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paraquat Pesticide Petition Filing 9/98


        
[Page 53902-53911]
>From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr07oc98-1037]

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ENVIRONMENTAL PROTECTION AGENCY

[PF-831; FRL-6026-3]

 
Notice of Filing of Pesticide Tolerance Petitions

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 the docket control number PF-831, must 
be received on or before November 6, 1998.

ADDRESSES: By mail submit written comments to: Public Information and 
Records Integrity Branch, Information Resources and Services Divison 
(7502C), Office of Pesticides Programs, Environmental Protection 
Agency, 401 M St., SW., Washington, DC 20460. In person bring comments 
to: Rm. 119, Crystal Mall (CM) #2, 1921 Jefferson Davis Highway, 
Arlington, VA.

[[Page 53903]]

    Comments and data may also be submitted electronically by following 
the instructions under ``SUPPLEMENTARY INFORMATION.'' No Confidential 
Business Information (CBI) should be submitted through e-mail.
    Information submitted as a comment concerning this document may be 
claimed confidential by marking any part or all of that information as 
CBI. CBI should not be submitted through e-mail. Information marked as 
CBI will not be disclosed except in accordance with procedures set 
forth in 40 CFR part 2. A copy of the comment that does not contain CBI 
must be submitted for inclusion in the public record. Information not 
marked confidential may be disclosed publicly by EPA without prior 
notice. All written comments will be available for public inspection in 
Rm. 119 at the address given above, from 8:30 a.m. to 4 p.m., Monday 
through Friday, excluding legal holidays.

FOR FURTHER INFORMATION CONTACT: The product manager listed in the 
table below:

------------------------------------------------------------------------
                                   Office location/
        Product Manager            telephone number          Address
------------------------------------------------------------------------
Leonard Cole..................  Rm. 209, CM #2, 703-    1921 Jefferson
                                 305-5412; e-mail:       Davis Hwy,
                                 cole.leonard@epamail.   Arlington, VA
                                 epa.gov.
Mark Dow......................  Rm. 214, CM #2, 703-    Do.
                                 305-5533; e-mail:
                                 Dow.mark@epamail.epa.
                                 gov.
James Tompkins................  Rm. 239, CM #2, 703     Do.
                                 305-5697; e-mail:
                                 tompkins.james@epamai
                                 l.epa.gov.
------------------------------------------------------------------------


SUPPLEMENTARY INFORMATION: EPA has received pesticide petitions as 
follows proposing the establishment of regulations for residues of 
certain pesticide chemicals in or on various raw food commodities 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 grantinig of the 
petition. Additional data may be needed before EPA rules on the 
petition.
    The official record for this notice, as well as the public version, 
has been established for this notice of filing under document control 
number PF-831 (including comments and data submitted electronically as 
described below). A public version of this record, including printed, 
paper versions of electronic comments, which does not include any 
information claimed as CBI, is available for inspection from 8:30 a.m. 
to 4 p.m., Monday through Friday, excluding legal holidays. The 
official record is located at the address in ``ADDRESSES''.
    Electronic comments can be sent directly to EPA at:
    opp-docket@epamail.epa.gov


    Electronic comments must be submitted as an ASCII file avoiding the 
use of special characters and any form of encryption. Comment and data 
will also be accepted on disks in Wordperfect 5.1/6.1 file format or 
ASCII file format. All comments and data in electronic form must be 
identified by the document control number (PF-831) and appropriate 
petition number. Electronic comments on this notice may be filed online 
at many Federal Depository Libraries.

    Authority: 21 U.S.C. 346a.

List of Subjects

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

    Dated: September 29, 1998.

James Jones,

Director, Registration Division, Office of Pesticide Programs.

Summaries of Petitions

    Below summaries of the pesticide petitions are printed. The 
summaries of the petitions were prepared by the petitioners. 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.


