Trump Administration Dismantles the EPA's Independent Science Arm and Sidelines Its Chemical-Risk Program

Details

Over the course of 2025 and early 2026, the Trump administration dismantled the Environmental Protection Agency's Office of Research and Development (ORD), the agency's primary scientific branch since its founding in 1970. ORD's roughly 1,500 scientists—chemists, toxicologists, biologists, and epidemiologists spread across about 10 laboratories from North Carolina to Oregon—were laid off, offered deferred resignations, pressured to retire, or reassigned to other parts of the agency. The office that remained was replaced by a smaller unit placed directly under the administrator, ending a structure designed for more than half a century to keep the agency's science insulated from political and industry pressure. In a parallel step, the agency retired the Integrated Risk Information System (IRIS), the 40-year-old program whose chemical toxicity assessments form the scientific foundation for pollution standards across the country and abroad.

According to the New York Times, more than 1,500 researchers were laid off, reassigned, or pushed to retire, leaving roughly 124 scientists who faced a choice in spring 2026 between abandoning their research or relocating to different parts of the agency or the country. An internal memo reviewed by the Times said future research in one office would have to align with agency and administration priorities.

What ORD Did

Since 1970, ORD served as the EPA's in-house research arm, mandated under the 1978 Environmental Research, Development, and Demonstration Authorization Act to provide the best available science for the agency's regulatory decisions. Its work spanned developing methods to detect and measure chemicals, studying how toxic substances move through air and water, running controlled human-exposure studies, and funding external research grants to academic scientists.

The office operated what former officials describe as the world's only laboratory specializing in controlled human-exposure studies—experiments measuring the health effects of vehicle exhaust, wildfire smoke, ozone, and other pollutants on volunteers. That laboratory has closed. ORD scientists had also created a technique to search for fluorinated chemicals in water supplies, which they used to detect the toxic compound GenX in North Carolina's Cape Fear River Basin; many of those researchers have been reassigned. During the Biden administration, ORD research into the health consequences of climate change found, among other results, that extreme heat could significantly worsen dementia. The reorganized agency no longer has researchers dedicated to climate science.

Jennifer Orme-Zavaleta, who led ORD during the first Trump administration, told the Times that the agency had destroyed a well-performing organization that made a difference both domestically and globally, and that there is no longer anyone with a comprehensive, independent perspective watching over the quality of the country's environment and health.

Timeline of the Dismantling

The breakup unfolded in stages over roughly a year.

In May 2025, Administrator Lee Zeldin announced a reorganization and the creation of a new Office of Applied Science and Environmental Solutions (OASES).

On July 18, 2025, the agency formally announced the elimination of ORD alongside a reduction in force that would bring total EPA staffing down to 12,448—a cut of more than 3,700 positions, or nearly 23 percent of the workforce since January 2025. Agency documents reviewed by Democrats on the House Science Committee indicated that as many as 1,155 chemists, biologists, and other scientists could be laid off. The move followed a Supreme Court ruling that cleared the way for the administration's broader downsizing of the federal workforce. Officials said the changes would ultimately save the agency nearly $750 million.

The plan drew objections that were not confined to one party. When word of the closure first leaked in spring 2025, Representative Chellie Pingree of Maine and Senator Jeff Merkley of Oregon, both Democrats, warned in a joint letter that stripping the EPA of its independent research capacity would turn the agency into a rubber stamp for corporate interests. More notably, the Senate appropriations subcommittee overseeing the EPA—chaired by Republican Lisa Murkowski of Alaska—said in a report that it was appalled by the plan and cautioned that shuttering ORD could pose immeasurable risk to public health and the environment. Zeldin eliminated the office anyway.

On September 22, 2025, Zeldin sent a memo to staff launching the reorganization in earnest and confirming that OASES would sit within the Office of the Administrator rather than operate as an independent division.

On February 13, 2026, the EPA notified Congress of the formal elimination of ORD and the reallocation of its remaining resources. According to former employees who spoke to Chemical & Engineering News, about 150 staff remained in ORD that day; most received letters saying they would be reassigned in March, without being told which offices they were going to.

