(CNN)At least two people were killed and dozens were injured after an acetic acid leak at the LyondellBasell facility near La Porte, Texas, officials said Tuesday.
"The leak has been isolated, and air monitoring at the facility perimeter indicates no offsite impact. There is no shelter in place or other protective actions being recommended at this time," the La Porte Office of Emergency Management said in a tweet.
"Right now we can confirm two fatalities," Harris County Fire Marshal's Office spokeswoman Rachel K. Neutzler told CNN. At least four people sustained burns, according to a statement from LyondellBasell.
In addition to the two fatalities at the scene, there were 35 people who suffered minor symptoms, five who were transported to the hospital with more serious symptoms and two people who were in critical condition, Neutzler told CNN.
The leak involved a chemical acid used in food grade vinegar, Harris County Fire Marshal Laurie Christensen said during a news conference.
Those exposed to the chemical can experience irritation and burns to the skin and difficulties breathing and swallowing, she said.
The investigation into what caused the leak is ongoing, but investigators have determined there was no explosion or fire at the facility, the fire marshal's office said in a tweet.
According to LyondellBasell, all personnel have been accounted for. LyondellBasell's earlier statement said there was "an acetic acid leak" at the facility.
The marshal's office said it turned the investigation over to the Harris County Precinct 8 Constable's Office, which will have jurisdiction.
The first report of a problem came in at around 7:30 p.m., La Porte's public information officer Lee Woodward told CNN.
"LyondellBasell La Porte requested support from La Porte EMS regarding a mass casualty incident at their facility," he said.
The area is in unincorporated Harris County, next to the city of La Porte, Woodward said.
LyondellBasell specializes in plastics, chemicals and refining.