice regarding carbon nanotubes (CNTs). The notice reminds manufacturers and importers that they must notify EPA 90 days prior to the manufacture or import of new chemical CNTs for commercial purposes, in accordance with TSCA Section 5 regulations for new chemicals at 40 C.F.R. 720.22.

Next steps  UPDATED!

DTSC has reviewed the comments and suggestions received as of December 19, 2009.  The final questions to be included in the formal request letter for carbon nanotubes are as follows:

  1. What is the value chain for your company? For example, in what products are your carbon nanotubes used by others? In what quantities? Who are your major customers (e.g., polymer industry, electronics industry, etc.)?
  2. What sampling, detection and measurement methods are you using to monitor (detect and measure) the presence of your carbon nanotubes in the workplace and the environment? Provide a full description of all required sampling, detection, measurement and verification methodologies. Provide full QA/QC protocol.
  3. What is your knowledge about the current and projected presence of your carbon nanotubes in the environment that results from manufacturing, distribution, use, and end-of-life disposal?
  4. What is your knowledge about the safety of your carbon nanotubes in terms of occupational safety, public health and the environment?
  5. What methods are you using to protect workers in the research, development and manufacturing environment?
  6. When released, do your carbon nanotubes constitute a Hazardous Waste under California Health & Safety Code provisions? Are discarded off-spec carbon nanotubes a hazardous waste? Once discarded are the carbon nanotubes you produce a hazardous waste? What are your waste handling practices for carbon nanotubes?

A formal information request letter will be sent in January 2009 to manufacturers who produce or import carbon nanotubes in California.   The letter will also outline the time frame that manufacturers are required to respond under the law.


DTSC Nanotechnology Series

NEW!  DTSC Nanotechnology III Symposium, "NanoRegulation - Anticipating the Smallest Threats and the Largest Opportunities"

DTSC will be hosting a full-day nanotechnology symposium on Thursday, March 19th in Sacramento. This event will be free and open to the public. It will also be available via web cast. 

This event will focus on the regulatory aspects of nanotechnology, EPA's role, and DTSC's chemical information call-in program including nanoscale materials.  Federal interest in nanomaterial regulation and California's efforts in this area provide a great opportunity for fostering technological advances that recognize environmental and public health concerns.  The goal is to create a partnership where we can enhance research where needed and promote sustainable processes as well as applications.  Speakers include:

Please check this site periodically over the next months for updates or subscribe to our nanotechnology listserv to receive updates on this symposium.

You can view the proceedings for past DTSC nanotechnology symposia on-line.


What is nanotechnology?
Nanotechnology is the design, characterization, production, and application of structures, devices, and systems by controlling the shape and size at the nanometer scale. A nanometer (nm) is one billionth of a meter. For comparison, a single human hair is about 80,000 nm wide, a red blood cell is approximately 7,000 nm wide and a water molecule is almost 0.3 nm across. The nanoscale generally is defined in nanotechnology to be from 100 nm down to the size of atoms (approximately 0.2 nm). Understanding and controlling matter at the nanoscale interests researchers in the sciences, medicine, agriculture, and industry because a material’s properties at the nanoscale can be very different from those at a larger scale. As reports of new discoveries and applications for nanotechnology emerged, governmental, industrial, and public stakeholders recognized the need to develop a standard nanotechnology terminology to facilitate communication among the various communities. A globally recognized terminology standard is

nanobouquet

Flower Bouquet, a 3-dimensional nanostructure grown by controlled nucleation of silicon carbide nanowires on gallium catalyst particles. As the growth proceeds, individual nanowires 'knit' together to form 3-dimensional structures. Photo: ©Ghim Wei Ho and Prof. Mark Welland, Nanostructure Center, University of Cambridge

not only critical to the development of the nanotechnology industry by allowing precise descriptions of the chemical compositions and physical forms of these nanoscale materials, but without a such a precise and accepted terminology standard, efforts to understand the risks and benefits of nanotechnology are unlikely to lead to successful outcomes. For example, the American Society for Testing and Materials (ASTM) noted that the term 'carbon nanoparticles' has been used to describe a range of very diverse nanomaterials such as carbon-60, single-walled carbon nanotubes, and even diesel exhaust. The ASTM, the American National Standards Institute (ANSI) and International Organization of Standards (ISO) have formed workgroups consisting of industry, academia, and government participants to address the need for common terms and definitions. In December 2006, the ASTM and their partners published standard E2456-06, Terminology for Nanotechnology. This standard is the first step in developing common terms associated with nanotechnology and will be updated as new terms emerge. Some of the definitions in E2456-06 useful for our present discussion are:

  • agglomerate, n—in nanotechnology, a group of particles held together by relatively weak forces (for example, Van der Waals or capillary), that may break apart into smaller particles upon processing, for example.
  • aggregate, n—in nanotechnology, a discrete group of particles in which the various individual components are not easily broken apart, such as in the case of primary particles that are strongly bonded together (for example, fused, sintered, or metallically bonded particles).
  • nanotechnology, n – A term referring to a wide range of technologies that measure, manipulate, or incorporate materials and/or features with at least one dimension between approximately 1 and 100 nanometers (nm). Such applications exploit the properties, distinct from bulk/macroscopic systems, of nanoscale components.
  • nanoparticle, n—in nanotechnology, a sub-classification of ultrafine particles with lengths in two or three dimensions greater than 0.001 micrometer (1 nanometer) and smaller than about 0.1 micrometer (100 nanometers) and which may or may not exhibit a size-related intensive property.

Developing common terminology is essential in effectively communicating results and information associated with this emerging technology.


