[Federal Register: November 24, 2009 (Volume 74, Number 225)]
[Notices]
[Page 61380-61383]
[DOCID:fr24no09-82]

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COMMODITY FUTURES TRADING COMMISSION

SECURITIES AND EXCHANGE COMMISSION

[Release No. 34-61027]

Joint Order Modifying the Listing Standards Requirements Under
Section 6(h) of the Securities Exchange Act of 1934 and the Criteria
Under Section 2(a)(1) of the Commodity Exchange Act

    The Securities Exchange Act of 1934 (``Exchange Act'') and the
Commodity Exchange Act (``CEA'') set forth the types of securities on
which security futures \1\ can be based. The Exchange Act provides that
it is unlawful for any person to effect transactions in security
futures that are not listed on a national securities exchange or a
national securities association registered pursuant to Section 15A of
the Exchange Act.\2\ The Exchange Act further provides that such
exchange or association is permitted to trade only security futures
that conform with listing standards filed with the Securities and
Exchange Commission (``SEC'') and that meet the criteria specified in
Section 2(a)(1)(D)(i) of the CEA.\3\ Section 2(a)(1)(D)(i) of the CEA
permits the Commodity Futures Trading Commission (``CFTC'') to
designate a board of trade as a contract market with respect to, or to
register as a derivatives transaction execution facility to list or
execute, transactions in security futures if the board of trade and the
applicable contract meet the criteria specified in that section.
Similarly, the Exchange Act requires that the listing standards filed
with the SEC by an exchange or

association meet specified requirements.\4\
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    \1\ Security futures are futures contracts on single securities
and narrow-based security indexes. See Section 3(a)(55)(A) of the
Exchange Act, 15 U.S.C. 3(a)(55)(A), and Section 1a(31) of the CEA,
7 U.S.C. 1a(31).
    \2\ Section 6(h)(1) of the Exchange Act, 15 U.S.C. 78f(h)(1).
    \3\ Section 6(h)(2) of the Exchange Act, 15 U.S.C. 78f(h)(2).
See also 7 U.S.C. 2(a)(1)(D)(i).
    \4\ Section 6(h)(3) of the Exchange Act, 15 U.S.C. 78f(h)(3).
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    Among other things, the Exchange Act and the CEA require that any
security underlying a security future, including each component
security of a narrow-based security index, except as otherwise provided
in a rule, regulation, or order, be registered pursuant to Section 12
of the Exchange Act.\5\ In 2006, the SEC and CFTC (together, the
``Commissions'') adopted SEC Rule 6h-2 \6\ and an amendment to CEA Rule
41.21,\7\ respectively, to permit security futures to be based on
individual debt securities or narrow-based indexes composed of such
securities.\8\ However, because most debt securities are not registered
under Section 12 of the Exchange Act,\9\ few security futures based on
debt securities can be listed.
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    \5\ Section 6(h)(3)(A) of the Exchange Act, 15 U.S.C.
78f(h)(3)(A), and Section 2(a)(1)(D)(i)(I) of the CEA, 7 U.S.C.
2(a)(1)(D)(i)(I).
    \6\ 17 CFR 240.6h-2.
    \7\ 17 CFR 41.21.
    \8\ See Securities Exchange Act Release No. 54106 (July 6, 2006)
71 FR 39534 (July 13, 2006) (``2006 Rulemaking'').
    \9\ In this regard, the Commissions note that, in a 2005 request
for exemptive relief to permit its members, brokers, and dealers to
trade certain unregistered debt securities, the New York Stock
Exchange (``NYSE'') estimated that, out of over 22,000 publicly
offered corporate bond issues having a par value in excess of $3
trillion, only 8% of the $3 trillion par value of these debt
securities was registered under the Exchange Act. See Securities
Exchange Act Release No. 51998 (July 8, 2005), 70 FR 40748 (July 14,
2005). The SEC granted the NYSE's request for exemptive relief,
subject to certain conditions. See Securities Exchange Act Release
No. 54766 (November 16, 2006), 71 FR 67657 (November 22, 2006) (File
No. S7-06-05) (``NYSE Exemption'').
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    In addition, the Exchange Act \10\ and the CEA \11\ require that
security futures be based upon common stock and such other equity
securities as the Commissions may jointly determine to be appropriate.
Pursuant to this authority, the Commissions previously issued joint
orders to permit depository shares \12\ and shares of Exchange-Traded
Funds, Trust Issued Receipts, and shares of registered closed-end
management investment companies \13\ to underlie security futures
(together, the ``Prior Joint Orders''). There are, however, other types
of securities that underlie listed options that are neither common
stock nor covered by the Prior Joint Orders.
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    \10\ 15 U.S.C. 78f(h)(3)(D).
    \11\ 7 U.S.C. 2(a)(1)(D)(i)(III).
    \12\ See Securities Exchange Act Release No. 44725 (August 20,
2001).
    \13\ See Securities Exchange Act Release No. 46090 (June 19,
2002), 67 FR 42760 (June 25, 2002).
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    Section 6(h)(4)(A) of the Exchange Act \14\ and Section
2(a)(1)(D)(v)(I) of the CEA \15\ provide that the Commissions, by rule,
regulation, or order, may jointly modify the listing standard
requirements specified in Sections 6(h)(3)(A) and (D) of the Exchange
Act \16\ and the criteria specified in Sections 2(a)(1)(D)(i)(I) and
(III) of the CEA \17\ to the extent that such modification fosters the
development of fair and orderly markets in security futures products,
is necessary or appropriate in the public interest, and is consistent
with the protection of investors. For the reasons and subject to the
conditions discussed below, the Commissions believe that jointly
modifying these requirements to permit any security that is eligible to
underlie options traded on a national securities exchange to also
underlie security futures, and to permit debt securities that are not
registered under Section 12 of the Exchange Act (``unregistered debt
securities'') to underlie security futures, will foster the development
of fair and orderly markets, is necessary or appropriate in the public
interest, and is consistent with the protection of investors.
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    \14\ 15 U.S.C. 78f(h)(4)(A).
    \15\ 7 U.S.C. 2(a)(1)(D)(v)(I).
    \16\ 15 U.S.C. 78f(h)(3)(A) and (D).
    \17\ 7 U.S.C. 2(a)(1)(D)(i)(I) and (III).
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I. Discussion

A. Security Futures Based on Securities Eligible To Underlie Options
Traded on a National Securities Exchange

    Section 6(h)(3)(D) of the Exchange Act \18\ and Section
2(a)(1)(D)(i)(III) of the CEA \19\ require that security futures be
based upon common stock and such other equity securities as the
Commissions jointly determine appropriate. Section 6(h)(4)(A) of the
Exchange Act \20\ and Section 2(a)(1)(D)(v)(I) of the CEA \21\ provide
that the Commissions, by rule, regulation, or order, may jointly modify
this requirement to the extent that such modification fosters the
development of fair and orderly markets in security futures products,
is necessary or appropriate in the public interest, and is consistent
with the protection of investors.
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    \18\ 15 U.S.C. 78f(h)(3)(D).
    \19\ 7 U.S.C. 2(a)(1)(D)(i)(III).
    \20\ 15 U.S.C. 78f(h)(4)(A).
    \21\ 7 U.S.C. 2(a)(1)(D)(v)(I).
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    The Commissions now believe that modifying the requirement in
Section 6(h)(3)(D) of the Exchange Act and Section 2(a)(1)(D)(i)(III)
of the CEA to permit any security that is eligible to underlie options
traded on a national securities exchange to also underlie security
futures will foster the development of fair and orderly markets in
security futures products, is appropriate in the public interest, and
is consistent with the protection of investors.
    To be eligible to underlie options traded on a national securities
exchange, and, pursuant to this order, eligible to underlie security
futures, a security must meet securities options listing standards of a
national securities exchange. Options listing standards of a national
securities exchange are rules of an exchange, and, as such, must be
filed with the SEC pursuant to Section 19(b) of the Exchange Act,\22\
and comply with Section 6(b) of the Exchange Act.\23\ Section 6(b)(5)
of the Exchange Act,\24\ in particular, requires, among other things,
that the rules of a national securities exchange be designed to prevent
fraudulent and manipulative acts and practices, to promote just and
equitable principles of trade, to remove impediments to and perfect the
mechanism of a free and open market and a national market system and,
in general, to protect investors and the public interest. The SEC may
not approve an options exchange's proposed rule, including a proposed
options listing standard, unless the SEC finds that it is consistent
with the requirements of the Exchange Act, including Section 6(b),\25\
and the rules and regulations under the Exchange Act. Accordingly, the
Commissions believe that it is appropriate in the public interest and
consistent with the protection of investors to modify the listing
standard requirements in Section 6(h)(3)(D) of the Exchange Act and
Section 2(a)(1)(D)(i)(III) of the CEA to permit any security that is
eligible to underlie options traded on a national securities exchange
to also underlie security futures. In addition, the Commissions believe
that this modification of the listing standard requirements in the
Exchange Act and the CEA will reduce impediments to the listing of
security futures by allowing the creation of potentially useful new
financial instruments, thereby fostering the development of fair and
orderly markets in security futures. The Commissions believe, further,
that it is appropriate, in the public interest, and consistent with the
protection of investors to permit the listing and trading of security
futures based on any security that is eligible to underlie an exchange-
listed option because such security futures may facilitate price
discovery in, and be a useful hedge for, the underlying securities,
including

