### Question
How does Tax on Certain Imported Substances define taxable substance?


### Answer
Under *26 U.S.C. § 4672*, **taxable substance** is defined as:

> any substance which, at the time of sale or use by the importer, is listed as a taxable substance by the Secretary for purposes of this subchapter

#### Citation:
  - *26 U.S.C. § 4672*
  - Heading: **Subtitle D-Miscellaneous Excise Taxes > CHAPTER 38-ENVIRONMENTAL TAXES > Subchapter C-Tax on Certain Imported Substances**

