On Monday, a federal judge accepted a guilty plea from the CEO of a Port Arthur, Texas chemical company for the poisoning death of two drivers.

In July 2012, a grand jury indicted Matthew Bowman, CEO of defunct chemical company Port Arthur Chemical and Environmental Services (PACES) for the deaths of truck drivers Joey Sutter and Charles Sittig.

Prosecutors said that Bowman’s actions led to the death of the drivers.

According to the Courthouse News Service, Sutter died of asphyxia and poisoning by hydrogen sulfide inhalation and Sittig died from acute myocardial infraction.

“PACES production operations, the disposal of hydrogen sulfide wastewater, and ensuring implementation of employee safety precautions. In some cases, Bowman personally handled the investigation of work-related employee injuries, directed the transportation of PACES wastewater, and determined what safety equipment could be purchased or maintained. In the cases at issue, hazardous materials were transported illegally with false documents and without the required placards. Most importantly, the workers were not properly protected from exposure to hazardous gases. The exposure resulted in the deaths of two employees, Joey Sutter and Charles Sittig, who were truck drivers, at the PACES facility on Dec. 18, 2008, and Apr. 14, 2009. Placarding is critical to ensure the safety of first responders in the event of an accident or other highway incident. Bowman and PACES were indicted by a federal grand jury on July 18, 2012,” the Department of Justice stated.

The indictment states that Bowman’s company “did not have permits to treat hazardous waste, recycle waste oil and treat commercial wastewater during the relevant periods of this indictment.”

Last month, Bowman pleaded guilty to two of the 13 charges. He pleaded guilty to violating the Occupational Safety and Heath Act and causing Sutter’s death. In addition, Bowman pleaded guilty to making a false statement, which stemmed from “a hazardous waste manifest Bowman drafted that misidentified wastewater as coming from [Bowman’s other company] when it was, in fact, coming from PACES.

On Monday, U.S. District Judge Marcia Crone accepted Bowan’s guilty plea.

Bowman faces up to five years in federal prison and a $250,000 fine.

“The plea agreement reached today sends a strong signal to all who would illegally transport hazardous materials,” said Max Smith, regional Special Agent-in-Charge, U.S. Department of Transportation, Office of Inspector General. “Working with our law enforcement and prosecutorial colleagues, we will continue our efforts to ensure safety in the transport of these materials and vigorously pursue those who violate the law.”