[Federal Register Volume 72, Number 60 (Thursday, March 29, 2007)]
[Notices]
[Pages 14816-14818]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-5831]


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DEPARTMENT OF HEALTH AND HUMAN SERVICES


National Toxicology Program (NTP); Office of Chemical Nomination 
and Selection; Announcement of and Request for Public Comment on 
Toxicological Study Nominations to the NTP

AGENCY: National Institute of Environmental Health Sciences (NIEHS), 
National Institutes of Health.

ACTION: Notice; request for comments and additional information.

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SUMMARY: The NTP continuously solicits and accepts nominations for 
toxicological studies to be undertaken by the program. Nominations of 
substances of potential human health concern are received from federal 
agencies, the public, and other interested parties. These nominations 
are subject to several levels of review before selections for testing 
are made and toxicological studies are designed and implemented. This 
notice (1) Provides brief background information and preliminary study 
recommendations regarding nine nominations for study by the NTP (Table 
1), (2) solicits public comment on the nominations and study 
recommendations, and (3) requests the submission of additional relevant 
information for consideration by the NTP in its continued review of 
these nominations. An electronic copy of this announcement, supporting 
documents for each nomination, and further information on the NTP and 
the NTP Study Nomination and Review Process can be accessed through the 
NTP Web site (http://ntp.niehs.nih.gov/; select ``Nominations to the 
Testing Program'').

DATES: Comments or information should be submitted by May 10, 2007.

ADDRESSES: Correspondence should be addressed to Dr. Scott A. Masten, 
Director, Office of Chemical Nomination and Selection, NIEHS/NTP, 111 
T.W. Alexander Drive, P.O. Box 12233, Research Triangle Park, North 
Carolina 27709; telephone: 919-541-5710; FAX: 919-541-3647; e-mail: 
<a href="/cdn-cgi/l/email-protection#721f130106171c321c1b171a015c1c1b1a5c151d04"><span class="__cf_email__" data-cfemail="0865697b7c6d664866616d607b26666160266f677e">[email protected]</span></a>.

SUPPLEMENTARY INFORMATION:

Background Information

    The NTP actively seeks to identify and select for study chemicals 
and other substances for which sufficient information is not available 
to adequately evaluate potential human health hazards. The NTP 
accomplishes this goal through a formal open nomination and selection 
process. Nominations can be submitted to the

[[Page 14817]]

NTP at http://ntp.niehs.nih.gov/; select ``Nominations to the Testing 
Program'' or by contacting Dr. Scott Masten (see ADDRESSES above). 
Substances considered appropriate for study generally fall into two 
broad yet overlapping categories: (1) Substances judged to have high 
concern as possible public health hazards based on the extent of human 
exposure and/or suspicion of toxicity and (2) substances for which 
toxicological data gaps exist and additional studies would aid in 
assessing potential human health risks, e.g., by facilitating cross-
species extrapolation or evaluating dose-response relationships. 
Nominations are also solicited for studies that permit the testing of 
hypotheses to enhance the predictive ability of future NTP studies, 
address mechanisms of toxicity, or fill significant gaps in the 
knowledge of the toxicity of classes of chemical, biological, or 
physical agents.
    Study nominations may entail the evaluation of a variety of health-
related effects including, but not limited to, reproductive and 
developmental toxicity, genetic toxicity, immunotoxicity, 
neurotoxicity, metabolism and disposition, and carcinogenicity in 
appropriate experimental models. In reviewing and selecting nominations 
for study, the NTP also considers legislative mandates that require 
responsible private sector organizations to evaluate their products for 
health and environmental effects. The possible human health 
consequences of anticipated or known human exposure, however, remain 
the over-riding factor in the NTP's decision to study a particular 
substance.
    Nominations undergo a multi-step, formal process of review. 
Briefly, during the entire nomination review and selection process, the 
NTP works with staff at other federal agencies and interested parties 
to supplement information about nominated substances and ensure that 
regulatory and public health needs are addressed. The nomination review 
and selection process is accomplished through the participation of 
representatives from the NIEHS, other federal agencies represented on 
the Interagency Committee for Chemical Evaluation and Coordination 
(ICCEC), the NTP Board of Scientific Counselors (BSC)--an external 
scientific advisory body, the NTP Executive Committee--the NTP federal 
interagency policy body, and the public. Preliminary study 
recommendations for each nomination are developed and refined by the 
nominator, NTP staff, and the ICCEC and may be further refined as the 
formal review process continues. The NTP considers recommendations from 
the BSC and the NTP Executive Committee, public comments received on 
the nominations, and other available information in selecting candidate 
substances for study. The NTP initiates appropriate toxicology and 
carcinogenicity studies as time and resources permit.
    The nomination review and selection process is described in further 
detail on the NTP Web site (http://ntp.niehs.nih.gov/; select 
``Nominations to the Testing Program'').

