An NDA for fire response? That's kinda odd

Well, this is a little unusual: 

COUSHATTA, La. – Federal investigators are now looking into an explosion at a Red River Parish plant Thursday afternoon that left two workers burned. 

Juan Rodriguez, deputy regional director for the U.S. Department of Labor, said Friday afternoon that the Occupational Safety and Health Administration is investigating the explosion at ADA Carbon Solutions. No additional details could be released since it's an ongoing investigation, he said. 

Other than confirmation of an explosion and injured workers, not much more information was available by anyone else contacted by KTBS. 

The Red River Parish Sheriff’s Office confirmed there were injuries in the blast at the plant located on Red River Mine Road east of state Highway 1. KTBS requested additional details but have yet to hear back from the sheriff's office.

Acting Red River Parish Fire Chief Jeremy Neal said his firefighters responded to a call at the plant and there were “a few” injuries. Firefighters were on the scene for four hours. No firefighters were injured.

However, Neal said he was prohibited from providing detailed information about what happened because of a confidentiality contract signed by the previous fire chief. The contract, which he said other area fire districts also signed, prevents the fire district from talking about what goes on on ADA Carbon Solutions’ property.

Bienville Parish Fire District Wards 4&5 also responded for mutual aid but likewise are bound by the same confidentiality agreement, Neal said.

Looks like ADA Carbon makes activated carbon for trapping mercury in coal plant flue gases. I imagine that this sort of thing is hazardous and offers plenty of opportunity for explosions - certainly unusual to have the local fire folks sign a NDA, and it's kind of surprising that they went along with it. Developing...