French prosecutors said Thursday they had charged the French subsidiary of US chemicals firm Lubrizol over a massive fire at a factory in northern France last September that spewed a vast cloud of acrid smoke across the region. Lubrizol is owned by American billionaire Warren Buffett. Lubrizol France was charged with pollution and failing to meet safety standards for potentially dangerous industrial sites, the Paris prosecutor's office said in a statement. edy-bl-jt/cb/mlr/har