By Jessica Domel
Multimedia Reporter

The Environmental Protection Agency (EPA) is taking additional action to address diesel exhaust fluid (DEF) system failures.

“We took actions last year making it easier for people to use DEF and minimizing the impact of a failure of equipment, but what we’ve heard time and time again from people across the country is they are doing the right thing,” Aaron Szabo, assistant administrator for EPA’s Office of Air and Radiation said. “They’re putting DEF in their system. They’re trying to meet the laws, but the system itself is failing, and then they can’t operate their truck or their tractor. That’s not how our regulations should work.”

EPA recently demanded information from major diesel engine manufacturers on critical DEF system failures that will help EPA evaluate those failures and inform next steps.

“We’ve seen these failures. We put out guidance, but we currently don’t have enough information on what exactly is failing,” Szabo said. “So, we’ve demanded from 14 manufacturers, which cover over 80% of all the products that are made in this country related to DEF, to have them tell us what is everything that is failing within your DEF system so that we can better understand ‘is this system working properly for the American people?’”

EPA is asking for information on warranty claims, failure rates and repair information for model years 2016, 2019 and 2023 emission control products to determine whether ongoing DEF system failures are related to a specific generation of products.

Manufacturers have 30 days to turn over the information to EPA, who will then study it.

“We’re going to use that information to help us figure out a way to not punish people for doing the right thing,” Szabo said. “We’re also going to look at, because this is historical data, is there anything we need to do with the fleets and tractors that are currently on the road right now and operating? We understand it’s much more difficult to go back and fix things that have already been in progress, but our goal is to make sure Americans can do their jobs.”

The administration will then likely take additional action on DEF later this year related to what they’ve learned.

“We don’t want to destroy anyone’s business or release confidential business information, but we will be putting something else out about this in this year on this information,” Szabo said. “We’re also going to be doing more, even before a report comes out related to this new reconsideration on the rulemaking, this spring. So, we’re doing a rulemaking this spring that we’re going to be proposing that is going to be impacting future trucks and tractors.”

The agency reports it is actively working on the reconsideration of the 2022 Heavy-Duty Engine and Vehicle NOx rule. The rules set more stringent emission regulations on heavy duty vehicles starting with model year 2027.

“We believe in the Trump EPA we can grow the economy while protecting the environment,” Szabo said. “We are committed to protecting air quality and human health at the forefront of every action that we take, but there’s a lot of actions that we have found over the past decades that don’t make sense, aren’t good for Americans and don’t protect human health and air quality,” Szabo said. “Our goal is to fix all of it.”

Since 2010, EPA has required most on-road diesel trucks, tractors and construction machinery to use catalytic reduction systems that inject DEF into the exhaust systems to reduce nitrogen oxide emissions.

When a machine runs out of DEF, or the system fails, its speed drops drastically or becomes inoperable.

In August, EPA issued guidance to allow heavy duty trucks to receive a warning light, allowing them to operate for 650 miles or 10 hours after there is a fault in the DEF system.

After that time passes, the engine will be mildly impacted, allowing truck drivers additional time to address the issue.

Under the guidance, tractors see no impact to their operation for the first 36 hours after a DEF warning light. After that, there’s a slight reduction in operation.

EPA also issued guidance that starting with manufacturing year 2027, all new diesel on-road trucks must be engineered to avoid sudden and severe power loss after running out of DEF.