“Right now, the question is whether or not we can actually get in and assess the full scale of the impact from an environmental standpoint to an infrastructure stand point,” Federal Emergency Management Agency (FEMA) Administrator Brock Long said at a news briefing.
“By all means, yes, the plume is incredibly dangerous.”
Local authorities had a different view, insisting the resulting smoke presented “no danger to the community at all.”
At a news conference Thursday, Assistant Harris County Fire Chief Bob Rayall said different grades of organic peroxides in a semi-trailer caught fire not long after midnight. Rayall said the fire emitted a 30- to 40-foot flames and black smoke.
Rayall did not refer to any blasts, but Harris County Fire Marshal spokeswoman Rachel Moreno said there had been “small explosions.”
Harris County Sheriff Ed Gonzalez says some deputies suffered irritated eyes from the smoke.
Arkema said the company had no way to prevent fires because the plant is swamped by about 6 feet (1.83 m) of water due to flooding from Harvey, which came ashore in Texas last week as a powerful Category 4 hurricane, knocking out power to its cooling system.
The company said it was notified at about 2 a.m. by the Harris County Emergency Operations Center of two explosions and black smoke coming from the plant in Crosby.
“Organic peroxides are extremely flammable and, as agreed with public officials, the best course of action is to let the fire burn itself out,” the company said.
The Harris County Sheriff’s Office said on Twitter the deputy had been taken to hospital and nine others drove themselves to the hospital as a precaution.
“Remain well clear of the area and follow directions of local officials,” The National Weather Service said after the explosions, noting that winds were from the west to the east from 4 to 9 mph.
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.
“We want local residents to be aware that product is stored in multiple locations on the site, and a threat of additional explosion remains. Please do not return to the area within the evacuation zone,” Arkema said.
Shares in the French chemical company fell 2.3 percent in trading on Thursday.
Richard Rowe, chief executive officer of Arkema’s North America unit, told reporters on Wednesday that chemicals on the site would catch fire and explode if they were not properly cooled.
The company said it opted not to move chemicals before the storm but made extensive preparations. The plant is 25 miles northeast of Houston.
Rowe said a fire would not pose any “long-term harm or impact.”
The plant has been without electric service since Sunday. It lost refrigeration when backup generators were flooded, and workers transferred products from warehouses into diesel-powered refrigerated containers.
The company said some refrigeration of back-up containers has been compromised because of high water levels. It said it was monitoring temperature levels remotely.
The Federal Aviation Administration has temporarily barred flights near the plant because of the risk of fire or explosion.
This report includes material from Reuters and The Associated Press.
