California Air Resources Board

CARB’s diesel engine regulations and programs cover a wide range of equipment operating in California and are designed to reduce air pollution caused by diesel-powered and other non-gas fossil-fuel powered equipment. Mobile sources including cars, trucks, ships, and off-road equipment continue to contribute a majority of smog-forming NOx and the largest portion of GHG emissions in California. They are also a significant source of toxic air contaminants such as diesel particulate matter (PM) and formaldehyde that directly impact community health. Enforcement of these regulations helps move California closer to our clean-air goals, promotes a level-playing field for compliant businesses and individuals, and supports the health of communities, especially disadvantaged communities most impacted by pollution.

CARB Enforcement takes a compliance-based approach to measure and address the highest areas of non-compliance and combines that with significant deterrence tools to drive compliant behavior. CARB is investing in and refining technologies to better identify sources of emissions, such as the Portable Emissions Acquisition System (PEAQS), which screens for high-emitting vehicles as they drive by. In addition to ensuring compliance, these efforts inform CARB’s environmental justice efforts and provide communities information to advocate for change.