3. Zeneca Ag. Products

PP 5F1625/5H5088

    EPA has received pesticide petitions PP 5F1625 and 5H5088 from 
Zeneca Ag Products, 1800 Concord Pike, P.O. Box 15458, Wilmington, 
Delaware 19850-5458, 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 a tolerance for residues of the 
herbicide paraquat (1,1-dimethyl-4,4'-bypyridinium) derived from the 
corn harvest-aid application of the dichloride salt (calculated as the 
cation) in or on the raw agricultural commodities corn, pop, grain at 
0.05 part per million (ppm); corn, field, grain at 0.05 ppm; corn, 
field, forage at 3.0 ppm; corn, pop, forage at 3.0 ppm; corn, field, 
stover at 10.0 ppm; corn, pop, stover at 10 ppm; and corn, flour at 0.1 
ppm.
    An adequate analytical method (spectrophotometric method) has been 
accepted and published in the Pesticide Analytical Manual (PAM Vol. II) 
for the enforcement of tolerances in plant

[[Page 53909]]

commodities. EPA has determined that the petition contains 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 supports granting of 
the petition. Additional data may be needed before EPA rules on the 
petition.

A. Residue Chemistry

    1. Plant metabolism. The qualitative nature of the residue in 
plants is adequately understood based on studies depicting the 
metabolism of paraquat in carrots and lettuce following pre-emergence 
treatments and in potatoes and soybeans following desiccant treatment. 
The residue of concern in plants is the parent, paraquat; the current 
tolerance expression for plant commodities, as defined in 40 CFR 
180.205(a) and (b).
    2. Analytical method. An adequate analytical method (spectrometric 
method) has been accepted and published in the The Pesticide Analytical 
Manual (PAM Vol. II) for the enforcement of tolerances in plant 
commodities.
    3. Magnitude of residues. Paraquat residues on corn forage ranged 
from <0.025 to 3 ppm and on corn fodder ranged from 0.025 to 6 ppm 
following preemergence and post-directed applications as described for 
MRID 41151523 and 41151506. Residue data submitted in tolerance 
petition PP 5F1625 (MRID 00114426) for corn harvest-aid use of paraquat 
indicate that corn grain residues would not exceed the established 
tolerance of 0.05 ppm when applied broadcast postemergence at 0.5 lbs 
ai/A with a 7-day pre-harvest interval. Residue data submitted in 
tolerance petition PP 5F1625 (MRID 00114426) for corn harvest-aid use 
of paraquat indicate that corn fodder (stover) residues range from 1.3 
to 10.0 ppm when applied broadcast postemergence at 0.5 lbs ai/A with a 
7-day pre-harvest interval. These data support a corn forage tolerance 
of 3 ppm and a corn stover tolerance of 10 ppm.

