### Question
What is the definition of alcohol concentration?


### Answer
The definition of **alcohol concentration** is as follows in *23 U.S.C. § 164*:

> grams of alcohol per 100 milliliters of blood or grams of alcohol per 210 liters of breath

#### Citation:
  - *23 U.S.C. § 164*
  - Heading: **CHAPTER 1-FEDERAL-AID HIGHWAYS**