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Why is nanotechnology of interest?

ldm-nanotech_04-0

Photo: Phillips

 The unique physical, chemical, and biological properties of materials at the nanoscale enable novel applications and functions with the potential to promote enormous societal and economic benefits. Some current innovative applications of nanotechnology include the use of nanomaterials in liquid filtration and water purification, as catalysts in petroleum refining and catalytic converters, and in nanoscale biological imaging. In the near future of two to five years, nanotechnology will be integrated into advanced drug delivery systems, real-time medical diagnostic tools, sensors for airborne chemicals or other toxins, and photovoltaics (solar cells), fuel cells and portable power to provide inexpensive, clean energy.

The properties of materials at the nanoscale are attributed to two main factors. First, nanomaterials have a relatively larger surface area when compared to the same mass of material produced in a larger form. This can make materials more chemically reactive (in some cases materials that are inert in their larger form are reactive when produced in their nanoscale form), and affect their strength or electrical properties. Second, quantum effects can begin to dominate the behavior of matter at the nanoscale - particularly at the lower end of the scale affecting the optical, electrical and magnetic behavior of materials. The photo above shows an example of quantum dots. Particles of inorganic semiconducting crystals with nanometer scale dimensions ("quantum dots") exhibit size-dependent optical properties. In other words, the color of a cadmium-selenium (CdSE) quantum dot will vary depending on the quantum dot’s size, even though the chemical composition of the dot has not changed. Companies are investigating quantum dots to develop composite materials such as those used as light-emitting diodes (LEDs) where the color is determined by the size of the quantum dots. The superior optical properties of quantum dots are being studied for use in diode lasers, optical amplifiers and switches, biological sensors, and solid-state quantum computing.

The unique properties exhibited by nanomaterials for commercial applications also raise concerns regarding potential environmental and human impact of these materials. Scientists, regulators, and the public are asking the question: What do we know about the safety of nanotechnology and nanomaterials?


Why is DTSC interested in nanotechnology?
DTSC sees nanotechnology as the new “plastic” because it will show up in many industrial applications and consumer products. Materials and devices designed at the nanoscale level are being used or considered for use in applications as diverse as cancer treatment to scratch-resistance automotive coatings.  Because of the unique properties of nanomaterials, DTSC is gathering information on nanotechnology and monitoring the efforts of other regulatory agencies about this emerging technology.  DTSC sees a need to understand this industrial sector and its products.  DTSC also wants to work with this emerging industrial sector to incorporate the benefits of "green chemistry" approaches, pollution prevention techniques, and sustainable manufacturing strategies to prevent potential adverse public health and environmental consequences.  "High technologies" such as nuclear power, genetically modified organisms, and ever-smaller consumer electronics have begun to leave their legacy.  The benefits of nuclear power in preventing global warming and genetically modified organisms in increased food production are obscured by public fear of perceived consequences.  Consumer electronics, while providing entertainment and ease today, at the end of their service life produce an increasing burden of "e-waste" the heavy metals of which can cause harm in many ways. Nanotechnologies are diverse in form, substance, function, and  promise. DTSC is working toward a partnership with this industrial sector to develop an industrial ecology of manufacturing to product stewardship approach that will protect public health and the environment. DTSC will also continue to explore the merits of pro-active industrial initiatives and traditional governmental regulatory approaches.

Cover for the report entitled Thinking Big About Thinking Small An Action Agenda for California

Thinking Big About Thinking Small An Action Agenda for California

As a starting point in this process, DTSC reviewed the December 2004 report issued by the Blue Ribbon Task Force on Nanotechnology addressed major areas of concern in promoting nanotechnology research and development, commercialization, facilities and infrastructure, policies and ethics, and education.  The members of the Task Force came from many backgrounds including academia, government, corporate California, start-up and consulting firms, non-profit groups, and industry associations.  Several recommendations called for CalEPA’s involvement in understanding and communicating the environmental, social, and even ethical implications of nanotechnology.


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What are its current applications in industry?

Picture of clothing

Some examples of nanotechnology used in clothing are stain-resistant pants and shorts with built-in sunscreen.

Assortment of vegetables

Examples of agrifood research include developing bacterial pathogen detectors from nanochemicals for use post-harvest.

 Some examples of nanotechnology used in clothing are stain-resistant pants and shorts with built-in sunscreen.  Examples of agrifood research include developing bacterial pathogen detectors from nanochemicals for use post-harvest.  Most science and technology experts consider nanotechnology to be an industrial revolution on the horizon that will have an enormous social and economic impact.  However, currently the applied use of nanomaterials and nanotechnology is limited, except in the electronics and information technology industries, where semiconductor devices with a certain minimum feature size have been at the nanoscale for several decades.  Companies have introduced nanotechnology in several consumer products such as cosmetics, food and clothing.  The Woodrow Wilson International Center for Scholars developed searchable databases listing the uses of nanotechnology in consumer products and the research being conducted on agrifood (e.g., food, agriculture, forestry, and agroecosystems).  Other applications include new detection systems, filtration media, and electronic chip design.

Additional information

Nanotechnology Related Web Site Links

Nanotechnology Events Calendar (non-DTSC events are provided only for the reader’s information).

General

Environmental Cleanup

Research


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Questions, Comments, and Suggestions
If you have any comments or suggestions regarding this web page or questions related to nanotechnology and the environment, please send them to nanotechnology@dtsc.ca.gov.  If you would like to receive updates on DTSC related activities regarding nanotechnology, please subscribe to the DTSC Nanotechnology listserv.
 
 
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