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A Train Derails in Paulsboro, N.J., Releasing 23,000 Gallons of Toxic Vinyl Chloride Gas

6 Comments

Seven train cars derailed when the bridge over the Mantua Creek collapsed Friday morning. Four tank cars containing vinyl chloride were dumped into the creek. Nearby residents were evacuated and schools were locked down. Nearly 20 people complained of respiratory distress from the vinyl chloride vapor that leaked from the tank cars. (Photo: Rae Lynn Stevenson/South Jersey Times. All rights reserved.)

Seven train cars derailed when the bridge over the Mantua Creek collapsed Friday morning. Four tank cars containing vinyl chloride were dumped into the creek. Nearby residents were evacuated and schools were locked down. Nearly 20 people complained of respiratory distress from the vinyl chloride vapor that leaked from the tank cars. (Photo: Rae Lynn Stevenson/South Jersey Times. All rights reserved.)

UPDATED DECEMBER 7, 2012 — On November 30, 2012, a train transporting the chemical vinyl chloride derailed while crossing a bridge that collapsed over Mantua Creek, in Paulsboro, N.J., near Philadelphia. Four rail cars fell into the creek, breaching one tank and releasing approximately 23,000 gallons of vinyl chloride.

Local, state, and federal emergency personnel responded on scene. A voluntary evacuation zone was established for the area, and nearby schools were ordered to immediately take shelter and seal off their buildings.

Overview of the overturned train cars carrying vinyl chloride

A detailed overview of the overturned train cars carrying vinyl chloride in New Jersey’s Mantua Creek. The rail car in the foreground is being used as an anchor to stabilize the derailed cars. (Conrail Derailment Incident Command)

Vinyl chloride, which is used to make plastics, adhesives, and other chemicals, is a toxic gas. During this accident, most of the chemical was released directly to the air, and response teams are still determining how much might have dissolved in the creek’s waters, which feed into the Delaware River.

U.S. Coast Guard Sector Delaware Bay contacted NOAA’s Office of Response and Restoration (OR&R) and requested scientific support for this environmental and public health threat.

The OR&R scientific support team worked to address early concerns about the air hazard, centering around possible health effects, evacuation decisions, proper protective equipment for responders, impacts to the Philadelphia airport two miles away, and reactivity between vinyl chloride and another rail car containing ethyl alcohol.

OR&R develops software products responders use to address these issues: ALOHA, an air dispersion model, and CAMEO Chemicals, a hazardous material database.

OR&R had a Scientific Support Coordinator (SSC) at the scene of the spill to work with the Coast Guard as they attempted to salvage the derailed cars from the creek and collapsed bridge. While the SSC departed on Dec. 6, a NOAA incident meteorologist remains at the incident command post to provide custom weather forecasts for the affected area, for air monitoring and to identify safe operating conditions for the crane work and other salvage operations.

OR&R’s Emergency Response Division remains involved from NOAA’s Seattle offices, where they are investigating potential problems which might occur if vinyl chloride accidentally is discharged into the water as salvage operations continue.

In addition, two scientists from NOAA’s Center for Operational Oceanographic Products and Services (CO-OPS) have been dispatched to Paulsboro to deploy a current meter and forecast the tides specifically for Mantua Creek (which is driven by tidal flows) to schedule safe crane and dive operations. To help the National Transport Safety Board’s investigation into this incident, CO-OPs scientists also will recreate the tidal cycle conditions during the time of the incident.

Removing the derailed train cars is a logistically complicated process. The Coast Guard coordinated the removal of the last 600 gallons of vinyl chloride from the breached tank by using acetone and suctioning out the vapors before attempting to move the tank. Next, the response team is bringing in cranes and barges to remove the rail cars and bridge debris from Mantua Creek.

The evacuations have ended and families slowly are returning to their homes near the creek. The process has been slow because each family is accompanied by a police officer and an air monitor, who goes into the home first to check for the presence of vinyl chloride before allowing families inside.

