Environmental Protection Agency (EPA).
Notice; request for nominations for membership.
As mandated by the Federal Food, Drug, and Cosmetic Act, as amended by the Food Quality Protection Act of 1996, EPA is implementing an Endocrine Disruptor Screening Program (EDSP). This notice proposes the establishment of an Endocrine Disruptor Methods Validation Subcommittee (EDMVS) as a Subcommittee under the National Advisory Council for Environmental Policy and Technology (NACEPT), and requests nominations for members of the EDMVS from interested organizations. NACEPT is a chartered federal advisory committee subject to the provisions of the Federal Advisory Committee Act. Through NACEPT, the EDMVS will provide technical advice an recommendations to EPA regarding validation of the Tier 1 Screening and Tier 2 Testing methods for its Endocrine Disruptor Screening Program (EDSP). Background information regarding the Agency's Endocrine Disruptor Screening Program (EDSP) and the mission of the EDMVS are discussed in Unit IV. of SUPPLEMENTARY INFORMATION. This information is being provided to allow interested organizations to review the scope of proposed activities to nominate qualified individuals for membership on the EDMVS.
Nominations must be received on or before June 6, 2001.
Nominations for membership may be submitted by mail, electronically, or in person. Please follow the detailed instructions for each method as provided in Unit III. of the SUPPLEMENTARY INFORMATION. To ensure proper receipt by EPA, your request must identify docket control number OPPTS-42212C in the subject line on the first page of your response.Start Further Info
FOR FURTHER INFORMATION CONTACT:
For general information contact: TSCA Hotline, Environmental Assistance Division (7408), Office of Pollution Prevention and Toxics, Environmental Protection Agency, 401 M St., SW., Washington, DC 20460. Telephone: 202-554-1404; TDD: 202-554-0551; e-mail: TSCA-Hotline@epa.gov.
For technical information contact: Anthony Maciorowski, Senior Technical Advisor, Office of Prevention, Pesticides and Toxic Substances; telephone: 202-260-3048; e-mail address: firstname.lastname@example.org or
Gary Timm, Senior Technical Advisor, Office of Prevention, Pesticides and Toxic Substances; telephone: 202-260-1859; e-mail address: email@example.com.End Further Info End Preamble Start Supplemental Information
I. Does This Notice Apply to Me?
This action is directed to the public in general. You may be interested in nominating members to the subcommittee set forth in this notice if you produce, manufacture, use, consume, work with, or import pesticide chemicals, substances that may have an effect cumulative to an effect of a pesticide, or substances found in sources of drinking water. To determine whether you or your business may have an interest in this notice you should carefully examine section 408(p) of the Federal Food, Drug, and Cosmetic Act (FFDCA), as amended by the Food Quality Protection Act (FQPA) of 1996 (Public Law 104-170), 21 U.S.C. 346a(p) and amendments to the Safe Drinking Water Act (SDWA) (Public Law 104-182), 42 U.S.C. 300j-17. Since other entities may also be interested, the Agency has not attempted to describe all the specific entities that may be affected by this action. If you have any questions regarding the applicability of this action to a particular entity, consult the technical persons listed under FOR FURTHER INFORMATION CONTACT.
II. How Can I Get Additional Information, Including Copies of This Document or Other Related Documents?
1. Electronically. You may obtain electronic copies of this document, and certain other related documents that might be available electronically, from the EPA Internet Home Page at http://www.epa.gov/scipoly. To access this document, on the Home Page select ``Endocrine Disruptors'' which will take you to the OSCP Endocrine Disruptor Screening Program web site.
