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Pendimethalin - Pesticide Petition Filing 8/99

[Federal Register: September 1, 1999 (Volume 64, Number 169)]
[Notices]
[Page 47795-47806]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr01se99-97]

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ENVIRONMENTAL PROTECTION AGENCY

[PF-885; FRL-6096-8]

Notice of Filing Pesticide Petitions to Establish a Tolerance for
Certain Pesticide Chemicals in or on Food

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice.

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SUMMARY: This notice announces the initial filing of pesticide
petitions proposing the establishment of regulations for residues of
certain pesticide chemicals in or on various food commodities.

DATES: Comments, identified by docket control number [PF-885], must be
received on or before October 1, 1999.

ADDRESSES: Comments may be submitted by mail, electronically, or in
person. Please follow the detailed instructions for each method as
provided in Unit I.C. of the SUPPLEMENTARY INFORMATION section. To
ensure proper receipt by EPA, it is imperative that you identify docket
control number PF-885 in the subject line on the first page of your
response.

[[Page 47796]]

FOR FURTHER INFORMATION CONTACT:  By mail: Shaja Brothers, Registration
Support Branch, Registration Division (7505C), Office of Pesticide
Programs, Environmental Protection Agency, 401 M St., SW., Washington,
DC 20460; telephone number: (703) 308-3194; and e-mail address:
brothers.shaja@epa.gov.
    For technical questions, contact the appropriate Product Manager:
Joseph Tavano, telephone number: (703) 305-6411 and e-mail address:
tavano.joseph@epa.gov.; or Cynthia Giles-Parker (PM 22), telephone
number: (703) 305-7740 and e-mail address: giles-
parker.cynthia@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

    You may be affected by this action if you are an agricultural
producer, food manufacturer or pesticide manufacturer. Potentially
affected categories and entities may include, but are not limited to:

------------------------------------------------------------------------
                                                          Examples of
           Categories                    NAICS            potentially
                                                       affected entities
------------------------------------------------------------------------
Industry                          111                 Crop production

                                  112                 Animal production

                                  311                 Food manufacturing
                                  32532               Pesticide
                                                       manufacturing
------------------------------------------------------------------------

    This listing is not intended to be exhaustive, but rather provides
a guide for readers regarding entities likely to be affected by this
action. Other types of entities not listed in the table could also be
affected. The North American Industrial Classification System (NAICS)
codes have been provided to assist you and others in determining
whether or not this action might apply to certain entities. If you have
questions regarding the applicability of this action to a particular
entity, consult the person listed in the "FOR FURTHER INFORMATION
CONTACT" section.

B. How Can I Get Additional Information, Including Copies of this
Document and Other Related Documents?

    1. Electronically. You may obtain electronic copies of this
document, and certain other related documents that might be available
electronically, from the EPA Internet Home Page at http://www.epa.gov/.
To access this document, on the Home Page select "Laws and
Regulations" and then look up the entry for this document under the
"Federal Register--Environmental Documents." You can also go directly
to the Federal Register listings at http://www.epa.gov/fedrgstr/.
    2. In person. The Agency has established an official record for
this action under docket control number PF-885. The official record
consists of the documents specifically referenced in this action, any
public comments received during an applicable comment period, and other
information related to this action, including any information claimed
as confidential business information (CBI). This official record
includes the documents that are physically located in the docket, as
well as the documents that are referenced in those documents. The
public version of the official record does not include any information
claimed as CBI. The public version of the official record, which
includes printed, paper versions of any electronic comments submitted
during an applicable comment period, is available for inspection in the
Public Information and Records Integrity Branch (PIRIB), Rm. 119,
Crystal Mall #2, 1921 Jefferson Davis Highway, Arlington, VA, from 8:30
a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The
PIRIB telephone number is (703) 305-5805.

