US EPA Proposes Snur for Carbon Nanotube Substance

The US EPA has proposed a significant new use rule (Snur) for a carbon nanotube substance that was subject of a pre-manufacture notice (PMN).

The substance – bimodal mixture consisting of multi-walled carbon nanotubes and other classes of carbon nanotubes (generic) – is intended to be used as a specialty additive, according to its PMN.

The EPA says it has identified concerns for pulmonary toxicity and oncogenicity based on test data of analogous respirable, poorly soluble particulates and nanocarbon materials. It therefore imposed a consent order on it.

To apply these protections to future users of the substance, the agency is now issuing a Snur. This proposes to designate as significant new uses the absence of the following protective measures, consistent with the consent order:

use of certain personal protective equipment (PPE);

submission of a dustiness test within six months of notice of commencement of manufacture (NOC);

submission of certain physical chemical properties;

use of the substance outside of those specified in the consent order, including an application method that generates a vapour, mist or aerosol (unless the application method occurs in an enclosed process); and

releases to water beyond those described in the PMN.

It has also recommended the development of certain test data.

The agency had previously issued the Snur as a direct final rule, but withdrew it following receipt of a notice of intent to submit adverse comment.

The commenter noted a discrepancy between the direct final Snur and the consent order: namely, that it designated as a significant new use any purposeful or predictable releases to surface water, whereas the consent order allowed limited releases. The EPA has aligned the requirements in this proposed Snur.

Comments will be accepted until 10 July.