This bill would prohibit the Environmental Protection Agency from using any assessment generated by the Integrated Risk Information System (IRIS) as the basis for developing, finalizing, or issuing rules or regulations, or for carrying out regulatory, enforcement, or permitting actions. It would also bar IRIS assessments from informing air toxics assessments or other mapping or screening tools.
The measure is short and narrowly focused, asserting a blanket prohibition with a preemption-like clause. It does not specify an effective date or a detailed implementation plan, leaving questions about how EPA would source alternative data for risk assessment if IRIS were excluded.
At a Glance
What It Does
Section 2 prohibits EPA from using IRIS assessments as the basis for rulemaking, enforcement, permitting actions, or informing air toxics assessments and related mapping tools. The prohibition is stated as not allowing any IRIS-based assessments to be used in these processes.
Who It Affects
EPA and its regulatory programs would be directly constrained. Federal agencies and contractors that rely on IRIS for risk communication or regulatory planning may need to adjust, and states or localities implementing federal programs could face changes in their risk assessment inputs.
Why It Matters
IRIS is a long-standing federal data source for health risk assessments. By removing IRIS as a basis for regulatory actions, the bill could shift risk-communication standards and affect the consistency of federal risk assessments across programs.
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What This Bill Actually Does
The No IRIS Act of 2025 would block the Environmental Protection Agency from using IRIS assessments as the foundation for creating or finalizing rules, regulations, or any regulatory, enforcement, or permitting actions. It would also prevent IRIS assessments from informing air toxics studies or mapping and screening tools.
The prohibition carries a broad, superseding-claims tone, making IRIS effectively unavailable as an input in federal decision-making related to risk. The law is intentionally narrow in scope, focusing on the source of risk information rather than broader regulatory reform, but it raises questions about what data will replace IRIS and how EPA will maintain consistent risk assessments across programs.
Because the text provides no explicit date of applicability or enforcement mechanism, implementing agencies would need to determine how to operate without IRIS and what alternative data sources to rely on. In short, if enacted, the bill would force a shift in EPA risk assessment practices and potentially ripple through states and regulated industries that currently anticipate IRIS-based inputs in rulemaking and permitting processes.
The Five Things You Need to Know
The bill would bar EPA from using any IRIS assessment as the basis for rules or regulations.
It would also prohibit IRIS from informing enforcement or permitting actions.
IRIS could not be used to inform air toxics assessments or related mapping tools.
The prohibition is paired with a 'Notwithstanding any other provision of law' clause to affirm precedence over other statutes.
The text comprises two sections: Short Title and the prohibition; there is no explicit effective date in the bill.
Section-by-Section Breakdown
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Short title
This section designates the act as the No IRIS Act of 2025. It situates the bill within the broader framework of federal environmental regulation by naming its purpose and making clear its targeted scope: restricting EPA’s use of IRIS assessments in regulatory contexts.
Prohibition on use of IRIS assessments
Section 2 prohibits the EPA Administrator from using any IRIS-generated assessment as a basis to develop, finalize, or issue rules or regulations; to carry out regulatory, enforcement, or permitting actions; or to inform air toxics assessments, mapping, or screening tools. The language anchors the prohibition with a broad 'Notwithstanding any other provision of law' clause, creating a preemptive effect relative to other statutes or rules.
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Every bill creates winners and losers. Here's who stands to gain and who bears the cost.
Who Benefits
- Chemical manufacturers and other heavily regulated industries may benefit from less IRIS-driven rigidity in EPA risk assessments and potential shifts toward alternative data sources.
- Industry trade groups representing energy, manufacturing, and chemical sectors may benefit from reduced likelihood that IRIS-based risk thresholds drive new or stricter standards.
- State and local permitting authorities could see greater alignment with non-IRIS risk inputs, potentially simplifying intergovernmental regulation in some contexts.
Who Bears the Cost
- EPA would incur the administrative and technical burden of sourcing alternative risk data and rebuilding risk-assessment workflows without IRIS inputs.
- Public health advocates and groups that rely on IRIS-derived benchmarks might fear less transparent or less consistent risk assessments across federal programs.
- Some regulated entities could face uncertain or shifting risk standards as EPA adjusts its evidentiary basis for risk, potentially impacting compliance planning.
Key Issues
The Core Tension
The central dilemma is balancing the standardization and transparency of IRIS-based risk assessments against the desire to avoid over-reliance on a single data source and to allow agencies flexibility in choosing risk inputs.
The bill’s central design choice shifts the federal risk-assessment baseline away from IRIS, which could disrupt established rulemaking and permitting workflows. It does not specify alternative data sources, timelines, or transitional provisions, leaving implementation questions to agencies and potentially prompting litigation or rapid policy shifts in practice.
The broader policy implication is a recalibration of how health risk data informs federal environmental regulation, with knock-on effects for states, industry, and public health oversight.
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