An investigation was underway following an explosion in the pre-dawn hours Wednesday at the TPC Group Port Neches Operations facility east of Houston, where a tank holding butadiene exploded, injuring three people on site and temporarily shutting the Sabine-Neches Channel that connects Houston Ship Channel traffic to the Gulf of Mexico.

The TPC facility in Jefferson County was evacuated following the incident, which was reported at about 1 a.m. CT Wednesday. Assistance initially was requested from the Port Neches Fire Department as well as Huntsman, which has assets nearby. The incident also was reported to local, state and federal authorities.

About 100 emergency responders were on the scene Wednesday afternoon, with water being sprayed not on the fire itself but on the three adjoining tanks “to keep the other tanks cool so that they don’t blow up,” Jefferson County’s emergency management coordinator Michael A. Brown told NGI on Wednesday afternoon. The preventive measures seemed to be working, he said, as the plume was smaller and was “not as black as it was.”

There was no timetable Wednesday as to when the fire might be extinguished because responders were letting the product burn, Brown said.

Two employees and one contractor were said to have suffered minor injuries and were transported to Memorial Hermann in the Texas Medical Center in Houston for treatment. In addition, “there were some residents who got some glass fragments, things like that from the explosion,” Brown said. He estimated that five residents were treated for minor injuries.

A half-mile radius around the plant was under a mandatory evacuation order on Wednesday afternoon. There also was a five-mile downwind shelter-in-place order. The orders won’t be lifted “until the fire’s out,” Brown said.

A TPC spokesperson said teams were “dispatched to conduct air monitoring along the fence line of the facility and in surrounding neighborhoods through mutual aid.” The company could not yet “speak to the cause of the incident or the extent of damage, but TPC is assembling a team to conduct a full and thorough investigation.”

Following the incident, regional staff of the Texas Commission on Environmental Quality conducted handheld monitoring for volatile organic compounds, benzene, lower explosive limits, hydrogen sulfide, carbon monoxide, sulfur dioxide and radiation outside the evacuation zone. No impacts to water quality initially were reported.

Also responding was the U.S. Environmental Protection Agency’s Airborne Spectral Photometric Environmental Collection Technology, aka ASPECT, to provide fixed-winged aircraft for real-time chemical and radiological detection, infrared and photographic imagery.

TPC was working with its insurance provider to establish a claims processing hotline for area residents impacted by the event, the spokesperson said. The company remained “focused on protecting the safety of responders and the public, and minimizing any impact to the environment. We encourage area residents to stay tuned to information from Jefferson County Emergency Management and local responders.”

A Community Assistance Helpline was established by TPC for area residents impacted by the event. For information, call (866)-601-5880 to file a claim with its insurance provider.

Houston-based TPC was taken private in late 2012 by SK Capital Partners and First Reserve Corp. The Port Neches facility manufactures products derived from petrochemical raw materials such as C4 hydrocarbons for products that include butadiene and butene-1. The products are sold for specialty and intermediate segments, including synthetic rubber, fuels, lubricant additives, plastics and surfactants.

TPC also provides infrastructure and logistics services along the Gulf Coast, with manufacturing facilities in the industrial corridor adjacent to the Houston Ship Channel and Port Neches. In addition, it operates a product terminal in Lake Charles, LA.