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.

A small chlorine gas leak from the Westlake Chemical vinyls plant in Geismar on March 4 was the ninth accidental release since the start of 2018. Here are the others:

Feb. 6, 2018: A loose pipe flange in the vinyl chloride monomer unit leaked nearly 51 pounds of hydrochloric acid. Amount is less than would be required for reporting, but Westlake did so anyway. 

March 10: High temperatures in a quench column at the VCM unit triggered the preventable release of 4.5 pounds of vinyl chloride and nearly 14 pounds of chloroform, both amounts that require reporting due to the chemicals' toxicity. Carbon tetrachloride, benzene and host of other chemicals released in far smaller amounts.

March 21: A balky emergency relief valve in the polyvinyl chloride unit prematurely released 2,102 pounds of vinyl chloride, a known carcinogen.

May 13: Malfunctioning temperature gauge at VCM unit sparks emergency valve to release 737 pounds of flammable ethylene. 

May 17: A release of ethylene dichloride and other chemicals happened after incinerators designed to destroy chemicals tripped at VCM unit. Amounts were less what would be required for emergency reporting, though Westlake did so anyway. 

May 30: Primary incinerator blower suddenly failed and caused chemical incinerator to trip, releasing a mix of raw vapors of flammable, toxic or carcinogenic gases, including 672 pounds of ethylene dichloride, 281 pounds of vinyl chloride, 817 pounds of chloroform and 145 pounds of benzene, a known carcinogen.

July 31: VCM unit releases estimated 621 pounds of hydrogen chloride. Westlake wasn't required to report release because of small amount but did so anyway. Other details not available.

August 29: Corroded pipes in VCM unit break loose and release thousands of pounds of toxic chemicals, including 4,196 pounds of flammable and poisonous ethylene dichloride. Westlake deems failure not preventable but promises to step up inspections.

Sources: Westlake Chemical; Louisiana Department of Environmental Quality.

Follow David J. Mitchell on Twitter, @NewsieDave.