certain unregistered debt securities.\26\ Finally, the Commissions note
that all security futures will continue to be required to meet the
requirements of Sections 6(h)(3)(B), (C), and (E)-(L) of the Exchange
Act \27\ and Sections 2(a)(1)(D)(i)(II) and (IV)-(XI) of the CEA.\28\
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    \22\ 15 U.S.C. 78s(b).
    \23\ 15 U.S.C. 78f(b).
    \24\ 15 U.S.C. 78f(b)(5).
    \25\ 15 U.S.C. 78s(b).
    \26\ The listing standards applicable to options generally
require, among other things, that the underlying security be
registered under Section 12 of the Exchange Act, be an NMS Stock, as
defined in Regulation NMS under the Exchange Act, 17 CFR
242.600(b)(47), and have a substantial number of outstanding shares
that are widely held and actively traded. See, e.g., CBOE Rule 5.3
(Criteria for Underlying Securities). To date, the only securities
not registered under Section 12 of the Exchange Act (other than U.S.
government securities) that the SEC has approved to underlie
exchange-listed options are certain corporate debt securities. See
Securities Exchange Act Release No. 55976 (June 28, 2007), 72 FR
37551 (July 10, 2007) (order approving a proposal by the CBOE to
list options on certain unregistered corporate debt securities).
Among other things, these corporate debt securities must have
substantial trading volume, initial principal amount, and
outstanding float; the issuer of the corporate debt security must
have at least one class of equity security registered under Section
12(b) of the Exchange Act; and the issuer's equity securities must
satisfy the exchange's criteria to underlie options. See CBOE Rule
5.3.12.
    \27\ 15 U.S.C. 78f(h)(3)(B), (C) and (E)-(L).
    \28\ 7 U.S.C. 2(a)(1)(D)(i)(II) and (IV)-(XI).
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    Unless the Commissions jointly determine otherwise, some securities
eligible to underlie options traded on a national securities exchange
currently may not be eligible to underlie security futures because such
securities may not be common stock or covered by the Prior Joint
Orders. By permitting any security eligible to underlie options to also
underlie security futures, the Commissions are modifying the listing
standard requirements in the Exchange Act and the criteria in the CEA
to eliminate the requirement that any security underlying security
futures, including each component security of a narrow-based security
index, be common stock or such other equity securities as the
Commissions may jointly determine. Instead, as long as a security may
underlie options traded on a national securities exchange and the
listing standards and the criteria for futures on such security meet
the requirements of Sections 6(h)(3)(B), (C), and (E)-(L) of the
Exchange Act and Sections 2(a)(1)(D)(i)(II) and (IV)-(XI) of the CEA,
such security may underlie security futures.\29\
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    \29\ The Commissions note that Section 6(h)(3)(C) of the
Exchange Act, 15 U.S.C. 78f(h)(3)(C), which will continue to apply,
requires that listing standards for security futures be no less
restrictive than comparable listing standards for options traded on
a national securities exchange or national securities association.
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    Further, Section 6(h)(2) of the Exchange Act \30\ provides that a
national securities exchange or a national securities association is
permitted to trade only security futures that (A) conform with listing
standards that the exchange or association files with the SEC under
Section 19(b) of the Exchange Act, and (B) meet the criteria specified
in Section 2(a)(1)(D)(i) of the CEA.\31\ Such security futures listing
standards must also meet the requirements specified in Section 6(h)(3)
of the Exchange Act,\32\ including the requirement that the listing
standards for security futures be no less restrictive than comparable
listing standards for options traded on a national securities exchange
or a national securities association.\33\ Before listing and trading
security futures on any security eligible to underlie options traded on
a national securities exchange, a national securities exchange or a
national securities association must file with the SEC, pursuant to
Section 19(b)(7) of the Exchange Act \34\ and Rule 19b-7
thereunder,\35\ a proposed rule change relating to its listing
standards. An exchange or an association also must concurrently file
its proposed listing standards with the CFTC pursuant to Section
19(b)(7)(B) of the Exchange Act.\36\
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    \30\ 15 U.S.C. 78f(h)(2).
    \31\ 7 U.S.C. 2(a)(1)(D)(i).
    \32\ 15 U.S.C. 78f(h)(3).
    \33\ See Section 6(h)(3)(C) of the Exchange Act, 15 U.S.C.
78f(h)(3)(C).
    \34\ 15 U.S.C. 78s(b)(7).
    \35\ 17 CFR 240.19b-7.
    \36\ 15 U.S.C. 78s(b)(7)(B).
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B. Security Futures Based on Unregistered Debt Securities

    Section 6(h)(3)(A) of the Exchange Act \37\ and Section
2(a)(1)(D)(i)(I) of the CEA \38\ require that any security underlying
security futures, including each component security of a narrow-based
security index, be registered pursuant to Section 12 of the Exchange
Act. Thus, although options are permitted to be listed on unregistered
debt securities under exchange listing standards,\39\ such securities
would not be permitted to underlie security futures without modifying
this requirement. As stated above, Section 6(h)(4)(A) of the Exchange
Act and Section 2(a)(1)(D)(v)(I) of the CEA provide that the
Commissions by rule, regulation, or order, may jointly modify this
requirement to the extent that the modification fosters the development
of fair and orderly markets in security futures products, is necessary
or appropriate in the public interest, and is consistent with the
protection of investors.
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    \37\ 15 U.S.C. 78f(h)(3)(A).
    \38\ 7 U.S.C. 2(a)(1)(D)(i)(I).
    \39\ See supra note 26.
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    Pursuant to this authority, the Commissions previously adopted SEC
Rule 6h-2 \40\ and amended CEA Rule 41.21 \41\ to modify the statutory
listing standards for security futures to permit the trading of
security futures based on debt securities and indexes composed of
certain debt securities.\42\ These rules permit the listing and trading
of new and potentially useful financial products. The Commissions
similarly believe that modifying the statutory listing standards for
security futures to permit, under certain conditions, the trading of
security futures based on certain unregistered debt securities, and
narrow-based indexes composed of such securities, will reduce
impediments to the listing of security futures based on debt securities
and serve the public interest by allowing the creation of potentially
useful new financial instruments, thereby fostering the development of
fair and orderly markets in security futures. The Commissions also
believe it is appropriate, in the public interest, and consistent with
the protection of investors to permit, subject to the conditions
discussed below, the listing of such security futures because they may
facilitate price discovery in, and be a useful hedge for, debt
securities.
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    \40\ 17 CFR 240.6h-2.
    \41\ 17 CFR 41.21.
    \42\ See 2006 Rulemaking, supra note 8.
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    An issuer of debt securities that are registered under Section 12
of the Exchange Act must provide comprehensive public information. This
joint order may permit the listing and trading of security futures on
debt securities that are not registered under Section 12 of the
Exchange Act. However, because the Commissions believe that the public
interest and the protection of investors is served by having
information about the underlying debt securities and their issuers
available, the Commissions are placing certain conditions on this
order. In particular, as discussed below, this order is conditioned on
an issuer of unregistered debt securities that underlie security
futures being subject to the periodic reporting requirements of the
Exchange Act. This condition is designed to ensure that information
about the issuers and their securities is available to investors and
futures traders.
    More specifically, the listing and trading of security futures on
unregistered debt would be permissible so long as the following four
conditions

