Tex. Gov't Code § 2158.007

In purchasing, leasing, maintaining, or converting vehicles for use with compressed natural gas, liquefied natural gas, liquefied petroleum gas, methanol or methanol/gasoline blends of 85 percent or greater, ethanol or ethanol/gasoline blends of 85 percent or greater, biodiesel or biodiesel/diesel blends of 20 percent or greater, or electricity, including electricity to power a plug-in hybrid motor vehicle, the comptroller shall comply with all applicable safety standards adopted by the United States Department of Transportation and the Railroad Commission of Texas.