Photo: Roy Luck/Flickr

EPA Needs to Trust Its Own Scientists and Protect Us from Ethylene Oxide

, Lead science and policy analyst | March 27, 2019, 11:12 am EST
Bookmark and Share

Later this afternoon I will be providing comment to the EPA at a public hearing related to its proposed rule on facilities producing hydrochloric acid (HCl). In addition to HCl, many of these sites emit ethylene oxide, a flammable colorless gas that EPA’s Integrated Risk Information System (IRIS) determined was carcinogenic to humans back in 2016. According to the proposed rule, communities near these facilities experience a lifetime cancer risk of 600-in-1-million, which is six times EPA’s unsafe level. What is the agency doing to protect people from this risk? There is no regulatory action proposed in the rulemaking—instead, the agency is asking for comment on the use of the IRIS ethylene oxide risk value for “regulatory purposes,” calling into question the work of its own scientists in the IRIS program.

The IRIS program conducted a systematic review of toxicological and epidemiological evidence that took ten years to complete and included interagency review, input from the EPA Science Advisory Board, and public comment. It concluded that ethylene oxide is carcinogenic to humans, causing an increased risk of cancer of leukemia, lymphoma and breast cancer in women. Recently released National Air Toxics Assessment (NATA) data incorporating the new IRIS risk value revealed that the probability of developing cancer from air pollutants was beyond the EPA’s acceptable level of risk, and 91 percent of the risk can be attributed to ethylene oxide, formaldehyde, or chloroprene. The threat of cancer from ethylene oxide is real and present in so many communities across the country. In places like St. Charles, Louisiana right in the backyard of the largest ethylene oxide emitter in United States, exposure to ethylene oxide is just one toxin in a chemical cocktail of industrial exposures that the community faces. Areas like St. Charles rely on the EPA to use its own rigorous assessments of the science to set health-protective limits. EPA has no time to waste complying with industry requests to question its own science. It must act with urgency to use its own science to protect all of the people whose lives are at risk due to ethylene oxide exposure.

Here’s my full comment:

Good afternoon, I would like to thank the EPA for the opportunity to provide this comment today. My name is Genna Reed. I am the lead science and policy analyst at the Center for Science and Democracy at the Union of Concerned Scientists. The Center for Science and Democracy at UCS advocates for improved transparency and integrity in our democratic institutions, especially those making science-based public policy decisions.

I am here today to urge the agency to cease consideration of the IRIS ethylene oxide cancer risk value in the proposed rulemaking for hydrochloric acid (HCl) production source category on the National Emissions Standards for Hazardous Air Pollutants (NESHAP). Ethylene oxide is included in the rulemaking because these facilities are often collocated with those that use and emit this chemical. The rule asks for comments on the use of the updated IRIS value for “regulatory purposes.” This is ill-advised. The agency should understand best the history of the EPA IRIS assessment on the carcinogenicity of ethylene oxide issued in 2016 which incorporated public comment opportunities, interagency review, and scientific peer review by EPA’s Science Advisory Board. The IRIS risk value is based on the best available science regarding health effects from this chemical. Agency policymakers evaluating regulations for the HCl production source category should not seek to disregard this established science, especially when the facilities addressed in this rulemaking are only one part of a serious problem. Questioning the use of the IRIS cancer risk value is out of the authority of the Office of Air Quality Planning and Standards program, and to do it within a rulemaking on the source-focused proposal for an entirely separate chemical would set a dangerous precedent. Burying this request for comments in a rulemaking on HCl appears to be an attempt by the agency to limit community and expert input, while dismissing its own scientific experts within the agency.

The EPA IRIS program serves a critical scientific service to EPA and to the public, providing assessments that inform the decisions that protect us from hundreds of environmental contaminants. The IRIS program is housed in the National Center for Environmental Assessment within the Office of Research and Development and does important scientific work that is completely separate from the policymaking programs at EPA. Its placement is by design in order to ensure independent and objective assessments on hazardous chemicals that pose serious risks to Americans. The output of this office is not just important for federal policymaking, but IRIS assessments and associated toxicity values are used by state environmental and public health agencies, as well as community groups, to assess and address local risks to public health. This scientific expertise guides action that is essential to protect public health nationwide. It should be incorporated into and relied upon to set health-protective standards as EPA has done for years, rather than suddenly questioned in a rulemaking, for this or any other individual source of toxic air pollution.

Data on ethylene oxide released by the National Air Toxics Assessment (NATA) in 2018 revealed that the chemical is significantly contributing to higher cancer rates in areas surrounding chemical manufacturers and sterilizers using the chemical across the country. Just last week, the EPA issued its findings from air monitoring outside of the Sterigenics facility in Willowbrook, Illinois that was shut down by the state, comparing emissions before and after the shutdown. The monitors revealed levels 90 percent lower at the sites closest to Sterigenics, revealing the direct relationship between the facility’s operations and ethylene oxide levels. The systematic review conducted by IRIS evaluated the toxicological and epidemiological evidence available on the chemical and determined that it was carcinogenic to humans, leading to an increased risk of cancer of leukemia, lymphoma and breast cancer in women. The EPA should be taking swift action to issue ethylene oxide emissions standards to protect the over 100 communities across the country found to have cancer risk levels above the acceptable level of 100 in 1 million, as the Clean Air Act directs. The last thing communities exposed to ethylene oxide need is for EPA to try to ignore the science that has identified the problem.    

The chemical industry has attempted to undermine the work of the IRIS program time and time again, and there is now concern that the EPA itself is working to delay or halt IRIS assessments already underway, according to a recent GAO report. There is absolutely no good reason or time to question the agency’s own peer-reviewed science on ethylene oxide, which is robust and well-supported with substantial, independent evidence. In order for the EPA to meet its mission to protect human health and the environment, the EPA must rely on IRIS for its evaluations of the best available science and issue standards that best protect communities exposed to the highest emissions and associated health risks.

Thank you.

Photo: Roy Luck/Flickr

Posted in: Science and Democracy Tags: , , ,

Support from UCS members make work like this possible. Will you join us? Help UCS advance independent science for a healthy environment and a safer world.

Show Comments


Comment Policy

UCS welcomes comments that foster civil conversation and debate. To help maintain a healthy, respectful discussion, please focus comments on the issues, topics, and facts at hand, and refrain from personal attacks. Posts that are commercial, self-promotional, obscene, rude, or disruptive will be removed.

Please note that comments are open for two weeks following each blog post. UCS respects your privacy and will not display, lend, or sell your email address for any reason.

  • Hgb

    Hi– Thank you for the alert and info on the problem. Question: is there a known way to sequester/or better yet break down into non-toxic compounds the ethylene oxide? What solution can those of us in the activist sphere promote? Thanks in advance for any answer.