are satisfied.\43\ First, the offer and sale of the underlying debt
securities must have been registered under the Securities Act of 1933
(``Securities Act'').\44\ This condition is designed so that
participants in the security futures market have access to the detailed
disclosure in the Securities Act registration statement for the debt
securities underlying these security futures.
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    \43\ These four conditions are consistent with the conditions in
the NYSE Exemption, supra note 9.
    \44\ 15 U.S.C. 77a et seq.
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    Second, the issuer of such securities must have at least one class
of equity securities registered under Section 12(b) of the Exchange
Act.\45\ The debt securities of a wholly-owned subsidiary of a parent
company with at least one class of equity securities registered under
Section 12(b) of the Exchange Act may also underlie a security
future.\46\ This condition is designed so that there is public
availability of information about the issuer and the securities, even
though the particular debt securities underlying the security future
are not registered under Section 12 of the Exchange Act. Because any
security registered under Section 12(b) is listed on a national
securities exchange, this condition assures that a national securities
exchange is responsible for monitoring the listed securities of the
issuer of the debt securities underlying a security future and
enforcing compliance by that issuer with comprehensive listing
standards of the applicable national securities exchange.
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    \45\ 15 U.S.C. 78l(b).
    \46\ The terms ``parent'' and ``wholly-owned'' have the same
meanings as in Rule 1-02 of SEC Regulation S-X, 17 CFR 210.1-02.
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    Third, the transfer agent for the debt securities underlying the
security future must be registered under Section 17A of the Exchange
Act.\47\ This condition is designed so that the transfer agents
providing services to issuers of debt securities underlying security
futures are subject to SEC oversight and the requirements of the
Exchange Act, including Section 17A, and the rules thereunder. Fourth,
the indenture for the unregistered debt securities underlying the
security future must be qualified under the Trust Indenture Act of 1939
(``Trust Indenture Act'').\48\ This condition is designed so that the
specific protections afforded to debt holders under the Trust Indenture
Act apply to debt securities that underlie security futures. The trust
indenture for underlying debt securities registered under the
Securities Act is qualified under the Trust Indenture Act at the time
of registration of those underlying debt securities.
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    \47\ 15 U.S.C. 78q-1.
    \48\ 15 U.S.C. 77aaa-77bbbb.
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    As a result, by modifying the listing standard requirements such
that the debt securities need not be registered under Section 12 of the
Exchange Act, provided that the conditions set forth above are
satisfied, the Commissions are increasing the types of debt securities
on which security futures may be based while preserving the requirement
that information important in making investment and trading decisions
is available.

II. Conclusion

    For the reasons discussed above, the Commissions by order are
jointly modifying the requirement in Section 6(h)(3)(D) of the Exchange
Act \49\ and the criteria specified in Section 2(a)(1)(D)(i)(III) of
the CEA \50\ to permit any security to underlie a security future,
provided such security is eligible to underlie options traded on a
national securities exchange.
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    \49\ 15 U.S.C. 78f(h)(3)(D).
    \50\ 7 U.S.C. 2(a)(1)(D)(i)(III).
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    In addition, for the reasons discussed above, the Commissions by
order are jointly modifying the requirement specified in Section
6(h)(3)(A) of the Exchange Act \51\ and the criterion specified in
Section 2(a)(1)(D)(i)(I) of the CEA \52\ to permit an unregistered debt
security, or a narrow-based index composed of unregistered debt
securities, to underlie a security future if the following conditions
are met:
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    \51\ 15 U.S.C. 78f(h)(3)(A).
    \52\ 7 U.S.C. 2(a)(1)(D)(i)(I).
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    (1) Each such security is a note, bond, debenture, or evidence of
indebtedness that is not an equity security as defined in Section
3(a)(11) of the Exchange Act; \53\
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    \53\ 15 U.S.C. 78c(a)(11).
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    (2) The issuer of each such security has registered the offer and
sale of the security under the Securities Act;
    (3) The issuer of each such security, or the issuer's parent if the
issuer is a wholly-owned subsidiary (as such terms are defined in Rule
1-02 of SEC Regulation S-X),\54\ has at least one class of common or
preferred equity security registered under Section 12(b) of the
Exchange Act \55\ and listed on a national securities exchange;
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    \54\ 17 CFR 210.1-02.
    \55\ 15 U.S.C. 78l(b).
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    (4) The transfer agent of each such security is registered under
Section 17A of the Exchange Act; \56\ and
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    \56\ 15 U.S.C. 78q-1.
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    (5) The trust indenture for each such security has been qualified
under the Trust Indenture Act of 1939.\57\
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    \57\ 15 U.S.C. 77aaa-77bbbb.
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    Accordingly,
    It is ordered, pursuant to Section 6(h)(4) of the Exchange Act and
Section 2(a)(1)(D)(v)(I) of the CEA, that the requirements in Sections
6(h)(3)(A) and 6(h)(3)(D) of the Exchange Act and the criteria in
Sections 2(a)(1)(D)(i)(I) and 2(a)(1)(D)(i)(III) of the CEA are
modified, subject to the conditions set forth above, provided however,
this order does not affect the CFTC's exclusive jurisdiction under
Section 2(a)(1)(C) of the CEA over any futures contract based on an
index that is not a ``narrow-based security index,'' as defined in
section 3(a)(55) of the Exchange Act and Section 1a(25) of the CEA.
Accordingly, nothing in this order shall affect or limit the exclusive
authority and jurisdiction of the CFTC with respect to any futures
contract, now or in the future, including the CFTC's authority to
approve any futures contract that is based upon an index that is not a
``narrow-based security index.''

    Dated: November 19, 2009.

    By the Commodity Futures Trading Commission.\58\
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    \58\ Because the Commissions are jointly modifying the listing
requirements to permit security futures on any security that is
eligible to underlie options contracts traded on a national
securities exchange, this order supersedes and replaces the Prior
Joint Orders. See supra notes 12 and 13.

David A. Stawick,
Secretary.
    By the Securities and Exchange Commission.

Elizabeth M. Murphy,
Secretary.
[FR Doc. E9-28164 Filed 11-23-09; 8:45 am]

BILLING CODE 6351-01-P


UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C.  20460

OFFICE OF

PREVENTION, PESTICIDES AND

TOXIC SUBSTANCES

MEMORANDUM

Date:		20-FEB-2009

SUBJECT:		Tribufos.  Revised Human Health Assessment Scoping Document in
Support of 				Registration Review.

PC Code:  074801	DP Barcode:  D361529

Decision No.: 401604	Registration No.:  NA

Petition No.: NA	Regulatory Action: Registration Review Scoping

Risk Assessment Type: NA	Case No.: 2145

TXR No.: NA	CAS No.: 78-48-8

MRID No.: NA	40 CFR: 180.272

Ver.Apr.08

FROM:		William H. Donovan, Ph.D., Chemist

			John Doherty, Ph.D., Toxicologist

			Risk Assessment Branch V

			Health Effects Division (7509P)

			Office of Pesticide Programs

			AND

			Shalu Shelat, ORE Assessor

			Risk Assessment Branch VI

			Health Effects Division (7509P)

			Office of Pesticide Programs

THROUGH:	Jack Arthur, Branch Chief

			Danette Drew, Senior Scientist

			Risk Assessment Branch V

			Health Effects Division (7509P)

			Office of Pesticide Programs

TO:		Molly Clayton, CRM

			Reregistration Branch 3 (RB3)

			Special Review and Reregistration Division (7508P)

			Office of Pesticide Programs

Executive Summary

The Health Effects Division Tribufos Risk Assessment team has evaluated
the most recent human health assessments and database for the
insecticide tribufos to determine the scope of work necessary to support
the established tolerances.  The risk assessment used to support the
interim Reregistration Eligibility Decision (IRED), conducted in June,
2000, was the primary source for this evaluation.  That assessment
identified three outstanding toxicity studies necessary to complete the
toxicity database for tribufos: 1) acute neurotoxicity study in the rat,
2) subchronic neurotoxicity study in the rat, and 3) developmental
neurotoxicity study in the rat.  These studies were subsequently
submitted, reviewed and found to be acceptable.  However, in accordance
with current data requirements, two toxicity studies are required to
complete the toxicity database for tribufos: a Comparative
Cholinesterase Assay (CCA) and an immunotoxicity study.

