Nanocomp Technologies is the producer of carbon nanotube-based Miralon® products. Nanocomp’s products differ from other carbon nanotube materials because they are macro-structures (articles) and not loose powders (particles). This “article versus particle” distinction has many technical, regulatory, and safety advantages that are explained below.
Examples of Nanocomp’s Miralon® products are shown above. From left to right: Miralon yarn, tape, and dispersed product.
In the United States, the authority to regulate the manufacture of chemicals is with the Environmental Protection Agency (EPA) and much of the relevant authority with respect to carbon nanotube powders comes from the Toxic Substances Control Act (TSCA). The EPA has the power and the responsibility to require producers to determine the environmental, health, and safety effects of their chemicals. These chemicals must also be listed on the TSCA Inventory in order to receive approval for the manufacturer to sell these materials in the United States. A Consent Order is issued by the EPA, which gives the terms and conditions under which a manufacturer can produce and distribute its material.
Nanocomp received its Consent Order1 for sheet and yarn products in 2010, and in 2016 the Order was amended to include its dispersed products. However, the EPA did not require the same terms and conditions as would be typical for a chemical substance. This was due to several factors. First, the Miralon products emerge from their production reactors fully-formed as sheets and yarn. Nanocomp’s nanotubes are formed in the reactor into a network of interlocked, intertwined bundles of millimeter long nanotubes, not as single or small aggregates of nanotubes with micron lengths as is found in powder products.
This degree of assembly and its extent throughout the entire Miralon product line (sheet, tape, yarn and dispersed product) provides structural integrity, making them functionally and mechanically different from a nanotube powder. This is why they are classified as articles – bulk constructions – rather than particles – a loose collection of free tubes. The products are not considered chemicals by the EPA and, therefore, not subject to the same regulatory requirements.
With the classification of Miralon products as articles, the terms and conditions of the Consent Order instead focus on the markets and applications for the products. The Order specifies that Miralon product can be used in “Defense, Aerospace, and Industrial markets in relation to electrical, mechanical, and thermal applications.” Additionally, any final product form incorporating the Miralon materials (e.g., coating, composite panel, or conductive wire) is acceptable as long as it is being produced in an industrial setting. Products entering into the commercial or consumer space must be delivered in a fully finished state.
The structural integrity of Miralon products has also been verified by measurements in the field. Working with the scientists and engineers of the nanomaterials safety program at the National Institute for Occupational Safety and Health (NIOSH) in Cincinnati, OH and the Toxics Use Reduction Institute at the University of Massachusetts, Lowell, Miralon products were cut, torn, punctured, and put through other common industrial processes to check for the release of nanomaterials. While under some circumstances the material might shred, any pieces produced are large and easily visible to the eye. There was no release of nanomaterial and no special protective equipment or measures were required. This was confirmed through the use of a variety of particle detectors (shown below), each designed to sample a particular range of particle sizes.
Three different types of detectors used by Nanocomp to check for airborne nanomaterials. From left to right – a light scattering detector (good for particles down to 300 nm is size), an aerosol counter (good down to 10 nm in size), and a fast mobility sizer (good down to 5 nm in size).
Nanocomp has been collaborating with NIOSH since 2009 when a team visited the company in order to determine if workers were potentially exposed to nanomaterials during their duties. To confirm there was no health risk, the manufacturing environment and the workers were monitored using special particle collection systems and the detectors shown above. No nanospecific issues were discovered.
At NIOSH’s last site visit in 2014, air monitoring of both workers and the ambient environment was combined with new employee medical monitoring methods that were in development. Again, no nanospecific issues were discovered. These findings are attributed to the macro-structure, or article, forms of the products as well as the design of the manufacturing equipment.
The EPA, NIOSH and Nanocomp recognize that the EH&S knowledge of nanomaterials continues to evolve. Participating in a variety of EH&S conferences as subject matter experts from industry is one way Nanocomp is actively working with these agencies to extend and vet this knowledge.
For more information about safety in nanotechnology, including engineering controls put in place at Nanocomp, refer to NIOSH’s publication “Building a Safety Program to Protect the Nanotechnology Workforce: A Guide for Small to Medium-Sized Enterprises”.
If you have any concerns/questions, please discuss with your business development contact for more information.
1 The EPA Consent Order for Nanocomp is available upon request.