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TSCA Section 5 Significant New Use Rules

Section 5(a) of the Toxic Substances Control Act (TSCA) authorizes EPA to determine if a use of a chemical substance is a “significant new use.” EPA must make this determination by rule after considering all relevant factors, including those listed in TSCA section 5(a)(2):

Once EPA determines that a use of a chemical substance is a significant new use, TSCA section 5(a) requires persons to submit a significant new use notice (SNUN) to EPA at least 90 days before they manufacture (including import), or process the chemical substance for that use.

This provides EPA with an opportunity to review and evaluate the data before the submitter begins manufacturing (including importing), or processing for the significant new use. EPA may then regulate the manufacture (including import), or processing of that chemical substance before the initiation of the significant new use, if regulation is warranted.

EPA also uses significant new use rules (SNURs) in appropriate circumstances to ensure that, once a chemical has been phased out or taken off the market for certain uses, no company will be able to resume manufacturing or processing the chemical for that use without prior notice to the Agency. These are sometimes referred to as “dead chemical SNURs.” This action can prevent older chemical substances that we now know to be dangerous from returning to the market after responsible companies have replaced them with safer substances.

Examples of recent existing chemical substance SNURs include EPA’s:


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