Request for Comments and Additional Information

    The NTP invites interested parties to submit written comments or 
supplementary information on the nominated substances and study 
recommendations that appear in Table 1. The NTP welcomes toxicology 
study information from completed, ongoing, or anticipated studies, as 
well as information on current U.S. production levels, use or 
consumption patterns, human exposure, environmental occurrence, or 
public health concerns for any of the nominated substances. The NTP is 
interested in identifying appropriate animal and non-animal 
experimental models for mechanistic-based research, including 
genetically modified rodents and high-throughput in vitro test methods, 
and as such, solicits comments regarding the use of specific in vivo 
and in vitro experimental approaches to address questions relevant to 
the nominated substances and issues under consideration. Comments 
should be submitted by May 10, 2007; however, the NTP welcomes comments 
or additional information on these study nominations at any time. The 
NTP will not respond to submitted comments; however, all information 
received will become part of the official record that the NTP considers 
in its ongoing review of these nominations. Persons submitting comments 
should include their name, affiliation, mailing address, phone, fax, e-
mail address, and sponsoring organization (if any) with the submission. 
Written submissions will be made publicly available electronically on 
the NTP Web site as they are received (http://ntp.niehs.nih.gov/; 
select ``Nominations to the Testing Program'').

Background Information on the NTP Office of Chemical Nomination and 
Selection

    The NTP Office of Chemical Nomination and Selection (OCNS) manages 
the solicitation, receipt, and review of NTP toxicology study 
nominations. The OCNS conducts an initial review of each study 
nomination received to determine whether the substance or issue has 
been adequately studied or has been previously considered by the NTP. 
For nominations not eliminated from consideration or deferred at this 
stage, the OCNS initiates a formal review process, as described above. 
The OCNS also ensures adequate background information is available to 
support the review for each nomination and corresponds with interested 
parties regarding the status of NTP study nominations. For further 
information on the OCNS visit the NTP Web site (http://ntp.niehs.nih.gov; select ``Nominations to the Testing Program'') or 
contact Dr. Masten (see ADDRESSES above).

    Dated: March 21, 2007.
David A. Schwartz,
Director, National Institute of Environmental Health Sciences and 
National Toxicology Program.

         Table 1.--Testing Recommendations for Substances Nominated to the NTP for Toxicological Studies
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                                                                                           Preliminary study
        Substance [CAS No.]            Nominated by \1\       Nomination rationale        recommendations \2\
----------------------------------------------------------------------------------------------------------------
Aminopyridines: 2-Aminopyridine     NCI..................  Moderate production and     --Toxicological
 [504-29-0], 3-Aminopyridine [462-                          use; acutely toxic; lack    characterization
 08-8], 4-Aminopyridine [504-24-5].                         of adequate toxicological   including chronic
                                                            data; suspicion of          toxicity and
                                                            toxicity and                carcinogenicity studies
                                                            carcinogenicity based on    for 2-aminopyridine.
                                                            structure.                 --Short-term mechanistic
                                                                                        studies for 3- and 4-
                                                                                        aminopyridine.
                                                                                       --Comparative
                                                                                        neurotoxicity studies
                                                                                        for 2-, 3-, and 4-
                                                                                        aminopyridine.

