The Department of Justice and the EPA have filed a civil complaint charging three Mississippi-based companies with importing and selling more than 78,000 engines made in mainland China that do not meet federal air pollution standards. The complaint also alleges that the companies failed to (i) provide buyers with the full emission-system warranty required by the Clean Air Act for all of the non-road engines that were sold, (ii) install proper emission-compliance labels on many of the engines and (iii) fully respond to EPA's administrative information requests issued under the Clean Air Act. The DOJ and EPA are seeking civil penalties up to the maximum amount authorised by law as well as actions by the companies to remedy the violations and mitigate any excess pollutant emissions caused by the violations. The EPA estimates that the non-compliant engines have contributed to excess emissions of more than 150 tonnes of hydrocarbons and nitrogen oxides and more than 5,000 tonnes of carbon monoxide.

A joint agency press release states that this lawsuit is part of an ongoing effort to ensure that imported non-road engines and equipment comply with the Clean Air Act's emissions standards. The CAA prohibits any non-road engine from being imported and sold in the U.S. unless it is covered by a certificate of conformity indicating that the engine meets applicable emission standards. To obtain such a certificate, a manufacturer must submit an application that describes the engine and its emission control system and demonstrates that the engine will meet applicable federal emissions standards. After obtaining a certificate of conformity, applicants must also comply with specific labelling, warranty and other requirements to ensure that the engines will meet emissions standards in use.