B. Toxicological Profile

    1. Acute Toxicity. Acute toxicity studies conducted with the 45.6% 
paraquat dichloride technical concentrate give the following results: 
oral LD<INF>50</INF> in the rat of 344 mg/kg (males) and 283 mg/kg 
(females) (Category II); dermal LD<INF>50</INF> in the rat of 
<ls-thn-eq> 2,000 mg/kg for males and females (Category III); the 
primary eye irritation study showed corneal involvement with clearing 
within 17 days (Category II); and dermal irritation of slight erythema 
and edema at 72 hours (Category IV). Paraquat is not a dermal 
sensitizer. Acute inhalation studies conducted to EPA guideline with 
aerosolized sprays result in LD<INF>50</INF> of 0.6 to 1.4 <greek-m>g 
paraquat cation/Liter (L) (Category I). However, since paraquat 
dichloride has no measurable vapor pressure; and hydraulic spray 
droplets are too large to be respirable, inhalation exposure is not a 
concern in practice.
    2. Genotoxicity. Paraquat dichloride was not mutagenic in the Ames 
test using Salmonella typhinurium strains TA1535, TA1538, TA98, and 
TA100; the chromosomal aberrations in the bone marrow test system; or 
in the dominant lethal mutagenicity study with CD-1 mice. Additionally, 
paraquat dichloride was negative for unscheduled DNA synthesis in rat 
hepatocytes in in vitro and in vivo. Paraquat was weakly positive in 
the mouse lymphoma cell assay only in the presence of metabolic 
activation. Paraquat dichloride was weakly positive in mammalian cells 
(lymphocytes) and positive in the sister chromatid exchange (SCE) assay 
in Chinese hamster lung fibroblasts. Paraquat is non-mutagenic.
    3. Reproductive and developmental toxicity. A 3-generation 
reproduction study in rats fed diets containing 0, 25, 75, and 150 ppm 
which correspond to 0, 1.25, 3.75 or 7.5 mg of paraquat cation/kg/day, 
respectively. Paraquat, at all levels tested, had no effect on body 
weight gain, food consumption and utilization, fertility and length of 
gestation of the F<INF>0</INF> F<INF>1</INF> and F<INF>2</INF> parents. 
The NOAEL and LOEL for systemic toxicity are 25 ppm (1.25 mg/kg/day) 
and 75 ppm (3.75 mg/kg/day), respectively, expressed as paraquat 
cation. The NOAEL for reproductive toxicity is <gr-thn-eq>150 ppm (7.5 
mg/kg/day; HDT) expressed as paraquat cation, as there were no 
reproductive effects observed.
    Two developmental toxicity studies were conducted in rats given 
gavage doses of 0, 1, 5, and 10 mg/kg/day and 0, 1, 3, and 8 mg/kg/day, 
respectively, expressed as paraquat cation. In the first study, the 
NOAEL for maternal toxicity was 1 mg/kg/day based on clinincal signs of 
toxicity and decreased body weight gain at 5 mg/kg/day (the LOEL). The 
NOAEL for developmental toxicity was set at 5 mg/kg/day based on 
delayed ossification of the forelimb and hindlimb digits. In the 
second, study, the maternal and developmental NOAEL is 8 mg/kg/day 
(HDT) as there were no effects observed at any dose level even though 
the animals were examined more carefully in the manus and pes 
assessment. Based on both studies the overall NOAEL for maternal and 
developmental toxicity is at least 3 mg/kg/day.
    Two developmental toxicity studies were conducted in mice given 
gavage doses of 0, 1, 5, and 10 mg/kg/day and 0, 7.5, 15, or 25 mg/kg/
day paraquat ion, respectively. Both the maternal and developmental 
NOAEL's are at 15 mg/kg/day in the second study. The maternal LOEL of 
25 mg paraquat cation/kg/day is based on death, decreases in body 
weight and body weight gain, and other clinical signs. The 
developmental LOEL is 25 mg/kg/day. In the first study there was a 
statistically significant effect on ``partial ossification'' of the 4th 
sternebra at 10 mg/kg/day (HDT). However, it is not believed the 
ossification pattern of the 4th sternebra was affected by paraquat as 
evidenced by the lack of increase in ``4th sternebra - not ossified.''
    Additionally there were no statistically significant skeletal 
abnormalities seen in the second study. The developmental/maternal 
NOAEL should be based on the second study and is 15 mg/kg/day. Paraquat 
dichloride is not a developmental toxin.
    4. Subchronic toxicity. A 90 day feeding study in dogs fed doses of 
0, 7, 20, 60 or 120 ppm with a NOAEL of 20 ppm based on long effects 
such as alveolitis and alveolar collapse seen at the LOEL of 60 ppm.
    A 21 day dermal toxicity study in rabbits exposed dermally to doses 
of 0, 1.5, 3.4, 7.8 or 17.9 mg/kg/day with a NOAEL of 1.15 mg/kg/day 
and a LOEL of 2.6 mg/kg/day based on dermal irritation.
    A 21 day inhalation toxicity study in rats were exposed to 
respirable aerosols of paraquat at doses of 0, 0.01, 0.1, 0.5 and 1.0 
<greek-m>g/L with a NOAEL of 0.01 <greek-m>g/L and a LOEL of 0.10 
<greek-m>g/L based on histopathological changes to the epithelium of 
the larynx and nasal discharge.
    5. Chronic toxicity. In a 12-month feeding study in dogs fed dose 
levels of 0, 15, 30, or 50 ppm, expressed as paraquat cation. These 
levels corresponded to 0, 0.45, 0.93 or 1.51 mg of paraquat cation/kg/
day, respectively, in male dogs or 0, 0.48, 1.00 or 1.58 mg of paraquat 
cation/kg/day, respectively for female dogs. There was a dose-related 
increase in the severity and extent of chronic pneumonitis in the mid-
dose and high-dose male and female dogs. This effect was also noted in 
the low-dose male group, but was minimal when compared with the male 
controls. The systemic NOAEL is 15 ppm (0.45 mg/kg/day for males and 
0.48 mg/kg/day for females, expressed as paraquat cation). The systemic 
LOEL is 30 ppm (0.93 mg/kg/day for males and

