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.