PASADENA, Texas (KTRK) -- Investigators believe they've pinpointed the cause of an explosion and massive fire at a Pasadena plant on Wednesday -- and they say it was an accident.
One person was injured in the blast around 11:45 a.m. at the INEOS Phenol plant along Highway 225 near the East Beltway.
Houston TranStar cameras captured the large explosion and fireball. Smoke and flames could be seen from miles away.
Harris County Pollution Control said there weren't any impacts to air quality in the area.
"Fortunately, we have good wind blowing whatever was up high and aloft in the flame, and the fire, the smoke," Dr. Latrice Babin said. "So, we are not expecting there to be any impact."
In a statement from INEOS Phenol, the company said the driver of a third-party bulk truck sustained injuries in the explosion. He was conscious, alert and stable at the hospital, according to Harris County Sheriff Ed Gonzalez.
"The INEOS Phenol family has the individual and his family in their thoughts," the company said.
There's no word on the worker's identity or the nature of his injuries. Everyone at the plant was accounted for, officials said.
ORIGINAL REPORT: Crews extinguish massive fire after 'bleve explosion' reported at Pasadena chemical plant
The Harris County Fire Marshal's Office said the explosion was triggered as liquified petroleum gas was being offloaded from one tanker to another through a hose, and the first tanker had an unintentional leak.
"The LPG (liquid petroleum gas) was a mixture of propylene and propane, a raw material used in the production of cumene. Cumene is an intermediate chemical used to produce phenol, which is a refined product used to produce everyday consumer goods and construction materials," INEOS Phenol said.
The company said it's unclear exactly why the LPG ignited during the offloading process.
Harris County Commissioner Adrian Garcia described the incident as a "bleve explosion" involving over-the-road tanker trucks, not rail cars.
"When you have a liquid petroleum or a liquid propane inside a tank, the fire that occurred outside can heat the tank to the point that the inside is boiling and the pressure is so great that it overcomes the release mechanisms, the safety valves, and the container holding it explodes," Harris County Fire Marshal's Office Chief Investigator Mitchell Weston said when asked to describe a bleve explosion.
INEOS Phenol said the fire was extinguished by 1 p.m. Wednesday.
Residents who live around the plants in east Harris County said they're used to it.
"Well, you know, this is our life," Arnanoldo Contreras said. "We have to keep on going, whatever you have to do."
According to the company's website, INEOS makes several products related to oil and gas, as well as other chemicals such as PVC, plastic chemicals and chlorine.
INEOS Phenol said the facility is currently shut down as crews work with local law enforcement to determine the root cause of the incident.
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