EPA Orders Review of 500+ Chemical Risk Assessments Under Trump Appointee

The Environmental Protection Agency (EPA), under Administrator Lee Zeldin and former President Donald Trump, has issued a directive questioning the reliability of more than 500 chemical toxicity assessments compiled by the agency’s Integrated Risk Information System (IRIS) program.

For decades, IRIS has served as the EPA’s scientific authority on chemical hazards, providing data that underpins federal and state regulations, permits, and environmental standards. The program’s assessments determine safe exposure levels for chemicals, including carcinogens, and have been widely used both domestically and internationally.

In an internal memo obtained by ProPublica, EPA Deputy Administrator David Fotouhi criticized IRIS’s findings and ordered EPA offices to review any regulations based on its assessments. He also advised external entities—such as state agencies and private organizations—to reconsider using IRIS data in future regulatory decisions. The memo instructed the EPA to add a disclaimer to the IRIS website stating that its toxicity findings are not necessarily intended for regulatory use.

“This creates the opportunity for companies that pollute to push back on rules and regulations they don’t like. Anybody who wants to ignore a regulation, permit or enforcement action can now just point to this memo and say the IRIS number it was based on wasn’t valid. It’s a huge setback for the process of protecting people from chemicals.”

Fotouhi’s memo aligns with longstanding industry criticism that IRIS scientists overestimate chemical toxicity. Before joining the EPA, Fotouhi worked as a lawyer defending companies accused of toxic pollution, raising concerns about potential conflicts of interest.

In response, an EPA spokesperson stated that Fotouhi has complied with ethics obligations and that the directive would not weaken public health protections. The spokesperson emphasized that any changes to regulations or permits must follow public review processes, adding:

“Science is at the heart of the Agency’s work, and this memo reaffirms that point clearly and unequivocally.”

The IRIS program, established in 1985, has been a cornerstone of the EPA’s mission to assess chemical risks impartially. The agency previously highlighted IRIS’s role in safeguarding communities from hazardous substances, including setting limits for arsenic in drinking water and lead in paint and soil.