The Conrail train cars fell from the bridge near N. Commerce St. around 7:00 a.m. Friday.
Officials say that bridge was just rebuilt two years ago.
After the crash, officials say one of the tanks failed and vented the chemical vinyl chloride. That chemical is believed to have completely escaped the tank, leaving it empty.
However, there is still cause for concern. The cars will have to be removed and there is a risk that chemicals could be released from another car during that process.
The train was pulling a total of 84 cars on its way to a facility in Logan Township. Six cars were involved in the crash and four were carrying vinyl chloride, but so far only one has leaked.
A total of 28 people are being treated at the hospital. The early word is that those people were suffering respiratory problems. 11 people were taken by ambulance and 17 walked in on their own. So far, no one has been released.
Monitoring in the area shows the air is safe. Still, local residents and schools in the area remain under a "shelter-in-place" order as this incident continues to unfold.
An NJ DOT spokesman had a message for the residents of Paulsboro during a news conference on Friday, saying "This is a time of caution and you should remain very, very attuned to announcements as they occur."
There were no mass evacuations, NJ DOT said. There was a limited evacuation in the immediate area of the crash, involving people who worked in the area and possibly some homes.
According to the EPA's website, short-term exposure to vinyl chloride can cause dizziness, drowsiness, and headaches.
Long-term vinyl chloride exposure has been shown to increase the risk of a rare form of liver cancer, the EPA says, and has classified vinyl chloride as a Group A human carcinogen.
Stay with Action News and 6abc.com as more information becomes available.