EPA Issues Memo Questioning Chemical Toxicity Assessments

This latest memo represents a direct challenge to the validity of existing IRIS work.

“This creates the opportunity for companies that pollute to push back on rules and regulations they don’t like." — Robert Sussman, an attorney who has worked for chemical companies and environmental groups as well as the EPA (ProPublica).”

The directive echoes criticisms from industry groups that IRIS assessments are too cautious. For example, it references ethylene oxide, a chemical used in medical equipment sterilization, where a 2016 IRIS update identified higher cancer risks, leading to stricter regulations under the previous administration.

Companies have contested these findings, and the current administration has paused related protective efforts. Before his appointment, David Fotouhi represented companies like Medline in pollution cases as an attorney at Gibson, Dunn & Crutcher. The EPA stated that he has complied with ethics obligations and that any regulatory changes would involve public participation processes.

Environmental advocates argue the memo adopts industry talking points. Maria Doa, a scientist at the Environmental Defense Fund with over 20 years at the EPA, said it could leave people at risk from toxic chemicals.

The memo aligns with recommendations from the Heritage Foundation’s Project 2025, which called for eliminating IRIS due to questionable science and high economic costs. Congressional Republicans introduced legislation last year to bar IRIS use in regulations, though it did not advance to a vote.

Independent reviews, such as those from the National Academies of Sciences, Engineering, and Medicine, have noted past issues with IRIS report organization but acknowledged significant improvements in recent years. Despite this, the program has been valued for its independence from industry-funded science, which studies show can be biased.

“This is the EPA adopting the industry’s talking points. And it’s going to leave a lot of people at risk." — Maria Doa, a scientist at the Environmental Defense Fund (ProPublica). The EPA emphasized that science remains central to its work and that the memo reaffirms this. However, by tasking regulatory offices with toxicity assessments, it effectively ends IRIS's role as an independent entity. This shift could affect long-established standards, such as arsenic levels in drinking water and lead in paint and soil. Environmental scientists expressed concern that it undermines decades of protective measures based on IRIS data.”