On November 17, 2010, the U.S. Environmental Protection Agency (EPA) announced the second list of chemicals for which EPA intends to issue test orders under the Endocrine Disruptor Screening Program (EDSP). EPA also released its draft policies and procedures for requiring Tier 1 screening under the EDSP, and a new guidance document outlining weight-of-evidence (WoE) policies. This column explains why the issuance of the second list of EDSP screening chemicals, and the proposed policies and procedures for obtaining testing, are important developments.
[pullquote]New Additions
The second list of chemicals includes pesticides, perfluorocarbon compounds (PFC), pharmaceuticals, and those used as plasticizers or in the production of pharmaceutical and personal care products. The chemicals include a significant number of Toxic Substances Control Act (TSCA) chemicals that EPA has identified as priorities under the Safe Drinking Water Act (SDWA) and that may be found in sources of drinking water.
Significant Supplement
The draft policies and procedures are intended, according to EPA, to supplement the policies and procedures that the agency published in April 2009. The policies and procedures address both substantive and administrative issues.
EPA's draft, "Weight-of-Evidence Guidance Document: Evaluating Results of EDSP Tier 1 Screening to Identify Candidate Chemicals for Tier 2 Testing," is intended "to set forth some general principles, criteria and considerations EPA generally believes to be relevant using a WoE approach to evaluate data submitted as part of EPA's EDSP" Tier 1 screening assays.
EPA summarizes the EDSP as a "two-tiered paradigm for screening and testing chemicals with the potential to interact with the endocrine system." Tier 1 screening identifies substances that have the potential to interact with the estrogen, androgen or thyroid hormonal systems. Tier 2 testing aims to identify further and characterize chemical-induced interactions with estrogen, androgen or thyroid hormonal systems for risk assessment. EPA states that it expects the diversity in endocrine endpoints within the Tier 1 screening assays to provide corroborating information and support a WoE evaluation to yield a decision as to whether the chemical identified in Tier 1 requires additional testing in Tier 2.
The guidance itself notes that this approach is not meant to be any different in its application to the endocrine program than from other areas of scientific assessment where EPA utilizes a WoE approach. It is interesting that this announcement acknowledges that the approach will be used to evaluate "other scientifically relevant information" — which has been a controversial element of EPA's endocrine testing program. Many interested parties insist that if EPA fairly and fully evaluates the body of existing data already developed and submitted to EPA, the need for the now-required "lower-tier" endocrine effect tests would not be justified.
Putting it in Perspective
This list builds on the earlier requirements originating under the 1996 Food Quality Protection Act. EPA's endocrine testing program first broadened to include chemicals used in pesticide formulations that otherwise would be subject to TSCA testing. This latest list expands EPA's domain from pesticide and toxics programs to chemicals in other EPA program areas such as drinking water.
The expansion of the endocrine program's domain indicates that EPA may intend to use its authority to address concerns with other chemicals arising out of other programs and agencies; and to compensate, to some degree, for the shortcomings in testing authority found in other statutes administered by both EPA and other federal agencies. The latest list, for example, incorporates pharmaceuticals that have drinking water exposures as EPA believes they may present endocrine effect risks. This lets EPA take the lead from the Food and Drug Administration in this regard. Plainly, EPA's approach could greatly expand the number of chemicals subject to testing orders.
Chemical manufacturers and downstream users of these chemicals should monitor this program carefully. Although a chemical's inclusion in the second list does not mean the substance is an endocrine disruptor, certain inferences will nonetheless be drawn and manufacturers and users of chemicals subject to screening could be subject to deselection or other adverse commercial consequences. Stakeholders should monitor the docket, be aware of comments submitted, and watch for new developments as to chemicals of concern. This listing is the first step in a series that can be expected to have commercial consequences.
Lynn L. Bergeson is Chemical Processing's Regulatory Editor. You can e-mail her at [email protected].
