Public Workgroup to Discuss Potential Inclusion of Renewable Diesel in Amendments to the In-Use Off-Road Diesel-Fueled Fleets Regulation

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August 26, 2021

Public Workgroup to Discuss Considerations of Renewable Diesel in the Amendments to the In-Use Off-Road Diesel-Fueled Fleets Regulation

Public Workgroup on September 10, 2021

California Air Resources Board (CARB) staff invites you to participate in a public workgroup to begin discussion of allowing the potential use of renewable diesel in the proposed amendments to the In-Use Off-Road Diesel-Fueled Fleets Regulation (Off-Road Regulation). 

Renewable diesel is a diesel fuel that is derived from non-petroleum renewable resources such as vegetable oils and animal fats, and meets CARB motor vehicle fuel specifications.  It is considered a “drop-in” fuel that can be used as a diesel fuel in California “neat” (without blending) or blended with conventional petroleum-based CARB diesel in any amount, and used with existing infrastructure and diesel engines.  Greenhouse gas emissions from the production and use of renewable diesel in diesel engines are generally significantly lower than those from the production and use of conventional CARB diesel.  Additionally, current knowledge indicates that the use of renewable diesel in diesel engines without advanced emissions control systems results in reduced tailpipe emissions of particulate matter and nitrogen oxides (NOx), both criteria pollutants, in comparison to conventional petroleum-based CARB diesel.

The primary goal of these proposed amendments is to reduce emissions of criteria pollutants and toxics from off-road diesel vehicles operating in California, beyond the reductions being achieved via the ongoing implementation of the existing Off-Road Regulation.  At this workgroup, staff will be soliciting input from stakeholders on the use of renewable diesel in the off-road sector, and exploring the potential benefits and emissions reductions associated with the use of renewable diesel.  Staff will also discuss potential ways renewable diesel could be included in the proposed amendments to help achieve the emissions reduction goals outlined in the 2020 Mobile Source Strategy and the State Implementation Plan, in addition to helping achieve California’s ambitious climate goals.

CARB is following directives from the Governor’s Executive Orders N-29-20 and N‑33-20 as well as the California Department of Public Health’s recommendations regarding public gatherings. As a result, the public workgroup will be held as a remote meeting only, via webinar; there will be no physical public access location.

Webinar Information

Date:                 Friday, September 10, 2021
Time:                 1:00 p.m. – 3:00 p.m. (PT)

Webinar Registration

Interested parties must register to participate. Staff presentation material will be posted one week before the workgroup on the In-Use Off-Road Diesel-Fueled Fleets Regulation website.

More Information

The workgroup will consist of a presentation by staff, followed by a question and answer session. Please note that the workgroup may end prior to the specified end time if all questions and comments are addressed prior to the designated webinar end time.


Mobile sources, including on-road vehicles and off-road equipment, contribute a majority of smog-forming NOx and the largest portion of greenhouse gas (GHG) emissions in California, and are a significant source of toxic air contaminants that directly impact community health in California.  These harmful emissions must be reduced from all sources of air pollution in California to not only meet the federal standards, but also to minimize negative health effects on the State’s most impacted and disadvantaged communities, and CARB is committed to adopting and enforcing policies to reduce these harmful emissions.  CARB develops a multi-pollutant planning document called the Mobile Source Strategy to determine the pathways available to the various mobile sectors to achieve these emissions reduction goals. Information on the Draft 2020 Mobile Source Strategy can be found here:

More Information

This planning document highlights the need for additional emissions reductions from the in­-use off-road diesel equipment sector in order to meet CARB’s emissions reduction goals, with special considerations for federally designated air quality non-attainment regions, such as the South Coast Air Basin and the San Joaquin Valley. 

The in-use heavy-duty off-road diesel equipment sector includes equipment used in industries such as construction, mining, industrial, oil drilling, and others, and covers mobile, diesel-fueled vehicles with 25 horsepower and greater engines. Common examples are loaders, backhoes, excavators, forklifts, and oil rigs.  The diesel equipment in this category is currently subject to CARB’s Off-Road Regulation, adopted by the Board in 2007, with significant amendments approved by the Board in 2009 and 2010. To achieve emissions reductions from this sector, the existing rule requires fleets to meet an increasingly stringent set of annual fleet average targets, through 2023 for large and medium fleets, and through 2028 for small fleets.  While the Off-Road Regulation has resulted in significant emissions reductions from the sector, the regulation in its current structure does allow the oldest and dirtiest equipment to continue operating indefinitely with no activity restrictions (depending on the mix of other equipment owned by the fleet).

The intent of this workgroup’s discussion is to consider how renewable diesel could be included in the potential amendments to the Off-Road Regulation in order to provide additional benefits and achieve further emissions reductions from the in-use off-road diesel sector. 


We welcome and encourage the public’s participation in this process. For questions regarding the workgroup or the potential amendments to the Off-Road Regulation, please contact Mr. Nathan Dean, Air Pollution Specialist.

CARB staff will use the Off-Road Equipment (In-Use) Control Measure email list to notify stakeholders of updates to this measure's development and proposal, and of opportunities for public input throughout the process. To sign up for the Off-Road Equipment (In-Use) Control Measure email list, please visit:


Special Accommodations

If you require a special accommodation or need this document in an alternate format (i.e. Braille, large print) or another language, please contact Mr. Thien Tran as soon as possible, but no later than 10 business days before the scheduled event.

Para ayuda en español, por favor mande un mensaje por correo electrónico a Victor Sierra.