Lawyers for a chemical company accused of releasing what environmentalists say are "dangerous" amounts of a chemical called chloroprene into the air in St. John the Baptist Parish say that a lawsuit against the company should be dismissed because local residents have failed to show the chemical is harmful.

Attorneys for Denka Performance Elastomer made the argument in a legal filing Friday, the first time that the company has responded to the suit brought over the summer by 13 St. John residents who live near the chemical plant.

The residents sued both Denka and E.I. du Pont de Nemours and Co., the previous owner of the LaPlace facility, in an effort to reduce or stop production of what the U.S. Environmental Protection Agency considers a "likely carcinogen."

The lawsuit, which includes St. John the Baptist Parish Councilman Larry Sorapuru as a plaintiff, seeks class-action status. It asks that U.S. District Judge Martin Feldman order the plant to stop or reduce production until emissions reach levels deemed safe by the EPA. 

The residents are not asking for compensation for physical injury, in part because the evidence linking various concentrations of chloroprene emissions and physical harm to humans is "undeveloped," their lawyers say.

However, they do seek damages for various other issues, including lost property value and "emotional distress" resulting from "release of excessive concentrations" of the chemical.

Lawyers for the plant, on the other hand, want the judge to throw out the entire suit because they say the residents have failed to show that the chemical has caused any of them "irreparable injury," or that any alleged injury to them outweighs the damage an injunction would cause the chemical plant.

Forcing the plant to dramatically reduce or halt production would be so costly that it "could ultimately result in the shuttering of the ... facility," the filing says.

Justin Marocco, a lawyer for Denka, said the plaintiffs can't prove any "ruin, vice or defect" in the plant and haven't shown how the chemical company has been negligent.

The company also says the plaintiffs filed their lawsuit too late for the court to entertain it, as the vast majority of Louisiana personal injury claims have a one-year statute of limitations.

Denka took over the plant in November 2015.

It had been operating for nearly half a century before then, with little scrutiny. It wasn't until 2010 that the EPA reclassified chloroprene as a "likely carcinogen," saying that exposure to quantities above 0.2 micrograms per cubic meter of air puts people at increased risk.

Then, in December 2016, the EPA released its National Air Toxic Assessment, which found that, because of the Denka plant's emissions, residents of St. John the Baptist Parish have the highest potential risk of cancer from airborne pollutants of any community in the country. 

Since then, EPA data have shown that chloroprene levels in St. John have at times reached up to 765 times the agency's risk threshold.

Denka pledged to reduce airborne emissions of chloroprene by 85 percent by the end of this year. The company is wrapping up a $25 million retrofitting project designed to achieve that.

In the meantime, residents, state regulators, scientists, company officials and lawyers have all engaged in intense debate over the health ramifications of chloroprene exposure.

Dr. Jimmy Guidry, the state health officer, has said that measuring the risk has been difficult, largely because "there's not a whole lot of science about chloroprene."

Variables include the proximity of the exposed person to the site, the amount of time chloroprene stays in the body and the tendency for chloroprene levels in the air to spike and dip over time.

The lawsuit was initially filed in July in Louisiana's 40th Judicial District Court, but it was moved to federal court in New Orleans in August. It's unclear when the judge will rule on Denka's motion.

The affected area laid out in the petition is bounded by Interstate 10 on the north, the St. James Parish line on the west, La. 3127 on the south and the community of Killona and the Bonnet Carre Spillway on the east.

That's the area where St. John residents and their lawyers see "a pattern of excessive measurements of chloroprene in the air," lawyer Eberhard Garrison said in July.

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