An investigation Criminal_investigation conducted Action by the United States Environmental Protection Agency ( EPA ) concluded in 1996 that the explosion Attack was initiated Process_start by an accelerated thermal decomposition reaction Response as `` a direct result of unsafe operating Being_in_operation procedures and conditions '' at the plant .

Tests showed Presence that Newson had a blood alcohol level of 80 mg/100 ml—the level at which one can be prosecuted Legality for drink-driving , though the alcohol may have been produced by the natural decomposition process over four days at a high temperature .