Smoke and an explosion were reported on Thursday at the flood-hit Arkema SA chemical plant in Crosby, Texas, following floods caused by Hurricane Harvey.
The company evacuated remaining workers at the damaged plant on Tuesday, and Harris County ordered the evacuation of residents within a 1.5-mile (2.4-km) radius of the plant, which makes organic peroxides used in the production of plastic resins, polystyrene, paints and other products.
Houston TV station Fox 26 reported the explosion.
A police officer has been taken to hospital after inhaling fumes produced by the double blast at about 2am local time. Nine other people drove themselves to hospital as a precaution.
“We want local residents to be aware that the product is stored in multiple locations on the site, and a threat of additional explosion remains,” Arkema said in a statement.
“Please do not return to the area within the evacuation zone until local emergency response authorities announce it is safe to do so,” the French company added.
The facility holds large amounts of sulfur dioxide, a toxic chemical, and methylpropene, a flammable gas. It had been battered by floodwaters from Hurricane Harvey, with levels reaching 6ft within its perimeter.
— NWS Houston (@NWSHouston) August 31, 2017
The company had warned of a potential explosion in an update on its website on Wednesday afternoon.
Rich Rowe, its North America chief executive, said: “Our Crosby facility makes organic peroxides, a family of compounds that are used in everything from making pharmaceuticals to construction materials.
“But organic peroxides may burn if not stored and handled under the right conditions. At Crosby, we prepared for what we recognised could be a worst case scenario. We had redundant contingency plans in place.
“Right now, we have an unprecedented 6ft of water at the plant. We have lost primary power and two sources of emergency backup power.
“As a result, we have lost critical refrigeration of the materials on site that could now explode and cause a subsequent intense fire. The high water and lack of power leave us with no way to prevent it.”
— Courtney Fischer (@CourtneyABC13) August 31, 2017
Arkema submitted a plan to the federal government in 2014 outlining a worst-case scenario that said potentially 1.1 million residents could be affected by such…