The residue chemistry database is complete; however, in the registration
review process, the dietary burden to ruminants should be reevaluated to
account for the recently reduced estimate of the contribution of cotton
gin byproducts to ruminant diets (Table 1 Feedstuffs, June 2008).  In
addition, the dietary exposure analysis should be updated to include
current anticipated residue levels, current percent crop treated
information and updated estimates of drinking water concentrations.  An
updated occupational exposure assessment, which shows risk levels of
concern for several scenarios, is provided in this document.
Consequently, in order to refine worker risk levels, a biomonitoring
study or a similar study that provides exposure data that can be used to
refine occupational handler and post-application risk estimates, is
needed.  HED will conduct a revised human health risk assessment when
all of the required toxicity and worker exposure studies are submitted
and reviewed.

1.  Introduction

Tribufos [S,S,S-tributyl phosphorotrithioate] is an emulsifiable
concentrate (EC) cotton defoliant registered for use as a total
defoliant and as a bottom defoliant to reduce or prevent losses from
boll rot organisms, and also as a mix with the last insecticide
application to accelerate the aging of cotton leaves.

As with other organophosphates, the principal toxic effects induced by
tribufos are related to its cholinesterase-inhibiting activity. It
produces the associated clinical signs, such as tremors, unsteady gait,
decreased activity, salivation, and disturbed balance in rats and
rabbits, and decreased cholinesterase activity (plasma, brain) in rats
and rabbits following acute, subchronic, and chronic oral exposure.  No
risks of concern were identified in previous dietary risk assessments.

Tolerances are established in 40 CFR §180.272 for cotton and livestock
commodities.  The residue of concern in plants and livestock consists of
parent tribufos (Metabolism Committee Issues Memo, C. Eiden, 4/27/1995 &
Metabolism Decision Memo, C. Eiden, 6/7/1995).

Tribufos-containing products currently registered include: 1) Def 6
Emulsifiable Defoliant (EPA Reg. No. 264-730) [Bayer CropScience], 2)
Folex 6 EC Cotton Defoliant (EPA Reg. No. 5481-504) [AMVAC Chemical
Corporation], and 3)  DFT 6 EC Cotton Defoliant (EPA Reg. No. 34704-867)
[Loveland Products, Inc.].

The Agency published an interim Reregistration Eligibility Decision
(IRED) for tribufos in September 2000.  Tribufos was included in the
cumulative assessment for the organophosphate insecticides (July 2006).
With the completion of the cumulative assessment, the tribufos IRED was
considered a completed RED document.

2.  Hazard Identification

Tribufos is an organophosphate (OP) pesticide. As with other OPs, the
principal clinical signs for toxic effects induced by tribufos are
related to its cholinesterase (ChE)-inhibiting activity. It produces the
associated clinical signs, such as tremors, unsteady gait, decreased
activity, salivation, and disturbed balance.  Evidence of
anticholinesterase activity occurs by all routes (oral, dermal, and
inhalation) and durations (acute, subchronic and chronic) of exposure.
By the oral and dermal routes, technical tribufos is placed in Toxicity
Category II and by the inhalation route, Category III.  Primary skin and
eye irritation are both assigned to Toxicity Category IV.  Tribufos is
not a dermal sensitizer. The metabolism of tribufos in rats indicates
that >90% of the administered dose was excreted in 72 hours and there
was no significant tissue residue.  Absorbed material was extensively
and completely metabolized.  Tribufos is not a developmental or a
reproductive toxicant.  There was no evidence of increased
susceptibility to rat or rabbit fetuses following in utero exposures or
in the offspring following pre- or post-natal exposure to rats.

The HED Cancer Peer Review Committee (CPRC) [now designated as Cancer
Assessment Review Committee (CARC)] classified tribufos as unlikely to
be a human carcinogen at low doses since all tumor increases in mice
occurred only at the highest dose tested (48 mg/kg/day in males and 63
mg/kg/day in females) and were accompanied by severe ChE inhibition and
increased mortality in the later weeks of the study (TXR# 0012242, E.
Rinde and R. Zendzian, 22-MAY-1997).  The CPRC recommended a
non-quantitative approach for the purpose of risk characterization
utilizing the most sensitive toxic endpoint.  The most sensitive
endpoint for chronic toxicity was plasma ChE inhibition in the one year
dog study, for which the NOAEL was 0.1 mg/kg/day.  In addition, there
was no apparent concern for mutagenicity, and no structural analogs of
concern were identified.

In the tribufos risk assessment prepared in 2000, an extra 10X database
uncertainty factor was retained because of data gaps for acute and
subchronic neurotoxicity studies in the rat and for a developmental
neurotoxicity study.  All of these studies have been submitted to the
Agency, reviewed, and found to be acceptable.  Specifically, the acute
neurotoxicity study (2000, MRID 45194401) was determined to be
acceptable/guidelines and satisfies the series 870.6200 guideline
requirement for an acute neurotoxicity screen study in rats (TXR #
0050380, J. Doherty, 13-JUN-2002).  This study determined an LOAEL for
cholinesterase inhibition of 20 mg/kg based on inhibition of both plasma
ChE and RBC AChE, with a NOAEL of 2 mg/kg.  The subchronic neurotoxicity
study (2001, MRID 45369101) was classified as acceptable/guideline and
demonstrated a NOAEL of 0.17 mg/kg/day and a LOAEL of 3.54 mg/kg/day for
systemic effects based on decreased  body weight and food consumption in
females and a NOAEL of 0.14 mg/kg/day in males and 0.17 mg/kg/day in
females and LOAEL of 2.89 mg/kg/day in males and 3.54 mg/kg/day in
females based on inhibition of plasma and RBC ChE (TXR # 0050405, J.
Doherty, 13-JUN-2002).  The developmental neurotoxicity study (2001,
MRID 45499501) was classified as acceptable/non-guideline (TXR# 0050231,
W. Greear, 13-SEP-2005).  This study determined a maternal
cholinesterase LOAEL of 3.4 mg/kg/day and a maternal cholinesterase
NOAEL of 0.4 mg/kg/day.  The offspring cholinesterase LOAEL was 16.4
mg/kg/day (the highest dose tested).

A comparative cholinesterase (CCA) study is required for organophosphate
pesticides that inhibit ChE.  The CCA study is required whether or not a
series 870.6300 developmental neurotoxicity study has been submitted
unless the Agency agrees that the DNT study contains equivalent CCA
data.  For tribufos, the DNT study was determined not to contain
equivalent CCA data, so the CCA study is needed (see Attachment).

An immunotoxicity study is required based on the Revised Part 158
Toxicology Data Requirements for Conventional Pesticides for the reasons
specified in the Attachment.  Tribufos is currently regulated based on a
NOAEL of 0.1 mg/kg/day for chronic dietary exposure and 1 mg/kg/day for
acute exposure.  Once all outstanding toxicology studies have been
received and reviewed, the Tribufos Risk Assessment Team will reexamine
the endpoints and safety factors used for the tribufos risk assessment.
A summary of the existing toxicology doses and endpoints is provided in
Table 1.

Table 1.  Summary of Toxicological Doses and Endpoints for Tribufos Used
in Previous Dietary Human Health Risk Assessments

Exposure/

Scenario	Point of Departure	Uncertainty Factors	RfD, PAD, Level of
Concern for Risk Assessment	Study and Toxicological Effects

Acute Dietary general population	NOAEL = 1.0 mg/kg	UFA= 10x

UFH=10x

FQPA SF = 10X	Acute RfD = 0.01 mg/kg

Acute PAD = 0.001 mg/kg/day	Prenatal Developmental Toxicity study in the
rat (MRID 40190601)

LOAEL = 2 mg/kg, based on increased incidence of clinical signs, changes
in the majority of the FOB parameters and decreased plasma and brain
cholinesterase in males and females

Chronic Dietary

all populations

NOAEL =  0.1 mg/kg/day	UFA= 10x

UFH=10x

FQPA SF = 10X	Chronic RfD = 0.001 mg/kg/day

Chronic PAD = 0.0001 mg/kg/day	chronic study in the dog (MRID 42007203)

LOAEL = 0.35 mg/kg/day, based on decreased plasma and brain
cholinesterase activity in males and females

Short and Intermediate Term Dermal

LOAEL Adj = 14 mg/kg/day	UFA= 10x

UFH=10x

UFDB = 3X (lack of NOAEL)	Occupational LOC for MOE = 300	21-Day dermal
toxicity study in the rabbit (MRID 42007201)

LOAEL = 2 mg/kg/day, based on inhibition of plasma (males) and red blood
cells (females) cholinesterase activity.  Use of 7X conversion factor to
account for differences in dermal absorption between species (rabbit vs.
monkey).  No NOAEL determined.

