xvEPA
           United States        Prevention, Pesticides    September 24, 2OO3
           Environmental Protection  and Toxic Substances    EPA 738-R-O4-OO2
           Agency          (75O8C)
           Report of the Food Quality Protection
           Act (FQPA) Tolerance Reassessment
           Progress and Risk Management
           Decision (TRED) for Lactofen

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                       UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
                                     WASHINGTON, D.C. 20460
                                                                                OFFICE OF
                                                                         PREVENTION, PESTICIDES
                                                                         AND TOXIC SUBSTANCES
CERTIFIED MATT.

Dear Registrant:

       This is the Environmental Protection Agency's (hereafter referred to as EPA or the Agency)
"Report of the Food Quality Protection Act (FQPA) Tolerance Reassessment Progress and Risk
Management Decision for Lactofen," which was approved on September 24, 2003. This document is
also known as a Tolerance Reassessment Decision, or TRED. A Notice of Availability of this
tolerance reassessment decision and an announcement of a 30-day public comment period will be
published in the Federal Register shortly.

Regulatory Determination

       The Federal Food, Drug and Cosmetic Act (FFDCA), as amended by FQPA, requires EPA to
reassess all the tolerances for registered chemicals in effect on or before the enactment of the FQPA on
August 3, 1996. In reassessing these tolerances, the Agency must consider, among other things,
aggregate risks from non-occupational sources of pesticide exposure, whether there is increased
susceptibility to infants and children, and the cumulative effects of pesticides with a common
mechanism of toxicity.  Once a safety finding has been made that aggregate risks are not of concern,
the tolerances are considered reassessed. Existing tolerances associated with lactofen must be
reassessed in accordance with FFDCA, as amended by FQPA. Ecological and occupational
assessments were originally conducted when lactofen was first registered.  Therefore, no further
ecological or occupational assessments are being conducted as part of this  TRED.

       The Agency has evaluated the dietary risk associated with all currently registered uses of
lactofen and has determined that there is a reasonable certainty that no harm to any population
subgroup will result from aggregate exposure to lactofen when considering dietary exposure and all
other non-occupational sources of pesticide exposure for which there is reliable information.
Therefore, no mitigation measures are needed, and the two (2) tolerances established for residues of
lactofen in/on raw agricultural commodities are now considered reassessed as safe under section
408(q) of the FFDCA.

       As part of the TRED, the Agency also considered petitions for establishment of new food uses
and associated tolerances of lactofen on cotton and peanuts. To evaluate the tolerance petition and
determine if new tolerances should be established, EPA considered all of the criteria described above
to ensure that the FQPA safety standard was met.  For the proposed new food uses of lactofen on

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cotton and peanuts, the Agency has determined that there is a reasonable certainty that no harm to any
population subgroup will result from aggregate exposure to lactofen. However, because the TRED
pertains only to the existing tolerances, the establishment of the new food uses and associated
tolerances is outside the scope of this TRED and will be determined by a separate decision.

       The Agency's human health findings for the pesticide lactofen are summarized in the enclosed
chemical overview of the risk assessments. For further details, please refer to the enclosed list of risk
assessments  and other technical documents pertaining to the lactofen TRED, which are available on
the Internet at  http: //www. epa. gov/e-dockets and in the public docket for viewing.

FQPA Assessment

       FQPA requires that EPA consider "available information" concerning the cumulative effects of
a particular pesticide's residues and "other substances that have a common mechanism of toxicity."
The Agency considers other substances because low-level exposures to multiple chemical substances
that cause a common toxic effect by a common mechanism could lead to the same adverse health
effect, as would a higher level of exposure to any of the other substances individually.

       Lactofen belongs to the diphenyl ether class of chemicals. The Agency has not yet determined
whether lactofen and the other diphenyl ether herbicides exhibit a common mechanism of toxicity.
Therefore, the  Agency defers any cumulative risk assessment to a later date.  For the purposes of
tolerance reassessment for lactofen, EPA is assuming no common mechanism with other compounds.
Therefore, a cumulative assessment was not  conducted  for this TRED. However, because lactofen is
expected to degrade to acifluorfen in the environment, EPA did consider the contribution of
acifluorfen from use of sodium acifluorfen as an  herbicide and as an environmental degradate of
lactofen in the aggregate assessment.

       Based  on currently available data, lactofen does not appear to be an endocrine disrupter.
However, when the appropriate screening and/or testing protocols being considered under the
Agency's Endocrine Disrupter Screening Program have been developed, lactofen may be subjected to
additional screening and/or testing to better characterize effects related to endocrine disruption.

