The Environmental Protection Agency (EPA) announced Tuesday the largest voluntary recall of medium- and heavy-duty trucks following the finding of faulty emissions control systems.

The recall of roughly 500,000 trucks made from 2010 to 2015 by Cummins Inc. will be to replace a defective emissions control component that the EPA found causes excess emissions of nitrogen oxides. The emissions lead to smog and collect in the atmosphere.

ADVERTISEMENT

The recall is not connected to the "defeat device" systems previously found in Volkswagen cars meant to permanently mask emissions, which ultimately lead to a multibillion-dollar settlement with the EPA.

The administration hailed the recall as an effective partnership between the EPA and the private sector.

"Today’s recall is a great example of how government and industry work together to protect health and the environment.” said Bill Wehrum, assistant administrator of the EPA's Office of Air and Radiation.

“This is the way it’s supposed to work. Our follow-up testing seeks to make sure that pollution controls work throughout an engine’s useful life. And, if they don’t, then companies step up to set things right.”

The EPA has faced strong criticism from Democrats and environmentalists for being too industry-friendly and for lacking transparency under previous its administrator, Scott Pruitt Edward (Scott) Scott PruittJuan Williams: Swamp creature at the White House Science protections must be enforceable Conspicuous by their absence from the Republican Convention MORE.

The agency's new acting administrator, Andrew Wheeler, on Monday sent a staff-wide memo laying out steps the agency is taking to increase transparency, a move that's seen as an effort to differentiate himself from his predecessor.

Cummins is already involved in another recall of nearly 232,000 Dodge Rams. In total about 770,000 trucks will be recalled.