HOUSTON (ICIS)--The US Chemical Safety Board (CSB) has begun an investigation into the explosions at TPC Group's butadiene (BD) plant in Port Neches, Texas, a spokeswoman for the federal agency said on Monday.
Spokeswoman Hillary Cohen said an investigator from the CSB arrived at the site on Friday two days after blasts rocked the plant and caused a mass evacuation.
Cohen said three more investigators were headed there and should arrive at TPC on 2 December.
The CSB is an independent federal agency that conducts investigations on chemical accidents. Its board does not issue citations or fines, but does make safety recommendations to companies, industry organisations, labour groups and regulatory agencies.
Meanwhile, a third distillation tower fell at the TPC plant on Monday morning, according to media reports.
The latest collapse happened early on Monday. One report quoted Jefferson County Judge Jeff Branick as saying that the collapse caused no effects outside of the plant.
One distillation tower collapsed on the day of the explosion. Another fell on Saturday.
Authorities have said the blaze has been contained. The site had nine fires burning at one point after the initial explosion.
Authorities on Friday lifted the evacuation order, though the plant site continued to react to the fires, with distillation towers falling down.
The plant's two lines can produce a total of 426,000 tonnes/year of BD, which ICIS estimates accounts for 16.4% of US capacity and 2.7% of global capacity. TPC also stores methyl tertiary butyl ether (MTBE) at the site.
The explosion happened at a tank with finished BD located in the site's south processing unit.
The subsequent fire involved the unit 10 processing unit and the block 5 spherical tank unit of the complex.
Following the blast, Huntsman shut down a propylene oxide (PO) unit at its complex that is nearby the TPC plant.
Huntsman did not specify which other units it may have shut down as a precaution. The company also makes MTBE at Port Neches, and it could use feedstock provided by the TPC complex.
Huntsman is still running its crackers and some of the units downstream from it, the company said.
Lion Elastomers shut down production of its emulsion synthetic butadiene styrene (ESBR) plant in Port Neches as a precaution.
Meanwhile, TPC Group declared force majeure (FM) on BD from Port Neches.
The fire at the TPC plant comes amid a price slump for BD, caused by rising supplies from the new fleet of US crackers and weaker demand from downstream rubber markets.
The Port Neches explosions prompted the fourth investigation of chemical plant incidents in Texas this year by the federal agency.
In late October, the CSB updated its investigation into the Intercontinental Terminals fire in Deer Park, Texas earlier this year, saying the massive blaze stemmed from a naphtha storage tank that had no emergency shutoff valve.
Additional reporting by Al Greenwood
Photo credit: JDrago Photo/Shutterstock
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