You're listening to shortwave from NPR.

So East Palestine is an Ohio town of about 4,800 people near the Pennsylvania border.

And on February 3rd, just before 9pm local time, a Norfolk southern train derailed.

Nobody was hurt in the accident, but 11 of the derailed train cars contained hazardous materials.

Developers of the train derailed and toxic chemical spill in Ohio.

The National Transportation Safety Board could...

Karen Danimiller heard about the derailment from a news app on her phone.

I think I felt the sense of uncertainty that a lot of people did at the time of just not knowing exactly what had happened and where a lot of these contaminants were going.

And Karen understands chemical spills more than most.

She's an associate professor at the Ohio State University and combines her training and engineering and public health to understand difficult questions, particularly around exposures in the built environment.

I actually grew up in Northeast Ohio not too far away, maybe about an hour away from where this happened.

And there were multiple chemicals on board that train that were released onto the ground and waterways and into the air as the train cars caught fire.

And one of the top chemicals of concern is vinyl chloride.

That's the chemical used in manufacturing often to create PVC.

The compound tends to partition into the gas phase at room temperature.

So I knew when this happened that a lot of this was probably going to end up into the gas phase.

And vinyl chloride is also flammable.

So officials were worried about the train cars exploding.

So a few days after the derailment, they pursued a controlled explosion, first evacuating residents within a one mile radius, and then intentionally releasing more vinyl chloride into the environment.

Thing is, as vinyl chloride burns, it can form byproducts.

And the two compounds that were of greatest concern at the time were hydrogen chloride and fostering gas.

And both of these can be acutely hazardous.

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