California Air Resources Board

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Regulation Background

CARB adopted the TRU ATCM in 2004 (and amended it in 2010 and 2011) to reduce diesel PM emissions and resulting health risk from diesel-powered TRUs. Despite the progress made, additional TRU emission reductions are needed to further protect communities from near-source pollution impacts, help meet the current health-based ambient air quality standards across California, and support the State’s climate goals. On February 24, 2022, CARB approved amendments to the TRU ATCM (2022 Amendments) to achieve additional emission and health risk reductions from diesel-powered TRUs and increase the use of zero‑emission technology in the off-road sector. The 2022 Amendments will help meet the State’s multiple risk reduction, air quality, and climate goals, as well as the directive of Executive Order N-29-20, which set a goal for 100 percent zero-emission off-road vehicles and equipment in the State by 2035.

Below is a summary of the 2022 Amendments. Note that there are multiple compliance deadlines, the earliest starting December 31, 2022.

For regulation and amendment FAQ, please view the TRU ATCM FAQ.

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What You Need to Know to Comply with the Transport Refrigeration Unit Regulation

2022 Amendments

New amendments to the TRU ATCM became effective October 1, 2022.

Below is a summary of the 2022 Amendments. Note that there are multiple compliance deadlines, the earliest starting December 31, 2022.

1. Lower global warming potential refrigerant – Beginning December 31, 2022, newly-manufactured truck TRUs, trailer TRUs, and domestic shipping container TRUs shall use refrigerant with a global warming potential less than or equal to 2,200, or no refrigerant at all.
2. More stringent PM emission standard – Beginning December 31, 2022, model year 2023 and newer trailer TRU, domestic shipping container TRU, railcar TRU, and TRU generator set engines shall meet a PM emission standard of 0.02 grams per brake horsepower-hour or lower (aligns with the United States Environmental Protection Agency Tier 4 final off-road PM emission standard for 25-50 horsepower engines).
3. Requirements for vehicle owners and drivers– Beginning December 31, 2022, vehicle owners of TRU-equipped trucks or tractor-trailers equipped with a TRU shall ensure the TRU is compliant. If requested, drivers shall allow CARB personnel to conduct a visual inspection of their TRU.
4. Applicable facility requirements – Beginning December 31, 2023, owners of refrigerated warehouses or distribution centers with a building size of 20,000 square feet or greater, grocery stores with a building size of 15,000 square feet or greater, seaport facilities, and intermodal railyards with TRU activity (applicable facilities) shall register the facility with CARB, pay fees every three years, and report all TRUs that operate at their facility to CARB quarterly, or alternatively ensure that only compliant TRUs operate at their facility (i.e., those with a valid CARB compliance label or showing as compliant on CARB’s website).
5. Expanded TRU reporting – Beginning December 31, 2023, TRU owners shall report all TRUs (including out-of-state based) that operate in California to CARB. 6. TRU operating fees and compliance labels – Beginning December 31, 2023, TRU owners shall pay TRU operating fees and affix CARB compliance labels to their TRU every three years, for each TRU operated in California.
6. Zero-emission truck TRU requirement3 – Beginning December 31, 2023, TRU owners shall turnover at least 15 percent of their truck TRU fleet (defined as truck TRUs operating in California) to zero-emission technology each year (for seven years). All truck TRUs operating in California shall be zero-emission by December 31, 2029.
7. Zero-emission truck TRU assurances – OEMs of zero-emission truck TRUs shall be required to provide a comprehensive warranty for zero-emission truck TRUs and have an authorized service-and-repair facility located in California to perform warranty repairs.
8. Compliance extensions due to private financing, equipment manufacture delays, or installer delays – Compliance extensions due to private financing, equipment manufacture delays, or installer delays may be granted for a maximum of six months (previously four months).
9. Requirements for lessors and lessees – TRU owners (lessors) may delegate compliance responsibility to the TRU operator (lessee) if the rental or lease agreement is for a period of one year or longer

Compliance Schedule

In-Use Model Year 2022 and Older TRUs

New Model Year 2023 and Newer TRUs

Zero-Emission Truck TRU Fleet Compliance Schedule

The phase-in schedule for different size truck TRU fleets is shown in the table below. Note that owners should use basic rounding methodology when calculating the required number of zero-emission truck TRUs. If the calculated number of required zero-emission truck TRUs is not equal to a whole number, round up to a whole number when the fractional part is equal to or greater than 0.5, and round down if less than 0.5.

Compliance Exemptions & Extensions

TRU owners or operators may apply for compliance extensions based on the unavailability of compliance technology, as well as zero-emission infrastructure, manufacturer, installer, or financing delays. An exemption is available for mobile catering companies that provide mobile catering services for emergency incidents. More information and application forms for extensions and exemptions are available at TRU Forms.

Reporting

Owners may report their TRU(s) to CARB by applying for a CARB identification number (IDN) via ARBER Registration Help.

Applications are also available at TRU Forms and may be submitted by email to arber@arb.ca.gov, or by mail to:

California Air Resources Board
Transportation and Toxics Division (TRU)
P.O. Box 2815
Sacramento, CA 95812

Verify Compliance

The public may use the following links to search CARB’s Equipment Registration (ARBER) system to check the compliance status of TRUs and TRU generator sets and provide comments or provide tips on violations about specific TRUs. CARB will monitor these comments/tips and follow up with enforcement action, if warranted.

You can also report noncompliant TRUs to CARB's Complaint Program.

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What You Need to Know to Comply with the Transport Refrigeration Unit Regulation