Westlake Chemical Geismar site (copy)

Westlake Chemical in Geismar. 

Gaseous hydrochloric acid leaked from a pipe at Westlake Chemical's vinyl chloride monomer unit in Ascension Parish, creating a visible haze Wednesday afternoon to the north of the plant across a highway, company officials said Thursday.

Weather conditions Wednesday, rain and wind out of the south/southwest, combined with the small leak to create the haze across La. 73 in Geismar, Westlake officials said in a statement.

Greg Langley, spokesman for the state Department of Environmental Quality, said Thursday that one early concern raised by the hydrochloric acid leak during those weather conditions was that the acid could mix with moisture in the air to form an acid cloud.

But, according to a state report, Westlake officials told DEQ they don't believe an acid cloud ever actually formed from the leak.

As a precautionary measure, however, company officials called for a local emergency incident and the temporary closure of La. 73. A shelter-in-place order was also issued for employees at a neighboring plant to the northwest of Westlake's facility, which is at the corner of La. 73 and La. 30.

"To the company’s knowledge, there have been no injuries reported as a result of the incident," the Westlake statement says.

The DEQ report on the incident says Westlake's air monitoring did not detect off-site escape of the chemical. 

Westlake officials said the leak at the VCM unit, which is used to make a key chemical component of polyvinyl chloride plastic, was discovered about 3:30 p.m. Company officials blamed the leak on a faulty pipe flange, the DEQ report says. 

Since 2018, Westlake has had a few other chemical leaks due to equipment failures, including of hydrochloric acid, past DEQ reports show, but company officials said earlier this year the plant went through significant maintenance.

Company officials have said they maintain a strong safety culture at the 185-acre facility off La. 30.

Westlake officials worked with local officials to shut down the VCM unit and stop the source of the leaking gas. The problem was secured within about an hour, the company said.

Chip Swearngan, a Westlake spokesman, said emergency response crews sprayed water around the leak, a chemical industry best practice known as a "water curtain," to suppress the hydrochloric acid fumes.

Swearngan said the company is still calculating how much hydrochloric acid escaped but will report their findings by a state deadline. 

Email David J. Mitchell at dmitchell@theadvocate.com

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