Letter to the Editor: EO risk value fundamentally inaccurate

The U.S. Environmental Protection Agency (EPA) recently published its 2014 National Air Toxics Assessment (NATA), which includes a presentation about impacts of Ethylene Oxide (EO) emissions at various facilities around the country. The impacts the report suggests are fundamentally inaccurate and rely on faulty numbers that dramatically overstate risks. No change to any federal or state emissions limit has been proposed based on the IRIS value.

The NATA presentation’s conclusions are based on a number calculated by the Integrated Risk Information System (IRIS) that is meant to signal risk of health impacts. NATA combines that number with expected emissions to suggest risks in general areas.

However, the number IRIS calculated is drastically lower than commonly accepted studies, so the NATA’s suggestions are dramatically inflated.

In fact, a peer-reviewed scientific study determined IRIS’s risk value is 19,000 times lower than the naturally occurring levels of EO created by our bodies and much lower than levels found in clean, ambient air. That means the IRIS number suggests normal human metabolism and breathing clean, ambient air could be sufficient to cause risk of health impacts.

After the NATA report was published, The Ethylene Oxide Panel of the American Chemistry Council (ACC) reviewed its suggestions and found many errors with its scientific methods and information. In response, the ACC filed a formal Request for Correction with EPA in late September petitioning the agency to replace the IRIS risk value with an alternative number supported by the best available science and correct the NATA presentation’s suggestion of impacts in communities around the country.

Many chemical manufacturing facilities around the United States, including several in Louisiana, have safely produced and used EO, an intermediate product used to make plastics, polyester fibers, household cleaners and other products, for decades. Emissions limits for facilities in Louisiana are set by the Louisiana Department of Environmental Quality (LDEQ) and based on its annual ambient air standard for EO, 1 microgram per cubic meter, which is more stringent than many other states’ limits. The IRIS-recommended exposure level is an average of .003 microgram per cubic meter over a lifetime.

Over the past 40 years, the Louisiana Tumor Registry has compiled cancer incidence and mortality rate information in each parish across the state. The tumor registry released its latest report on Cancer in Louisiana in September, which concluded that there are not more incidences of cancer in the 7-parish industrial corridor including Ascension, Iberville, East Baton Rouge, St. Charles, St. James, St. John and West Baton Rouge Parishes compared with the Louisiana average. Historically, cancer incidence along the industrial corridor has not differed significantly from statewide rates.

LCA will continue to work with ACC, LDEQ and EPA to correct inaccuracies in the NATA presentation and ensure any risk value for ethylene oxide is based on best available science and protective of human health.

Greg Bowser
President, Louisiana Chemical Association


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