Transport Refrigeration Unit
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.
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2022 Amendments to the TRU ATCM
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 amendments aim to further reduce emissions and health risks from diesel-powered TRUs, promote the use of zero-emission technology in the off-road sector, and help meet the state’s multiple risk reduction, air quality, and climate goals. On January 3, 2025, U.S. EPA waived federal preemption for all but the zero-emission TRU requirements. CARB posted a TRU ATCM Implementation Update 2025 and accompanying Frequently Asked Questions (FAQs) document to assist with compliance efforts related to this action.