C. How and to Whom Do I Submit Comments?

    You may submit comments through the mail, in person, or
electronically. To ensure proper receipt by EPA, it is imperative that
you identify docket control number PF-885 in the subject line on the
first page of your response.
    1. By mail. Submit your comments to: Public Information and Records
Integrity Branch (PIRIB), Information Resources and Services Division
(7502C), Office of Pesticide Programs (OPP), Environmental Protection
Agency, 401 M St., SW., Washington, DC 20460.
    2. In person or by courier. Deliver your comments to: Public
Information and Records Integrity Branch (PIRIB), Information Resources
and Services Division (7502C), Office of Pesticide Programs (OPP),
Environmental Protection Agency, Rm. 119, Crystal Mall #2, 1921
Jefferson Davis Highway, Arlington, VA. The PIRIB is open from 8:30
a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The
PIRIB telephone number is (703) 305-5805.
    3. Electronically. You may submit your comments electronically by
E-mail to: "opp-docket@epa.gov," or you can submit a computer disk
as described above. Do not submit any information electronically that
you consider to be CBI. Avoid the use of special characters and any
form of encryption. Electronic submissions will be accepted in
Wordperfect 5.1/6.1 or ASCII file format. All comments in electronic
form must be identified by docket control number PF-885. Electronic
comments may also be filed online at many Federal Depository Libraries.

D. How Should I Handle CBI That I Want to Submit to the Agency?

    Do not submit any information electronically that you consider to
be CBI. You may claim information that you submit to EPA in response to
this document as CBI by marking any part or all of that information as
CBI. Information so marked will not be disclosed except in accordance
with procedures set forth in 40 CFR part 2. In addition to one complete
version of the comment that includes any information claimed as CBI, a
copy of the comment that does not contain the information claimed as
CBI must be submitted for inclusion in the public version of the
official record. Information not marked confidential will be included
in the public version of the official record without prior notice. If
you have any questions about CBI or the procedures for claiming CBI,

please consult the person identified in the "FOR FURTHER INFORMATION
CONTACT" section.

E. What Should I Consider as I Prepare My Comments for EPA?

    You may find the following suggestions helpful for preparing your
comments:
     1. Explain your views as clearly as possible
     2. Describe any assumptions that you used.
     3. Provide copies of any technical information and/or data you
used that support your views.
     4. If you estimate potential burden or costs, explain how you
arrived at the estimate that you provide.
     5. Provide specific examples to illustrate your concerns.
     6. Make sure to submit your comments by the deadline in this
notice.
     7. To ensure proper receipt by EPA, be sure to identify the docket
control number assigned to this action in the subject line on the first
page of your response. You may also provide the name, date, and Federal
Register citation.

II. What Action is the Agency Taking?

    EPA has received pesticide petitions as follows proposing the
establishment and/or amendment of regulations for residues of certain
pesticide chemicals in or on various food commodities

[[Page 47797]]

under section 408 of the Federal Food, Drug, and Comestic Act (FFDCA),
21 U.S.C. 346a. EPA has determined that these petitions contain data or
information regarding the elements set forth in section 408(d)(2);
however, EPA has not fully evaluated the sufficiency of the submitted
data at this time or whether the data supports granting of the
petition. Additional data may be needed before EPA rules on the
petition.

List of Subjects

    Environmental protection, Agricultural commodities, Feed additives,
Food additives, Pesticides and pests, Reporting and recordkeeping
requirements.

    Dated: August 19, 1999.

James Jones,

Director, Registration Division, Office of Pesticide Programs.

Summaries of Petitions

    Petitioner summaries of the pesticide petitions are printed below
as required bysection 408(d)(3) of the FFDCA. The summaries of the
petitions were prepared by the petitioners and represent the views of
the petitioners. EPA is publishing the petition summaries verbatim
without editing them in any way. The petition summary announces the
availability of a description of the analytical methods available to
EPA for the detection and measurement of the pesticide chemical
residues or an explanation of why no such method is needed.