[[Page 53910]]

1.00 mg/kg/day for females, expressed as paraquat cation).
    In a 2-year chronic feeding/carcinogenicity study, rats were fed 
doses of paraquat dichloride at 0, 25, 75, or 150 ppm which 
corresponded to 0, 1.25, 3.75, or 7.5 mg of paraquat cation/kg/day. 
Paraquat enhanced the development of ocular lesions in all of the 
treated groups. The predominant lesions detected opthalmoscopically 
were lenticular opacities and cataracts. At test week 103, dose-related 
statistically significant (P<0.001) increases in the incidence of 
ocular lesions were observed only in the mid-dose and high-dose male 
and female groups. Based on these findings, the NOAEL (approximate) and 
the LOEL for systemic toxicity, for both sexes, are 25 ppm (1.25 mg/kg/
day) and 75 ppm (3.75 mg/kg/day), respectively.
    In another 2-year chronic feeding/carcinogenicity study, rats were 
dosed at 0, 6, 30, 100 or 300 ppm, expressed as paraquat dichloride 
(nominal concentrations), equivalent to 0, 0.25, 1.26, 4.15, or 12.25 
mg/kg/day, respectively (males) and 0, 0.30, 1.5, 5.12 or 15.29 mg/kg/
day respectively (females), expressed as paraquat dichloride. The 
incidence of ocular changes were low and not caused by paraquat in this 
study. The systemic NOAEL is 100 ppm of paraquat dichloride (4.15 and 
5.12 mg/kg/day, for males and females, respectively); or 3.0 mg/kg/day 
(males) and 3.7 mg/kg/day (females), expressed as paraquat cation. The 
systemic LOEL is 300 ppm of paraquat dichloride (12.25 and 15.29 mg/kg/
day, for males and females, respectively); or 9.0 mg/kg/day (males) and 
11.2 mg/kg/day (females), expressed as paraquat cation.
    A chronic feeding/carcinogenicity study in rats fed dose levels of 
0, 25, 75 or 150 ppm, expressed as paraquat cation (nominal 
concentrations). These doses corresponded to 0, 1.25, 3.75, or 7.5 mg 
paraquat cation/kg/day, respectively. There was uncertain evidence of 
carcinogenicity (squamous cell carcinomas in the head region; ears, 
nasal cavity, oral cavity and skin) in males at 7.5 mg/kg/day (HDT) 
with a systemic NOAEL of 1.25 mg/kg/day. Upon submission of additional 
data to EPA, the incidence of pulmonary adenomas and carcinomas was 
well within historical ranges and it was determined that paraquat was 
not carcinogenic in the lungs and the head region of the rat.
    In another chronic feeding/carcinogenicity study, rats were fed 
dose levels of 0, 6, 30, 100 or 300 ppm, expressed as paraquat 
dichloride. There were no carcinogenic findings in this study at the 
highest dose tested. In a two year chronic feeding/oncogenicity study, 
SPF Swiss derived mice were fed paraquat dichloride at dose levels of 
0, 12.5, 37.5, or 100/125 ppm, expressed as paraquat cation. These 
rates correspond to 0, 1.87, 5.62, and 15 mg/kg/day as cation. Because 
no toxic signs appeared after 35 weeks of dosing, the 100 ppm level was 
increased to 125 ppm at week 36. There were no carcinogenic effects 
observed in this study.
    The systemic NOAEL for both sexes is 12.5 ppm (1.87 mg/kg/day) and 
the systemic LOEL is 37.5 ppm (5.6 mg/kg/day), each expressed as 
paraquat cation based on renal tubular degeneration in males and weight 
loss and decreased food intake in females.
    Paraquat is classified Category E for carcinogenicity (no evidence 
of carcinogenicity in animal studies).
    6. Animal metabolism. The qualitative nature of the residue in 
animals is adequately understood based on the combined studies 
conducted with ruminants (goats and cows), swine, and poultry. The 
residue of concern in eggs, milk, and poultry and livestock tissues is 
the parent, paraquat.
    7. Metabolite toxicology. The nature of residues in plants and 
animals is adequately understood. The residue of concern in eggs, milk, 
poultry, livestock, and in crops is the parent paraquat. There are no 
metabolites.
    8. Endocrine disruption. EPA is required to develop a screening 
program to determine whether certain substances (including all 
pesticides and inerts) ``may have an effect produced by a naturally 
occurring estrogen, or such other endocrine effect .'' The Agency is 
currently working with interested stakeholders, including other 
government agencies, public interest groups, industry and research 
scientist in developing a screening and testing program and a priority 
setting scheme to implement this program. Congress has allowed 3 years 
from passage of FQPA (August 3, 1999) to implement this program. At 
that time, EPA may require further testing of this active ingredient 
and end use products for endocrine disrupter effects.