2. In person. The Agency has established an administrative record for the EDMVS under docket control number OPPTS-42212C. The administrative record consists of the documents specifically referenced in this notice, any public comments received during an applicable comment period, and other information related to the Endocrine Disruptor Methods Validation Subcommittee Organizational Meeting. This administrative record includes the documents that are physically located in the docket, as well as the documents that are referenced in those documents. The public version of the administrative record, which includes printed, paper versions of any electronic comments that may be submitted during an applicable comment period, is available for inspection in the TSCA Nonconfidential Information Center, North East Mall Rm. B-607, Waterside Mall, 401 M St., SW., Washington, DC. The Center is open from noon to 4 p.m., Monday through Friday, excluding legal holidays. The telephone number of the Center is (202) 260-7099.Start Printed Page 23023
III. How Can I Nominate Potential Members to the Endocrine Disruptor Methods Validation Subcommittee?
You may nominate technically qualified persons for membership to the Endocrine Disruptor Methods Validation Subcommittee through the mail, in person, or electronically. Nominations for membership should be submitted by the nominating organization, and must include a curriculum vitae of the nominee detailing his or her specific area of relevant scientific expertise. Members of the EDMVS will be selected on the basis of their relevant scientific expertise and diversity of perspectives on mammalian, ecological, and in vitro endocrine disruptor screening and testing methods and procedures, toxicity test methods standardization and validation, and chemical and pesticide regulatory processes. Members will be appointed for 2 years. Subcommittee members shall be appointed with balanced representation from among the following sectors: the agrichemical and commodity chemical industries; environmental/public interest organizations; public health organizations; animal welfare organizations; Federal agencies; State, local and tribal governments; academia; consumers, and the public. Your nomination must be received by EPA on or before June 6, 2001. To ensure proper receipt by EPA, it is imperative that you identify docket control number OPPTS-42212C in the subject line on the first page of your request.
1. By mail. You may submit a written nomination to: Document Control Office (7407), Office of Pollution Prevention and Toxics (OPPT), Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460.
2. In person or by courier. You may deliver a written nomination to: OPPT Document Control Office (DCO) in the East Tower Rm. G-099, Waterside Mall, 401 M St., SW., Washington, DC. The DCO is open from 8 a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The telephone number for the DCO is (202) 260-7093.
3. Electronically. You may submit your nomination electronically by e-mail to: firstname.lastname@example.org. Use Wordperfect 6.1/8.0 or ASCII file format and avoid the use of special characters and any form of encryption. All comments in electronic form must be identified by docket control number OPPTS-42212C.
Two laws enacted in 1996 authorize the Agency to screen pesticides and other chemicals found in food or in drinking water sources to determine whether they may cause estrogenic or other endocrine effects in humans. The impetus for development of EPA's Endocrine Disruptor Screening Program was an amendment to FFDCA, contained in the FQPA of 1996 (Public Law 104-170). The FFDCA (21 U.S.C. 346a(p) as amended requires EPA to:
develop a screening program, using appropriate validated test systems and other scientifically relevant information, to determine whether certain substances may have an effect in humans that is similar to an effect produced by a naturally occurring estrogen, or such other endocrine effect as the Administrator may designate.
21 U.S.C. 346a(p)(3), also states that in carrying out its screening program, EPA
(A) shall provide for the testing of all pesticide chemicals and (B) may provide for the testing of any other substance that may have an effect that is cumulative to an effect of a pesticide chemical if the Administrator determines that a substantial population may be exposed to such a substance.
Additionally, Congress amended the SDWA (42 U.S.C. 300j-17) authorizing EPA to provide for the testing under the screening program authorized in the FFDCA
. . .of any other substance that may be found in sources of drinking water if the Administrator determines that a substantial population may be exposed to such substance. (42 U.S.C. 300j-17).
Through the amended FFDCA, Congress directed EPA to develop an endocrine disruptor screening program using appropriate validated test systems and other scientifically relevant information by August 3, 1998, implement the program by August 3, 1999, and report progress to Congress by August 3, 2000.
EPA may rely upon FIFRA and TCSA testing authority. Under FIFRA section 3(c)(2)(B), if EPA determines that additional data are required to maintain in effect an existing pesticide registration, it can require pesticide registrants to provide EPA with additional data in support of the registrant. Likewise, TSCA section 4 provides EPA authority to require testing of certain industrial chemicals.
