By Erwin Seba
HOUSTON (Reuters) -A fire at Shell (LON:RDSa) Plc's Deer Park, Texas chemical plant appeared to be contained by 6 p.m. CDT (2300 GMT), said Harris County Sheriff Ed Gonzalez at a news conference.
Five people were taken for evaluation of possible injuries due to exposure to chemicals burned in the fire on an olefins unit at the Shell plant in the Houston suburb of Deer Park, Gonzalez said.
Shell said in a statement that the fire broke out shortly before 3 p.m. CDT.
"The cause of the explosion will be subject of a future investigation," Shell said.
A large column of black smoke could be seen rising from the fire in the olefins unit located near Highway 225 in southeast Houston.
All personnel at the plant at the time the fire broke out had been accounted for by 4 p.m. CDT.
Operations at the neighboring Pemex refinery were continuing despite the fire in the chemical plant, said sources familiar with the refinery's operations.
Pemex issued a statement saying the fire was not at one of its units and its emergency response team was assisting in battling the blaze.
The fire was being monitored by the Houston Fire Department and the Texas Commission on Environmental Quality had deployed monitoring units in the area to check air quality.
No shelter-in-place orders had been issued because of the fire.
Olefins like ethylene, propylene and butadiene are used to make plastics and other products like detergent and rubber.