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Notice of Availability of the Framework for Metals Risk Assessment

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Environmental Protection Agency (EPA).


Notice of document availability.


The U.S. Environmental Protection Agency (EPA) is announcing the availability of the final “Framework for Metals Risk Assessment” (EPA 120/R-07/001, March 2007). The purpose of the Framework is to present key guiding principles based on the unique attributes of metals (as differentiated from organic and organometallic compounds) and to describe how these metals-specific attributes and principles may then be applied in the context of existing EPA risk assessment guidance and practices. This Framework document is not a prescriptive guide on how any particular type of assessment should be conducted within an EPA program or regional office. Rather, it outlines key metal principles and describes how they should be considered in conducting human health and ecological risk assessments to advance our understanding of metals impact and foster consistency across EPA programs and regions. As a result the Framework is a science-based document that describes basic principles that address the special attributes and behaviors of metals and metal compounds to be considered when assessing their human health and ecological risks. EPA's Risk Assessment Forum oversaw the development of this document, which included input from stakeholders and experts throughout the Agency, obtained through several expert workshops, followed by peer review by the EPA Science Advisory Board.

The Framework sets out a variety of principles that are general, fundamental properties of metals, which should be addressed and incorporated into all inorganic metals risk assessments. The five overarching principles are summarized as follows: (1) Metals are naturally occurring constituents in the environment and vary in concentrations across geographic regions; (2) All environmental media have naturally occurring mixtures of metals, and metals are often introduced into the environment as mixtures; (3) Some metals are essential for maintaining proper health of humans, animals, plants and microorganisms; (4) Metals, as chemical elements, and unlike organic chemicals, are neither created nor destroyed by biological or chemical processes, although, these processes can transform metals from one species to another (valence states) and can convert them between inorganic and organic forms; and (5) The absorption, distribution, transformation and excretion of a metal within an organism depends on the metal, the form of the metal or metal compound, and the organism's ability to regulate and/or store the metal.


The final document is available electronically through the EPA Office of the Science Advisor's Web site at:​osa/​metalsframework. A limited number of paper copies will be available from EPA's National Service Center for Environmental Publications (NSCEP), P.O. Box 42419, Cincinnati, OH 45242; telephone 1-800-490-9198 or 513-489-8190; facsimile 301-604-3408; e-mail Please provide your name and mailing addresses and the title and EPA number (as given above) of the requested publication.

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Dr. Randall S. Wentsel, Risk Assessment Forum Technical Writing Panel Co-chair, Mail Code 8101-R, Environmental Protection Agency, 1200 Pennsylvania Avenue, NW., Washington, DC 20460; telephone number: (202) 564-3214; fax number: (202) 564-2070, E-mail:

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In December 2002 EPA's Science Policy Council tasked an Agency workgroup, under the oversight of the Risk Assessment Forum, with developing a plan for ensuring the consistent application of scientific principles to metals risk assessment. A step-wise plan was developed beginning with the Metals Action Plan (MAP), which included brief descriptions of the Agency's current activities on metals, identified critical scientific issues, and recommended the scope of the metals framework. The MAP was reviewed by EPA's Science Advisory Board. Then, EPA commissioned individual scientists to develop issue papers on important topics in metals risk assessment, including environmental chemistry, exposure, human health effects, ecological effects, and bioavailability and bioaccumulation. The Framework was developed based, in part, on these issues papers and reviewed by the Agency-wide workgroup. Additional workshops and peer review activities were conducted at multiple intervals during the development of the Framework, and the Agency consulted with other federal agencies at key points during its development. Finally, the Framework underwent external peer review by EPA's Science Advisory Board.

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Dated: March 1, 2007.

George M. Gray,

EPA Science Advisor.

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[FR Doc. E7-4035 Filed 3-7-07; 8:45 am]