By the time the New York Times published its account in late April 2026, only about 124 researchers were left.

OASES and the Loss of Independence

The central structural change is not merely that there are fewer scientists, but that the science has lost its independence. ORD operated as a standalone branch; OASES is housed directly under the administrator and supervised by political appointees. Critics argue this is the point.

Nicole Cantello, president of the union local representing EPA Region 5 employees, said the placement of OASES directly under the administrator subjects the agency's research to political interference. Andy Miller, a former senior science adviser for ORD, noted to C&EN that the word "research" does not appear in the new office's name, and argued the administration was trying to eliminate exactly the kind of work that points out unresolved problems. As of early 2026, the top two positions in OASES remained without permanent appointees.

The EPA maintains it is still complying with its statutory obligation to operate a research arm. Spokeswoman Carolyn Holran told C&EN the restructuring reflected a commitment to gold-standard science, and spokeswoman Brigit Hirsch told the Times the agency had improved science by embedding researchers within program offices and was still conducting human-health and climate-change research. She called the notion of scientific losses an absurd narrative.

Sidelining IRIS

The most consequential follow-on action came on April 27, 2026, when Deputy Administrator David Fotouhi issued an internal memo directing that the agency would no longer use the Integrated Risk Information System to develop chemical hazard and dose-response assessments. Established in 1985, IRIS had functioned as the federal government's principal repository of chemical-specific toxicity values, with assessments covering more than 550 chemicals.

IRIS itself never wrote regulations. It answered two scientific questions—whether a chemical can harm human health and at what level of exposure—and sent those findings to the program offices, which estimated real-world exposure and set the actual rules. That separation, as environmental engineering professor and former ORD assistant administrator H. Christopher Frey wrote in The Conversation, let IRIS scientists act as neutral referees insulated from the offices that weigh economic and policy consequences. Under the new approach, the program offices—Air and Radiation, Water, Chemical Safety and Pollution Prevention, and others—will conduct all four parts of risk assessment themselves.

Fotouhi's memo directed EPA offices to re-review past assessments that relied on IRIS, advised outside parties to do the same, and ordered a disclaimer added to the IRIS website stating its values are not necessarily intended for use as regulatory levels. The reach extends well beyond the agency: as the law firm Holland & Knight noted, state agencies fold IRIS values into cleanup and air-toxics standards, and other federal and international regulators use them as benchmarks. ProPublica reported that countries without the resources to fund their own chemical reviews rely on IRIS reports to guide regulation.

The Case for the Changes

The administration and its allies frame the overhaul as a structural correction, not an attack on science.

The Project 2025 chapter on the EPA, written by former agency chief of staff Mandy Gunasekara, called ORD's scientific enterprise bloated and outcome-driven, and the Heritage Foundation argued that IRIS lacked congressional authorization and often set safe levels based on questionable science, resulting in billions in economic costs. Gunasekara said in an interview that researchers in the office were biased toward environmentalist viewpoints and that characterizing the reorganization as eliminating science was misleading.

Industry has long objected to specific IRIS assessments. The American Chemistry Council and 81 member companies asked the EPA to prohibit the use of IRIS values in regulation and backed the No IRIS Act, a House bill that would make such use illegal. The ACC notes that IRIS sat on the Government Accountability Office's high-risk list. Defenders point to IRIS's assessments of ethylene oxide—a sterilant whose cancer risk value the agency tightened in 2016 to a level industry groups call far below background human levels—and formaldehyde as examples of conclusions they consider overly conservative.

Notably, even some science-focused observers see merit in decentralization. The American Council on Science and Health, which is generally sympathetic to industry, wrote that returning hazard assessment to the program offices could let the EPA use more current data and methods better suited to each office's statutory duties—a needed correction to what had become a slow-moving choke point—while cautioning that without a coordinating mechanism the agency risks producing inconsistent toxicity values for the same chemical across different programs.

The EPA's Hirsch told the Daily Signal that the change would let offices develop more in-depth, specific, and timely analysis rather than a one-size-fits-all product, and rejected the claim that the move puts people at risk, noting that any change to a permit or rule must still go through public rulemaking.

