---
kind: "section"
citation: "40 C.F.R. § 721.4160"
title: "40"
number: "721.4160"
heading: "Hexafluoropropylene oxide."
url: "https://uscodex.org/cfr/40/721.4160"
---

# §721.4160. Hexafluoropropylene oxide.

- (a) **Chemical substance and significant new use subject to reporting.**
  - (1) The chemical substance hexafluoropropylene oxide (HFPO), CAS Number 428-59-1 [Listed in TSCA Inventory as oxirane, trifluoro(trifluoromethyl)-] is subject to reporting under this section for the significant new use described in [paragraph (a)(2)](#a-2) of this section.
  - (2) The significant new use is any use other than as an intermediate in the manufacture of fluorinated substances in an enclosed process.
- (b) **Specific requirements.** The provisions of subpart A of this part apply to this section except as modified by this paragraph.
  - (1) **Definitions.** In addition to the definitions in [§ 721.3](/cfr/40/721.3.md), the following definitions apply to this section:
    - (i) Enclosed process means a process that is designed and operated so that there is no intentional release of any substance present in the process. A process with fugitive, inadvertent, or emergency relief releases remains an enclosed process so long as measures are taken to prevent worker exposure to and environmental contamination from the releases.
    - (ii) [Reserved]
  - (2) [Reserved]

## Notes

### Amendments

[52 FR 41300, Oct. 27, 1987. Redesignated at 53 FR 2845, Feb. 2, 1988. Further redesignated at 58 FR 29946, May 24, 1993, as amended at 58 FR 34204, June 23, 1993]

### Authority

Authority: 15 U.S.C. 2604, 2607, and 2625(c).

### Source

Source: 49 FR 35018, Sept. 5, 1984, unless otherwise noted.

### Amendments

[52 FR 41300, Oct. 27, 1987. Redesignated at 53 FR 2845, Feb. 2, 1988. Further redesignated at 58 FR 29946, May 24, 1993, as amended at 58 FR 34204, June 23, 1993]