### Question
How does STRATOSPHERIC OZONE PROTECTION define class II substance?


### Answer
Under *42 U.S.C. § 7671*, **class II substance** is defined as:

> each of the substances listed as provided in section 7671a(b) of this title

#### Citation:
  - *42 U.S.C. § 7671*
  - Heading: **CHAPTER 85-AIR POLLUTION PREVENTION AND CONTROL > SUBCHAPTER VI-STRATOSPHERIC OZONE PROTECTION**

