EPA Unjustifiably Delays Release of Toxic Chemical Assessments

Published Mar 16, 2023

What happened: A report by the US Government Accountability Office (GAO) found that officials from the Office of Research and Development at the Environmental Protection Agency (EPA), from December 2018 to August 2020, sidelined and delayed the publication of reports from the EPA’s Integrated Risk Information System (IRIS) program. The GAO report concluded that the publication of IRIS chemical risk assessments faced unexplained delays and that the nominating process for new chemical assessments were based on arbitrary criteria that failed to consider the best available science.

Why it matters: When EPA officials interfere with science-based processes for nominating and publishing chemical risk assessments, the agency is unable to make timely and science-based decisions that could protect environmental and public health and inform risk management.


A US Government Accountability Office (GAO) report, published in December 2020, revealed that the Environmental Protection Agency’s (EPA) Office of Research and Development deprioritized and stifled publication of chemical assessments by the EPA’s Integrated Risk Information System (IRIS) program.

The report found that, as of August 2020, there were 15 chemical assessments in development, yet 13 of these were only in the first step (draft development) of a rigorous seven-step process. In fact, since December 2018, no ongoing assessments had progressed to the next step of the development process or had been completed and made public. This also comes after the EPA slashed the number of IRIS assessments it committed to complete from 22 to 13, with little justification provided for these decisions.

IRIS chemical assessments take years to complete, and in some cases, more than a decade. GAO’s 2020 report found that the timeline for chemical assessments were delayed by at least three months without explanation, including that for polychlorinated biphenyls, or PCBs, a highly toxic chemical associated with elevated cancer risk and neurological, reproductive, and immune system harm. In December 2018, the PCBs assessment was projected to reach the public comment draft period in the first quarter of 2021, yet as of June 2020, that deadline was delayed to the second quarter of 2024.

EPA has been unable to answer for these obscure and unclear actions. When asked about the delays, representatives from EPA’s Office of Congressional and Intergovernmental Relations stated that these changes “are typically the result of scientific complexities of each assessment and availability of staff with the appropriate expertise to address those complexities.” Agency officials did not provide additional details, including what constitutes “scientific complexity” or why program staffing was not adjusted to meet these needs.

While the EPA’s Office of Research and Development took some steps to improve intra-agency communication regarding assessment progress, major gaps remain, leading to confusion among agency staff. In 2018 and 2019, the office instituted a new process for soliciting IRIS assessment nominations yet did not provide program and regional offices with criteria or sufficient guidance for how chemical nominations would be selected. Furthermore, no justification was required when Assistant Administrators chose not to support a specific nomination. For example, in 2019, a regional office sent chemical assessment nominations to four program offices, yet these nominations were not sent to the Office of Research and Development and no explanation was given for this unusual omission.

In response to the report, Representative Eddie Bernice Johnson, Chairwoman of the House Committee on Science, Space, and Technology, and Senator Tom Carper, Ranking Member of the Senate Committee on Environment and Public Works, who requested this report, recommended that EPA implement GAO’s recommendations, review suspended assessments, increase public transparency, and rescind rules that restrict the use of the best available science in IRIS assessments. In EPA’s response to GAO’s report, however, the agency disagreed with most of the recommendations.

This is the latest blow against a program that was previously sidelined under the Trump administration. IRIS chemical assessments are considered the gold standard for determining the human health risks of a potentially toxic chemical and underpin many federal, state, and local regulations that determine the quality of our air and water. When nominations for IRIS assessments fall through the cracks, EPA is missing opportunities to use the best available science to regulate hazardous chemicals of significant public concern.

Political interference and obfuscation prevented the IRIS program from producing valuable assessments—many of which are decades outdated—and ultimately, hindered EPA’s ability to fulfill its mission to protect public health. Furthermore, delaying publication of chemical assessments continues to leave communities overburdened by pollution and exposure to toxic chemicals in harm’s way.