22 / TRANSPORT REFRIGERATION UNIT EMISSIONS REQUIREMENTS
Transport refrigeration unit emissions requirements
Refrigerated transport requires checks beyond the tractor: the diesel refrigeration unit has its own emissions program. A last-minute trailer swap illustrates which official program records to check before accepting the equipment.
Refrigerated transport requires checks beyond the tractor: the diesel refrigeration unit has its own emissions program. A last-minute trailer swap illustrates which official program records to check before accepting the equipment.
Diesel transport refrigeration/heating units described by CARB, including equipment on truck vans, semitrailers, containers and railcars. This introduction does not cover food-safety rules, temperature contracts or a complete technical TRU compliance determination.
Start with these requirements
Identify the refrigeration unit, not just the tractor
- What the rule requires
- CARB describes TRUs as diesel-internal-combustion-engine systems that refrigerate or heat perishable products in transport. Identify the unit and equipment type separately when checking emissions status; a tractor’s passing test does not establish the refrigeration unit’s compliance.
Transport Refrigeration Units (TRU) are refrigeration systems powered by diesel internal combustion engines designed to refrigerate or heat perishable products that are transported in various containers, including truck vans, semi-truck trailers, shipping containers, and railcars. More about this program
Uses a fixed source edition; check the original and statutory history for operative dates and exceptions.
Finding TRU fee, registration and compliance information
- What the rule requires
- CARB states that the 2022 amendments took effect October 1, 2022 and address TRU operating fees and applicable facility-registration fees; SB 153 in 2025 authorized related fee collection. Use the linked current guidance, registration and compliance tools to establish who owes what, when, and whether a unit complies. This page does not invent a universal fee or retirement date for every unit.
On February 24, 2022, CARB approved amendments (2022 Amendments) to the Transport Refrigeration Unit Air Toxic Control Measure (TRU ATCM) for In-Use Diesel-Fueled TRUs (Title 13 CCR §§ 2477–2477.24), effective October 1, 2022. The 2022 Amendments require TRU and facility owners or owner/operators to pay operating and registration fees, respectively. On September 17, 2025 Governor Newsom signed Senate Bill (SB) 153 granting CARB authority to impose fees on entities regulated under the 2022 Amendments to the TRU ATCM.
Guidance documents and answers to frequently asked questions are now available to assist stakeholders with TRU operating and applicable facility registration fee requirements.
Check TRU Compliance
Register Your TRU Online
TRU ATCM with 2022 Amendments
TRU Registration Help
Uses a fixed source edition; check the original and statutory history for operative dates and exceptions.
WORKED EXAMPLE
A last-minute refrigerated-trailer swap
Illustrative example: dispatch substitutes a refrigerated trailer, but the driver receives only the tractor’s emissions-test proof.
Obtain unit information
Ask the equipment provider for unit type, registration and compliance status and check the relevant CARB resources; this is an operational checking recommendation.
Keep the checks distinct
Record tractor and refrigeration-unit checks separately instead of using a tractor document for all equipment.
Treat the refrigeration unit as a separate check; do not declare compliance before its category and official status are established.
Common mistakes in day-to-day work
Misconception: TRU rules are food-temperature rules
CARB’s TRU page addresses air pollution. Cargo temperature, sanitation and contractual delivery conditions require separate checks and are not combined into one authorization here.
Full text and sources
OFFICIAL GUIDANCE · ENGLISH
Transport Refrigeration Unit
Transport Refrigeration Unit
- Source edition date
- Not provided
- Captured
Edition noteOfficial-source snapshot; current consolidated law and subsequent amendments have not been verified.
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Drafted from linked official texts and agency guidance. Both language interpretations are CTAC AI-assisted drafts pending human review; examples are illustrative, not member records. Capture dates are not legal effective dates.