1. IR-4 Project

 PP 6E4603, 6E4787, and 7E4878

    EPA has received pesticide petitions [PP 6E4603, 6E4787, and
7E4878] from the Interregional Research Project Number 4 (IR-4), New
Jersey Agricultural Experiment Station, P. O. Box 231 Rutgers
University, New Brunswick, NJ 08903 proposing pursuant to section
408(d) of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C.
346a(d), to amend 40 CFR part 180 by establishing tolerances for
combined residues of the herbicide, pendimethalin [N-(1-ethylpropyl)-
3,4-dimethyl-2,6-dinitrobenzenamine, and its 3, 5-dinitrobenzyl alcohol
metabolite (CL 202347) in or on the food commodities as follows:
    1 PP 6E4603. Proposes the establishment of a tolerance for carrots
at 0.5 parts per million (ppm).
    2 PP 6E4787. Proposes the establishment of a tolerance for citrus
fruit crop group at 0.1 ppm.
    3. PP 7E4878. Proposes the establishment of tolerances, with
regional registration for peppermint and spearmint tops at 0.2 ppm, and
peppermint and spearmint oil at 1.0 ppm. Registration will be limited
to Idaho, Oregon, and Washington based on the geographical
representation of the residue data submitted to EPA.
    EPA has determined that the petitions contain data or information
regarding the elements set forth in section 408(d)(2) of the FFDCA;
however, EPA has not fully evaluated the sufficiency of the submitted
data at this time or whether the data support granting of the
petitions. Additional data may be needed before EPA rules on the
petitions.

A. Residue Chemistry

    1. Plant metabolism. The qualitative nature of the residues of
pendimethalin in plants is understood based on adequate studies
conducted with [14 C]-pendimethalin on various crops.
Pendimethalin and its 3,5-dinitrobenzyl alcohol metabolite (CL202347)
are the only residues of concern.
    2. Analytical method. Section 408 (b)(3) of the amended FFDCA
requires EPA to determine that there is a practical method for
detecting and measuring levels of the pesticide chemical residue in or
on food and that the tolerance be set at a level at or above limit of
detection of the designated method. The Gas Chromatography (GC) of
pendimethalin and (CL202347) analytical methods, M691 and M692, are
proposed as the enforcement methods for the residues in carrots; M1999
is the proposed method for citrus fruit crop group, and processed
citrus commodities; and M1930.01 has been proposed for mint and mint
oil. All methods utilize electron capture detectors and have a limit of
quantitation (LOQ) of 0.05 ppm for the respective residues of concern.
    3. Magnitude of residues--i. Residue field trials were conducted in
seven major carrot producing states in the United States at both the 1x
rate of 2 pounds (lbs) active ingredient/acre (ai/A) and an exaggerated
rate of 4 lbs ai/A (2x the typical application rate). Maximum
pendimethalin residues recovered from carrot samples treated with these
applications were 0.10 ppm from the 1x treatment and 0.16 ppm from the
2x treatment. For the alcohol metabolite, CL202347, the maximum
recovered residues ranged from 0.29 ppm from the 1x treatment to 0.44
ppm from the 2x treatment. The registrant believes that the results
from these studies support the proposed tolerance of 0.5 ppm
pendimethalin in or on carrots.
    ii. Residue field trials were conducted on oranges, grapefruits,
and lemons in major citrus fruit crop group producing states in the
United States at a 1.5x rate of 6 lbs ai/A and an exaggerated 3x rate
of 12 lbs ai/A. The plots were treated with pendimethalin at a variety
of different intervals prior to harvest. The raw agricultural commodity
(RAC) samples were also processed into wet and dried pulp, molasses,
oil and juice. RAC samples taken from plots treated one day prior to
harvest, a worst case residue situation, resulted in residues of 0.008
ppm (in grapefruit) or less. No residues were recovered from wet pulp
and juice samples at the 0.005 ppm level. Residues of pendimethalin
were recovered at 0.005 ppm in dried pulp, 0.009 ppm in molasses and
0.026 ppm in orange oil. It should be noted that data for wet pulp and
molasses are no longer required as per Table I of the Residue Chemistry
Test Guidelines EPA OPPTS 860.1000. The registrant believes that the
results from these studies are adequate to support the proposed
tolerance of 0.1 ppm pendimethalin in or on citrus fruit crop group,
and in processed citrus commodities.
    iii. Residue field trials were conducted in two major mint
producing states in the United States at both the 1x rate of 2 lbs ai/A
and an exaggerated rate of 10 lbs ai/A (5x the typical application
rate). Fresh mint foliage samples were either harvested and directly
analyzed or processed into mint oil before analyses. The registrant
believes that the results from these studies support the proposed
tolerances of 0.2 ppm pendimethalin in mint foliage (leaves and stems)
and 1.0 ppm pendimethalin in mint oil.