Author: Office of Response and Restoration

The National Ocean Service's Office of Response and Restoration (OR&R) provides scientific solutions for marine pollution. A part of the National Oceanic and Atmospheric Administration (NOAA), OR&R is a center of expertise in preparing for, evaluating, and responding to threats to coastal environments. These threats could be oil and chemical spills, releases from hazardous waste sites, or marine debris.

6 thoughts on “A Train Derails in Paulsboro, N.J., Releasing 23,000 Gallons of Toxic Vinyl Chloride Gas

  1. what did the dispersion modeling indicate about the concentrations of VC in the air in Paulsboro after the spill within a half mile and mile radius of the spill? What did the reactivity model indicate about how the chemical would react with ethanol, with the water in the Mantua creek, and with the humidity n the air?

    • Thanks for your interest, Mark. We’ve posed your questions to the responders and chemists who were involved and knowledgeable about this case, and here’s what they said:

      Because of the situation, a federal government coordinating group called the IMAAC used a different air dispersion model (not our NOAA one) after the initial vinyl chloride release. Eventually, however, the U.S. Environmental Protection Agency provided air sampling to monitor vinyl chloride concentrations. Later in the incident (after the IMAAC was no longer involved), we used our model ALOHA to look at several different release scenarios (none of which occurred) in order to provide the Unified Command and local authorities with information to help make operational decisions, like defining areas where responders need to wear protective gear and weighing shelter in place versus evacuation for local residents.

      Another one of our chemical response tools, CAMEO Chemicals, provides information about chemical hazards, including reactivity. You can use it to verify that vinyl chloride does not react with ethanol. However, vinyl chloride has the capacity to undergo explosive reactions when exposed to heat or certain other chemicals. Common in the chemical industry, vinyl chloride is an example of a monomer, which is the molecular building block of materials like plastics (polymers).

      Under the right conditions, vinyl chloride will rapidly polymerize, or start forming chains of molecules, creating polymers, along with significant amounts of heat and pressure as gas byproducts break down and form. Uncontrolled, these reactions can lead to a serious runaway reaction with high temperatures and pressures. During transport of monomers, these materials typically are mixed with low levels of antioxidants (acting as “inhibitors”) to prevent these polymerization chain reactions. But over time and at higher temperatures, these inhibitors start to break down, increasing the danger of polymerization (risks that increase during an accident like this). In this case, the inhibitors also could have broken down more quickly because they dissolve more easily in water and ethanol. Fortunately, no evidence was found of a hazardous reaction between these materials. Still, extreme caution should be used in any contamination event, and the material should be presumed to be unstable until testing and consultation with experts. If you’d like more detail, one of our chemists would be happy to follow up with you.

      • Sorry just saw this. Yes I would like to understand more about what the IMAAC, ALOHA and CAMEO models actually showed and what it means that acid halogens could be formed in reaction to water

  2. Hi Mark,

    Here’s a reply to your questions from Mark Miller, our CAMEO Program Manager:

    The IMAAC, when activated, is under the authority of the Department of Homeland Security (DHS) so you would need to contact that organization for more details. I am also not sure what you mean when you ask about acid halogens forming in a reaction to water. Could you provide more details?

    As we stated in our previous reply, later in the incident (after the IMAAC was no longer involved), we used our model ALOHA to look at several different release scenarios (none of which occurred) in order to provide the Unified Command and local authorities with information to help make operational decisions. If you are interested, contact orr.cameo@noaa.gov, and I will send you the ALOHA scenario documents we provided to the Unified Command. ALOHA is freely downloadable from the web and contains extensive information in its Help section. You can find it here: http://response.restoration.noaa.gov/oil-and-chemical-spills/chemical-spills/response-tools/aloha.html

  3. I’ve seen the interim exposure map that IMAAC generated following the spill, which appears to conclude there was a 90% confidence level that AEGL-3 or AEGL-2 outcomes are possible within what looks like a fairly significant zone surrounding the spill site in Paulsboro. Who would be a knowledgeable individual to contact to help understand the significance of this conclusion, as well as the modeling information that was used that led to this conclusion. Any guidance would be greatly appreciated. Thanks!

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