### Question
How does the law define methamphetamine precursor chemicals?


### Answer
Under *6 U.S.C. § 220*, **methamphetamine precursor chemicals** is defined as:

> the chemicals ephedrine, pseudoephedrine, or phenylpropanolamine, including each of the salts, optical isomers, and salts of optical isomers of such chemicals

#### Citation:
  - *6 U.S.C. § 220*
  - Heading: **CHAPTER 1-HOMELAND SECURITY ORGANIZATION > SUBCHAPTER IV-DIRECTORATE OF BORDER AND TRANSPORTATION SECURITY > Part B-United States Customs Service**