B. Toxicological Profile

    1. Acute toxicity. The acute oral lethal dose (LD50)
values for pendimethalin technical in the Wistar rat are 1,250
milligrams/kilograms/body weight (mg/kg/bwt) (males) and 1,050 mg/kg/
bwt (females). The acute dermal LD50 was greater than 5,000
mg/kg in New Zealand white rabbits. The 4-hour rat inhalation lethal
concentration (LC50) was > 320 milligram per liter (mg/L)
(nominal concentration). Pendimethalin was shown to be slightly
irritating to rabbit eyes and non-irritating to rabbit skin.
Pendimethalin did not cause skin sensitization in guinea pigs.
    2. Genotoxicity. Extensive mutagenicity studies conducted to
investigate point and gene mutations, DNA damage and chromosomal
aberration, using in vitro and in vivo test systems show pendimethalin
to be non-genotoxic.

[[Page 47798]]

    3. Reproductive and developmental toxicity. Results from a 2-
generation rat reproduction study showed the no-observed adverse effect
level (NOAEL) for parental and reproductive toxicity to be 2,500 ppm
(172 mg/kg bwt/day) and the lowest-observed adverse effect level
(LOAEL) to be 5,000 ppm (346 mg/kg/bwt/day). No developmental toxicity
was observed in either the rat or rabbit developmental toxicity
studies, nor was there any evidence in the 2-generation rat
reproduction study that there was developmental or reproductive
toxicity at dose levels below those in which parental toxicity was
observed. For rabbits, the developmental toxicity NOAEL was > 60 mg/kg/
day, the highest dose tested (HDT). The maternal NOAEL was > 60 mg/kg/
day, based on mortality observed at 125 mg/kg/day in a pilot study. For
rats, there were no maternal or developmental effects at any dose level
and the NOAELs for both maternal and developmental effects were
≥ 500 mg/kg/day, the HDT.
    4. Subchronic toxicity. A 90-day feeding study was conducted in
rats and dogs. The NOAELs for these studies were 500 ppm (50 mg/kg/bwt/
day) and 2,500 ppm (62.5 mg/kg/bwt/day) for the rat and dog studies,
respectively.
    5. Chronic toxicity. The chronic toxicity of pendimethalin has been
extensively investigated in three species (i. e., the rat, mouse, and
dog). The results are as follows:
    i. Rats. In an initial 2-year feeding study in Sprague-Dawley rats,
conducted at dose levels of 0, 100, 500, and 5,000 ppm (corresponding
to dietary intakes of 0, 5, 25, and 250 mg/kg/bwt/day, respectively), a
clear NOAEL was established at 500 ppm (25 mg/kg/bwt/day). The LOAEL
was set at 5,000 ppm (250 mg/kg/bwt/day) based on decreased survival,
body weight gain and food consumption, increased gamma glutamyl
transferase and cholesterol, an increase in absolute and/or relative
liver weight, generalized icterus, dark adipose tissue in females,
diffusely dark thyroids and follicular cell hyperplasia of the thyroid.
In a second 2-year feeding study in rats, conducted at dose levels of
0, 1,250, 2,500, 3,750, and 5,000 ppm (corresponding to dietary intakes
of 0, 51, 103, 154, and 213 mg/kg/bwt/day, respectively), a NOAEL was
not determined. The LOAEL of less than or equal to 1,250 ppm