Short and Intermediate Term Inhalation

NOAEL = 0.9 mg/kg/day	UFA= 10x

UFH=10x

	Occupational LOC for MOE = 100	90-day Inhalation study in the rat (MRID
42399801)

LOAEL = 4.5 mg/kg/day, based on plasma and erythrocyte ChE inhibition

Long Term Dermal and Inhalation

Long-term dermal or inhalation occupational exposures are not expected
to occur for the registered uses of tribufos.

Cancer 	Classification:  unlikely to be a  human carcinogen at low doses

Point of Departure (PoD) = A data point or an estimated point that is
derived from observed dose-response data and  used to mark the beginning
of extrapolation to determine risk associated with lower environmentally
relevant human exposures.  NOAEL = no observed adverse effect level.
LOAEL = lowest observed adverse effect level.  UF = uncertainty factor.
UFA = extrapolation from animal to human (interspecies).  UFH =
potential variation in sensitivity among members of the human population
(intraspecies). PAD = population adjusted dose (a = acute, c = chronic)
= the NOEL/all appropriate uncertainty and safety factors. RfD =
reference dose.  MOE = margin of exposure.  LOC = level of concern.  N/A
= not applicable.

3. Dietary Exposure

The following refined dietary exposure assessments for tribufos were
conducted in support of the RED:  acute analysis (D251691, S. Piper,
02-MAR-1999) and chronic analysis (D253404, S. Law, 22-FEB-1999).
Anticipated residues used in the both assessments incorporated field
trial data, processing study data, and percent crop treated information.
 Drinking water was not included directly in the dietary assessment, but
accounted for using the drinking water level of comparison (DWLOC)
approach.  The acute and chronic dietary exposures were determined to be
well below HED’s level of concern.  Since the previous assessment, the
percent of cotton gin byproducts in the diets of ruminants has been
lowered to 5% (from 25%) (Table 1 Feedstuffs, June 2008).  In addition,
the percent crop treated value previously used for the chronic analysis
(35%) has dropped to 30% according to the latest report from BEAD
(Tribufos SLUA, 05-JUN-2008).  Consequently, a revised dietary risk
assessment is likely to find even lower exposures from food sources than
reported in past assessments.  Any new dietary risk assessment conducted
in association with registration review should directly include
potential tribufos exposures from drinking water sources.  In the
previous assessment, the estimated environmental concentrations (EECs)
provided by EFED were 5.8 ppb for acute exposure scenarios and 1.8 ppb
for chronic exposure scenarios, based on surface water models.  EFED
plans to update these EEC values for tribufos as part of registration
review, using the latest modeling methods.  Once these values are
available, they should be incorporated into a new dietary exposure
assessment together with updated percent crop treated information from
BEAD and revised anticipated residue levels taking into account the
revised dietary burden to ruminants. Additionally, any changes to
toxicity endpoints or safety factors should also be incorporated.

4.  Residue Chemistry

The tribufos risk assessment in 2000 determined that the residue
chemistry database was complete except for the following two data
deficiencies:  1) Independent Laboratory Validation LV) of the
analytical method for milk, and 2) crop field trials in support of
ultra-low volume (ULV) applications to cotton.  The ILV data deficiency
was satisfied through submission of a study described in MRID 44077401,
entitled “Independent Laboratory Validation for the Determination of
Tribuphos Residue in Animal Tissues and Milk” (D273879, C. Eiden,
18-MAY-2001).  A detailed review of the ILV method is available
(D229479, C. Eiden, 05-MAR-1997).  The current tribufos labels do not
include ULV application methods.  Hence residue data supporting ULV
applications are not needed.

During the registration review process, the tribufos tolerance levels
for livestock commodities should be reassessed in light of the update to
livestock feedstuff (Table 1 Feedstuffs, June 2008).  The only
tribufos-treated livestock feedstuff, cotton gin byproducts, has had a
significant reduction in the percent of diet (25 to 5%), thus resulting
in a lower dietary burden and likely lower tolerance levels than
previously recommended.

5.  Residential Exposure

There are currently no registered tribufos products intended for sale to
homeowners.  There are also currently no tribufos products that have
been identified as intended for use in homes, in/around schools, parks
or other public areas.

6.  Aggregate Risk Assessment

There are no residential uses of tribufos.  The aggregate assessments in
the most recent analyses considered only food and water.  Both the acute
and chronic aggregate analyses showed no risks of concern.  However, in
view of the identified data gaps in the toxicity database, likely
revisions to drinking water estimates, percent crop treated information
and anticipated residue levels, a new aggregate risk assessment may be
needed in registration review.

7. Occupational Exposures

	7.1 Occupational Handlers

Occupational handlers are likely to be exposed to tribufos during
mixing, loading, application, and other handling activities associated
with the use patterns of tribufos. In the most recent US EPA Human
Health Risk Assessment (2000), Pesticide Handlers Exposure Database
(PHED) Version 1.1 and chemical specific handler study data were used to
assess four major occupational handler exposure scenarios:

	(1a)	mixing/loading liquids for aerial application;

	(1b)	mixing/loading liquids for groundboom applications;

	(2) 	applying sprays with a fixed-wing aircraft;

	(3)	applying sprays with groundboom equipment; and;

	(4)	flagging for aerial spray applications.

In the most recent tribufos HED risk assessment (2000), handler risk
calculations were performed using the short and intermediate-term dermal
endpoint (LOAEL = 14mg/kg/day) from a 21-day dermal toxicity study in
rabbits (LOAEL = 2 mg/kg/day) with a conversion factor of seven to
compensate for the species difference in dermal absorption (rabbit vs.
monkey).  The short- and intermediate-term inhalation endpoint (NOAEL =
0.9 mg/kg/day) was established with a 90-day inhalation study in rats.
Given the registered uses of tribufos, long-term dermal or inhalation
occupational related exposures are not expected to occur, therefore only
short- and intermediate- term occupational risks were assessed.

At the time of the IRED, the maximum registered application rate for
tribufos was 1.875 pounds of active ingredient per acre (lb ai/A). The
registrant has since then proposed to reduce the application rate from
1.875 lbs ai/A to 1.125 lbs ai/A. Review of the product labels shows
that the reduction in application rate has taken effect. The reduction
in application rate applies to all cotton growing states except for
California and Arizona. The two states grow hardier varieties of the
cotton and thus require more defoliant.

Occupational handler risk assessments were conducted for all four
scenarios at application rates of both 1.875 lbs ai/A and 1.125 lb ai/A
(see Table 2 below).  Dermal risk estimates, using engineering controls,
for mixing/loading liquids for aerial applications and applying liquids
via aerial equipment both result in risks of concern (MOE <300) at an
application rate of 1.875 lb ai/A. The resulting Aggregate Risk Index
(ARI) for these two scenarios also resulted in risks of concern (ARI <
1).  Dermal risk estimates, using engineering controls, for
mixing/loading liquids for aerial applications and applying liquids via
aerial equipment also both result in risks of concern (MOE <300) at an
application rate of 1.125 lb ai/A. The resulting ARI for these two
scenarios also resulted in risks of concern (ARI < 1).

Dermal and inhalation risk estimates for groundboom application handlers
(mixers, loaders, applicators) are not of concern with baseline attire.
The ARI was determined to be greater than 1 for all groundboom
application activities and aggregate risks are not of concern.

For more details regarding the occupational handler exposure and risk
assessment, see the tribufos RED.