B. Development of EPA's Endocrine Disruptor Screening Program
Prior to the passage of the FQPA and SDWA, the Agency initiated several endocrine disruptors investigations including: the development of a special report and effects assessment (Ref. 6); a series of endocrine disruptor methods workshops funded by the World Wildlife Fund, Chemical Manufacturer's Association, and the Agency (Refs. 1, 3, and 7); and co-sponsorship (with the National Institute of Environmental Health Sciences and Department of the Interior) of an independent critical analysis of the literature on hormonally active agents in the environment by the National Academy of Sciences (Ref. 5). The foregoing activities coincided with the establishment and deliberations of the Endocrine Disruptor Screening and Testing Advisory Committee (Ref. 2).
The complexity of the scientific and regulatory issues surrounding the endocrine disruptor issue led EPA to seek broad expert advice and counsel beyond the Agency. EPA held a public meeting in May of 1996 requesting advice on how to develop a scientifically defensible, pragmatic approach to endocrine disruptor screening and testing. The stakeholder feedback indicated that a broad based multi-sector stakeholder committee should be established under the Federal Advisory Committee Act. Following a second public meeting and analysis of stakeholder interests (Keystone Center Convening Report, see www.epa.gov/scipoly/oscpendo), the Agency chartered the Endocrine Disruptor Screening and Testing Advisory Committee (EDSTAC).
EDSTAC was charged with providing advice and recommendations to the Agency regarding a strategy for testing chemical substances to determine whether they may have an effect in humans similar to an effect produced by naturally occurring hormones. EDSTAC consisted of 39 representatives from industry, environmental and public health advocacy groups, state government, other Federal agencies, and academic scientists. Over a 2-year period, EDSTAC held eight meetings. To facilitate regional public comment on the process, the meetings were held in different parts of the country (Chicago, San Francisco, New York, Houston, Orlando, Baltimore and Washington) and provided opportunities for public comment. In its final report, EDSTAC (Ref. 2, available at www.epa.gov/scipoly/oscpendo) provided 71 consensus recommendations regarding an endocrine disruptor screening program. Considering the EDSTAC's diverse membership, EPA found its consensus recommendations compelling and scientifically rigorous. Therefore, EPA closely followed EDSTAC's advice and recommendations in developing its Endocrine Disruptor Screening Program (EDSP).Start Printed Page 23024
EPA's EDSP is outlined in the August 11, 1998 Federal Register (63 FR 42852) (FRL-6021-3), and further developed as a proposed statement of policy in the December 28, 1998 Federal Register (63 FR 71542) (FRL-6052-9), available at www.epa.gov/fedrgstr/EPA-TOX/1998/December/Day-28/t34298.htm). The EDSP proposed statement of policy, including public comments, was subsequently reviewed by a joint panel of the FIFRA Scientific Advisory Panel (SAP) and the EPA Science Advisory Board (SAB) in May 1999. Like Gray et al. (Ref. 3), EDSTAC (Ref. 2) and the NRC (Ref. 5), the SAP/SAB (Ref. 8) final report concluded that a tiered approach relying on a combination of in vivo and in vitro screens for Tier 1 and a set of in vivo Tier 2 tests was scientifically reasonable. This conclusion was based upon each group's assessment of the current state-of-the-science on the evaluation of agents impacting the endocrine system. Another consistent conclusion was the need to validate the individual screens and tests in EDSP. The validation and peer review are science-based process steps, which are prerequisite to the final development and approval of test guidelines for regulatory use (Ref. 4).
EPA also received public comments on the proposed statement of policy which were considered by the SAP/SAB joint panel review. The Agency will respond to these public comments in a future Federal Register notice and final statement of policy prior to requiring regulatory testing.