(≥ 51 mg/kg/bwt/day) was based on non-neoplastic thyroid
follicular cell changes and increased liver weight.
    ii. Mouse. Pendimethalin technical was administered at dietary
concentrations of 100, 500, and 5,000 ppm (corresponding to dose levels
of 12.3, 62.3 and 622.1 mg/kg/bwt/day in males and 15.6, 78.3, and
806.9 mg/kg/ bwt/day in females) to CD-1 mice for 18-months. In this
study, the NOAEL was 500 ppm (62.3 mg/kg/bwt/day) and the LOAEL, based
on mortality, body weight decrease, organ weight changes and
amyloidosis, was 5,000 ppm (622.1 mg/kg/ bwt/day).
    iii. Dog. In a 2-year oral (capsule) study, conducted at dose
levels of 0, 12.5, 50 and 200 mg/kg/bwt/day, the NOAEL was equal to or
greater than the maximum dose tested ≥ 200 mg/kg/bwt/day with
no LOAEL established.
    Pendimethalin has been classified as a Group C, "possible human
carcinogen," chemical by EPA based on a statistically significant
increased trend and pairwise comparison between the high dose group and
controls for thyroid follicular cell adenomas in male and female rats.
EPA recommended using the chronic population adjusted dose (cPAD)
approach for quantification of human risk. Therefore, the cPAD is
deemed protective of all chronic human health effects, including
cancer.
    6. Animal metabolism. Adequate goat and poultry metabolism studies
are available for pendimethalin. As no poultry feed items are
associated with carrots, citrus fruit crop group processed citrus
commodities, or mint, poultry metabolism studies are not relevant to
this petition. In addition, the registrant has determined that there is
no reasonable expectation of finite pendimethalin residues of concern
in animal commodities as a result of use on multiple crops and no
tolerances for pendimethalin residues of concern in livestock
commodities are needed.
    7. Endocrine disruption. Collective results from several
mechanistic studies provide support that pendimethalin disrupts
thyroid-pituitary hormonal balance. An analysis of the data obtained
from these studies supports fluctuations in thyroid hormones (T3 and/or
T4) at dietary concentrations of 500 ppm (31 mg/kg/bwt/day) and
greater. However, no fluctuations in thyroid hormones were observed at
100 ppm (10 mg/kg/bwt/day) in either of the 14-day special feeding
studies, supporting a NOAEL for thyroid effects of 100 ppm or 10 mg/kg/
bwt/day. As the cPAD is based on the NOAEL of 10 mg/kg/bwt/day obtained
from these studies, thyroid hormonal changes are already accounted for
in the characterization of the potential risks to humans. Moreover,
because of species differences in thyroid gland physiology, slight
fluctuations in thyroid hormone levels noted in rats may not be
applicable to humans. In addition, collective organ weights and
histopathological findings from the 2-generation rat reproduction
study, as well as from the subchronic and chronic toxicity studies in 3
different animal species demonstrate no apparent estrogenic effects or
treatment-related effects on any other component of the endocrine
system.

