Better Hazard Information

Future Federal assessments of chemicals’ health hazards will be shorter and clearer and will present the scientific rationale behind them, the Environmental Protection Agency announced last week.

The changes affect EPA’s database of chemical toxicity information. Called the Integrated Risk Information System (IRIS), it contains the agency’s scientific judgments on the safe daily dose of more than 540 chemicals. Environmental and health regulators in the U.S. and around the world rely on IRIS as they decide on the degree of cleanup that polluters must undertake at a contaminated site or how much to limit human exposure to a chemical.

EPA’s assessments, which take years or even decades to complete, have come under attack from industry. For instance, chemical manufacturers have complained about the lack of information on how the agency chooses to include or exclude scientific studies in assessments.

Now, that situation is changing.

“People will be able to understand the basis of our calls, the basis of our determinations,” says Paul T. Anastas, head of EPA’s Office of Research & Development.

“EPA will evaluate and describe the strengths and weaknesses of critical studies in a more uniform way,” according to an agency statement. “EPA will also indicate which criteria were most influential in evaluating the weight of the scientific evidence supporting its choice of toxicity values.”

IRIS documents will always be scientifically and technically complex, Anastas says. But future assessments will convey information more clearly in part through greater use of graphs and tables of data.

The changes will be phased in over time and will most heavily affect chemical assessments that are now in their beginning stages, Anastas says.

“We’re pleased to see EPA recognizes the need to reform IRIS,” says Scott Jensen, spokesman for the American Chemistry Council, a trade association of chemical manufacturers.

EPA’s move implements recommendations for improving IRIS that the National Research Council tucked into its recent report criticizing the agency’s assessment of formaldehyde (C&EN, April 18, page 10). The NRC panel said EPA needed to improve accessibility to and transparency of its assessments.