CARB Regulatory Training on Transport Refrigeration Units (MS507)

Transport Refrigeration Units (TRUs) are used on semi-trailers, truck vans, shipping containers, and rail cars. Most TRUs are diesel-powered. Although TRU engines are relatively small, significant numbers of these engines congregate at distribution centers, truck stops, and other facilities, resulting in exposure to diesel particulate matter (PM) and health risks to those that live and work nearby. To reduce the risks of exposure to diesel PM from TRUs, owners, operators, dispatchers, and distribution centers must comply with the TRU Air Toxic Control Measure (ATCM).