Table 2 - Tribufos Handler Risks in Margin of Exposure (dermal LOC= 300;
Inhalation LOC= 100)

Exposure Scenario	Handler Risks at 1.875 lb ai/ acre	Handler Risks at
1.125 lb ai/ acre

	Short & Intermediate Term Dermal 	Short & Intermediate Term Inhalation
ARI	Short & Intermediate Term Dermal 	Short & Intermediate Term
Inhalation	ARI

(1a) mixing/loading liquids for aerial applicationa	49	330	0.16	82	560
0.26

(1b) mixing/loading liquids for groundboom applicationsb	760	5100	2.4
1300	8400	4.1

(2)  applying sprays with a fixed-wing aircrafta	90	410	0.2	150	690	0.47

(3) applying sprays with groundboom equipmentb	470	570	1.2	780	950	2.5

(4) flagging for aerial spray applicationsa	2000	4000	5.9	3300	6700	9.5

a Based on maximum level of engineering controls

b Based on baseline assumptions

	7.2 Occupational Postapplication

Occupational postapplication exposure to tribufos was assessed in the
2000 HED risk assessment for tribufos. A chemical-specific study (MRID
42701601-01) from the registrant was used to determine both dermal and
inhalation exposures for the four major postapplication exposure
activities:

Picker Operators

Module Builder Operators

Rakers

Trampers- Trail-Harvesting System

The tribufos postapplication study was used to develop dermal transfer
coefficients for the four activities: picker operator 92.36 (50g
bolls/hour), module building operator 26.13 (50g bolls/hour), rakers
15.9 (50g bolls/hour), and trampers 212.76 (50g bolls/hour).
Occupational postapplication risk assessments were conducted at
application rates of 1.875 lbs ai/A and 1.125 lb ai/A (see Table 3
below) using the calculated dermal transfer coefficients. At 24 hours
after application, dermal MOEs resulted in risks of concern (MOE < 300)
at both application rates. At 7 days after application, MOEs for all
postapplication scenarios except building module activities resulted in
risks of concern at an application rate of 1.875 lb ai/A. All
postapplication activities were not of concern at an application rate of
1.125 lb ai/A.

The tribufos postapplication inhalation data does not provide exposure
information for activities that may be conducted prior to 15 days after
treatment.  According to the 2000 HED risk assessment, the risks to
inhalation exposure prior to day 15 were not estimated due to the
introduction of uncertainties that would arise from extrapolating the
data monitored on one day to another.  Given the physical and chemical
properties of tribufos, inhalation exposure is not likely to be a
concern 7 days after treatment.

The tribufos restricted entry interval (REI) was changed from 24 hours
to 7 days per the 2000 IRED. Based on the reduced application rate
(1.125 lb ai/A) and the 7 day REI, the MOEs for postapplication
activities do not exceed the level of concern. [Note: Risks of concern
still remain for most postapplication activities using the higher
application rate of 1.875 lbs ai/A (used only in CA and AZ) at the
current REI of 7 days.]

Table 3 - Tribufos Postapplication Dermal Risks in Margin of Exposure
(dermal LOC= 300)

Exposure Scenario	Postapplication Risks at 1.875 lb ai/ acre
Postapplication Risks at 1.125 lb ai/ acre	Postapplication Risks at
1.875 lb ai/ acre	Postapplication Risks at 1.125 lb ai/ acre

	Results at 24 hours after treatment	Results at 7 days after treatment

Picker Operators	47	78	210	350

Module Builder Operators	110	180	480	820

Rakers	45	74	200	340

Trampers	52	88	230	390

There is sufficient information available to assess occupational
exposure.  All of the occupational exposure scenarios for the registered
uses of tribufos have been assessed adequately. There remain risks of
concern regarding aerial mixing, loading, and application scenarios at
maximum engineering controls, and to workers entering cotton fields
following treatment at the 1.875 lb ai/A rate.  All other occupational
exposures were assessed adequately and do not present risks of concern.

A biomonitoring study was requested in the 2000 IRED to confirm risk
management decisions. In 2001, the request for the biomonitoring study
was placed on hold, pending submission of requested neurotoxicity
studies.  These studies have since been submitted and reviewed and found
not to change the dermal toxicity endpoint.  Accordingly, submission of
the previously requested biomonitoring study or similar study that
provides exposure data that can be used to refine occupational handler
and post-application risk estimates is required.

8.  Tolerance Assessment and International Harmonization

A summary of US tolerances, Codex Maximum Residue Limits (MRL), Mexican
MRLs, and Canadian MRLs is provided in Table 4 (see Attachments).  There
are no MRLs set for tribufos in Canada, Mexico, or through Codex; thus,
there are no international harmonization issues to resolve.

9.  Public Health and Pesticide Epidemiology Data.  A summary report
listing reported incidents for tribufos has been provided in the
memorandum entitled Updated Review of Tribuphos Incident Reports (M.
Hawkins and J. Cordova, 10/30/2008).  Only two incidents were cited,
however, the effects seen in those incidents were consistent with the
type of toxicological effects that are seen in the animal studies for
tribufos.  The reported incident data will be evaluated in more detail
during the development of the Final Work Plan (FWP) for tribufos.

10. Environmental Justice

Potential areas of environmental justice concerns, to the extent
possible, were considered in this human health risk assessment, in
accordance with U.S. Executive Order 12898, "Federal Actions to Address
Environmental Justice in Minority Populations and Low-Income
Populations,"   HYPERLINK
"http://www.epa.gov/compliance/resources/policies/ej/exec_order_12898.pd
f"
http://www.epa.gov/compliance/resources/policies/ej/exec_order_12898.pdf
.  The Office of Pesticide Programs (OPP) typically considers the
highest potential exposures from the legal use of a pesticide when
conducting human health risk assessments, including, but not limited to,
people who obtain drinking water from sources near agricultural areas,
the variability of diets within the U.S. (including different ages,
regions, and ethnicities), and people who may be exposed when harvesting
crops.  Should these highest exposures indicate potential risks of
concern, OPP further refines the risk assessments to ensure that the
risk estimates are based on the best available information.

11. Cumulative

The Food Quality Protection Act (FQPA) requires the Agency to consider
the cumulative risks of chemicals sharing a common mechanism of
toxicity.  Tribufos is a member of the organophosphate common mechanism
group.  The most recent cumulative risk assessment for the
organophosphates was published on July 31, 2006 and is available at
HYPERLINK
"http://www.epa.gov/pesticides/cumulative/2006-op/op_cra_main.pdf"
http://www.epa.gov/pesticides/cumulative/2006-op/op_cra_main.pdf .  No
cumulative risks of concern for tribufos were identified in that
assessment.

Prior to a final tolerance review decision for tribufos, the Agency will
determine if there is any new information, such as new hazard or
exposure data or information on changes to the use pattern, which would
affect the cumulative risk assessment.  Should the Agency determine that
new information on tribufos is available that could potentially impact
the cumulative risk assessment and result in a risk of concern, the
Agency will revisit the cumulative risk assessment.

12.  Human Studies

Tribufos risk assessments rely in part on data from studies in which
adult human subjects were intentionally exposed to a pesticide or other
chemical.  These studies, which comprise the Pesticide Handlers Exposure
Database (PHED), have been reviewed by the Agency and found on the basis
of available evidence to have been neither fundamentally unethical nor
significantly deficient relative to standards of ethical research
conduct prevailing when they were conducted.  There is no barrier in the
Agency’s “Protection of Human Subjects” regulation to reliance on
these studies.

13.  Data Needs

Toxicology

The following toxicity studies are required.  Detailed rationale for
requiring these studies is attached to this document.

870.7800 Immunotoxicity.  This study is required based on the Revised
Part 158 Toxicology Data Requirements for Conventional Pesticides.

870.6300 Comparative Cholinesterase Assay.  This study is needed to
address uncertainties with regard to susceptibility in the young
animals.

Occupational Exposure

Submission of the previously requested biomonitoring study or a similar
study that provides exposure data that can be used to refine
occupational handler and post-application risk estimates is required.

14.  References

Author	Barcode	Date	Title

M. Hawkins and J. Cordova	--	10/30/2008	Updated Review of Tribuphos
Incident Reports

R. Travaglini et al.

6/26/2000	Tribufos: Human Health Risk Assessment.

J. Doherty	TXR 0050380	6/13/2002	Tribufos: Review of an acute
neurotoxicity screen study.

J. Doherty	TXR 0050405	6/13/2002	Tribufos: Review of an subchronic
neurotoxicity study.

W. Greear	TXR 0050231	9/13/2005	Tribufos.  Evaluation of a Developmental
Neurotoxicity Study

E. Rinde and R. Zendzian	TXR# 0012242	5/22/1997	Carcinogenicity Peer
Review (2nd) of Tribufos (DEF)

C. Eiden	D273879	5/18/2001	Tribuphos.  RED Data Call-in (DCI)
Requirement for Independent Laboratory Validation (ILV) for Residue
Analytical Method for Animal Tissues.

