---
kind: "unit"
title: "40"
title_heading: "Protection of Environment"
key: "chI/subchR/part721"
level: "part"
label: "Part 721"
heading: "Significant New Uses of Chemical Substances"
release: "ecfr-current"
date: "2026-08-27"
url: "https://uscodex.org/cfr/40/chI-subchR-part721"
sections_count: 2654
---

# Part 721 — Significant New Uses of Chemical Substances

Title 40 C.F.R. — Protection of Environment › Chapter I — Environmental Protection Agency › Subchapter R — Toxic Substances Control Act

## Contents

- [Subpart A — General Provisions](/cfr/40/chI-subchR-part721-subpartA.md)
- [Subpart B — Certain Significant New Uses](/cfr/40/chI-subchR-part721-subpartB.md)
- [Subpart C — Recordkeeping Requirements](/cfr/40/chI-subchR-part721-subpartC.md)
- [Subpart D — Expedited Process for Issuing Significant New Use Rules for Selected Chemical Substances and Limitation or Revocation of Selected Significant New Use Rules](/cfr/40/chI-subchR-part721-subpartD.md)
- [Subpart E — Significant New Uses for Specific Chemical Substances](/cfr/40/chI-subchR-part721-subpartE.md)