[[Page 14818]]

 
Artificial butter flavoring         United Food and        Evidence of lung disease    --Chronic toxicity and
 mixture and certain components:     Commercial Workers     in exposed workers and      carcinogenicity studies
 Acetoin [513-86-0], Diacetyl [431-  International Union.   respiratory toxicity in     via inhalation in rats.
 03-8].                                                     short-term animal          --Mechanistic studies.
                                                            toxicity studies.
Asbestos, naturally occurring and   National Center for    Widespread community        --Mineral
 atypical forms [1332-21-4].         Environmental Health/  exposure in certain         characterization.
                                     Agency for Toxic       geographic locales;        --In vitro durability and
                                     Substances and         insufficient dose-          toxicity studies.
                                     Disease Registry,      response data to           --Subchronic and chronic
                                     U.S. Environmental     characterize risk from      toxicity/carcinogenicity
                                     Protection Agency.     exposure to                 studies via inhalation.
                                                            ``unregulated''            --Studies should utilize
                                                            asbestiform mineral         test materials
                                                            fibers and naturally        representative of
                                                            occurring fibrous mineral   minerals identified in
                                                            ``mixtures''.               Libby, MT and at other
                                                                                        Naturally Occurring
                                                                                        Asbestos (NOA) sites.
Diethyl phthalate [84-66-2].......  National Institute of  Widespread consumer         --Multigeneration oral
                                     Environmental Health   exposure through use in     reproductive and
                                     Sciences.              cosmetics and personal      developmental toxicity
                                                            care products;              studies
                                                            insufficient toxicity      --Toxicokinetic studies
                                                            data to assess potential    (oral and dermal
                                                            reproductive hazard.        routes).
2',2''-Dithiobisbenzanilide [135-   NCI..................  High production volume;     --Genotoxicity studies.
 57-9].                                                     potential worker and       --Metabolism studies.
                                                            consumer exposures; lack
                                                            of adequate toxicological
                                                            data; suspicion of
                                                            toxicity based on
                                                            structure.
2-Methoxy-4-nitroaniline [97-52-9]  NCI..................  High production volume;     --Toxicological
                                                            potential worker            characterization.
                                                            exposures; lack of         --Short-term mechanistic
                                                            adequate toxicological      studies to predict
                                                            data; positive              carcinogenic potential.
                                                            mutagenicity data; strong
                                                            suspicion of toxicity and
                                                            carcinogenicity based on
                                                            structure.
Nanoscale materials Nanoscale gold  U.S. Food and Drug     Widespread and increasing   --Nanoscale materials
 [7440-57-5] Nanoscale silver        Administration.        use in drug, food and       characterization.
 [7440-22-4].                                               cosmetic products; lack    --Metabolism and
                                                            of adequate toxicological   pharmacokinetic studies.
                                                            and pharmacokinetic data;  --Acute, subacute and
                                                            need to evaluate whether    subchronic toxicity
                                                            the current required        studies.
                                                            tests are adequate to      --Mechanistic studies to
                                                            detect adverse biological   assess the role of size
                                                            and toxicological events.   and surface coating on
                                                                                        biological disposition
                                                                                        and toxicity.
Pentaethylenehexamine [4067-16-7].  NCI..................  High production volume;     No studies at this time
                                                            potential worker            due to the irritant and
                                                            exposures; lack of          corrosive nature of this
                                                            adequate toxicological      compound.
                                                            data; positive
                                                            mutagenicity data.
o-Phthalaldehyde [643-79-8].......  National Institute     Widespread and increasing   --Toxicological
                                     for Occupational       use as a disinfectant in    characterization
                                     Safety and Health.     health care settings;       including studies to
                                                            lack of adequate and        assess dermal
                                                            publicly available          irritation, dermal
                                                            toxicological data;         toxicity, and
                                                            potential skin and          sensitization and
                                                            respiratory sensitizer.     asthmagenic potential.
----------------------------------------------------------------------------------------------------------------
\1\ National Cancer Institute (NCI).
\2\ The term ``toxicological characterization'' in this table includes studies for genotoxicity, subchronic
  toxicity, and chronic toxicity/carcinogenicity as determined to be appropriate during the conceptualization
  and design of a research program to address toxicological data needs. Other types of studies (e.g., metabolism
  and disposition, immunotoxicity, and reproductive and developmental toxicity) may be conducted as part of a
  complete toxicological characterization; however, these types of studies are not listed unless they are
  specifically recommended.

 [FR Doc. E7-5831 Filed 3-28-07; 8:45 am]
BILLING CODE 4140-01-P


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