C. Implementation of EPA's Endocrine Disruptor Screening Program
EPA's ongoing implementation of Endocrine Disruptor Screening Program (EDSP) is science-driven, and based on the recommendations and comments of EDSTAC (Ref. 2), the FIFRA SAP/SAB Joint Panel (Ref. 8), and the NAS (Ref. 5). In keeping with its FFDCA-mandated deadline, the Agency forwarded a Report to Congress in August 2000, providing the Agency's progress on implementation of the EDSP. The above referenced Federal Register Notices, SAB/SAP report, Endocrine Disruptor Screening Program Report to Congress, and other EPA EDSP-related information are available at www.epa.gov/scipoly/oscpendo. The Agency's Implementation is currently proceeding on two fronts. EPA is completing development of the Endocrine Disruptor Priority Setting Database and the compartment-based approach that the Agency will use to establish priorities for screening chemicals at a later stage of implementation. EPA has also initiated prevalidation and validation studies on some of the of Tier 1 and Tier 2 assays that are likely to be part of the EDSP. The Endocrine Disruptor Methods Validation Subcommittee will provide advice and comment on both the ongoing and new studies necessary to validate the EDSP assays.
1. Priority setting. Priority setting processes will not be included in the mission statement to the EDMVS, but EPA's ongoing activities are briefly summarized here for background information purposes. As many as 87,000 chemicals may be sorted into categories for priority setting. However, EPA anticipates that tens of thousands of chemicals will be exempted from screening. Priority setting tools and processes are being developed by EPA, its contractors and cooperators. Until the Agency completely finalizes its priority setting tools and process, accurate estimates of how many chemicals may actually be candidates for screening remain premature. Yet, EPA expects that 10% or less of the universe of chemicals will undergo actual screening.
Public review and comment during development of the EDSP priority setting process has been provided through two public workshops held in January 1999 and June 2000 (Federal Register notices and workshop reports are available at www.epa.gov/scipoly/oscpendo). The priority setting approach is based on development and application of a relational database titled The Endocrine Disruptor Priority Setting Database (EDPSD). The EDPSD consolidates existing information and data on exposure and effects to rank chemicals. The chemicals are ranked within compartments. A number of compartments may be configured on the basis of exposure and effects characteristics, separately or in combination. The current version of the EDPSD may be examined at http://www.ergweb.com/endocrine.
Recognizing that little relevant effects information for endocrine disruption exists for the vast majority of chemicals, the Agency is considering approaches for providing additional information to assist priority setting. Initially, high throughput pre-screening (HTPS) technology was viewed as an approach to provide information on the ability of a chemical to bind with hormone receptors, thereby improving the assignment of a high screening priority for endocrine active chemicals. An HTPS feasibility study was completed by the Agency in 1999. Following external scientific peer review by the FIFRA SAP/EPA SAB Joint Panel (Ref. 8), the HTPS reporter gene methods used in the feasibility study were deemed unreliable for routine regulatory use. Presently, EPA is not conducting any Agency-sponsored studies on HTPS. The Agency is continuing discussions with the Japanese Government on the development of a different reporter gene based HTPS system. However, the Japanese studies remain ongoing, and must await completion and scientific evaluation before being further considered.
EPA has also engaged in the development of QSAR models to predict endocrine receptor binding activity from the molecular structure of chemicals. The Agency is presently working with the Food and Drug Administration to refine and validate two-dimensional pharmacophore screening models and three-dimensional CoMFA (comparative molecular field analysis) models, as well as the Unversity of Bourgas on three dimensional COREPA (Common Reactivity Pattern) models. The Agency is developing estrogen and androgen receptor binding data to verify the model results. The QSAR model approaches have the potential to be incorporated in the EDPSD, provided they prove to be reliable upon completion of ongoing studies and scientific peer review.
Priority setting is not part of the charge to the EDMVS. However, the Agency will keep the subcommittee informed of these activities, in that the results have implications for the development of in vitro screening and pre-screening methods. The latter will be part of the charge to the subcommittee.
