Officials in Jefferson County are telling the city's residents to evacuate amid air quality concerns a week after two explosions and a fire at a chemical plant in Port Neches.
The evacuation order is voluntary, and was issued "out of an abundance of caution," the county said in a statement. Prior to the order, which was issued late Wednesday night, residents had been advised to shelter in place. Port Neches has about 13,000 residents.
"It is recommended you leave the area as quickly and safely as possible as a protective action," Wednesday night's statement said.
Multiple reports, including from the Associated Press, say the order was prompted by elevated levels of butadiene in the air. According to the federal Occupational Safety and Health Administration, butadiene is an extremely flammable colorless gas often used to make synthetic rubber. Exposure to low doses of the gas can irritate the eyes, nose, throat and lungs. Higher doses can cause more serious issues such as vertigo, nausea, low blood pressure and fainting.
"Unified Command is continuously monitoring air in the community and will provide an update once an all clear is given," the county's statement said.
The facility where the explosion occurred is owned by owned by Houston-based Texas Petroleum Chemicals, or TPC Group. The fire at the plant was contained on Nov. 29, according to the Associated Press.
The facility has been considered a high priority violator by the U.S. Environmental Protection Agency for more than two years. State data shows the facility has reported spewing more air pollution than allowed by its government-issued permits five times this year, including hundreds of pounds of butadiene.