ExxonMobil says its investigators determined the Feb. 11 fire at the Baton Rouge refinery was caused by air accidentally getting into a line containing hydrocarbon material and igniting it.
No one was injured in the fire.
In a letter provided to the Louisiana Department of Environmental Quality, as part of a 60-day update on the incident, ExxonMobil said the line was in an elevated pipe rack; when the fire broke out, it caused the pipe to leak.
"The pipe leak then affected other lines in a nearby elevated pipe rack," ExxonMobil said in the letter, which it provided to The Advocate.
"ExxonMobil will ensure the valves associated with the air ingress are locked in a closed position to prevent recurrence," the letter says.
Tens of thousands of pounds of unspecified flammable vapor were released during the fire, but most of the material was consumed by the blaze and none of it escaped the plant in concentrations that could have posed a risk to people, ExxonMobil has said.
ExxonMobil says tens of thousands of pounds of unspecified flammable vapor were released during a spectacular fire at its Baton Rouge refinery…