2. Validation of EDSP assays. The EDSP assays that EPA is developing and validating on a priority basis are identified below:
Tier 1 Screening Battery Methods
- Estrogen (ER) and androgen receptor (AR) binding assays
- ER and AR assays with w/transcriptional activation
- Steroidogenesis assay
- Uterotrophic assay
- Hershberger assay
- Pubertal female assay w/thyroid endpoints
- Frog metamorphosis
- Fish reproductive screening assay
Tier 1 Screening Battery Alternate Methods
- Pubertal male assay w/thyroid endpoints
- Aromatase assay
- Rodent in utero through lactation assay
Tier 2 Testing Battery Methods
- Two-generation mammalian reproductive toxicity study with endocrine endpointsStart Printed Page 23025
- Two-generation avian reproductive toxicity study with endocrine endpoints
- Two-generation fish reproductive study with endocrine endpoints
- Two-generation mysid shrimp reproductive study with endocrine endpoints
3. The Validation Process. As a charter member and co-chair of the Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM), EPA (and the EDMVS) will follow the interagency validation framework outlined in Validation and Regulatory Acceptance of Toxicological Test Methods (Ref. 4) for validating the EDSP screening and testing methods. The National Institute of Environmental Health Sciences (NIEHS) established ICCVAM as a standing committee of Federal agencies to coordinate and facilitate interagency validation, acceptance, and harmonization of toxicological test methods with an emphasis on reducing animal use, refining procedures involving animals to make them less stressful and replacing animals where scientifically appropriate.
The ICCVAM validation process was designed as a flexible, adaptable framework applicable to conventional and alternative methods, and to meet the needs of diverse test sponsors, Federal agencies and regulatory processes. The framework provides a number of stages and outcomes including research, methods development, prevalidation, validation, peer review, and regulatory acceptance. All stages and outcomes are part of the interagency ICCVAM process. However, as indicated in Validation and Regulatory Acceptance of Toxicological Test Methods: “ICCVAM does not ordinarily address methods applicable to only one agency” (Ref. 4, p. 46); and “test method sponsors may elect to arrange for independent peer review by third parties prior to submission of a method to an agency or ICCVAM” (Ref. 4, p. 47). Regulatory approval of test guidelines remains the sole responsibility of each regulatory agency.
Although there is widespread interest in EPA's EDSP, the screening and testing methods are being developed and validated with the specific goal of developing test guidelines for EPA regulatory use. The test guidelines will ultimately be used by chemical manufacturers, pesticide registrants, and other entities to develop data for submission to EPA in support of the Agency's statutorily mandated chemical risk management programs.
EPA will manage the validation process for the EDSP with substantial involvement of ICCVAM personnel. EPA and ICCVAM have mutually agreed to this administrative arrangement to ensure that EDSP validation meets ICCVAM interagency validation principles (Ref. 4), as well as EPA guideline development, review, and regulatory approval processes for EPA's chemical risk management programs. EPA will manage the process set forth by ICCVAM for the validation of all of the specific in vitro and in vivo EDSP methods. ICCVAM and the National Toxicology Program will manage and peer review a background review document and summarize literature derived performance criteria into a generic guidance document that could be used for validating estrogen receptor and androgen receptor binding/reporter gene assays.
In addition to EPA's domestic EDSP validation program, certain screening assays and tests for international use are also being conducted by the Organization for Economic Cooperation and Development (OECD) Test Guidelines Program. EPA is an active member of the OECD Test Guidelines Program activities, as well as the latter's Endocrine Disruptor Testing and Assessment Workgroup. EPA will rely upon the OECD mechanism for validating those EDSP screens and tests of international interest. The OECD, EPA and ICCVAM have also mutually agreed to this administrative arrangement to ensure that all appropriate validation and peer review steps are achieved in both domestic and international efforts.