C. Aggregate Exposure

    In examining aggregate exposure, FQPA directs EPA to take into 
account available information concerning exposures from the pesticide 
residue in food and all other exposures for which there is reliable 
information. These other sources of exposure including drinking water, 
and non-occupational exposures, e.g., to pesticides used in and around 
the home. For estimating acute and chronic risks the Agency considers 
aggregate exposures from the diet and from drinking water. Exposures 
from uses in and around the home that may be short term, intermediate 
or other duration may also be aggregated as appropriate for specific 
chemicals.
    1. Dietary exposure. The Residue Chemistry data base for paraquat 
is substantially complete, and the nature of the residues in plants and 
animals is adequately understood. The residue of concern is the parent, 
paraquat; the current tolerance expression for plants and animal 
commodities, as defined in 40 CFR 180.205(a) and (b), is adequate. The 
Reference Dose (RfD) for chronic dietary assessments is 0.0045 mg/kg/
day, based on a NOAEL of 0.45 mg/kg/day from a 1 year dog study and the 
addition of a standard uncertainty factor of 100.
    2. Food. --i. Chronic dietary assessment. A chronic dietary 
exposure analysis was performed using current and reassessed tolerance 
level residues, contributions from the proposed use as a corn harvest 
aid, and 100% crop treated information to estimate the Theoretical 
Maximum Residue Contribution (TMRC) for the general population and 22 
subgroups. The resulting TMRC for the general U.S. population from all 
established uses is 0.001669 mg/kg/day (37% of the RfD). For children 
ages 1-6, the most highly exposed subgroup, the resulting TMRC is 
0.003679 mg/kg/day (82% of the RfD). A refined chronic dietary 
assessment using percent crop treated data provided a more accurate 
estimate of exposure, called the Anticipated Residue Contribution 
(ARC). The resulting ARC for the general population is 0.00037 mg/kg/
day (8.0% of the RfD), and 0.001 mg/kg/day (22% of the RfD) for 
children ages one to six.
    ii. Acute dietary assessment. EPA has determined that current data 
on paraquat shows no acutedietary endpoint of concern. Therefore, an 
acute dietary risk assessment is not required for paraquat.
    3. Drinking water. Paraquat is not expected to be a contaminant of 
groundwater. Paraquat dichloride binds strongly to soil clay particles 
and it did not leach from the surface in terrestrial field dissipation 
studies. There were, however, detections of paraquat in drinking water 
wells from 2 states cited in the Pesticides in Ground Water Database 
(1991). These detections are not considered to be representative of 
normal paraquat use. Therefore, paraquat is not expected to be a 
groundwater contaminant or concern based on normal use patterns.
    Due to its persistent nature, paraquat could potentially be found 
in surface

[[Page 53911]]

water systems associated with soil particles carried by erosion, 
however, paraquat is immobile in most soils, and at very high 
application rates (50-1,000X), there was no desorption of paraquat from 
soils. Therefore, based on paraquat's normal use patterns and unique 
environmental fate characteristics, exposures to paraquat in drinking 
water are not expected to be obtained from surface water sources.
    4. Non-dietary exposure. Paraquat dichloride has no residential or 
other non-occupational uses that might result in non-occupational, non-
dietary exposure for the general population. Paraquat products are 
Restricted Use, for use by Certified Applicators only, which means the 
general public cannot buy or use paraquat products.