C. Aggregate Exposure

    Pendimethalin is widely used as a pre-emergent herbicide to control
broad-leaf weeds in both food and non-food crops, as well as non-
agricultural use sites including residential lawns. In examining
aggregate exposure, FQPA directs EPA to consider available information
concerning exposures from the pesticide residue in food and water
(dietary) and all other non-occupational exposures. The primary non-
food sources of exposure the Agency evaluates include drinking water
(whether from groundwater or surface water), and exposure through
pesticide use in gardens, lawns, or buildings (residential and other
indoor uses). The potential for aggregate exposure from all registered
and proposed uses is discussed below:
    1. Dietary (food) exposure. Tolerances have been established (40
CFR 180.361) for the combined residues of pendimethalin and its 3,5-
dinitrobenzyl alcohol metabolite (CL 202347) in or on a variety of food
commodities at levels ranging from 0.05 ppm in rice grain to 0.1 ppm in
corn, peanuts, soybeans and other commodities. Based on conservative
assumptions of tolerance level residues and 100% crop treatment with
pendimethalin, the EPA's Dietary Exposure Evaluation Model (DEEM)
estimates chronic dietary exposure to pendimethalin from all currently
registered uses to be only 0.00042 mg/kg/day (< 1% cPAD) for the
overall U. S. population. The estimated most highly exposed DEEM
subgroup for pendimethalin is non-nursing infants at a level of 0.00140
mg/kg/day (< 2%).
    Additional maximum dietary contributions, (of up to 0.000498 mg/kg/
bwt/day and 0.001294 mg/kg/bwt/day for the general U.S. population and
for non-nursing infants less than 1-year old, respectively) anticipated
from use on carrots and citrus fruit crop group will still utilize < 1%
(actual 0.5%) and < 2% (actual 1.3%) of the cPAD for the respective
population subgroups. The additional dietary burden that will result
from the pendimethalin tolerances in mint and mint oil will also be
insignificant. Thus, the American Cyanamid Company believes that there
should be no reason for concern from the additional dietary burden that
will result from the proposed tolerances of pendimethalin in carrots,
citrus fruit

[[Page 47799]]

crop group, and mint because the contribution to the cPAD will be
insignificant.
    i. Drinking water. Pendimethalin has low water solubility and a
strong absorption to soil, which makes it essentially immobile in all
soil types. Therefore, American Cyanamid Company concludes that there
is no concern for the potential for pendimethalin to runoff to surface
water or leach to ground water. No Maximum Concentration Level and no
Health Advisory Level has been established for residues of
pendimethalin in drinking water. A pendimethalin drinking water
exposure analysis for a 10 kg child shows that a chronic exposure from
a worst case dietary intake (drinking water only) of 0.0018 mg/kg/day
would utilize < 2% of the cPAD. Thus, the American Cyanamid Company
believes that contributions to the dietary burden from residues of
pendimethalin in water, alone, would be inconsequential.
    2. Non-dietary exposure. Pendimethalin is currently registered for
use on the following residential and non-food sites: ornamental lawns,
grasses, ground covers, turf, and ornamental plantings, which are
short- and intermediate-term non-occupational exposure scenarios. Thus,
the American Cyanamid Company believes that the estimates margins of
exposure (MOEs) for residential applicators (MOE = 833) and residential
post-application exposures to children (MOE = 111) are more than
adequate.

D. Cumulative Effects

    The Agency has not yet published guidelines to determine whether
pendimethalin has a common mechanism of toxicity with other substances
or how to include this pesticide in a cumulative risk assessment.
Unlike other pesticides for which EPA has followed a cumulative risk
approach based on a common mechanism of toxicity, pendimethalin does
not appear to produce a toxic metabolite produced by other substances.
For the purposes of this tolerance action, the American Cyanamid
Company assumes that pendimethalin does not have a common mechanism of
toxicity with other substances.

