International Paper Co. has settled another federal lawsuit stemming from a 2008 explosion that killed a contract worker at a Mississippi plant and injured nearly two dozen others.

Cases involving several injured workers are still pending.

The most recent case to settle was closed Tuesday by U.S. Magistrate John M. Roper. The terms of the agreement were not disclosed. At least three other federal lawsuits ended in settlements in September. The terms of those deals were also sealed.

The explosion killed 28-year-old Marcus Christopher Broome and injured 22 others at International Paper’s Redwood plant on May 3, 2008. The plant, about 30 miles west of Jackson, cooks fiber to make liner board, which is used for manufacturing corrugated containers.

Several workers were left with serious burns or other injuries when a 12-story recovery boiler exploded as workers tried to restart it after annual maintenance.

“The manner in which the recovery boiler was brought on line at the Redwood plant was extremely reckless and in complete disregard for the welfare of everyone working on and around the boiler that day,” said Billy Quin, an attorney for plaintiffs in several cases.

“We believe that these lawsuits and the settlements that have been reached to date have caused International Paper to overhaul the safety standards associated with the startup of recovery boilers at all of its plants,” Quin said Wednesday during a phone interview. “We can only hope that the remainder of the industry will take notice and follow suit.”

Among plaintiffs in the pending lawsuits are brothers Darren and David Clark, both contract welders from Mooresville, N.C.

The Clark brothers’ lawsuit, among other things, claims International Paper recklessly ignited the boiler when it was filled with combustible gas.

International Paper spokeswoman Amy Sawyer said Wednesday that the company doesn’t discuss litigation and wouldn’t reveal the terms of the settlements. In addition to the criminal cases in federal court, a lawsuit is pending in Warren County Circuit Court.

Sawyer has said the company works “very hard to ensure the safety of everyone at our mill every day.”

The U.S. Department of Labor’s Occupational Safety and Health Administration fined IP $77,000 in the months following the explosion for two alleged violations. For one, OSHA said IP started the boiler without adequate steam.

The agency also said in its report that there were no written procedures to determine if enough odorant was being added to the natural gas supply line. The odor is a needed additive so workers know when the highly volatile gas is present.