DC Circuit rebuffs effort to dump EPA cancer risk rule for sterilizing chemical

WASHINGTON (CN) — A D.C. Circuit panel on Tuesday rejected an industry-led effort joined by Texas Attorney General Ken Paxton to overturn a federal cancer risk assessment for ethylene oxide, a chemical used to manufacture antifreeze, plastics and adhesives. 

The chemical, a flammable, colorless gas, is also used to sanitize medical and dental equipment. When inhaled in the short term, it can cause central nervous system depression and irritation to the eyes, while long-term inhalation can lead to lymphoid cancer and breast cancer. 

The U.S. Environmental Protection Agency determined in 2016 after an extensive 18-year process that the chemical was 30 times more carcinogenic than previously thought. For people living in communities near sterilization plants, their maximum lifetime risk of cancer from exposure to the chemical was four times higher than the EPA’s acceptable range. 

In 2020, the EPA then used its findings to promulgate a rule to regulate the emissions of organic chemical manufacturers for ethylene oxide along with toluene, methanol, hydrogen chloride, methane chloride and xylene. The agency estimated that, once in effect, the rule would reduce hazardous air pollutant emissions by 16,800 tons per year, and eventually reduce ethylene oxide emissions nationwide by 90%.

A three-judge panel, made up of U.S. Senior Circuit Judge Judith Rogers and Circuit judges Karen Henderson and Brad Garcia — appointed by Bill Clinton, George H.W. Bush and Joe Biden, respectively — found the industry groups had failed to prove the EPA had acted illegally in its assessment. 

Garcia, writing the panel’s opinion, said the challenges did not warrant further review of the EPA’s decision to tighten emission standards for certain natural chemical facilities.

“Petitioners dispute EPA’s assessment of the cancer risk from exposure to those facilities’ ethylene oxide emissions,” Garcia wrote. “EPA addressed and rejected petitioners’ arguments in detail, and petitioners fail to show that in doing so EPA acted arbitrarily, capriciously, or otherwise contrary to law. We therefore deny the petitions for review.” 

The challenge, brought by Huntsman Petrochemical LLC and the American Chemistry Council — with amicus briefs filed by Texas Attorney General Ken Paxton, the Chamber of Commerce of the U.S. and the National Association of Manufacturers — asked the EPA to consider an analysis by the Texas Commission on Environmental Quality. 

In its assessment, the Texas environmental agency estimated a cancer risk for ethylene oxide 3,000 times lower than what the EPA estimated. Petitioners cited the state analysis during the EPA’s comment period in March 2020, while it was still in draft form and had yet to undergo peer review. 

Huntsman Petrochemical and the American Chemistry Council brought their suit in 2020, but were put on hold as the EPA reconsidered the use of the 2016 assessment before affirming it in December 2022. Another industry group, the Louisiana Chemical Association, joined the challenge to review the EPA’s second determination. 

The 2020 rule would impact nearly 90 commercial sterilization facilities across the country, according to the EPA. California has the most facilities, with 12 in the Golden State.

According to a 2021 ProPublica and Texas Tribune investigation, the EPA had failed to communicate the potential risks caused by ethylene oxide to communities in Texas who lived near sterilization plants, which primarily included lower-income and minority communities along the Texas-Mexico border.

Analyses by the Texas Department of Health Services in 2022 found that one border town, Laredo, had higher cancer rates of acute lymphocytic leukemia, breast cancer and non-Hodgkin lymphoma compared to other parts of the state.

The petitioners’ challenge involved three prongs: the EPA’s modeling of lymphoid cancer risk of ethylene oxide was arbitrary, it committed procedural errors in the initial and re-affirmed rules and Section 7412(f) of the Clean Air Act, which allows the EPA to tighten emission standards for certain hazardous chemicals, is an unconstitutional delegation of constitutional authority. 

Garcia found that the petitioners failed to poke holes in the EPA’s decision-making throughout its assessment, finding that the agency had provided more than adequate explanations for each step. 

That included the use of data by the National Institute for Occupational Safety and Health, which tracked the cancer rates of sterilizer workers from 1938-1986, to model the current risks of lymphoid cancer from plants emitting ethylene oxide. 

Garcia also shot down an argument by the industry groups that certain studies had purportedly shown no link between ethylene oxide and lymphoid cancer in tobacco smokers. He agreed with the EPA that the studies were unreliable. 

On the petitioners’ second prong, Garcia found no merit in their argument that the EPA had failed to respond to recommendations by the National Academy of Sciences and avoided meaningful public comment on its decisions. 

Again, Garcia sided with the EPA and its explanation that it had considered such recommendations, but they would not have changed the assessment’s result. He highlighted the agency’s decision to reconsider its findings after the Texas environmental agency released its cancer-risk assessment, but again came to the same conclusion. 

Additionally, the EPA had provided ample opportunity for public comment, with two rounds during the 18-year process leading to the 2016 assessment, an initial round of public comment and further comments on reconsideration, all while responding to comments submitted outside those periods. 

Garcia again found no merit in the industry group’s argument that a part of the Clean Air Act was an “unconstitutional delegation of congressional authority.” He concluded the petitioners had failed to raise the argument during the rulemaking process, as required by the Clean Air Act’s mandatory exhaustion rule. 

Petitioners Huntsman Petrochemical and the American Chemistry Council did not respond to requests for comment, nor did the Texas attorney general’s office. 

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