What's burning at the chemical plant in Deer Park?

DEER PARK, Texas – A massive fire erupted at a Deer Park chemical plant Sunday, sending a thick plume of black smoke towering into the air.

The fire originally engulfed two tanks at the Intercontinental Terminals Company location near Tidal Road and Independence Parkway. On Tuesday, officials said that a temporary loss of water pressure allowed the fire to spread to a total of eight tanks.

Here are the answers to some of the most common questions people have asked.

What is burning?

According to ITC, the tanks that are on fire contain toluene, naphtha, xylene and pyrolysis gasoline.

Toluene is used in the production of nail polish remover, glues and paint.

Naphtha and xylene are components of gasoline that are also used in the production of base oil used for machine lubricant.

Pyrolysis gasoline, known in the industry as "Pygas,"  is a byproduct of a chemical process involving naphtha.

What is in the air?

Air monitoring is ongoing. 

According to ITC, low levels of particulate matter have been detected.

“A single volatile organic compound detection has been found 6 miles southwest of the facility,” ITC officials said in a written statement. “These readings are currently well below hazardous levels.”

Deer Park officials said in their 6 a.m. Monday update that no air quality readings have exceeded action levels.

Jeff Lindner, a meteorologist for Harris County, said that winds blowing from the east are pushing the plume to the west. He said that the plume was at an elevation of nearly 4,000 feet above Houston, but that will likely lower to about 400 feet by Tuesday morning. He said that the quality of the air would become a problem if the plume made it to the ground.

ITC officials released air quality data Monday from the company being used to conduct mobile monitoring -- Center for Toxicology and Environmental Health, LLC.

What symptoms should I watch for?

According to Harris County Public Health, the most common symptoms to chemical exposure are coughing, difficulty breathing, burning, irritation and redness in your eyes, nose and throat. Some people may also experience headaches, nausea or dizziness.

“The elderly, children and those who have respiratory issues may be adversely impacted,” Harris County health officials said in a written statement Sunday. “Please seek medical attention if you are experiencing these symptoms or if they worsen.”

Could there be an explosion?

According to ITC, the risk of an explosion is minimal, but precautions are being taken to further reduce the risk.

“Emergency responders continue to work on controlling the fire using foam and are working to prevent the fire from spreading further,” ITC officials said in the statement.

Officials said pumping operations are underway to reduce the amount of combustible material in the tank containing naphtha.

How long will the fire burn?

State fire officials said the blaze will burn until the fuel has been exhausted or is removed.

ITC officials said operations are underway to pump out the combustible material in the naphtha tank.

One official said Monday that it could take as long as two days before the fire is extinguished.

Additional firefighting resources were being brought to the site Tuesday morning, officials said.

Which roads are closed?

State Highway 225 was closed in the immediate aftermath of the fire, but was reopened to traffic Monday morning. 

Parts of Independence Parkway will remain closed until further notice, Deer Park officials said.

Has anyone been injured?

According to ITC, everyone is accounted for and no injuries have been reported.