The U.S. Environmental Protection Agency (EPA) has announced changes to its process for assessing the human health effects of common chemical substances. The revised process will allow the White House Office of Management and Budget (OMB) to play a larger role in the evaluation of the substances.

EPA's Integrated Risk Information System (IRIS) serves as a publicly searchable database for studies and information on the human health effects of chemical substances. EPA scientists and policymakers use the information in the database to make determinations about the risk of various substances. EPA studies both the carcinogenic and noncarcinogenic effects of substances and determines safe or tolerable exposure thresholds when possible.

IRIS assessments can inform regulatory action intended to protect humans from the harmful effects of certain substances. "Through IRIS, EPA provides the highest quality, science-based, human-health assessments to support EPA's policymaking activities," according to the agency. Researchers and regulatory bodies in other nations also use IRIS assessments to inform decision making, according to EPA.

On April 10, EPA announced policy changes to its process for determining risk under IRIS. EPA will now involve OMB at every stage of the IRIS assessment process. Previously, OMB reviewed a final version of the draft assessment before EPA subjected it to external peer review. OMB already reviews — and often edits — agencies' proposed and final regulations. The office will now have several opportunities to review and alter the scientific findings that serve as the basis for chemical exposure standards.

Before EPA assesses a substance under IRIS, the agency asks the public and other federal agencies or interested parties for nominations. Under the new IRIS process, EPA will now consult with other federal agencies and OMB after receiving nominations to determine which substances EPA will evaluate.

After EPA, OMB, and other agencies select a chemical for assessment, EPA will conduct a literature search assessing available studies and information on the chemical in question. Under the old process, after conducting a literature search, EPA would perform a quantitative toxicological review. Now, EPA will have to put the process on hold and ask the public, other agencies, and OMB for additional studies or information on the chemical being assessed.

After reviewing all relevant information, EPA will prepare a qualitative assessment of the chemical. The qualitative assessment is to include potential health risks, susceptible populations, and potential uncertainties, among other things. EPA will then solicit comments on the qualitative assessment from the public, other agencies, and OMB — another new requirement.

EPA will then draft a quantitative toxicological assessment based on the qualitative assessment and relevant comments. EPA also prepares questions to pose to the external peer review panel that will eventually review the toxicological assessment. EPA will submit both the draft toxicological assessment and the peer review questions to OMB for review by the White House and other federal agencies. In the revised process, EPA explicitly states that the OMB/interagency review is deliberative and therefore is not subject to public disclosure requirements.

EPA will then make public the toxicological assessment and convene a public meeting of external peer reviewers. The old IRIS process contained a similar requirement.

After the external peer review, EPA will revise the assessment. Then, EPA will send the assessment to OMB for one final review. Under the old IRIS process, OMB did not have the opportunity to alter the assessment after it underwent a rigorous external peer review. Now, OMB can pressure EPA to make last minute changes before finalizing and publishing the assessment.

The revised IRIS process will also allow EPA to abdicate to another federal agency its power to study a substance, so long as that agency can prove the substance is critical to its mission. The provision raises the possibility of a conflict of interest within the federal government if an agency is assessing a substance it frequently uses.

For example, a Natural Resources Defense Council (NRDC) investigation showed the Department of Defense, with the support of the White House, pressured the National Academies of Science to downplay the adverse health effects of perchlorate. Perchlorate is an ingredient in rocket fuel. The Pentagon and defense contractors use rocket fuel for a variety of purposes.

Perchlorate has been shown to cause brain damage in fetuses and infants, according to NRDC. Nonetheless, the federal government passed up numerous opportunities to regulate perchlorate, citing the need for more research.

Under EPA's revised IRIS process, federal agencies such as the Department of Defense will have new opportunities to exert pressure on EPA to suppress or cast doubt on public health science.

Sen. Barbara Boxer (D-CA), chair of the Environment and Public Works Committee, criticized EPA's decision to revise the IRIS process. In a statement, Boxer says the changes "put politics before science by letting the White House and federal polluters derail EPA's scientific assessment of toxic chemicals." The statement also says the process will now "take place behind closed doors due to the administration's refusal to make federal agency comments public."

EPA's revised IRIS process may reflect changes to the regulatory process President Bush announced in January 2007. Those changes imposed new requirements on federal agencies' "significant guidance documents" — documents which are not rules or regulations but rather statements of policy that may impact the economy or other parts of society. The new requirements include an expanded OMB review period and mandatory public comment periods.

EPA does not mention the new guidance document policy in its revised IRIS process, nor does it indicate whether it considers IRIS assessments to be guidance documents at all. OMB Watch criticized Bush for attempting to increase the White House's role in agency activity and for failing to adequately define guidance documents, fearing scientific assessments such as those conducted under IRIS would be swept in.