[Federal Register Volume 64, Number 96 (Wednesday, May 19, 1999)]
[Notices]
[Pages 27262-27266]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-12482]


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ENVIRONMENTAL PROTECTION AGENCY

[PF-873; FRL-6079-8]


Notice of Filing of Pesticide 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-873, must 
be received on or before June 18, 1999.

ADDRESSES: By mail submit written comments to: Information and Records 
Integrity Branch, Public Information 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, 
CM #2, 1921 Jefferson Davis Highway, Arlington, VA.

    Comments and data may also be submitted electronically by following 
the instructions under ``SUPPLEMENTARY INFORMATION.'' No confidential 
business information 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 
``Confidential Business Information'' (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:.Sidney Jackson, Registration Support 
Branch, Registration Division (7505C), Office of Pesticide Programs, 
Environmental Protection Agency, 401 M St., SW., Washington, DC 20460. 
Office location, telephone number, and e-mail address: Rm. 272, Crystal 
Mall #2, 1921 Jefferson Davis Highway, Arlington, VA 22202, (703) 305-
7610; e-mail:jackson. [email protected].
SUPPLEMENTARY INFORMATION: EPA has received pesticide petitions as 
follows proposing the establishment and/or amendment of regulations for 
residues of certain pesticide chemical in or on various 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 
contains 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

[[Page 27263]]

petition. Additional data may be needed before EPA rules on the 
petition.

    The official record for this notice of filing, as well as the 
public version, has been established for this notice of filing under 
docket control number [PF-873] (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'' at the beginning of this document.

    Electronic comments can be sent directly to EPA at:
    [email protected]



    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 docket control number (PF-873) and appropriate 
petition number. Electronic comments on this notice may be filed online 
at many Federal Depository Libraries.

List of Subjects

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

    Dated: May 7, 1999.

Peter Caulkins,

Acting Director, Registration Division, Office of Pesticide Programs.

Summary of Petition

    The petitioner summary of the pesticide petitions is printed below 
as required by section 408(d)(3) of the FFDCA. The summary of the 
petitions was prepared by the petitioner and represents the views of 
the petitioner. EPA is publishing the petitions 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. Interregional Research Project No. 4

 PP 6E4629, 6E4760, 8E4993, 8E5009, 9E5084, 9E5069, and 9E5064

    EPA has received pesticide petitions (6E4629, 6E4760, 8E4993, 
8E5009, 9E5084, 9E5069, and 9E5064) from Interregional Research Project 
No. 4 (IR-4), New Jersey Agricultural Experiment Station, P. O. Box 
231, Rutgers University, New Brunswick, NJ 08903 and FMC Corporation, 
Agricultural Group, Philadelphia, PA 19103 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 
residues of the insecticide bifenthrin, 2-methyl-(1,1'-biphenyl)-3-yl 
methyl-3-(2-chloro-3,3,3-trifluoro-1-propenyl)-2,2 dimethylcyclopropane 
carboxylate in or on the raw agricultural commodities (RAC):

    1. PP 6E4629 proposes the establishment of a tolerance for 
artichoke at 1 part per million (ppm).

    2. PP 6E4760 proposes the establishment of a tolerance for crop 
group 9 cucurbit vegetables at 0.4 ppm.

    3. PP 8E4993 proposes the establishment of a tolerance for crop 
subgroup 6B edible-podded legume vegetables at 0.2 ppm.

    4. PP 8E5009 proposes the establishment of a tolerance for eggplant 
at 0.05 ppm.

    5. PP 9E5084 proposes the establishment of a tolerance for rapeseed 
including, canola and crambe seed, at 0.05 ppm.

    6. PP 9E5069 proposes the establishment of a tolerance for crop 
subgroup 5A Head and Stem Brassica, excluding cabbage, at 0.6 ppm and 
cabbage at 4.0 ppm.

    7. PP 9E5064 proposes the establishment of a tolerance for crop 
subgroup 6B, succulent shelled peas and beans at 0.5 ppm.

2. FMC Corporation

 PP 8F5014

    EPA has received a pesticide petition (8F5014) from FMC 
Corporation, Agricultural Group, Philadelphia, PA 19103 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 insecticide bifenthrin in or on the raw 
agricultural commodity: sweet corn at 0.05 ppm and proposes to amend 
the existing tolerance for corn forage from 2.0 to 3.0 ppm.

    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 metabolism of bifenthrin in plants is 
adequately understood. Studies have been conducted to delineate the 
metabolism of radiolabelled bifenthrin in various crops all showing 
similar results. The residue of concern is the parent compound only.

    2. Analytical method. The practical analytical method for detecting 
and measuring levels of bifenthrin in or on food with a limit of 
detection that allows monitoring of food with residues at or above the 
levels set in these tolerances Gas Chromatography with Electron Capture 
Detection (GC/ECD) analytical method P-2132M.

    3. Magnitude of residues. Field bifenthrin residue trials for each 
commodity, unless otherwise noted, were conducted according to approved 
protocol that include 5 applications of the active ingredient (a.i.) at 
a rate of 0.1 pounds (lbs.) a.i./ acre(A).

