A minor amount of hydrogen chloride was released at Axiall's Westlake plant on Thrusday, which sent 22 contractors to the company’s medical office.
Alan Chapple, Axiall’s director of communications, said all 22 contractors were sent to the clinic for observation and were released.
“They were sent there as a precautionary measure,” he added.
Chapple said the release occurred at one of the plant’s units. He added that it was contained within 12 minutes.
Chapple said he did not know how much of the hydrogen chloride was released but it reached a level that was not reportable.