The fire has worried residents because of the strong, dark smoke, even as the authorities tried to assure them that air quality remained in good to moderate range.
The fire began on Sunday afternoon in a single tank at the Intercontinental Terminals Company, a warehouse in Deer Park, Texas, and quickly spread to a second tank, the company said. Officials had hoped the fire could be out by Wednesday, but now it seems the timeline is getting longer.
Four tanks burned late Tuesday night in the ITC plant, which was a reduction of seven that same day, according to Harris County.
Several school districts near the facility, including Deer Park and La Porte, have closed on Wednesdays and canceled activities outside of school due to fire conditions and weather changes.
"Weather forecasts for Tuesday evening and Wednesday call for conditions that could cause the plume of fire to directly affect our school district, and in La Porte ISD, the ISD has decided to class for Wednesday, March 20 "to cancel" according to the declaration of the district.
Schools and shops reopened on Tuesday, although some worries about the air quality in the area. ITC said that air monitoring near the facility has shown readings "well below dangerous levels" and that no injuries have been reported.
The cause of the flame is being investigated.
How They Fight Fire
A Louisiana fire department team used to fight the fire using foam and water, ITC officials said.
According to Ray Russell, spokesman for Channel Industries Mutual Aid, a non-profit organization dedicated to fire, rescue and hazardous materials in the local refining and petrochemical industries, the battle has turned from a defensive one developed into an offensive fight.
He said they believe the fire will not spread out of the 15-tank area.
"If it were up to me, we would end it today and put out the fire, but it is not," Deer Park Mayor Jerry Mouton Jr. told reporters on Tuesday. "It's a developing situation that is very volatile and changes from moment to moment."
Air Quality Issues
Ryan Sitton, Commissioner at the Texas Railroad Commission, regulates oil and natural gas in the state, said several teams, including the chemical plant and the Environmental Protection Agency, monitor the air quality.
"There is a plethora of air quality monitoring in progress all the time, and I am confident that the people in the region are currently not at an increased risk," he said Tuesday.
Despite such assurances, some health officials expressed continued concern about the effects of the fire on their health.
"I'm worried when officials expect no health impact," said Winifred Hamilton, environmental scientist at Baylor College of Medicine, opposite CNN's subsidiary KPRC-TV. "You're really talking about acute, immediate health effects, and maybe we'll see some of them."
The burning tanks contain chemicals that are used to make gasoline, including xylene, naphtha and pyrolysis gasoline, known as pygas.
Sitton said chemicals such as xylene and toluene can burn in a "disgusting spot," but there were no toxins, but particles.
Due to health concerns from residents, ITC has set up a hotline and a site for claims that believe they have suffered damage or loss from the fire.
ITC spokeswoman Alice Richardson became emotional on Tuesday when a reporter asked if the company wanted to apologize to the residents of Deer Park.
"This is not an event we wanted or planned," she said when her voice broke.
She estimates that about 30% of employees live in Deer Park.
"They fight this fire as best they can … Their family is worried, so ITC would of course apologize to each one of them."
According to ITC, the Deer Park terminal opened in 1972 and has a capacity of 2.2 million cubic meters – more than half a billion gallons – for the storage of 'all types of petrochemical liquids and gases as well as heating oil, bunker oil and distillates ".
The Texas Department of Environmental Quality and Harris County had been involved in litigation over accidents in the facility in previous years, according to court records.
Amir Vera of CNN, Emanuella Grinberg, Keith Allen, Eliott C. McLaughlin and Dave Alsup contributed to this report.