4. Studies initiated to date by EPA. A number of studies have been initiated by EPA to provide the data necessary for the validation of individual methods. The results of these ongoing studies, as well as advice regarding the design of new studies will be the primary work of the EDMVS. A summary of studies that have been initiated by EPA is shown below.
|Assays/tests||Literature review||Initial protocol demonstration||Prevalidation studies||Validation studies|
|ER/AR binding assay||•||•||•||•|
|Pubertal female assay||•||•||•|
|Pubertal male assay||•||•||•|
|Frog metamorphosis assay||•|
|Fish reproductive screen||•|
|Mammalian 2-generation test||•|
|Avian 2-generation test||•|
|Invertebrate 2-generation test||•|
V. Endocrine Disruptor Methods Validation Subcommittee Mission Statement
A. Purpose and Authority
This mission statement establishes the Endocrine Disruptor Methods Validation Subcommittee (EDMVS) in accordance with the Federal Advisory Subcommittee Act (5 U.S.C. App. 2 section 9(c)). The EDMVS is being established as a subcommittee under the auspices of EPA's National Advisory Council for Environmental Policy and Technology. The purpose of the EDMVS is to provide advice and counsel to the EPA on scientific issues associated with the conduct of studies necessary for validation of Tier 1 and Tier 2 methods for the EPA's Endocrine Disruptor Screening Program (63 FR 71542). The EDMVS will provide advice and recommendations regarding: the development of initial protocols; prevalidation study designs; validation study designs; and synthesis of prevalidation and validation study results for the EDSP Tier 1 and Tier 2 methods into documents suitable for external peer review. The EDMVS advice and recommendations will be forwarded to the Agency through NACEPT. Taking into account this advice and recommendations, EPA will manage and conduct prevalidation and validation laboratory studies.
EDMVS provides independent advice and counsel to the Agency through NACEPT, on scientific and technical issues related to validation of EDSP Tier 1 and Tier 2 methods, including the reduction of animal pain suffering and use. Following validation of the individual screening methods, the collective data will be integrated and evaluated to optimize the configuration of the Tier 1 screening battery. EDMVS may also examine new or innovative methods that may be applicable for inclusion in a second phase of validation. Specific areas for advice and counsel include:
1. Initial protocol development. The development and/or review of Endocrine Disruptor Screening Program (EDSP) initial protocols based on existing information and experience (past and current research). The initial protocols will serve as the starting point for all subsequent prevalidation studies. EPA will prepare a Background Review Document (BRD) addressing all critical areas outlined in Validation and Regulatory Acceptance of Toxicological Test Methods (Ref. 4) will be prepared for each method to summarize, explain, and document decisions regarding the relevant principles, methods and techniques for the initial protocol.
2. Prevalidation studies. The further development and optimization of specific EDSP initial protocols through targeted investigations. The targeted investigations will be designed to address questions necessary for an optimized, transferable protocol suitable for inter-laboratory validation studies.
3. Validation studies. The design and interpretation of comparative inter-laboratory studies to establish the reliability and relevance of the EDSP optimized transferable protocols. Following validation, the optimized transferable protocols will provide the basis for endocrine disruptor test guidelines for regulatory use.
4. Preparation of EDSP Method Validation documents for external peer review. All EDSP methods must be peer reviewed prior to approval for regulatory use. With advice and recommendations of the EDMVS, EPA will synthesize and interpret data and information generated in protocol development, prevalidation studies and validation studies into EDSP method-specific documents suitable for external peer review. External scientific peer review of the EDSP methods will be arranged by EPA through an Agency-approved external scientific peer review panel.
C. Scope of the Activity
The EDMVS and NACEPT will provide a forum for a diverse group of individuals representing a broad range of interests and backgrounds from across the country to consult with and make recommendations to the Agency on matters relating to the validation and external scientific peer review of endocrine disruptor screening and testing methods. The subcommittee will analyze issues, review data and protocols, compile information, make recommendations to the Agency, and undertake other activities necessary to meet its responsibilities.
