---
kind: "section"
citation: "15 U.S.C. § 8931"
title: "15"
title_heading: "Commerce and Trade"
number: "8931"
heading: "Definitions"
release: "119-102"
date: "2026-07-12"
url: "https://uscodex.org/usc/15/8931"
units:
  - "Chapter 115 — Perfluoroalkyl and Polyfluoroalkyl Substances and Emerging Contaminants"
  - "Subchapter III — Usgs Performance Standard"
---

# §8931. Definitions


In this subchapter:

- (1) **Director—** The term “Director” means the Director of the United States Geological Survey.
- (2) **Highly fluorinated compound—**
  - (A) **In general—** The term “highly fluorinated compound” means a [perfluoroalkyl substance](#2-B-ii) or a [polyfluoroalkyl substance](#2-B-iii) with at least one [fully fluorinated carbon atom](#2-B-i).
  - (B) **Definitions—** In this paragraph:
    - (i) **Fully fluorinated carbon atom—** The term “fully fluorinated carbon atom” means a carbon atom on which all the hydrogen substituents have been replaced by fluorine.
    - (ii) **Perfluoroalkyl substance—** The term “perfluoroalkyl substance” means a chemical of which all of the carbon atoms are [fully fluorinated carbon atoms](#2-B-i).
    - (iii) **Polyfluoroalkyl substance—** The term “polyfluoroalkyl substance” means a chemical containing at least one [fully fluorinated carbon atom](#2-B-i) and at least one carbon atom that is not a [fully fluorinated carbon atom](#2-B-i).

## Source credit

(Pub. L. 116–92, div. F, title LXXIII, § 7331, Dec. 20, 2019, 133 Stat. 2281.)