E. Safety Determination

    1. U.S. population. Using the conservative exposure assumptions
described above and based on the completeness and reliability of the
toxicity data, the American Cyanamid Company concludes that the total
aggregate exposure to pendimethalin from food will utilizes less than
1% of the cPAD for the overall U.S. population. EPA generally has no
concern for exposures below 100% of the cPAD because the cPAD
represents the level at or below which daily aggregate dietary exposure
over a lifetime will not pose appreciable risks to human health.
Despite the potential for exposure to pendimethalin in drinking water
and from non-dietary non-occupational exposures, the American Cyanamid
Company does not expect the aggregate exposure to exceed 100% of the
cPAD. The registrant concludes that the aggregate risks estimated from
the following three scenarios: (i) < 4% of the cPAD for chronic dietary
exposures (food plus water), (ii) MOE = 680 for chronic dietary
exposures (food plus water) plus residential applicator exposures, and
(iii) MOE = 107 for chronic dietary exposures (food plus water) plus
residential post-application exposures to children, do not exceed the
Agency's levels of concern. Thus, the American Cyanamid Company
concludes that there is a reasonable certainty that no harm will result
from aggregate exposure to pendimethalin residues as a result of the
establishment of the proposed tolerance in carrots, citrus fruit crop
group, and processed citrus commodities, mint and mint oil.
    2. Infants and children. The major identifiable subgroup with the
highest aggregate exposure is non-nursing infants less than 1-year old.
In assessing the potential for additional sensitivity of infants and
children to residues of pendimethalin, the data from developmental
toxicity studies in the rat and rabbit, and a 2-generation reproduction
study in the rat has been considered. The developmental toxicity
studies are designed to evaluate adverse effects on the developing
organism resulting from maternal pesticide exposure during prenatal
development. Reproduction studies provide information relating to
effects on the reproductive capabilities of parental animals from
exposure to the pesticide as well as additional data on systemic
toxicity.
    The prenatal and postnatal toxicology data base for pendimethalin
is complete with respect to current toxicological data requirements.
The data base does not indicate a potential for increased sensitivity
from prenatal or postnatal exposure. As mentioned in item B.3. above,
no developmental toxicity was observed in either the rat or rabbit
developmental toxicity studies, nor was there any evidence in the 2-
generation rat reproduction study that there was developmental or
reproductive toxicity at dose levels below those in which parental
toxicity was observed. For rabbits, the developmental toxicity NOAEL
was > 60 mg/kg/day, the HDT. The maternal NOAEL was > 60 mg/kg/day,
based mortality observed at 125 mg/kg/day in a pilot study. For rats,
there were no maternal or developmental effects at any dose level and
the NOAELs for both maternal and developmental effects were ≥
500 mg/kg/day, the HDT. In the 2-generation reproductive toxicity study
in rats, the parental and reproductive NOAELs were 172 mg/kg/day. The
reproductive LOAEL of 346 mg/kg/day was based on decreased pup weight,
which occurred in the presence of parental (systemic) toxicity at 346
mg/kg/day.
    FFDCA section 408 provides that EPA may apply an additional tenfold
margin of safety for infants and children in the case of threshold
effects to account for prenatal and postnatal toxicity and the
completeness of the data base. Based on current toxicological data
requirements, the toxicology data base for pendimethalin is complete.
Furthermore, the reproductive NOAEL of 172 mg/kg/day is seventeen-fold
higher than the NOAEL of 10 mg/kg/day used for the cPAD. Additionally,
the reproductive LOAEL occurred in the presence of parental (systemic)
toxicity, and there was no evidence of developmental toxicity in either
the rat or the rabbit studies. Therefore, the American Cyanamid Company
believes that these proposed tolerances do not represent any
unacceptable prenatal or postnatal risk to infants and children.
    Using the conservative exposure assumptions described above, and
based on previous EPA reports, the American Cyanamid Company has
concluded that aggregate exposure to pendimethalin from food will
utilize less than 2% of the cPAD for infants and children. EPA
generally has no concern for exposures below 100% of the cPAD because
the cPAD represents the level at or below which daily aggregate dietary
exposure over a lifetime will not pose appreciable risks to human
health. Despite the potential for exposure to pendimethalin in drinking
water and from non-dietary, non-occupational exposure, the American
Cyanamid Company does not expect the aggregate exposure to exceed 100%
of the cPAD. Thus, the registrant concludes that there is a reasonable
certainty that no harm will result to infants and children from
aggregate exposure to pendimethalin residues.

 F. International Tolerances

     There are no Codex, Canadian or Mexican International Maximum
Residue Levels established for residues of pendimethalin in carrots,
citrus fruit

[[Page 47800]]

crop group and processed citrus commodities, or mint at this time.

 [FR Doc. 99-22455 Filed 8-31-99; 8:45 am]
BILLING CODE 6560-50-F