There are more answers on why state and local leaders decided to conduct the controlled burn three days after the Norfolk Southern train derailment in East Palestine.

The Ohio EPA sent a statement to 21 News Thursday on the decision.

"Vinyl chloride is a complex compound," Ohio EPA representative James Lee said. "In the simplest of terms, an attempt to "gather and remove" the vinyl chloride that would have been released out of the pressurized environment (tank cars) would have been physically impossible as it would immediately turn into an extremely hazardous toxic gas. The act of burning the vinyl chloride as it was released literally burned off and destroyed the hazardous substance instead of allowing it to linger and spread into the air."

We reached out to Andrew Whelton, an independent expert and professor at Purdue University, said the EPA's explanation makes sense.

"Vinyl chloride likes to be in gaseous form, not liquid form. So, yes that makes sense," Whelton said. "When it warms up it transitions to a gas faster. It would have been a toxic cloud like if a chlorine gas cylinder ruptures, except way more of it. My read on it is that they wanted to destroy as much as possible at the site so if any escaped it would be in much lower quantities than without a combustion."