D. Cumulative Effects

    In assessing the potential risk from cumulative effects of paraquat 
and other chemical substances, the Agency has considered structural 
similarities that exist between paraquat and other bipyridylium 
compounds such as diquat dibromide. Examination of the toxicology 
databases of paraquat and diquat dibromide, indicates that the two 
compounds have clearly different target organs. Based on available 
data, the Agency does not believe that the toxic effects produced by 
paraquat would be cumulative with those of diquat dibromide.

E. Safety Determination

    1. U.S. population. Based on the information provided in this 
notice, EPA has determined that for the aggregate exposure assessment 
the only exposure route of concern for paraquat is chronic dietary. The 
toxicology database for paraquat is considered by EPA to be complete 
and reliable. Using the conservative assumptions presented earlier, EPA 
has established an RfD of 0.0045 mg/kg/day. This was based on the NOAEL 
for the 1-year dog study of 0.45 mg/kg/day and employed a 100-fold 
uncertainty factor. Results of this aggregate exposure assessment, 
which includes EPA's reassessment of tolerances for existing crops and 
the addition of corn harvest aid, utilize a maximum of 22% of the RfD. 
Generally, exposures below 100% of the RfD are of no concern because it 
represents the level at or below which daily aggregate dietary exposure 
over a lifetime will not pose appreciable risk to human health. Thus, 
there is reasonable certainty that no harm will result from aggregate 
exposures to paraquat residues.
    2. Infants and children. EPA has determined that the established 
tolerances for paraquat, with amendments and changes as specified in 
this notice, meet the safety standards under the FQPA amendments to 
section 408(b)(2)(C) for infants and children. The safety determination 
for infants and children considers the factors noted above for the 
general population, but also takes into account the possibility of 
increased dietary exposure due to specific consumption patterns of 
infants and children, as well as the possibility of increased 
susceptibility to the toxic effects of paraquat residues in this 
population subgroup.
    In determining whether or not infants and children are particularly 
susceptible to toxic effects from paraquat residues, EPA considered the 
completeness of the database for developmental and reproductive 
effects, the nature and severity of the effects observed, and other 
information.
    Based on the current data requirements, paraquat has a complete 
database for developmental and reproductive toxicity. In the 
developmental studies effects were seen (delayed ossification in the 
forelimb and hindlimb digits) in the fetuses only at the same or higher 
dose levels than effects in the mother. In the reproduction study, no 
effects on reproductive performance were seen. Also because the NOAELs 
from the developmental and reproduction studies were equal to or 
greater than the NOAEL used for establishing the reference dose, EPA 
concludes that it is unlikely that there is additional risk concern for 
immature or developing organisms. Finally, the Agency has no 
epidemiological information suggesting special sensitivity of infants 
and children to paraquat. Therefore, the Agency finds that the 
uncertainty factor (100X) routinely used in RfD calculations is 
adequately protective of infants and children, and an additional 
uncertainty factor is not warranted for paraquat.
    Zeneca estimates that paraquat residues in the diet of non-nursing 
infants (less than 1 year) account for 18% of the RfD and 22% of the 
RfD for children aged 1-6 years. Further, residues in drinking water 
are not expected. Therefore, the Zeneca has determined that there is 
reasonable certainty that dietary exposure to paraquat will not cause 
harm to infants and children.

F. International Tolerances

    Codex maximum residue levels (MRL) are established for residues of 
paraquat for corn grain at 0.1 ppm. The proposed tolerances for corn 
grain at 0.05 ppm differ from the Codex MRL's based on field residue 
data generated in the United States for this use (Pesticide Petitions 
5F1625 and 5H5088 for corn grain. Differences in use patterns and pre-
harvest intervals may account for the differences between the Codex 
MRLs and the tolerance values generated from the pesticide residue 
trials in the United States.        (Jim Tompkins)

[FR Doc. 98-26783 Filed 10-6-98; 8:45 am]
BILLING CODE 6560-50-F