### Question
Can you define what clean alternative fuel means?


### Answer
**Clean alternative fuel** is defined as the following in *42 U.S.C. § 7581*:

> only a fuel with respect to which such vehicle was certified as a clean-fuel vehicle meeting the standards applicable to clean-fuel vehicles under section 7583(d)(2) of this title when operating on clean alternative fuel (or any CARB standards which replaces such standards pursuant to section 7583(e) of this title)

#### Citation:
  - *42 U.S.C. § 7581*
  - Heading: **CHAPTER 85-AIR POLLUTION PREVENTION AND CONTROL > SUBCHAPTER II-EMISSION STANDARDS FOR MOVING SOURCES > Part C-Clean Fuel Vehicles**