The EDMVS shall be composed of 25 members approved by the Administrator. Members will be selected on the basis of their relevant scientific expertise and diversity of perspectives on endocrine disruptor screening and testing methods and procedures, toxicity test methods standardization and validation, and chemical and pesticide regulatory processes. Members will be appointed for 2 years. Subcommittee members shall be appointed with balanced representation from the following sectors: The agrichemical and commodity chemical industries; environmental/public interest organizations; public health organizations; animal welfare organizations; Federal agencies; State, local and tribal governments; academia; consumers, and the public. The Agency will appoint a Chair and Deputy Chair for the Subcommittee.
E. Workgroups and Ad Hoc Teams
Workgroups and ad hoc teams may be established on an as-needed basis consisting of EDMVS members, or supplemented with specialists qualified in the technical area of the workgroup or team appointed by the Agency. Such teams will develop in-depth technical issues or analyses that may be necessary for the EDMVS to conduct its deliberations.
The EDMVS will hold up to six meeting a year. A regular employee of EPA will act as the Designated Federal Officer who will be present or represented at all meetings and is authorized to adjourn any such meetings whenever the official determines it to be in the public interest. All EDMVS meetings will be called, announced, and held in accordance with FACA and NACEPT rules, which require open meetings and an opportunity for interested persons to file comments before or after meetings, or to make statements during the public meetings to the extent time permits. The date, time, location and any public participation instructions for each meeting will be announced in the Federal Register at least 30 days before the meeting date. Each meeting shall be conducted in accordance with an agenda approved in advance by the Designated Federal Officer. The meeting information and agenda will be posted on the Agency's web site as soon as it is available, and no later than 15 days before the meeting date.
1. Ankley, G. T. et al. 1998. Overview of a workshop on screening methods for detecting (anti)-estrogenic/androgenic chemicals in wildlife. Environmental Toxicology Chemistry. 17: 68-87.
2. Endocrine Disruptor Screening and Testing Advisory Committee: Final Report. 1998. U. S. Environmental Protection Agency, Office of Prevention, Pesticides, and Toxic Substances, Washington, DC.
3. Gray. L. E. et al. 1997. Endocrine Screening Methods Workshop Report: Detection of Estrogenic and Androgenic Hormonal and Antihormonal Activity for Chemicals that Act via Receptor or Start Printed Page 23027Steroidogenic Enzyme Mechanisms. Reproductive Toxicology 11:719-750.
4. National Institute of Environmental Health Sciences. 1997. Validation and Regulatory Acceptance of Toxicological Test Methods: A report of the ad hoc Interagency Coordinating Committee on the Validation of Alternative Methods. NIH Publication No. 97-3981, NIEHS, Research Triangle Park, NC,105 pp.
5. National Research Council. Hormonally Active Agents in the Environment. National Academy Press, Washington, DC, 429 pp.
6. U. S. EPA. 1997. Special Report on Environmental Endocrine Disruptors: An Effects Assessment and Analysis. U. S. Environmental Protection Agency, Office of Research and Development, EPA/630/R-96/012, Washington, DC, 116 pp.
7. U.S. EPA. 1997. Screening Methods for Chemicals that Alter Thyroid Hormone Action, Function, and Homeostasis. U. S. Environmental Protection Agency, Office of Research and Development, EPA/6000/R-98/057, Washington, DC, 44 pp.
8. U. S. EPA. 1999. Review of the EPA's Proposed Environmental Endocrine Disruptor Screening Program. U. S. Environmental Protection Agency, Science Advisory Board, EPA-SAB-EC-99-013, Washington, DC, 35 pp.Start List of Subjects
List of SubjectsEnd List of Subjects Start Signature
Dated: April 24, 2001.
Stephen L. Johnson,
Acting Assistant Administrator, Office of Prevention, Pesticides and Toxic Substances.
[FR Doc. 01-11412 Filed 5-4-01 8:45 am]
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