Ohio train derailment: What we know about the toxic chemical spill

A train derailed and caught fire in eastern Ohio, releasing hazardous chemicals into the air, soil and water – and raising concerns about health effects for residents

By Corryn Wetzel and James Dinneen

Just before 9 pm on 3 February, a train carrying hazardous chemicals partially derailed and caught fire in eastern Ohio, sending thick black smoke into the air. More than 1000 people in the town of East Palestine and surrounding areas were evacuated under orders from the state governor.

On 8 February, state and local officials announced that air quality monitoring had not detected contaminants of concern above levels considered safe for humans, and it was safe for people to return home. “The Ohio Department of Agriculture (ODA) is assuring Ohioans its food supply is safe and the risk to livestock remains low following the East Palestine train derailment,” the agency said in a statement to WKBN news.

However, some residents remain concerned about exposure to contaminants following reports of fish and chickens dying in the area. The Ohio Department of Natural Resources said the spill had killed thousands of fish following the crash, but the chicken incident has not officially been linked to the spill.

Which chemicals were on board the train?

According to the US Environmental Protection Agency (EPA), around 50 of the train’s 150 cars were affected by the derailment; 20 cars on the train were listed as containing hazardous materials, including several containing vinyl chloride, a carcinogen, according to a letter sent to Norfolk Southern Railway, the company that operated the train.

In response, the EPA set up air-quality monitoring instruments around the burning train, and took soil and water samples from surrounding streams.

The agency found that hazardous chemicals from the train – including vinyl chloride, butyl acrylate and ethylhexyl acrylate – were released to the air, soil and water following the derailment, according to the letter.

The most dangerous of these is vinyl chloride, chronic exposure to which can cause liver damage. At high concentrations, it can cause dizziness, drowsiness and headaches. According to the EPA website, these chemicals may produce an odour at concentrations below safe levels.

What actions have been taken to contain the chemicals?

Norfolk Southern contractors built a dam to contain contaminated water at the site. They also used a vacuum truck and absorbent pads to recover spilled chemicals.

On 6 February, due to concerns about a large explosion, an EPA team conducted what officials called a controlled burn of vinyl chloride from five cars, diverting the chemical into a trench and burning it off. When burned, vinyl chloride creates phosgene and hydrogen chloride, which are toxic to people at high concentrations.

The burn generated a massive fireball and column of black smoke above the site, images of which spawned the hashtag #OhioChernobyl on social media.

Is the air safe to breathe?

Air quality monitoring around East Palestine did not detect contaminants of concern in the days after the crash or following the controlled burn, according to the EPA.

Detected levels of volatile organic compounds, including vinyl chloride and butyl acrylate, have remained below levels the EPA considers dangerous to human health, though particulate matter was detected above safe levels after the derailment and following the controlled burn.

The EPA is continuing to monitor air quality around East Palestine, and is testing individual homes near the derailment as part of a “re-entry” screening process. As of 13 February, schools, the town’s library and 291 homes had been screened with no detections of vinyl chloride or hydrogen chloride. 181 homes had not yet been screened.

Is the region’s drinking water contaminated?

The day after the derailment, the East Palestine Water Treatment Plant had not been affected, according the EPA website. Water treatment operators downstream on the Ohio River also said they had detected no changes in the river at their intake, but were taking precautionary steps, such as installing another intake on a different river.

The Ohio state environmental agency and a contractor hired by the railroad company have also sampled soil at the derailment site and water in surrounding streams. Until laboratory results return from those samples, however, state officials have advised residents with private wells to drink bottled water.

On 10 February, Norfolk Southern released a plan to clean up the site, including digging wells to test and monitor groundwater.

How does the EPA determine safe levels of hazardous chemicals?

Based on general screening levels set by health agencies such as the US Centers for Disease Control and Prevention, the EPA sets a minimum risk level for different chemicals in air, water and soil. Exposure to chemicals above that screening level has potential to damage human health, though damage depends on different factors, such as the length of the exposure and the age or health of the person exposed.