On April 6, 2011, the NanoSafety Consortium submitted to the U.S. Environmental Protection Agency (EPA) a proposed testing agreement under Section 4 of the Toxic Substances Control Act (TSCA). The Consortium consists of a group of single-, double-, and multi-walled carbon nanotube manufacturers, including: Angstron Materials LLC, Applied Sciences, Inc., Cheap Tubes, Inc., Continental Carbon Nanotechnologies, Inc., Nano-C, Inc., NanoLab, Nanoshel, LLC, Pyrograf Products, SouthWest NanoTechnologies, Inc., and XG Sciences, Inc.
Under the proposed testing agreement, the substances to be tested may include multi-walled carbon nanotubes, double-walled carbon nanotubes, single-walled carbon nanotubes, and graphene nanoplatelets (defined by EPA as thin flakes or sheets of a form of carbon graphene). According to the Consortium's legal counsel, key elements include:
- The chemical substances to be tested may include representative (i) purified multi-walled carbon nanotubes ranging from 4 to 600 nanometers in diameter and less than 30 micrometers in length; (ii) purified double-walled carbon nanotubes ranging from 1.5 to 4 nanometers in diameter and less than 5 micrometers in length; (iii) purified single-walled carbon nanotubes ranging from .7 to 2 nanometers in diameter and less than 30 micrometers in length; and (iv) purified graphene nanoplatelets in flake/sheet form ranging from .5 nanometers to 100 nanometers thick. All test materials will be purified by the National Institute of Standards and Technology to be at least 99 percent pure. Final test materials will be approved by the EPA and will be selected to represent adequately the constituency of the final signatories to the testing agreement.
- The characteristic for which testing will be conducted is subchronic inhalation toxicity in rodents, or other toxicity testing as may be approved by EPA to achieve the intent and purpose of the testing agreement. As appropriate, consideration will be given to using in vivo instillation rather than inhalation test methods.
- Test data will be developed under standards based on TSCA test guidelines in 40 C.F.R. Parts 796, 797, and 798, Organization for Economic Cooperation and Development (OECD) test guidelines, or other suitable test methodologies. Specifically, the signatories will conduct a 90-day inhalation toxicity study in rats with a post-exposure observation period of up to three months, including broncholaveolar lavage fluid analysis (OPPTS 870.3465 or OECD 413), or such other testing as may be approved by the EPA to achieve the intent and purpose of the testing agreement. Testing guidelines will be modified to account for nanoscale properties of the materials being tested. Such modifications are subject to EPA approval and will be incorporated into the study plan referenced in the proposed testing agreement.
Under the proposed testing agreement, if EPA promulgates a TSCA Section 5(a)(2) significant new use rule (SNUR) applicable to the test substances, then the testing agreement would have the status of a TSCA Section 5(b)(1)(A) test rule. The NanoSafety Consortium asked that EPA 'expeditiously consider' the proposed testing agreement and begin the public comment and negotiation process at its 'earliest possible convenience.' The agreement is available at this link.
Under applicable TSCA rules, the next step is for EPA to consider whether it wishes to accept the proposed testing agreement; it must publish a Federal Register notice and initiate a public process to negotiate the terms of the proposed testing agreement. During this process, entities that have identified themselves as persons who have asked to participate in or monitor the negotiations (interested parties) will be invited to comment on the appropriateness and suitability of all aspects of the proposed testing agreement. Under the controlling rules, EPA will enter into a consent agreement under which the contemplated testing will occur only if there is a consensus among EPA, affected manufacturers, and all interested parties.
Significance of the Testing Proposal
The proposed testing agreement is important for several reasons.
First, it is the first such agreement proffered by nanoscale material manufacturers pursuant to TSCA Section 4. The proposal reflects a solid, good faith attempt to provide EPA with needed information while at the same time avoiding unnecessary and potentially duplicative testing that would otherwise be required in the absence of a testing proposal along these lines.
Second, it reflects a shared view among at least certain carbon nanotube manufacturers that producing such data as a consortium is a viable and sensible way to proceed.
Third, if EPA is willing to accept the premise of a testing alternative to the terms and conditions set forth in response to any specific TSCA notification (as EPA plainly seems to be), the final testing proposal could well set a precedent for future testing initiatives that will enable EPA to obtain needed testing information on nanoscale materials more quickly and efficiently.
While it remains to be seen how the diverse community of nano stakeholders who are expected to identify themselves as 'interested' for purposes of any forthcoming negotiation will react to the testing proposal, the hope is all such parties come to the table with good intentions and a genuine commitment to produce a solid testing agreement. The text of proposed agreement could be found here.