The Case Against

The counterweight is that the criticisms of IRIS, while real, do not support eliminating its independence—and that the National Academies have repeatedly said so. Reviews of IRIS in 2014, 2018, and 2021 found the program had made significant improvements in scientific rigor, systematic-review methods, and transparency. As Frey argued, the long timelines critics cite reflected extensive interagency review and limited staffing, not poor science: delay is not the same as bad evidence. He also noted that for a change of this magnitude, the agency consulted neither its Science Advisory Board nor the National Academies, calling it a predetermined decision the agency was working backward to rationalize.

Former administrators from both parties have condemned the dismantling of ORD. Paul Anastas, who headed the office under President Obama, told Chemistry World that its destruction was a tragedy and that OASES could not assume its responsibilities, adding that you cannot do science after firing your scientists or find contamination you have stopped looking for. Christine Todd Whitman, who led the EPA under President George W. Bush, said the moves endanger the health of Americans and the land. Justin Chen, president of the union council representing thousands of EPA employees, called ORD the heart and brain of the agency and said its destruction would devastate public health.

A Test Case: Ethylene Oxide

The stakes of removing the agency's independent science are visible in the EPA's reversal on ethylene oxide, a gas widely used to sterilize medical equipment and a hazardous air pollutant regulated under the Clean Air Act. About a decade ago, ORD scientists determined that the cancer risk from the chemical was at least 30 times greater than the agency had previously estimated, with chronic low-level exposure linked to an elevated risk of breast cancer, lymphoma, and leukemia. That finding led the EPA in 2024 to issue a more protective emissions standard for the commercial sterilization plants that use the gas—many of them, as the New Yorker reported, located in predominantly Black and Latino neighborhoods near schools and day-care centers.

In spring 2026, just before the new standard was to take effect, Zeldin pulled it back. The administration invited sterilizers that could not or would not meet the 2024 rule to request exemptions by email, framing the waivers as a matter of national security; roughly 40 facilities received them. The EPA then replaced the standard with a weaker one, justifying the move by saying it had lacked the authority to reassess the chemical's risks in the first place—the same argument the sterilizer industry's trade group had made in a 2024 legal filing. One affected facility, Sterilization Services of Virginia outside Richmond, sits in an area where an estimated 100,000 people live within five miles and only about a quarter are white. The episode illustrates the through-line critics describe: the office that generated the underlying risk assessment has been dismantled, and the assessment it produced has been set aside.

The deeper objection is legal and structural. When hazard assessments are produced inside the offices that also weigh costs and policy, it becomes harder to keep evidence evaluation separate from its regulatory consequences—and, as Frey observed, courts give weight to agency expertise only when decisions rest on a clear, well-documented scientific record. By making it easier to revisit or set aside past IRIS assessments, the change could leave hundreds of chemical-safety determinations vulnerable to legal challenge. Robert Sussman, an attorney who has represented chemical companies, environmental groups, and the EPA itself, told ProPublica that the directive creates an opening for polluters to push back on rules they dislike.

Measurable Effects So Far

Output has already fallen. According to data compiled by Public Employees for Environmental Responsibility and reported by Federal News Network, the EPA released 61 peer-reviewed publications by agency scientists in the first months of 2026, a pace that would yield about 163 for the full year. The EPA reduced its headcount by roughly 3,000 between fiscal 2025 and 2026—about a fifth of its workforce—and Chen estimated that 25 to 30 percent of those positions were science roles. He said peer-reviewed research at the agency had effectively ground to a halt or been heavily delayed.

The agency has also imposed an "advance notice" policy requiring internal review before the release of most public-facing research, particularly work in areas of priority to the administrator, the White House, or Congress, or likely to draw media attention. The EPA disputes the framing of decline: a spokesperson noted that peer-reviewed output peaked during the first Trump administration—the agency published a record 432 publications in 2018—and fell during the Biden years, though such publications can take years to move through review.