C. Eiden	D229479	3/5/1997	Tribufos - Report of the FQPA Safety Factor
Committee

C. Eiden	--	4/27/1995	Tribuphos.  Issues to be Presented to the HED
Metabolism Committee.

C. Eiden	--	6/7/1995	Tribuphos.  Outcome of the 5/9/1995 Meeting of the
HED Metabolism Committee.

S. Law	D253404	2/22/1999	Tribufos – Chronic Dietary Exposure Analysis

S. Piper	D251691	3/2/1999	Monte Carlo Acute Dietary Exposure Estimates
for Tribufos

S. Knizner	D253352	2/18/1999	Revised Chronic Anticipated Residues for
Tribufos.

--	--	7/31/2006	Organophosphorus Cumulative Risk Assessment – 2006
Update

Attachments

Table 4.  Summary of US and International Tolerances and Maximum Residue
Limits

US	Canada	Mexico1	Codex

Residue Definition:

40CFR  180.272

Tribuphos (S,S,S-tributylphosphorotrithioate)

	None	None	None

Commodity Tolerance (ppm) /Maximum Residue Limit (mg/kg)

Commodity	US	Canada	Mexico	Codex

Cattle, fat	0.15	None	None	None

Cattle, meat	0.02

	Cattle, meat byproducts	0.02

	Cotton, gin byproducts	40

	Cotton, undelinted seed	4.0

	Goat, fat	0.15

	Goat, meat	0.02

	Goat, meat byproducts	0.02

	Hog, fat	0.15

	Hog, meat	0.02

	Hog, meat byproducts	0.02

	Horse, fat	0.15

	Horse, meat	0.02

	Horse, meat byproducts	0.02

	Milk	0.01

	Sheep, fat	0.15

	Sheep, meat	0.02

	Sheep, meat byproducts	0.02

	1 As of 2004, latest date for available information.  General practice
is for Mexico to defer to US or Codex tolerances for its export
purposes.

(*) = absent at the limit of quantitation.

Po = post harvest

Rationale for Requiring Immunotoxicity and CCA Studies

Guideline Number: 870.7800

Study Title:  Immunotoxicity

Rationale for Requiring the Data

This is a new data requirement under 40 CFR Part 158 as a part of the
data requirements for registration of a pesticide (food and non-food
uses).

The Immunotoxicity Test Guideline (OPPTS 870.7800) prescribes functional
immunotoxicity testing and is designed to evaluate the potential of a
repeated chemical exposure to produce adverse effects (i.e.,
suppression) on the immune system. Immunosuppression is a deficit in the
ability of the immune system to respond to a challenge of bacterial or
viral infections such as tuberculosis (TB), Severe Acquired Respiratory
Syndrome (SARS), or neoplasia.  Because the immune system is highly
complex, studies assessing functional immunotoxic endpoints are helpful
in fully characterizing a pesticide’s potential immunotoxicity.  These
data will be used in combination with data from hematology, lymphoid
organ weights, and histopathology in routine chronic or subchronic
toxicity studies to characterize potential immunotoxic effects.

Practical Utility of the Data

How will the data be used?

These animal studies can be used to select endpoints and doses for use
in risk assessment of all exposure scenarios and are considered a
primary data source for reliable reference dose calculation. For
example, animal studies have demonstrated that immunotoxicity in rodents
is one of the more sensitive manifestations of TCDD
(2,3,7,8-tetrachlorodibenzo-p-dioxin) among developmental, reproductive,
and endocrinologic toxicities.  Additionally, the EPA has established an
oral reference dose (RfD) for tributyltin oxide (TBTO) based on observed
immunotoxicity in animal studies (IRIS, 1997).

How could the data impact the Agency's future decision-making?

If the immunotoxicity study shows that the test material poses either a
greater or a diminished risk than that given in the interim decision’s
conclusion, the risk assessments for the test material may need to be
revised to reflect the magnitude of potential risk derived from the new
data.

If the Agency does not have this data, a 10X database uncertainty factor
may be applied for conducting a risk assessment from the available
studies.

Guideline Number: NA

Study Title:   Comparative Cholinesterase Assay

Rationale for Requiring the Data

Tribufos is a member of the organophosphate (OP) family of pesticides.
The mode of toxic action for OP pesticides is inhibition of the enzyme,
acetylcholinesterase (AChE) via phosphorylation of the active site
leading to accumulation of acetylcholine and to clinical signs of
neurotoxicity.

The CCA is needed to evaluate any potential for increased cholinesterase
sensitivity in juvenile animals compared with that of adult animals.
Inhibition of acetylcholinesterase (AChE) is the critical regulatory
endpoint for tribufos.  CCA studies have been submitted to HED for more
than 20 other organophosphates (OPs), and for many of these OPs the CCAs
have shown juveniles to be more sensitive than adults.  Based on this
additional knowledge gained since 1999 and because there is food use for
tribufos, a CCA is required.

Typically for the OPs, the CCA includes several components:  1)
Gestational exposures to pregnant dams followed by sacrifice at
gestational day 20.  Brain and blood ChE activity is measured in dams
and fetuses; 2) Acute, direct dosing to post-natal day (PND) 11 and
young adult rats; and  3) Eleven (11) day repeated, direct, dosing to
juvenile rats (PND 11-21) and young adult rats.  Each study includes a
control group and at least 3 treatment groups.  Both the acute and the
repeat-dose studies are typically accompanied by range-finding and time
to peak effect study.   All three components are required for tribufos.

Practical Utility of the Data

How will the data be used?

CCA studies provide critical scientific information needed to
characterize potential hazard to the human population on the inhibition
of cholinesterase from pesticide exposure. Since epidemiologic data on
the effects of chemical exposures on cholinesterase inhibition are
limited and are inadequate to characterize a pesticide’s potential for
effects in humans, animal studies are used as the most sensitive
endpoint for risk assessment.  These animal studies can be used to
select endpoints and doses for use in risk assessment of all exposure
scenarios and are considered a primary data source for reliable
reference dose calculation. The current endpoints are based on adult
data, and it is likely that young animals may be more sensitive to ChE
inhibition based on data for other organophosphate pesticides.

How could the data impact the Agency's future decision-making?

If the CCA study shows that the test material poses either a greater or
a diminished risk to the young animal than that given in the interim
decision’s conclusion, the risk assessments for the test material may
need to be revised to reflect the magnitude of potential risk derived
from the new data.

If the Agency does not have this data, a 10X database uncertainty factor
may be applied for conducting a risk assessment from the available
studies.

Page   PAGE  1  of   NUMPAGES  14


[Federal Register: March 15, 2006 (Volume 71, Number 50)]
[Notices]
[Page 13367-13368]
[DOCID:fr15mr06-74]

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DEPARTMENT OF ENERGY

Federal Energy Regulatory Commission

[Docket No. RP06-244-000]

High Island Offshore System L.L.C.; Notice of Tariff Filing

March 8, 2006.
    Take notice that on March 1, 2006, High Island Offshore System
L.L.C. (HIOS) tendered for filing as part its FERC Gas Tariff, Third
Revised Volume No. 1, the following tariff sheets, with an effective
date of April 1, 2006:

Third Revised Sheet No. 11
Fourth Revised Sheet No. 69
Second Revised Sheet No. 104
Fourth Revised Sheet No. 105
Original Sheet No. 105A
Second Revised Sheet No. 106
First Revised Sheet No. 107
First Revised Sheet No. 108
Second Revised Sheet No. 173A
First Revised Sheet No. 173B

    HIOS states that these primary tariff sheets are being filed as
part of the first annual fuel tracker filing, as well as to propose
modifications to the annual fuel tracker mechanism contained in the
HIOS tariff. In the event that these primary tariff sheets are not
accepted, HIOS is submitting the following alternate tariff sheet:

