One of the materials on the derailed Ohio train is linked to a rare and “exceptionally deadly” cancer. Here’s what to know about the other substances on board.

The train that derailed in East Palestine, Ohio, on Feb. 3 was filled with several hazardous chemical compounds, documents from the railway company show — including the residue of one that is known for its link to genetic mutations. 

During the accident, 38 rail cars derailed and an additional 12 cars were damaged by a fire, according to an investigative update published by the Norfolk Southern Railway Company on Tuesday. Of the 20 hazardous material cars in the train, half derailed, the company said. 

Five of those cars were carrying vinyl chloride, a gas used to make plastic, which the Norfolk Southern Railway Company then released in a controlled burn on Feb. 6. There was particulate matter detected because of the fire, but the EPA said that it did not detect chemical contaminants of concern in the hours following. 

“Residents in the area and tens of miles away may smell odors coming from the site. This is because the byproducts of the controlled burn have a low odor threshold,” the agency said at the time. “This means people may smell these contaminants at levels much lower than what is considered hazardous.”

But according to documents published by the EPA on Monday, the cars were holding far more hazardous materials. 

In a remedial action work plan that the Norfolk Southern Railway Company submitted to the EPA on Feb. 10, the company said that the train cars that derailed contained several other hazardous materials, including butyl acrylate, ethylene glycol monobutyl ether, ethylhexyl acrylate and isobutylene. Two cars also had benzene residue. 

The company says that it has finished recovering separate-phase liquids that had collected onto nearby surface water and that air sampling continues. Here’s what to know about the materials that were on board the derailed train cars. 

Vinyl chloride 

Vinyl chloride is a known human carcinogen, according to the National Cancer Institute. The colorless manmade gas is used to make polyvinyl chloride, commonly referred to as PVC, a type of hard plastic resin. According to the Institute, the gas is linked to “an increased risk of a rare form of liver cancer” known as hepatic angiosarcoma. That type of cancer accounts for only 2% of liver tumors, and according to a 2018 journal publication, is “exceptionally deadly.” The average life expectancy for those who are diagnosed is just 10 months. 

It is also linked to primary liver cancer, brain and lung cancers, lymphoma and leukemia. 

The gas can be consumed by humans through inhalation, and the institute says that if a water supply becomes contaminated with the substance, the gas can also make its way into homes that use that water source for showering, cooking or laundry. 

Five train cars were carrying this substance at the time of the accident, according to a report published by the EPA on Sunday. According to a 2006 publication by the Agency for Toxic Substances and Disease Registry, the substance breaks down in the air within a few days, forming other chemicals such as hydrochloric acid, formaldehyde and carbon dioxide.

Officials were worried that the burn would lead to phosgene and hydrogen chloride in the air, the former of which is a “major industrial chemical” that is a poisonous gas at 70 degrees Fahrenheit and was “used extensively during World War I as a choking (pulmonary) agent,” according to the CDC. 

“Among the chemicals used in the war, phosgene was responsible for the large majority of deaths,” the agency said. 

Hydrogen chloride can irritate the eyes, throat, skin and nose, according to the CDC.

As of Monday, there have been “no detections of vinyl chloride or hydrogen chloride” found in screened homes in the area, although more than 180 homes had yet to be screened. 

Butyl acrylate 

Butyl acrylate is a combustible liquid that can cause problems through inhalation, skin absorption, ingestion, and skin or eye contact, according to the CDC. If someone comes into contact with the liquid, their eyes, skin and upper respiratory system could all be irritated. They could also get dermatitis and experience breathing difficulties, according to the CDC. If it’s swallowed, medical attention is needed immediately. 

According to the New Jersey Department of Health, it can pose a “serious” hazard to health, although the National Fire Protection Association says it only poses a “moderate” risk. Repeatedly being exposed to the liquid can cause permanent lung damage, according to the New Jersey state agency.  

One train car was carrying butyl acrylates, according to a report, and lost its entire load during the accident. The report says that the car commodity has since been stabilized, and the railway company’s work plan says that two 20-cubic-yard containers of absorbents impacted by butyl acrylate and petroleum have been staged on-site to remove it. 

A memo from Cincinnati City Manager Sheryl Long on Feb. 10 said that low levels of the compound were found in samples of the Ohio River “downstream of the incident.” 

Ethylene glycol monobutyl ether 

Otherwise known as 2-Butoxy Ethanol, this colorless liquid can cause harm to the eyes, skin, kidneys and blood, according to the CDC, and people can be exposed through inhalation, skin absorption, ingestion and skin or eye contact. It’s used as a solvent in paint strippers, thinners and household cleaners, 

In 2015, the EPA said that the compound has “potential to cause serious or irreversible chronic health effects in humans, specifically, liver toxicity and concerns for hematological effects.”

Ethylhexyl acrylate

This compound is also used to make plastics, as well as protective coatings and to treat paper. According to the National Library of Medicine, it could irritate the skin and respiratory system, and if inhaled in a concentrated amount, it could also cause drowsiness and convulsions. It’s also listed as being “possibly carcinogenic to humans,” although more evidence for such is needed. 

When inhaled, the substance can cause shortness of breath and that higher exposures can “cause a build-up of fluid in the lungs,” according to a fact sheet from the New Jersey Department of Heath.

“Ethyl acrylate is a reactive chemical and an explosion hazard,” the document adds. 

The one train car that was carrying ethylhexyl acrylate during the accident was breached and the amount of product that is still in the car is marked as “pending.” 

Isobutylene

This colorless gas, which is transported as a “liquefied gas under its own vapor pressure,” according to the National Library of Medicine, is used to help create rubber for tires and inner tubes. When inhaled in moderate concentrations, the library says that it can cause dizziness, drowsiness and even unconsciousness. If touched, it can also irritate the skin and eyes, and its liquid form could cause frostbite. 

One car was carrying isobutylene, and there was “some flame impingement,” according to the report, but “no signs of breach.” 

Benzene

Benzene was not being actively carried on the train when it derailed, but officials said that there was residue of the substance from past shipments. Documents from the company show that two tank cars labeled as empty had been used to carry the compound. Those tanks, according to the document, were damaged by the fire, but were not breached.  

The New Jersey Department of Health lists benzene as a potentially “severe” hazard to human health – the highest of the hazard ranking system used. According to the agency, it’s both a carcinogen and mutagen, meaning that it can cause genetic mutations, and should be handled “with extreme caution.” 

“Benzene can cause headaches, dizziness, nausea and vomiting. Convulsions and coma, or sudden death from irregular heartbeat, may follow high exposure,” the department says. “Repeated exposure can cause damage to the blood cells.”