The NanoSafety Consortium for Carbon just submitted a proposed toxicity testing agreement to EPA under Section 4 of the Toxic Substances Control Act covering a range of nanoscale materials including multi-walled carbon nanotubes, double-walled carbon nanotubes, single-walled carbon nanotubes, and graphene.
Key elements for the curious:
- 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 adequately represent 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 such 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 CFR 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 3 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 below-referenced study plan.
If EPA decides to pursue the proposed testing agreement, it will initiate a six-month negotiation and comment period which will open to the public pursuant to 40 C.F.R. § 790.28.