Alternate Third Revised Sheet No. 11

    Any person desiring to intervene or to protest this filing must
file in accordance with Rules 211 and 214 of the Commission's Rules of
Practice and Procedure (18 CFR 385.211 and 385.214). Protests will be
considered by the Commission in determining the appropriate action to
be taken, but will not serve to make protestants parties to the
proceeding. Any person wishing to become a party must file a notice of
intervention or motion to intervene, as appropriate. Such notices,
motions, or protests must be filed in accordance with the provisions of
section 154.210 of the Commission's regulations (18 CFR 154.210).
Anyone filing an intervention or protest must serve a copy of that
document on the Applicant. Anyone filing an intervention or protest on
or before the intervention or protest date need not serve motions to
intervene or protests on persons other than the Applicant.
    The Commission encourages electronic submission of protests and
interventions in lieu of paper using the ``eFiling'' link at http://www.ferc.gov.
 Persons unable to file electronically should submit an

original and 14 copies of the protest or intervention to the Federal
Energy Regulatory Commission, 888 First Street, NE., Washington, DC
20426.
    This filing is accessible on-line at http://www.ferc.gov, using the

``eLibrary'' link and is available for review in the Commission's
Public Reference Room in Washington, DC. There is an ``eSubscription''
link on the Web site that enables subscribers to receive e-mail
notification when a document is added to a subscribed docket(s). For
assistance with any FERC Online service, please e-mail
<EMAIL_ADDRESS>or call<PHONE_NUMBER> (toll free). For

TTY, call<PHONE_NUMBER>.

Magalie R. Salas,
Secretary.
 [FR Doc. E6-3667 Filed 3-14-06; 8:45 am]

BILLING CODE 6717-01-P


[Federal Register Volume 88, Number 109 (Wednesday, June 7, 2023)]
[Notices]
[Pages 37238-37239]
[FR Doc No: 2023-12183]

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DEPARTMENT OF ENERGY

Federal Energy Regulatory Commission

Combined Notice of Filings # 1

    Take notice that the Commission received the following electric
rate filings:

    Docket Numbers: ER23-2027-000.
    Applicants: Midcontinent Independent System Operator, Inc.
    Description: Sec.  205(d) Rate Filing: 2023-05-31_Timeline and
Process for Handling Market Implementation Errors to be effective 7/31/
2023.
    Filed Date: 5/31/23.
    Accession Number: 20230531-5311.
    Comment Date: 5 p.m. ET 6/21/23.

    Docket Numbers: ER23-2028-000.
    Applicants: Pacific Gas and Electric Company.
    Description: Sec.  205(d) Rate Filing: May 2023 Western WDT Service
Agreement Biannual Filing (SA 17) to be effective 8/1/2023.
    Filed Date: 5/31/23.
    Accession Number: 20230531-5323.
    Comment Date: 5 p.m. ET 6/21/23.

    Docket Numbers: ER23-2029-000.
    Applicants: Pacific Gas and Electric Company.
    Description: Sec.  205(d) Rate Filing: May 2023 Western
Interconnection Biannual Filing (SA 59) to be effective 8/1/2023.
    Filed Date: 5/31/23.
    Accession Number: 20230531-5326.
    Comment Date: 5 p.m. ET 6/21/23.

    Docket Numbers: ER23-2030-000.
    Applicants: Baconton Power LLC.
    Description: Baconton Power, LLC submits Notice of cancellation of
the Common Bus Ownership Agreement with SOWEGA Power LLC.
    Filed Date: 5/30/23.
    Accession Number: 20230530-5318.
    Comment Date: 5 p.m. ET 6/20/23.

    Docket Numbers: ER23-2031-000.
    Applicants: El Paso Electric Company.
    Description: Sec.  205(d) Rate Filing: OATT Revisions Filing of
Attachment M Related to Interconnection Queue to be effective 8/1/2023.
    Filed Date: 5/31/23.
    Accession Number: 20230531-5351.
    Comment Date: 5 p.m. ET 6/21/23.

    Docket Numbers: ER23-2032-000.
    Applicants: Louisiana Generating LLC.
    Description: Request to Recover Costs Associated with Acting as a
Local Balancing Authority of Louisiana Generating LLC.
    Filed Date: 5/30/23.
    Accession Number: 20230530-5322.
    Comment Date: 5 p.m. ET 6/20/23.

    Docket Numbers: ER23-2033-000.
    Applicants: ITC Midwest LLC.
    Description: Request for Authorization for Abandoned Plant
Incentive Rate Treatment of ITC Midwest.
    Filed Date: 5/30/23.
    Accession Number: 20230530-5323.
    Comment Date: 5 p.m. ET 6/20/23.

    Docket Numbers: ER23-2034-000.
    Applicants: Louisiana Energy & Power Authority.
    Description: Request to Recover Costs Associated with Acting as a
Local Balancing Authority of Louisiana Energy and Power Authority.
    Filed Date: 5/31/23.
    Accession Number: 20230531-5425.
    Comment Date: 5 p.m. ET 6/21/23.

    Docket Numbers: ER23-2035-000.
    Applicants: ISO New England Inc., Versant Power.
    Description: Sec.  205(d) Rate Filing: ISO New England Inc. submits
tariff filing

per 35.13(a)(2)(iii): ISO-NE and Versant Power; Original Service
Agreements.
    Filed Date: 6/1/23.
    Accession Number: 20230601-5112.
    Comment Date: 5 p.m. ET 6/22/23.

    Docket Numbers: ER23-2036-000.
    Applicants: Niagara Mohawk Power Corporation, New York Independent
System Operator, Inc.
    Description: Sec.  205(d) Rate Filing: Niagara Mohawk Power
Corporation submits tariff filing per 35.13(a)(2)(iii): NMPC 205: SGIA
between Niagara Mohawk and Lyons Falls, SA No. 2780 to be effective 5/
2/2023.
    Filed Date: 6/1/23.
    Accession Number: 20230601-5152.
    Comment Date: 5 p.m. ET 6/22/23.

    Docket Numbers: ER23-2037-000.
    Applicants: Consolidated Edison Company of New York, Inc.
    Description: Sec.  205(d) Rate Filing: Standby Rate Exemptions to
be effective 6/1/2023.
    Filed Date: 6/1/23.
    Accession Number: 20230601-5165.
    Comment Date: 5 p.m. ET 6/22/23.

    Docket Numbers: ER23-2038-000; TS23-5-000.
    Applicants: Chevelon Butte RE LLC, Chevelon Butte RE LLC.
    Description: Request for Temporary Waiver of Open-Access
Requirements of Order Nos. 888, et al. of Chevelon Butte RE LLC.
    Filed Date: 5/25/23.
    Accession Number: 20230525-5207.
    Comment Date: 5 p.m. ET 6/15/23.

    Docket Numbers: ER23-2039-000.
    Applicants: Entergy Mississippi, LLC.
    Description: Sec.  205(d) Rate Filing: MDEA LBA Agreement to be
effective 6/1/2023.
    Filed Date: 6/1/23.
    Accession Number: 20230601-5215.
    Comment Date: 5 p.m. ET 6/22/23.

    Take notice that the Commission received the following electric
securities filings:

    Docket Numbers: ES23-45-000.
    Applicants: Tri-State Generation and Transmission Association, Inc.
    Description: Supplement to Application Under Section 204 of the
Federal Power Act for Authorization to Issue Securities of Tri-State
Generation and Transmission Association, Inc.
    Filed Date: 5/30/23.
    Accession Number: 20230530-5314.
    Comment Date: 5 p.m. ET 6/9/23.

    The filings are accessible in the Commission's eLibrary system
(https://elibrary.ferc.gov/idmws/search/fercgensearch.asp) by querying
the docket number.
    Any person desiring to intervene or protest in any of the above
proceedings must file in accordance with Rules 211 and 214 of the
Commission's Regulations (18 CFR 385.211 and 385.214) on or before 5:00
p.m. Eastern time on the specified comment date. Protests may be
considered, but intervention is necessary to become a party to the
proceeding.
    eFiling is encouraged. More detailed information relating to filing
requirements, interventions, protests, service, and qualifying
facilities filings can be found at: http://www.ferc.gov/docs-filing/efiling/filing-req.pdf. For other information, call<PHONE_NUMBER>
(toll free). For TTY, call<PHONE_NUMBER>.

    Dated: June 1, 2023.
Debbie-Anne A. Reese,
Deputy Secretary.
[FR Doc. 2023-12183 Filed 6-6-23; 8:45 am]
BILLING CODE 6717-01-P