Tolerance Summary

       Tolerances for lactofen in or on raw agricultural commodities for plants are currently
established for the combined residues of lactofen and its associated metabolites containing the
diphenyl ether linkage, but will be revised to include only lactofen per se.  The two existing tolerances
for lactofen have been reassessed and will be lowered from 0.05 ppm to 0.01 ppm. There are currently
no tolerances for lactofen in processed  commodities or  animal commodities, and the available residue
data indicate that tolerances for these commodities are not necessary.  No maximum residue limits
(MRLs) for lactofen have been established or proposed by Codex. Therefore, there are no
international compatibility issues with respect to  U.S. tolerances.  A summary of the lactofen tolerance
reassessment and recommended modifications in commodity definitions are presented in Table 1.

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Table 1.  Tolerance Reassessment Summary for Lactofen.
Commodity
Established Tolerance
(ppm)a
Reassessed Tolerance
(ppm)b
Comment
[Correct Commodity Definition]
Tolerances listed under 40 CFR 180.432(a):
Beans, snap
Soybean
0.05
0.05
0.01
0.01
Beans, snap, succulent (excluding
Limas)
Soybean, seed
"       Expressed in terms of lactofen and its metabolites containing the diphenyl ether linkage
b       Expressed in terms of lactofen per se

       As previously mentioned, the Agency has considered petitions for new food uses on cotton and
peanuts in the TRED, but the decision to establish new tolerances will be made separately by the
Agency.  The residue chemistry data for cotton and peanuts has been reviewed and included in the
dietary risk assessment for this TRED.

Uses Subject to TRED and Label Amendments

       The food and feed uses and associated use patterns subject to this TRED are listed in Table 2.
The lactofen labels must conform with the use patterns and use limitations listed in Table 2, which
follows.  Table 2 does not include the forestry use, as this use is not expected to impact the dietary
exposure of any population subgroup and, therefore, is not included in this assessment.

Additional Generic Data Requirements

       As mentioned in the attached Overview of Lactofen FQPA Risk Assessment for Tolerance
Reassessment, several confirmatory data requirements have been identified for lactofen.  These are
listed in Table 3 and will be included in a Federal Insecticide, Fungicide, and Rodenticide Act
(FIFRA) section 3(c)(2)(B) data call in (DCI) to be sent under separate cover.  These data are not
expected to change the regulatory conclusions for lactofen described in this document.

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       This document summarizes the Agency's decision on the tolerance reassessment for lactofen.
Please contact Christina Scheltema of my staff with any questions regarding this decision.  She may be
reached by phone at (703)308-2201 or by e-mail at scheltema. christinaffiepa. gov.
                                          Sincerely,
                                         Betty Shackleford, Acting Director
                                         Special Review and
                                           Reregistration Division
Enclosures:    Technical Support Documents for the Lactofen TRED
              Overview of Lactofen FQPA Risk Assessment for Tolerance Reassessment

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Table 2. Food/Feed Use Patterns Subject to Tolerance Reassessment for Lactofen (PC Code 128888).
        Application Timing
         Application Type
       Application Equipment
 Formulation
[EPA Reg. No.]
  Max. Single
Application Rate
    (Ib ai/A)
   Max. #
Apps./season
  Minimum
 Retreatment
Interval (Days)
Use Limitations
                                                                Cotton (Non-Food Use)
 Postemergence directed ground
 applications to plants at least 6
 inches in height
 Ground equipment
  21b/galEC
  [59639-34]
      0.4
                  None
               A 70-day PHI is specified.
               A 12-hour REI is specified.
               Applications may include crop oil concentrate at up to 2
               pt/A or a non-ionic surfactant at 2 pt/100 gal of spray
               solution.
               For banded applications, the application rate and broadcast
               volume should be reduced in proportion to the area treated.
               Do not apply through any type of irrigation system.
               Do not graze animals on forage or stubble or utilize hay or
               straw for animal feed or bedding.
                                                                      Soybeans
 Broadcast and banded, pre- and
 postemergence applications
 Ground or aerial equipment
  2 Ib/gal EC
  [59639-34]
     0.3 -
 preemergence

     0.2-
 postemergence
                  None
               A 12-hour REI is specified.
               Do not apply within 45 days of harvest or after growth stage
               R6 (full seed); 90-day PHI is specified in NY.
               Do not graze animals on forage or stubble or utilize hay or
               straw for animal feed or bedding.
               Do not apply more than 0.3 Ib ai/A preemergence per
               season and more than a total of 0.4 Ib ai/A/season (0.2 Ib
               ai/A/season in NY)
               Do not apply through any type of irrigation system.
               Minimum application volumes of 5 and 10 gal/A are
               specified for aerial and ground applications, respectively.
               For banded applications, the application rate and broadcast
               volume should be reduced in proportion to the area treated.
               Applications may include 0.125-2% (v/v) of a crop oil
               concentrate or 0.25% of a non-ionic surfactant.

