The California Air Resources Board (CARB) approved amendments to its current rule for Transport Refrigeration Units (TRUs) operating in the state. The 2022 amendments will require a variety of actions designed to reduce the pollution these units produce, and accelerate their transition to zero-emission technologies.

The new requirements include the transition of diesel-powered truck TRUs to zero‑emission; a particulate matter emission standard for newly manufactured non-truck TRU engines (on trailers, domestic shipping containers, railcars, and generator set units); the use of lower global warming potential refrigerants; facility registration and reporting; expanded reporting and labeling; and fees.

The new requirements will help meet the current health-based ambient air quality standards across California, and further the state’s climate goals. They also build on progress achieved by the existing rule, which requires TRUs operating in California to meet in-use particulate matter performance standards after they turn seven years old.

Since implementation began in 2008, particulate matter emissions and resulting near-source health risk are almost 80% lower due to a combination of the current rule and federal emission standards for off‑road engines. Despite the progress made, TRU emissions still contribute to an increased health risk especially in communities that are already hard hit by air pollution from truck traffic, and where large numbers of these units congregate, such as refrigerated warehouses and distribution centers, grocery stores, seaport facilities, and intermodal railyards.

From 2022 to 2034, the amendments are expected to reduce PM_2.5 and NO_x emissions by approximately 1,258 tons and 3,515 tons, respectively, and result in estimated statewide health benefits (savings from avoided health care costs) of approximately $1.75 billion. Total net cost of the Proposed Amendments from 2022 to 2034 is estimated to be $1.04 billion.

Reductions of PM_2.5 and NO_x emissions will also reduce cancer risk to individual residents and off-site workers near facilities where TRUs operate, including those located in and near disadvantaged communities.

Key elements of the newly-adopted requirements include the following:

Beginning 31 December 2022:

• Newly-manufactured truck TRUs, trailer TRUs, and domestic shipping container TRUs are required to use a refrigerant with a global warming potential less than or equal to 2,200, or no refrigerant at all.

• Model-year 2023 and newer trailer TRUs, domestic shipping container TRUs, railcar TRUs, and TRU generator set engines are required to meet a lower particulate matter emission standard that aligns with the United States Environmental Protection Agency Tier 4 final off‑road particulate matter emission standard for 25‑50 horsepower engines.

Beginning December 31, 2023:

• Owners of refrigerated warehouses and distribution centers, grocery stores, seaport facilities, and intermodal railyards (building size of ≥20,000 square feet), referred to as “applicable facilities”, are required to register with CARB, pay fees every three years, and report all TRUs that operate at their facility. Alternatively they may attest that only compliant TRUs operate at their facility.

• TRU owners are required to report all TRUs (including those based out-of-state) that operate in California to CARB, pay TRU operating fees, and affix CARB compliance labels to their TRU every three years.

• TRU owners are required to turnover at least 15% 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 are required to be zero‑emission by 31 December 2029.