EPA move risks politicizing chemical risk assessments, ex-official says

According to a leaked internal memo from US Environmental Protection Agency deputy administrator David Fotouhi, the agency is changing the way it conducts chemical risk assessments to be consistent with President Donald J. Trump’s May 23, 2025, executive order “Restoring Gold Standard Science.” But critics say the proposed process is inefficient and inconsistent, and it opens the door for direct political interference with scientific findings.  

In the memo, dated April 27, Fotouhi says the EPA will no longer use the Integrated Risk Information System (IRIS) program to create hazard and dose-response assessments for chemicals. Going forward, the EPA policy offices, such as the Office of Air and Radiation, the Office of Water, and the Office of Chemical Safety and Pollution Prevention, will be responsible for all parts of the chemical-risk-assessment process. Fotouhi cites both internal and external complaints about overly conservative assessments, a need for continuity, and not adequately considering important scientific issues as reasons to end the IRIS program. He directs EPA offices to review how they’ve used IRIS information “in their specific regulatory or programmatic actions and determine if any updates or changes are warranted.” The memo says a “disclaimer” will be added to the IRIS website saying the values “are not necessarily intended for use as regulatory levels.”

The change “just opens the door for the policy to influence the scientific findings, which is something the agency has worked really hard to avoid,” says Chris Frey, assistant administrator for research and development at the EPA from 2021 to 2024, where he led the now-shuttered Office of Research and Development (ORD).

Losing the science-policy barrier at the EPA

Previously, specialists in the ORD would perform the hazard and dose-response assessments under the IRIS program for chemicals flagged for review by the policy offices. They would send these results to the policy offices, which would perform exposure- and risk-characterization assessments for each chemical and then combine all four parts for the full chemical risk assessment. The policy offices would then use the full assessment to make policy decisions. 

The EPA formally moved to close the ORD in February. The approximately 1,500 employees of the office were moved elsewhere at the EPA or left the agency.

In an emailed statement, EPA press secretary Brigit Hirsch tells C&EN, “The goal of EPA’s memo on the future of risk assessments is to empower EPA’s [policy] offices addressing air, land, water, and chemicals to conduct robust risk assessments that are directly tied to EPA’s regulations.” The assessments will now happen in the offices that inform EPA actions, with the EPA reorganization having added scientists and staff to policy offices, she says.

“This is hugely inefficient,” says Maria Doa, senior director of chemicals policy at the Environmental Defense Fund, an advocacy group. “EPA has lost many staff and significant expertise. It will be difficult to produce assessments of the same quality as IRIS assessments in a reasonable amount of time given the significant staff cuts and reassignments,” she says.

Hirsch says this shouldn’t be a problem. “The changes in how risk assessments are developed will support them being completed in a timely manner,” Hirsch says.

Instead of having dedicated staff in the science office to produce hazard and dose-response assessments, “they will fragment and silo this work into separate policy offices,” Frey says. There are a number of issues with this system, he says. One is that it’s inefficient because instead of the dedicated staff keeping track of the first parts of the risk assessment, now two different offices could assess the same chemical, each without the other knowing, which would be duplicating work. Another is that this system is going to lead to confusing results, Frey says. “Say multiple offices assess the same chemical; they very likely would come up with different findings,” he says. In this case, which office’s decision stands, and even who decides which office’s decision stands, is unclear. “The memo acknowledges that consistency was the original purpose of the IRIS program, but it doesn’t talk about how consistency will be achieved under the process that they set forth,” Frey says.

But the biggest issue is removing the protective layer between the science and regulatory decisions, Frey says. “Having a centralized, specialized staff meant that we could have world-class experts in a scientific organization that firewalls them from the [policy] offices that are developing policy,” he says. “In the policy offices, there’s a lot of pressure to come up with regulatory decisions that are often driven by the White House or the agency political leadership,” Frey says. “It’s just setting the stage for, at best, managerial interference in what the scientific findings are and, probably more likely, direct political interference.”

Scapegoating the science

The chemical industry has long been pushing to get rid of IRIS, saying the program was too conservative with its chemical assessments, “out of step” with up-to-date science, and not open to peer review and external recommendations.

The industry group the American Chemistry Council (ACC) “has highlighted concerns about EPA’s IRIS program, which has lacked scientific rigor and remains on the [US Government Accountability Office’s] High-Risk List for programs that are vulnerable to fraud, waste, abuse, or mismanagement,” says ACC vice president of regulatory and scientific affairs Kimberly Wise White in an emailed statement. She points to a letter (PDF) from the ACC and 81 industry members asking the EPA to prohibit the use of IRIS assessments in regulations and says the group strongly supported the No IRIS Act, a House bill that would make using the program illegal. The bill is in a House subcommittee and has not been put up for a vote. 

The elimination of IRIS was also outlined in the Heritage Foundation’s Project 2025, saying that use of the program was not authorized by Congress and “often sets ‘safe levels’ based on questionable science and below background levels, resulting in billions in economic costs.” 

Blaming scientific assessments for regulations they don’t like is a long-standing tactic across industries, Frey says. He points to the tobacco industry in the 1960s and ’70s and more-recent attacks on climate change regulations as examples. “All of those examples are cases where industry uses the scientific process as a proxy battlefield to suppress the science that would then potentially lead to policy outcomes that that industry disfavors,” he says. Industries regulated by chemical risk assessments similarly “use IRIS as a scapegoat for regulatory outcomes,” Frey says.

Project 2025 and the ACC both point out that the National Academies of Science, Engineering, and Medicine (NASEM) have criticized IRIS in the past. But according to NASEM reviews of IRIS from 2014, 2018, and 2021, the program made significant improvements in scientific rigor, systematic review methods, and transparency, although there was still room for improvement in many areas, NASEM said in its 2021 report. NASEM hasn’t reviewed the program since 2021 and did not provide a comment on the EPA’s memo by the time of publishing.

For a policy change of this significance, the EPA should have consulted its Science Advisory Board or commissioned another NASEM study to assess the IRIS program and find suitable alternatives, Frey says. “But they didn’t do any of that,” he says. “This was just a predetermined decision that now they’re trying to rationalize.”

What Fotouhi says in the EPA’s memo isn’t consistent with what the agency has stood for over the last 50 years, Frey says. “It’s a science-based agency where the science informs decisions, not that the decisions dictate the science,” he says, “which is basically what they’re proposing.”