Eight people were injured, one of them seriously, after an explosion and a fire at a chemical plant in south-western France on Wednesday, officials in Dordogne department have said. Media reports said the factory in the town of Bergerac made cellulose nitrate, used for gunpowder and explosives, among other things. The blast tore through a warehouse, according to the Dordogne officials, who said the fire had been contained and was not spreading. There is no danger of toxic effects on the public due to the fire and explosion, according to France Info radio broadcaster. It was not initially clear…