Eight months after a LaPlace company asked the U.S. Environmental Protection Agency to soften its findings about the danger of exposure to chloroprene emissions, the federal agency has instead doubled down on its message that the pollutant could be putting thousands of local residents at risk.

In a 54-page report released late last month, the agency said the chemical that the Denka Performance Elastomer plant produces is so toxic that some scientists think it should be classified as definitely cancer-causing, rather than a “likely carcinogen.”

Denka has objected to the EPA’s assertions and claims the agency is using faulty science to assess the chemical’s danger to workers and community members.

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Robert Taylor II, 76, called 911 after he smelled a strong chemical odor coming from the East near here his home on East 26th Street in Reserve seen here in Reserve, La. Thursday, Dec. 22, 2016. The smell came from the Denka Performance Elastomer plant, formerly DuPont, that has been tasked with reducing the emissions by 85 percent of a chemical, chloroprene, that the EPA has found to be "likely" carcinogenic.

Plant officials "continue to be in dialogue" with the EPA to ensure that the agency's future requirements are based on "accurate, scientifically sound information,” plant manager Jorge Lavastida said last month.

The exchange comes nearly three years after the EPA said residents around the plant are at the highest risk in the country for cancer from airborne pollutants.

Denka says EPA estimates for chloroprene risk in St. John the Baptist Parish are too high; agency says science is sound

The Denka plant is the only U.S. manufacturer of neoprene, a synthetic rubber made using chloroprene for durable, waterproof products like wet suits, orthopedic braces and electric insulation.

St. John the Baptist Parish residents have been living near chloroprene production for about 50 years.

In recent years, the plant's emissions have resulted in air quality testing, a report outlining potential Clean Air Act violations and even a class-action lawsuit aimed at stopping the plant’s production.

Denka finishes installing equipment to reduce chemical emissions at LaPlace plant

The controversy stems from a stricter classification of chloroprene that was handed down by the federal agency in 2010, when the EPA asserted that a certain level of exposure to the chemical — specifically, more than 0.2 micrograms per cubic meter of air every day for a lifetime — puts people at increased risk of getting liver or lung cancers.

Then, in late 2015, the EPA released an air toxins study that found residents of St. John Parish have the highest potential risk in the country of cancer from airborne pollutants. It traced that risk to the LaPlace plant, putting the facility under increased scrutiny.

Since then, the EPA has conducted air monitoring throughout the parish as state and federal officials attempt to better understand the health problems the chemical could cause over the short and long terms.

Air monitoring over a single year, measured between 2016 and 2017, showed that the chemical plant at times exposed residents to between 12 and 58 times the amount of chloroprene the agency said could cause increased risk of cancer.

Plaintiffs in Denka suit: EPA should ignore company's request to change chloroprene guidelines

Denka pledged to lower its emissions by 85 percent through a $30 million retrofitting plan that wrapped up Jan. 11.

Data that will measure the results of that program should be available within the next month.

The chemical company, however, has said it can’t possibly lower chloroprene amounts to below the level defined as risky by the EPA, even with the help of advanced air pollution control measures.

Instead, plant officials in June asked the EPA to withdraw its assessment under the Information Quality Act, a law meant to ensure that federal agencies disseminate accurate data.

The company pointed to a review by third-party scientists with the organization Ramboll Environ, who found basic scientific issues with the EPA's conclusions.

Instead of saying chloroprene is “likely to be carcinogenic to humans,” the company wanted the EPA to say chloroprene has “suggestive evidence of carcinogenic potential.” Lavastida said the agency was creating "unnecessary public alarm."

The EPA formally denied the company’s request in January, saying the present classification is "appropriate and clearly justified based on the animal and genotoxicity data.”

"Six (out of six total) peer reviewers commented that the characterization of chloroprene as 'likely to be carcinogenic to humans' was appropriate," agency officials said. "In fact, two reviewers further suggested that the strength of the epidemiological evidence was sufficient to change the descriptor to 'carcinogenic to humans.’ "

Denka's lawyers argue that St. John residents offer no proof that chloroprene caused harm

Several residents who live near the plant have sued Denka. The company's attorneys have said the residents have no proof that any of the health issues mentioned in their suit were caused by chloroprene.

A hearing over Denka's motion to dismiss the lawsuit is scheduled for March.

In the meantime, Denka officials said in January they were planning to appeal the EPA's decision and noted they were in compliance with all permit requirements.

They added that Denka's health is important to the financial health of the region, as over 75 percent of its 235 employees live in the River Parishes and the company contributes about $80 million a year to the local economy.

"Denka Performance Elastomer is committed to regulatory compliance and protecting the environment as well as the health and safety of its employees and community as a whole," Lavastida said.

Follow Della Hasselle on Twitter, @dellahasselle.