Author Archive

Evacuations and the Isobutene Event in Baton Rouge, Louisiana

Thursday, August 23rd, 2012

Author: Steve Stage, Atmospheric Physicist/Dispersion Modeler, IEM

I-10hazmat camera shot

Photo taken by WBRZ photojournalist Troy Gaulden early Thursday morning on I-10

During yesterday’s isobutene incident in Baton Rouge, officials issued an evacuation order for people in the immediate area. How did they decide how large an area to evacuate?

In most cases, emergency responders refer to the Emergency Response Guidebook, or ERG, which provides quick information about how to respond. For a small spill or leak of isobutene, the ERG recommends keeping people at least 100 yards away. For large spills, such as most of the contents of a tank truck, the distance increases to ½ mile. If a railcar or tank truck is involved in a fire, the risk increases substantially due to the possibility of a large explosion and people should be kept at least 1 mile away.

Having worked as an Atmospheric Scientist and Dispersion Modeler for over 30 years, my specialty is studying how toxic chemical clouds move through the air and developing computer models to predict the areas that may be at risk so that people can be protected. The evacuation distances in the ERG are determined by running computer models like those I develop while assuming the worst-case situation and seeing how far downwind the plume might be dangerous. (more…)

Isobutene Leak on I-10 in Baton Rouge, Louisiana

Wednesday, August 22nd, 2012

Author: Steve Stage, Atmospheric Physicist/Dispersion Modeler, IEM

Early this morning, a tanker truck full of the toxic chemical isobutene was damaged in an accident on Interstate 10 in Baton Rouge, Louisiana.

isobutene Hazmat PlacardYou may have noticed diamond-shaped signs, or placards, containing a number on the back of tanker trucks. These placards are required on all trucks carrying hazardous material in the U.S. The identification number on the placard makes it easy for emergency responders to quickly determine what chemical they are dealing with. For this morning’s accident, the placard read “1075,” indicating that the chemical is isobutene. Every chemical tanker truck is also required to carry Material Safety Data Sheets (MSDS) that describe the chemicals being transported. (more…)