Chemical Selection Approach for Initial Tier 1 Screening

Highlights

Approach for Selecting the Initial List of Chemicals for Screening - Federal Register Notice [PDF file, 17pp., 125KB, About PDF]

Overview of the EDSP

The EDSP was established in response to a Congressional mandate in the Federal Food, Drug, and Cosmetic Act (FFDCA), to screen pesticides, chemicals and environmental contaminants for their potential to affect the estrogen, androgen or thyroid hormone systems. The core elements of the EDSP are:

Assay development and validation for Tier 1 screening and Tier 2 testing;
Priority setting of chemicals to be tested (i.e., the 2005 Federal Register Notice [PDF file, 17pp., 125KB, About PDF]; and
Development of program policies and procedures to require testing.

For more information on endocrine disruptors and the core elements of the screening program see the "Endocrine Primer."

Priority Setting - Approach for Initial Screening

The approach used by EPA for selecting 50 to 100 chemicals for initial screening under the Federal Food, Drug and Cosmetic Act is summarized below. Nothing in the approach for selecting the initial list would provide a basis to infer that any of the chemicals selected for the list interferes with or is suspected to interfere with the endocrine systems of humans or other species. This action may be of interest to those who are involved with, or are interested in, pesticide chemicals or the topic of endocrine disruptors.

The approach includes consideration of the most current databases and priority-setting tools available. For this approach EPA:

Focused chemical selection for this initial list on the subset of chemicals for which testing is required (i.e., pesticide chemicals);
Used exposure data as the primary basis for chemical selection;
Deferred consideration of nominations from the public;
Excluded mixtures; and
Excluded chemicals that are no longer produced or used in the United States.

The approach described in the September 2005 Federal Register notice further indicated that the following would be excluded from the list of chemicals for initial screening.

Substances anticipated to have low potential to cause endocrine disruption (e.g., most polymers with number average molecular weight greater than 1,000 daltons, strong mineral acids, and strong mineral bases);
"Positive control" chemicals used by EPA for the validation of the screening assays proposed for the Tier 1 battery.

EPA proposed the approach in a previously published December 30, 2002 Federal Register Notice [PDF file, 19pp., 119KB, About PDF] and received comments on it.

Subsequent Approaches for Chemical Selection

EPA anticipates that it may modify its chemical selection approach for subsequent screening lists based on experience gained from the results of testing of chemicals on the initial list, the need for a broader approach in the future to incorporate different categories of chemicals (e.g., non-pesticide substances) and additional pathways of exposure, and the availability of new priority-setting tools (e.g., High Throughput Pre-Screening (HTPS) or Quantitative Structure Activity Relationship (QSAR) models). In addition, the Agency intends to conduct a review of the data received from the screening to evaluate whether the program could be improved or optimized.

Initial List of Chemicals

EPA published the draft list of initial pesticide active ingredients and pesticide inerts to be considered for screening under the Federal Food, Drug and Cosmetic Act for public notice and comment in a 2007 Federal Register Notice [PDF file, 18pp., 131KB, About PDF]. The draft list was produced using the approach described in the September 2005 Federal Register Notice [PDF file, 17pp., 125KB, About PDF], and includes chemicals that the Agency has decided should be tested first, based upon exposure potential. How to comment.

This list should not be construed as a list of known or likely endocrine disruptors. Nothing in the approach for generating the initial list provides a basis to infer that any of the chemicals selected interfere with or are suspected to interfere with the endocrine systems of humans or other species.

The draft list of chemicals selected for initial screening include pesticide active ingredients and High Production Volume (HPV) chemicals used as pesticide inerts. After considering comments on this draft list of chemicals, EPA will issue a second Federal Register Notice containing the final list of chemicals.

Other Related Future EDSP Actions

Future actions will identify other aspects of the EDSP such as the administrative procedures EPA will use to require testing, the validated tests and battery that will be included in the EDSP, and the timeframe for requiring the testing or receiving the data. The details of the EDSP process that will apply to the initial chemical list, along with the other future actions of the EDSP, will be addressed in subsequent documents published in the Federal Register.

You will need the free Adobe Reader to view some of the files on this page. See EPA's PDF page to learn more. If you need help accessing these PDF documents, please contact William Wooge at 202-564-8476 or wooge.william@epa.gov for assistance.