Transport Refrigeration Units (TRUs) are refrigeration systems powered by diesel internal combustion engines designed to refrigerate or heat perishable products that are transported in various containers, including semi-trailers, truck vans, shipping containers, and rail cars. Although TRU engines are relatively small, ranging from 9 to 36 horsepower, significant numbers of these engines congregate at distribution centers, truck stops, and other facilities, resulting in the potential for health risks to those that live and work nearby. Since diesel particulate matter has been identified as a toxic air contaminant, the ARB adopted an Airborne Toxic Control Measure (ATCM) for TRUs and TRU generator sets on February 26, 2004. Information about this rulemaking is available on the ARB website.

Those interested in receiving more information may contact the TRU ATCM toll-free helpline — 888-TRU-ATCM (888-878-2826).

Formal Rulemaking Activity

The TRU ATCM was adopted by the Board on February 26, 2004. To view the formal documents related to this rulemaking including the formal regulatory language, please click here.

General Information

USEPA Waiver – Please be advised that the U.S. Environmental Protection Agency (USEPA) has not made a determination to deny the California Air Resources Board’s (ARB) waiver application for the Transport Refrigeration Unit (TRU) Airborne Toxic Control Measure (ATCM). ARB urges TRU fleet owners to continue to press forward with their plans to comply with the TRU ATCM. ARB has many pending waiver requests at USEPA. The waiver that USEPA denied is not related to the TRU ATCM waiver application. ARB will broadcast to the TRU list serve if and when there is any news about the TRU ATCM waiver application. On March 28, 2005, ARB requested the USEPA to grant a waiver of preemption under the federal Clean Air Act. USEPA expected to make a decision by the end of 2007, but has taken no action to date. Pending the EPA decision, ARB will continue to implement the TRU ATCM in accordance with state law.

Q&A for Rebuilt/Remanufactured TRU Engines – This document provides clarification of the requirements for rebuilt engines (and their labeling) that may be used to comply with the TRU ATCM.

TRU ATCM Status Update – January 2008–This document provides a brief overview of and period update on the implementation of the TRU ATCM

Transport Refrigeration Unit Tutorial – PowerPoint slides with textual script are provided to help interested parties understand the TRU ATCM.

How Do I Comply with the TRU ATCM? – Revised July 2007. This document provides logic flow charts and references to assist with TRU ATCM compliance.

Frequently Asked Questions and Guidelines for Compliance with the TRU ATCM – Revised July 2007. This document provides guidelines for compliance in a question and answer format.

TRU ATCM Information Brochure #2 – Released October 2007. What TRU and TRU Generator Set Owners and Operators Need to Know to Comply with the TRU ATCM. (Spanish version)

TRU ATCM Information Brochure #1 – Released April 2005. This document provides simple language about the regulation. (Spanish version)

Ash Handling (Hazardous Waste) Guidelines – Theseguidelines provide information for handling ash from diesel particulate filters.

TRU Advisory – Facility reports for the TRU ATCM were due to ARB by January 31, 2006. ARB has begun enforcement action against those facilities that failed to report. To learn more, use this link to review the TRU Advisory.

Hardcopy Forms for Facility Reporting Requirements of TRU ATCM – This link allows the download of hardcopy forms for compliance with requirements of TRU ATCM. Download the business form relative to the parent company (partnership, LLC, or corporation). A facility and TRU inventory form is required for each facility operating in California and applicable to the requirements of the TRU ATCM. As shown on the forms, a toll-free helpline is available for TRU inquiries — 888-TRU-ATCM (888-878-2826).

TRU ATCM Information Brochure – This document provides simple language about the regulation. (Spanish version)

Regulatory Advisory – This document provides introductory information about who the regulation applies to and how to comply.

Final Regulation Order – This document is the formal regulatory language.

TRU Listserve – To learn how to sign up for the TRU listserve.

TRU Verified Diesel Emission Control Strategy Information

HUSS FS-MK Series diesel particulate filters have been verified as a Level 3 verified diesel emission control strategy (VDECS) for use with 2006 and older model year off-road engines that are not equipped with either diesel oxidation catalysts or exhaust gas recirculation systems. Level 3 VDECS reduce diesel particulate matter emissions at least 85 percent. The HUSS FS 40-MKS and FS 50-MKS models could be used on all makes and models of TRU engines to comply with the TRU ATCM’s Low Emissions TRU In-Use Performance Standard (LETRU) or Ultra-Low-Emission TRU In-Use Performance standard (ULETRU). The HUSS FS-MK series DPFs use a silicon carbide wall-flow filter with a fuel burner for regeneration. The FS-MK system is compliant with the 2009 NO2 emission requirements (< 20% increase), and as such is designated as a Level 3 “Plus” system. Specific conditions for which the FS-MK Series has been approved may be found in the Executive Order which has been posted on the ARB website.

Thermo King’s PDPF™ Level 2 Plus (greater than or equal to 50 percent reduction in PM plus complies with the 20 percent NO2 limit before January 1, 2009) flow-through filter verification allows this VDECS to be used to comply with the Low-Emission TRU In-Use Performance Standard (LETRU) on most Thermo King trailer TRUs using 1985 through 2002 model year engines of the following models: Isuzu D201, Yanmar 4TNE82-TK and –ETK, and Yanmar 4TNE86-TK and –ETK. The Thermo King PDPFTM consists of a catalyzed knitted wire mesh flow-through filter with backpressure control system, an exhaust system insulation package, and a backpressure warning indicator. TRU owners should read about the specific conditions for which the PDPFTM has been approved in the Executive Orders which has been posted on the ARB website.