Two employees of Renewable Energy Group injured during a fire at a Geismar plant Thursday evening had their conditions upgraded from fair to good on Friday afternoon, according to hospital officials.

The two employees are being treated at Baton Rouge General’s Burn Center Mid City campus.

Also on Friday, the Occupational and Safety Health Administration, or OSHA, announced it will investigate the fire, said Diana Petterson, a regional spokeswoman for the U.S. Department of Labor.

The fire started around 7 p.m. Thursday after a seal on a hydraulic pump failed, sparking a fire that was put out about an hour later.

No one else at the plant was injured and all other employees were accounted for, according to a statement by the Renewable Energy Group.

Investigations into the accident continued Friday.

“DEQ responded to the initial report, and our responders did air monitoring at the scene. They did not get any readings that exceeded levels safe for human health and the environment,” said Gregory Langley, state Department of Environmental Quality spokesman, in a Friday email.

DEQ staff returned to the facility Friday to see if any environmental cleanup needed to be done.

“If there were pollutants released off-site, then the company will have to file a report with us detailing those releases and giving details of any releases that meet or exceed the reportable quantity for that substance,” Langley said. “Those figures go to the enforcement division, which determines if any further action will be taken. It’s still early in the process, and our responders are still in the assessment phase.”

Anthony Hulen, executive director for corporate affairs for Renewable Energy, said the company’s “thoughts and prayers go out to (the two injured employees) and their families for a speedy recovery.”

Hulen said an investigation into the cause of the fire and how much damage was done to the facility is ongoing.

“The biorefinery will remain shut down until such assessment is complete and repairs can be made,” Hulen said. “We are grateful to all the first responders, other emergency personnel and law enforcement who worked quickly and professionally to ensure the safety of the public, our employees and those at surrounding facilities.”

In 2008, the plant started as a partnership between Tyson Foods, which would supply the needed oils, and Syntroleum Corp., which had the technology to turn those biological oils into fuel. The facility was completed in 2010.

The joint-venture facility, called Dynamic Fuels, hit a roadblock after it experienced financial problems and shut down in 2012.

Renewable Energy Group purchased the facility from the partners, with the sale completed in 2014. The facility started operation in October as REG Geismar.

The facility still does the same work of taking animal fats and vegetable oils, and refining the materials into about 75 million gallons of hydrocarbon diesel and naphtha a year, according to the company’s website.

Based in Iowa, Renewable Energy Group runs 10 biofuel refineries around the country, but the one in Geismar is the only one in Louisiana, with others located in Iowa, Illinois, Minnesota, Texas and Florida.

Follow Amy Wold on Twitter, @awold10.