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Reviewing New Chemicals under the Toxic Substances Control Act (TSCA)

Filing a Significant New Use Notice (SNUN) under TSCA


Under section 5(a) of TSCA and 40 CFR part 721, if EPA promulgates a Significant New Use Rule (SNUR), a manufacturer or processor wishing to engage in a designated significant new use must submit a Significant New Use Notice (or "SNUN") to EPA at least 90 days before engaging in the new use. This notification provides EPA the opportunity to evaluate the new use and, if necessary, take action to prohibit or limit the activity.

EPA recommends that submitters consult with the Agency prior to submitting a SNUN to discuss what data may be useful in evaluating a significant new use. Discussions with the Agency prior to submission can afford ample time to conduct any tests that might be helpful in evaluating risks posed by the substance.

Joint SNUN submissions

Potential SNUN submitters should be aware of 40 CFR 721.25(b), which authorizes joint SNUNs by two or more persons -- for example, a manufacturer and several processors.

In many cases, EPA will need to respond to a SNUN by amending the SNUR to allow companies other than the SNUN submitter (such as the submitter's processor customers) to engage in the newly approved use(s). Note that before EPA amends the SNUR, even after a manufacturer submits a SNUN and the review period expires, processors (and other manufacturers) of the substance are still legally required to submit their own SNUN before engaging in the significant new use. 

Electronic submission

SNUNs are reported using the standard e-PMN form and are subject to a 90-day review process similar to that for a PMN. When submitting a SNUN, the submitter should include a cover letter that provides the Code of Federal Regulations citation of the SNUR and identifies the specific significant new use(s) for which the SNUN is being submitted.