### Question
Can you define what low-polluting fuel means?


### Answer
**Low-polluting fuel** is defined as the following in *42 U.S.C. § 7554*:

> methanol, ethanol, propane, or natural gas, or any comparably low-polluting fuel

#### Citation:
  - *42 U.S.C. § 7554*
  - Heading: **CHAPTER 83-ENERGY EXTENSION SERVICE > SUBCHAPTER II-EMISSION STANDARDS FOR MOVING SOURCES > Part A-Motor Vehicle Emission and Fuel Standards**

