What does “gross polluter” refer to?

The term “gross polluter” specifically refers to a vehicle that significantly fails emissions testing. This designation is mainly used to identify vehicles that contribute disproportionately to air pollution due to their inability to meet regulatory limits for harmful emissions. Vehicles classified as gross polluters usually exhibit severe malfunctions in their emission control systems, resulting in excess emissions of pollutants like hydrocarbons, carbon monoxide, and nitrogen oxides, which can have detrimental effects on air quality and public health.

In the context of emissions regulations, identifying gross polluters is essential for enforcing compliance with environmental standards and ensuring that the overall fleet of vehicles on the road contributes to cleaner air. These vehicles typically trigger mandatory repairs or more stringent inspections before they can be allowed back on the road, to mitigate their environmental impact. Other options refer to vehicles either meeting emissions standards, only experiencing minor issues, or being exempt from testing, but these do not align with the definition or implications associated with gross polluters.