California Air Resources Board

The goal of the In-Use Off-Road Diesel-Fueled Fleets Regulation is to reduce particulate matter (PM) and oxides of nitrogen (NOx) emissions from in-use (existing) off-road heavy-duty diesel vehicles in California.  The regulation covers a wide scope of vehicle types used in (but not limited to) industries as diverse as construction, air travel, manufacturing, landscaping, and ski resorts.  For more information, please contact the DOORS Hotline at (877) 59DOORS (877-593-6677).