The Broader Deregulatory Context

The science overhaul did not happen in isolation. On March 12, 2025, Zeldin announced what the agency billed as 31 deregulatory actions in "the greatest and most consequential day of deregulation in U.S. history," targeting vehicle and power-plant emissions rules, the social cost of carbon, and the 2009 endangerment finding, among others. Zeldin described the effort as driving a dagger into the heart of what he called the climate-change religion.

The capstone came on February 12, 2026, when the EPA finalized the rescission of the 2009 endangerment finding—the determination, rooted in the Supreme Court's 2007 ruling in Massachusetts v. EPA, that greenhouse gases threaten public health and welfare. The finding had been the legal foundation for nearly all federal climate regulation under the Clean Air Act. Its repeal eliminated greenhouse-gas standards for cars and trucks and opened the door to unwinding limits on power plants and oil and gas facilities. Without independent science inside the agency, critics note, there is little institutional capacity left to generate the findings that justify new pollution limits.

The repeal drew two waves of litigation in the U.S. Court of Appeals for the D.C. Circuit: a February 18 suit by health and environmental groups, consolidated as American Public Health Association v. EPA, and a March 19 suit by 24 states, the District of Columbia, the U.S. Virgin Islands, and more than a dozen cities and counties, all led by Democrats. The challengers argue the rescission revives legal theories the Supreme Court already rejected and ignores decades of peer-reviewed evidence; the National Academies stated last fall that the finding was accurate and had been reinforced by stronger evidence. Hirsch called the state suit politically motivated and pointed to a 2022 Supreme Court ruling limiting the Clean Air Act's reach over power-plant carbon emissions. The issue is widely expected to reach the Supreme Court.

Retaliation Against Dissenting Staff

The reorganization was accompanied by an unusually aggressive response to internal dissent. In June 2025, hundreds of EPA employees signed a public "Declaration of Dissent" accusing the administration of recklessly undermining the agency's mission and ignoring science to benefit polluters. The agency placed about 140 signers who used their names on administrative leave and opened an investigation.

The discipline that followed set the EPA apart. According to Public Employees for Environmental Responsibility, signers of comparable dissent letters at NASA, the National Science Foundation, and the NIH faced no adverse action, and FEMA reinstated employees it had placed on leave; the EPA was the only agency to fire, suspend, or otherwise discipline its signatories. Around 15 employees—including seven still in their probationary period—were terminated in early October 2025, with most others reprimanded or suspended for two weeks. Six fired workers, whose experience ranged from one to four decades, are appealing to the Merit Systems Protection Board on First Amendment and retaliation grounds.

Internal records have complicated the agency's position. Emails obtained through FOIA by E&E News show that an EPA assistant general counsel warned leadership on July 2, 2025, that disciplining the signers carried significant legal risk because the letter was likely protected speech—advice that was disregarded a day later. Agency ethics officials had separately concluded the letter raised no ethics or Hatch Act concerns. Zeldin has defended the investigation in congressional testimony, and the EPA says supervisors made individualized decisions; a spokesperson has said the agency's actions were lawful.

Status

As of mid-2026, ORD has been formally eliminated and its remaining scientists reassigned; OASES operates under the administrator with its top posts still unfilled on a permanent basis. The IRIS program's centralized assessments have been retired in favor of decentralized, program-office review, and a disclaimer now cautions against using IRIS values in regulation. The endangerment-finding repeal and the broader deregulatory package are tied up in litigation expected to run for years and potentially reach the Supreme Court, while the MSPB appeals of fired staff proceed before a board that unions say has been slowed under the current administration.

What is not in dispute is the scale of the loss of expertise. Since Zeldin took over, the agency's overall staff has fallen by roughly a quarter, with the departures weighted toward longtime employees and team leaders; about 700 of those who left held doctoral degrees, according to the New Yorker. Former NIST director Willie May told Science that changes of this significance should have required extensive deliberation, and Robert Kavlock, the retired EPA scientist who founded the agency's center for computational toxicology, called it an incredible loss of expertise. William K. Reilly, who ran the EPA under President George H.W. Bush, likened the strategy to "move fast and break things": by the time the courts catch up, he warned, the scientists, lawyers, and engineers will have moved on and will no longer be recoverable.