California Air Resources Board

Certifications

Pursuant to Sections 39600, 39601, 43013, 43018, and 43101 of the Health and Safety Code, the California Air Resources Board (CARB) adopted the Alternative Diesel Fuel regulation (ADF regulation) under title 13, California Code of Regulations (CCR), section 2293 et seq. Effective since January 1, 2016, the ADF regulation establishes a comprehensive, multi-stage process administering the commercialization of alternative diesel fuels in California. The ADF regulation governs the introduction and use of innovative alternative diesel fuels in California while preserving or enhancing public health, environmental and emission benefits of the existing motor vehicle diesel-fuel regulations. The ADF regulation includes specific provisions designed to control potential increases in oxides of nitrogen (NO_x) emissions that could otherwise be caused by the use of biodiesel under certain circumstances. Those provisions include a process for certification of additives or alternative diesel fuel formulations that have been shown to mitigate NO_x increases from the use of biodiesel. The following additives have been approved and certified pursuant to Appendix 1(a)(2)(H) of the ADF regulation as emissions equivalent additives for use with biodiesel blends B20 and below:

*Additives and formulations certified under the original certification procedures can no longer be used to meet the ADF regulation in-use requirements after July 31, 2021. Starting August 1, 2021, only those additives and formulations that are certified under the amended certification procedures that came into effect May 3, 2021 can be used to comply with the biodiesel in-use requirements. For more information please see the FAQ document posted in July 2021.

Fleet Exemptions

The ADF regulation includes specific provisions designed to control potential increases in oxides of nitrogen (NO_x) emissions that could otherwise be caused by the use of biodiesel under certain circumstances. These in-use requirements have been effective since January 1, 2018. The ADF regulation includes exemptions to the in-use requirements for qualifying fleets if owners or operators can demonstrate that they meet the exemption conditions specified in the ADF regulation section 2293.6(a)(5)(A)1, 2, and 3. A fleet exemption may be granted if the followings are met; 1) the fleet owner or operator can demonstrate to the Executive Officer that at least 90 percent of the fleet consists of a combination of light and medium duty vehicles and heavy duty NTDE vehicles and 2) any unmitigated biodiesel approved under this EO will only be used by the exempted fleet. The following fleets have been granted fleet exemptions from the in-use requirements of section 2293.6 of the ADF regulation:

Retail Fueling Station Exemptions

The ADF regulation includes specific provisions (in-use requirements) designed to control potential increases in oxides of nitrogen (NOx) emissions that could otherwise be caused by the use of biodiesel under certain circumstances. These in-use requirements have been effective since January 1, 2018. The ADF regulation also includes provisions that allow exemptions to the in-use requirements for qualifying retail fueling stations if owners can demonstrate that their stations meet the conditions specified in section 2293.6(a)(5)(B). 

A retail fueling station exemption may be granted if the owner can demonstrate that at least 90 percent of all sales at the station of biodiesel blends above the pollutant control level, are to a combination of light and medium duty vehicles and heavy duty vehicles with new technology diesel engines (NTDEs). The following companies have been granted retail fueling station exemptions:

Stage 1 Pilot Program

The multi-stage process governing the commercialization of new ADFs in California starts with a screening analysis that would allow limited sales of a regulated diesel substitute while it undergoes an initial evaluation (Stage 1); an intermediate stage with expanded sales governed by enhanced monitoring, testing, and a multimedia evaluation (Stage 2); and a final stage with full-scale commercial sales and provisions designed to maintain environmental and public health protections as needed (Stage 3).