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Application Timing
Application Type
Application Equipment
Formulation
[EPA Reg. No.]
Max. Single
Application Rate
(Ib ai/A)
Max. #
Apps./season
Minimum
Retreatment
Interval (Days)
Use Limitations
Soybeans (continued)

Postemergence broadcast or banded
applications
Ground equipment

2.4 Ib/gal EC
[59639-92]

0.13

2

None
A 60-day PHI is specified.
Do not graze animals on forage or stubble or utilize hay or
straw for animal feed or bedding.
A minimum application volume of 1 5 gal/A is specified.
Applications may include 1-2 pts./A of crop oil concentrate
or methylated seed oil.
Do not apply by air.
Do not rotate to crops other than soybeans or field com
within 30 days of the last application. Do not rotate to small
grains for at least 120 days after the last application.
Snap beans (in OR and TN only)

Preemergence broadcast application
within 48 hours of planting.
Ground equipment

21b/galEC
[59639-34]

0.22 - OR
0.25 - TN

1

Not Applicable
Restricted to use in OR and TN.
A 55-day PHI is specified.
Apply no later than 48 hours after planting.
Do not apply to soils with high sand contents (sandy loams,
loamy sands, and gravelly sandy loams)

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Table 3. Confirmatory Data Requirements for Lactofen
OPPTS Guideline Number
870,3700
860.1850
830.7050
Guideline Name
Prenatal developmental
toxicity study in rabbits
Confined Rotational Crop
Study
UV/Visible Absorption
Compound(s) Which
Must be Tested
Technical
Pure active ingredient
radiolabeled
Technical (76% ai)
EPA Reg. No. 59639-94
Formulation Intermediate
(60% ai)
EPA Reg. No. 59639-70
Comment/Rationale
Data gap
Required because confined
rotational crop study in root
crops indicated minimal
uptake of radioactivity in
carrots and radishes planted
after lactofen application.
New Guideline
Requirement

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                             Technical Support Documents
                                for the Lactofen TRED
1.   Michael Metzger (USEPA/OPPTS/OPP/HED). Lactofen.  Revisions to HED Tolerance
    Reassessment Risk Assessment. August 12, 2003.

2.   Christine Olmger (USEPA/OPPTS/OPP/HED). Lactofen:  Preliminary Human Health Risk
    Assessment for Tolerance Reassessment Incorporating Revised Cancer Unit Risks. October 12,
    2000.

3.   Robert Fricke (USEPA/OPPTS/OPP/HED). Lactofen: Report of the Mechanism of Toxicity
    Assessment Review Committee. March 12, 2001.

4.   (USEPA/OPPTS/OPP/HED). Cancer Assessment Document: Evaluation of Carcinogenic
    Potential of Lactofen (Second Review).  Cancer Assessment Review Committee. May 21, 2002.

5.   James Wolf (USEPA/OPPTS/OPP/EFED).  Drinking Water Exposure Assessment for Lactofen
    Updated for Prospective Ground Water (PGW) Monitoring Study. January 21, 2003.

6.   James Wolf (USEPA/OPPTS/OPP/EFED).  EFED Review of Lactofen Small Scale Prospective
    Ground Water Monitoring Study 166-1. February 26, 2003.

7.   Kit Farwell (USEPA/OPPTS/OPP/HED). Sodium Acifluorfen. Revision to the HED Chapter for
    the Reregistration Eligibility Document. July 14, 2003.

8.   Elizabeth Mendez (USEPA/OPPTS/OPP/HED). Lactofen: Toxicology Evaluation. March 2,
    2000.

9.   Brenda Tarplee (USEPA/OPPTS/OPP/EFED). Lactofen -  Report of the FQPA Safety Factor
    Committee. March 25, 2000

10.  George Keitt. (USEPA/OPPTS/OPP/BEAD). RED Use Profile Report for Lactofen. April 7,
    1998.

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