[Federal Register Volume 74, Number 66 (Wednesday, April 8, 2009)]
[Pages 15985-15986]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-7941]



Centers for Disease Control and Prevention

[Docket Number NIOSH-161]

Request for Information on Carbon Nanotubes (CNTs) Including 
Single-Walled Carbon Nanotubes (SWCNTs) and Multi-Walled Carbon 
Nanotubes (MWCNTs)

AGENCY: National Institute for Occupational Safety and Health (NIOSH) 
of the Centers for Disease Control and Prevention (CDC), Department of 
Health and Human Services (HHS).

ACTION: Notice of public comment period.


SUMMARY: The National Institute for Occupational Safety and Health 
(NIOSH) of the Centers for Disease Control and Prevention (CDC) intends 
to evaluate the scientific data on carbon nanotubes (CNTs) and develop 
appropriate communication documents, such as an Alert and/or Current 
Intelligence Bulletin, which will convey the potential health risks and 
recommend measures for the safe handling of these materials. NIOSH has 
developed guidelines for managing the potential health concerns 
associated with occupational exposures to engineered nanoparticles 
[see: http://www.cdc.gov/niosh/topics/nanotech/safenano/] which will 
provide the framework for developing specific recommendations for CNTs.
    NIOSH is requesting information on the following: (1) Published and 
unpublished reports and findings from in vitro and in vivo toxicity 
studies with CNTs, (2) information on possible health effects observed 
in workers exposed to CNTs, (3) information on workplaces and products 
in which CNTs can be found, (4) description of work tasks and scenarios 
with a potential for exposure, (5) workplace exposure data, and (6) 
information on control measures (e.g., engineering controls, work 
practices, personal protective equipment) that are being used in 
workplaces where potential exposures to CNTs occur.
    Public Comment Period: Comments must be received by May 15, 2009.

ADDRESSES: You may submit comments, identified by docket number NIOSH-
161, by any of the following methods:
     Mail: NIOSH Docket Office, Robert A. Taft Laboratories, 
MS-C34, 4676 Columbia Parkway, Cincinnati, OH 45226.
     Facsimile: (513) 533-8285.
     E-mail: [email protected].
    All information received in response to this notice will be 
available for public examination and copying at the NIOSH Docket 
Office, 4676 Columbia Parkway, Cincinnati, Ohio 45226. A complete 
electronic docket containing all comments submitted will be available 
on the NIOSH Web page at http://www.cdc.gov/niosh/docket, and comments 
will be available in writing by request. NIOSH includes all comments 
received without change in the docket, including any personal 
information provided.

Taft Laboratories, MS-C32, 4676 Columbia Parkway, Cincinnati, OH 45226, 
telephone (513) 533-8320.

SUPPLEMENTARY INFORMATION: Nanotechnology is generally defined as the 
intentional manipulation of matter to form novel structures with one or 
more dimension or features less than 100 nanometers (nm). 
Nanotechnology involves a wide range of chemistries and almost 
unlimited types of structures that have highly unpredictable 
interactions with biological systems. Carbon nanotubes (CNTs) are a 
type of nanomaterial comprised of a sheet of graphite (a hexagonal 
lattice of carbon) rolled into a cylinder that can have a length-to-
width ratio greater than 1,000. Carbon nanotubes are produced having a 
single cylinder carbon wall (single-walled carbon nanotubes [SWCNT]) or 
having multiple walls-cylinders nested within other cylinders (multi-
walled carbon nanotubes [MWCNT]). CNTs range in diameter from about 1-2 
nanometers for SWCNTs to dozens of nanometers for MWCNTs with lengths 
extending into the micrometer range.
    There are several major techniques used in the synthesis of CNTs. 
The arc-evaporation technique involves passing a current of about 50 A 
between two graphite electrodes in an atmosphere of helium in the 
presence of metal catalysts (Co, Ni). The second method is chemical 
vapor deposition, where nanotubes are formed by decomposition of a 
carbon-containing gas with use of nano-sized catalytic particles 
usually Fe, Co, Yt or Ni. The advantage of catalytic synthesis over 
arc-evaporation is the ability to scale-up for volume production. The 
third method for making CNTs, laser ablation, involves employment of a 
powerful laser to vaporize metal (Co and Ni)-graphite targets. Of the 
three major processes, chemical vapor deposition is the most prominent 
one that is currently used for CNT production.
    Due to their unique physical and chemical properties, CNTs have 
sparked much research into developing novel applications. CNTs are 
ideal non-biodegradable materials; they are stronger then steel, 
flexible, lightweight, heat resistant, and have high electrical 
conductivity. The market for CNTs is estimated to grow substantially 
over the next decade. They are currently used in a variety of 
applications including: Electronics, reinforced plastics, micro-
fabrication conjugated polymer activators, biosensors, enhanced 
electron/scanning microscopy imaging techniques, and in pharmaceutical/
biomedical devices for drug delivery and medical diagnostics. Estimates 
of the number of workers potentially exposed to CNTs are unavailable 
due to limited exposure data and its relatively recent introduction 
into domestic commerce.
    The toxic nature of SWCNTs and MWCNTs in humans is not known. 
Recently published in vitro and in vivo studies with some SWCNTs and 
MWCNTs describe adverse effects including their ability to be cytotoxic 
when tested in various cell cultures, and cause acute inflammation and 
early onset of fibrosis when delivered to the lungs of mice by 
pharyngeal aspiration or inhalation. No occupational exposure limits 
for CNTs have been established by NIOSH or the Occupational Safety and 
Health Administration (OSHA).
    NIOSH seeks to obtain materials, including published and 
unpublished reports and research findings, to evaluate the possible 
health risks of occupational exposure to CNTs. Examples of requested 
information include, but not limited to, the following: (1) 
Identification of industries or occupations in which exposures to CNTs 
may occur.
    (2) Trends in the production and use of CNTs.
    (3) Description of work tasks and scenarios with a potential for 
exposure to CNTs.
    (4) Workplace exposure measurement data in various types of 
industries and jobs.
    (5) Case reports or other health information demonstrating 
potential health effects in workers exposed to CNTs.
    (6) Research findings from in vitro and in vivo toxicity studies.

[[Page 15986]]

    (7) Information on control measures (e.g., engineering controls, 
work practices, PPE) being taken to minimize worker exposure to CNTs.

    Dated: March 31, 2009.
James D. Seligman,
Chief Information Officer, Centers for Disease Control and Prevention.
[FR Doc. E9-7941 Filed 4-7-09; 8:45 am]