In this chapter:
(1) "Commission" means the Texas Commission on Environmental Quality.
(1-a) "Diesel exhaust" means one or more of the air pollutants emitted from an engine by the combustion of diesel fuel, including particulate matter, nitrogen oxides, volatile organic compounds, air toxics, and carbon monoxide.
(2) "Incremental cost" has the meaning assigned by Section 386.001.
(3) "Program" means the clean school bus program established under this chapter.
(4) "Qualifying fuel" includes any liquid or gaseous fuel or additive registered or verified by the United States Environmental Protection Agency, other than standard gasoline or diesel, that is ultimately dispensed into a school bus that provides reductions of emissions of particulate matter.
(5) "Retrofit" has the meaning assigned by Section 386.101.