No injuries reported in fire at Westlake Chemical _lowres (copy.030819)

A fire in a refrigeration unit at Westlake Chemical Corp.'s vinyls plant in Geismar sends up a dark plume of smoke June 4, 2014, sparked by leaking organic peroxide. The reactive chemical that must be kept cool. Westlake has had a series of leaks in 2018 and early 2019.

GONZALES — An unexpected shutdown at the Westlake Chemical vinyls plant in Ascension Parish overwhelmed an emergency scrubber with toxic chlorine earlier this month, leading to the release of a small amount of the gas and sending a handful of workers at a downwind plant to the hospital, state regulators said.

The chlorine gas release is at least the ninth accidental leak since Jan. 1, 2018, that prompted the notification of emergency authorities. It was the first of that kind this year at the 185-acre plastics facility in Geismar, regulatory filings show.

Over the past 14 months, the complex off La. 30 has seen accidental releases of hydrochloric acid, vinyl chloride, ethylene, chloroform, ethylene dichloride, benzene and other toxic, flammable or cancer-causing chemicals, according to Westlake reports to the state Department of Environmental Quality. The leaks have been blamed on loose flanges and faulty pipes, shorting blowers, prematurely activating emergency relief valves, other flawed equipment or shutdowns.

State closes probe into Westlake fire in Geismar _lowres

Some environmentalists said they were worried Westlake isn't properly maintaining its equipment.

"We want industry to be a good neighbor, and people begin to get very afraid when they have ongoing upsets in a short amount of time," said Marylee Orr, director of the Louisiana Environmental Action Network.

A few of the accidental leaks since January 2018 were so small that Westlake wasn't required to notify emergency authorities, though the company did as a courtesy, a common industry practice.

But others were far larger, including one Aug. 29, 2018, when corroded pipes released a mix of chemicals into the air for 30 minutes at Westlake's vinyl chloride monomer unit, known as the VCM-E unit, the company told DEQ.

An estimated 4,196 pounds of ethylene dichloride, a flammable and poisonous gas, escaped along with 20 pounds of poisonous chloroform and 11 pounds of vinyl chloride, a flammable, sweet-smelling gas that federal health authorities say a known human carcinogen, according to Westlake estimates reported to DEQ.

All those chemicals were released in amounts that required emergency reporting to authorities. The ethylene dichloride was released in an amount more than 40 times greater that the level that would require reporting, the Westlake estimates say.

An array of other toxic and flammable chemicals, including benzene, another known human carcinogen, were released in far smaller amounts, the reported estimates say.

Vinyl chloride monomer is a key building block of polyvinyl chloride, or PVC, the ubiquitous plastic used in household and commercial plumbing pipes around the world.

Westlake, a publicly traded company headquartered in Houston that has Louisiana operations in Geismar, Lake Charles and Plaquemine, is the third largest PVC producer in the world, stock market filings say.

The Geismar plant employs 140 people and is part of an extensive industrial complex composed of a number of companies located along the Mississippi River in Ascension Parish.

Chip Swearngan, a spokesman for Westlake, said the company has a safety culture that puts it in the top quarter in industry performance and that has garnered the Geismar plant numerous safety awards from industry groups, including a safety excellence award from the Vinyl Institute in 2018 for Westlake's 2017 performance.

The company also has programs to verify the mechanical integrity of its equipment and conduct preventive maintenance and has an emergency response team to respond to incidents. 

"Westlake Chemical takes safety very seriously," Swearngan said.

DEQ spokesman Greg Langley said Friday none of the 2018 leaks have led to referrals to the agency's Enforcement Division, though he suggested some of them could still be in a phase where DEQ is waiting for Westlake to determine the cause of the incidents.

Westlake's Geismar plant previously ran afoul of state and federal regulators in recent years over other, earlier accidental releases that led to fires at the VCM unit in March 2012 and at a refrigeration unit in June 2014. 

The company later reached settlements with the U.S. Environmental Protection Agency and U.S. Occupational Safety and Health Administration to deal with air, workplace and chemical safety violations from those fires for a combined $144,400, online records show. Part of the EPA violations stemmed from the failure to inspect equipment frequently enough.   

Westlake and OSHA are still investigating the March 4 chlorine leak, spokespersons said. DEQ officials say the company will be required to provide more detailed explanations of what happened in the coming months. 

According to the latest information available, the leak happened about 5 a.m. after an "upset" in the chlor-akali unit, where Westlake makes chlorine and caustic soda, DEQ officials said.

An estimated 7.2 pounds of chlorine was released after the unit shutdown. Westlake wasn't required to report the release but did so anyway, DEQ and Westlake say.

Yet, even that small amount of the denser-than-air gas, which was once used to root out soldiers from World War I trench lines because it hugs the ground, prompted five workers at the neighboring Air Liquide facility to be evaluated for gas exposure. Three wound up at the hospital but were later released without treatment, Westlake said Friday.

Westlake or DEQ has not said whether the March 4 leak was preventable.

Like most of the other accidental leaks in 2018, Westlake told DEQ that the air release in August 2018 from the corroded pipe could not have been anticipated. Yet, Westlake also told DEQ that it would increase its inspection frequency for the pipe after they it is replaced.

Wilma Subra, a chemist and LEAN technical adviser, said corroded pipe and faulty equipment are preventable failures with proper maintenance, adding that the company's claims to the contrary are "ridiculous." 

DEQ records show seven of the 2018 leaks came from failures or shutdowns at the same vinyl chloride monomer unit. The other was in the PVC unit.

Westlake also officials have told DEQ that none of 2018 the leaks caused injuries or escaped the fence line of their site, though at least one, in February 2018, forced workers at Westlake and next-door Hexion to shelter in place.

But, Subra said that the company's own reporting to DEQ suggests that the risk of more serious problems may lie in the future without better maintenance.

"It seems like that sooner or later, it's going to get off-site and impact people," Subra said.

According to stock marketing filings and company officials, Westlake started a $140 million expansion of its Geismar plant last year that includes an upgrade of the VCM unit that's expected to be finished this year.

Swearngan said the company is also started a maintenance turnaround on the VCM unit Feb. 10 that is nearing completion. He described the turnaround as "proactive routine maintenance" that has "some tie-ins to the expansion."

Follow David J. Mitchell on Twitter, @NewsieDave.