Three days after a Norfolk Southern train loaded with toxic chemicals careened off the tracks in East Palestine, Ohio, town fire chief Keith Drabick gave the rail giant the green light to intentionally vent and burn five tanker cars full of vinyl chloride, a cancer-causing chemical used to make plastic.

That highly controversial move, which Norfolk Southern and others involved in the response said was necessary to prevent a potentially catastrophic explosion, released massive black plumes of noxious smoke.

In the year since, Norfolk Southern, the Environmental Protection Agency and Ohio EPA, a state agency, have repeatedly described the dramatic scene that unfolded that day as a controlled burn or controlled release language that would suggest the incineration was contained, limited and safe.

But many questions remain unanswered about the burn event, including how it will impact long-term public health, the extent to which those behind it considered alternatives and what, if anything, EPA did to try to prevent toxic chemicals from being spewed into the environment.

Kevin Garrahan, a retired EPA official of nearly 40 years, has struggled to make sense of his former agency adopting the controlled label. In the weeks after the derailment, he reached out to current EPA staffers and independent scientists to voice his concerns about the potential release of dioxins and other highly toxic chemicals, and to try to understand how EPA could have let the burn happen.

This just seems like an incredibly stupid and reckless decision, Garrahan wrote to his former colleague three weeks after the chemical burn, in an email exchange he shared with HuffPost. Am I missing something?

Later that day, Garrahan received what he described as a cryptic response. The EPA official he was emailing with mentioned the ongoing problem of OB/OD, or open burning and open detonation of hazardous materials, and said he shared Garrahans concerns about dioxins and the federal agencys response.

Our EPA and Ohio EPA at their best!! the current EPA official remarked sarcastically.

Garrahan, whose work at EPA included environmental risk assessment and hazardous waste cleanup, pressed his former colleague about the burn and EPAs public pronouncements that East Palestine was safe. He never heard back.

Dioxins are a family of extremely toxic compounds that take a long time to break down in the environment and can accumulate in the food chain. They are known to form when chlorinated chemicals like vinyl chloride combust. EPA has acknowledged that it never considered monitoring directly for dioxins during the burn event, and internal agency communications show that certain relevant EPA experts, including a top dioxin expert, were not consulted until a month after the derailment, HuffPost previously reported .

The open burning of toxic chemicals has been banned in the United States since 1980 due to risks to human health and the environment. The only exception is for explosives, primarily military munitions, that cannot otherwise be safely disposed of.

Garrahan referred HuffPost to an EPA memo , published in June 2022, outlining all the restrictions on what can legally be burned and how. The memo makes it clear, he said, that the so-called controlled burn of vinyl chloride in East Palestine meets the definition of an open burn that shouldnt have been allowed under EPAs own rules.

Garrahan views the EPA memo as a bombshell that raises questions about the burn event and EPAs disaster response.

If somebody is doing something that is illegal and they know about it, they have a duty to say, Hey, you are purposefully violating a major EPA regulation, Garrahan said. Its inconceivable that there wouldnt have been someone from the enforcement office, or general counsel, saying, Oh, Norfolk Southern wants to do an uncontrolled burn thats illegal, you cannot do that. Or if you do, youve got to go through these hoops.