    Field residue trials have been conducted at the maximum label rate 
for lima bean and succulent shelled peas. Results from these trials 
demonstrate that the proposed bifenthrin tolerance of 0.05 ppm for 
subgroup 6B succulent shelled peas and beans will not be exceeded when 
the product is applied following the proposed use directions.

    Field residue trials meeting EPA study requirements have been 
conducted at the maximum label rate for the crop canola. Results from 
these trials demonstrate that the proposed bifenthrin tolerance of 0.05 
ppm for rapeseed (including canola and crambe) will not be exceeded 
when the product is applied following the proposed use directions.

    Residues of bifenthrin in or on artichoke were evaluated in two 
field trials where artichokes were treated with bifenthrin at the rates 
of 0.1 lb a.i./A or 0.2 lb a.i./A. Samples were taken 5 days after the 
last treatment. Artichokes treated at the rate of 0.1 lb a.i./A had 
residues as high as 0.67 ppm. Artichokes treated at the rate of 0.2 lb 
a.i./A had residues as high as 0.62 ppm.

    Residue levels of bifenthrin in eggplant were evaluated in field 
trails after two treatments at a rate of 0.1 lbs. a.i./A and samples 
taken 7 days after the last application. No detectable residues

[[Page 27264]]

above the test method's limit of quantitation (L0Q) (0.05 ppm) were 
found in any of the test samples.

    Field residue trials conducted for the cucurbit vegetable group 
included a total of three foliar applications of bifenthrin at 0.1 lb 
a.i./A to cucumber, cantaloupe and summer squash. The first foliar 
application was applied prebloom; the second application was applied 
post bloom; the third application was made post bloom 7 to 10 days 
after the second application, except in one instance. In some trials, 
fruit were harvested 0, 3 and 7 or 8 days after the last application. 
In all cases, the maximum residue found did not exceed the proposed 
tolerance of 0.4 ppm.

    For the head and stem brassica crop subgroup (5A), IR-4 proposed 
that EPA establish a tolerance for bifenthrin on commodities, excluding 
cabbage, at 0.6 ppm, and that a separate tolerance for cabbage be 
established at 4.0 ppm. Samples were collected 6-8 days after the last 
application for the analysis of residues. Residues up to 0.56 ppm 
bifenthrin were found in broccoli and up to 0.19 ppm were found in 
cauliflower samples. Treated cabbage sampled showed residues as high as 
3.09 ppm in heads with wrapper leaves. The tolerance proposal for 
bifenthrin on cabbage is based on residue data for cabbage with wrapper 
leaves.

    Field residue trials were conducted at the maximum label rate for 
the crop subgroup edible-podded legume vegetables. Results from these 
trails demonstrate that the proposed bifenthrin tolerance of 0.2 ppm 
(crop subgroup edible-podded legume vegetables) and 0.5 ppm (crop 
subgroup succulent shelled pea) will not be exceeded when the product 
is applied following the proposed use directions.

B. Toxicological Profile

    1. Acute toxicity. For the purposes of assessing acute dietary 
risk, FMC has used the maternal no-observed adverse effect level 
(NOAEL) of 1.0 milligrams/kilogram/day (mg/kg/day) from the oral 
developmental toxicity study in rats. The maternal lowest-observed 
adverse effect level (LOAEL) of this study of 2.0 mg/kg/day was based 
on tremors from day 7-17 of dosing. This acute dietary endpoint is used 
to determine acute dietary risks to all population subgroups.

    2. Genotoxicity. The following genotoxicity tests were conducted on 
bifenthrin and all yielded negative results including: gene mutation in 
Salmonella (Ames); chromosomal aberrations in Chinese hamster ovary and 
rat bone marrow cells; hypoxanthine guanine phophoribosyl transferase 
(HGPRT) locus mutation in mouse lymphoma cells; and unscheduled DNA 
synthesis in rat hepatocytes.

    3. Reproductive and developmental toxicity--i. In the rat 
reproduction study, parental toxicity occurred (decreased bwt) at 5 mg/
kg/day with a NOAEL of 3 mg/kg/day. There were no developmental (pup) 
or reproductive effects up to 5.0 mg/kg/day highest dose tested (HDT). 
See discussion of developmental toxicity studies in section E.2 of this 
unit.

    ii. Postnatal sensitivity. Based on the absence of pup toxicity up 
to dose levels which produced toxicity in the parental animals, there 
is no evidence of special postnatal sensitivity to infants and children 
in the rat reproduction study.

    4. Subchronic toxicity The maternal NOAEL of 1.0 mg/kg/day from the 
oral developmental toxicity study in rats is also used for short- and 
intermediate-term margin of exposure (MOE) calculations (as well as 
acute, discussed in (1) above). The maternal LOAEL of this study of 2.0 
mg/kg/day was based on tremors from day 7-17 of dosing.

    5. Chronic toxicity--i. The reference dose (RfD) has been 
established at 0.015 mg/kg/day. This RfD is based on a 1-year oral 
feeding study in dogs with a NOAEL of 1.5 mg/kg/day, based on 
intermittent tremors observed at the LOAEL of 3.0 mg/kg/day; an 
uncertainty factor of 100 is used.

    ii. Bifenthrin is classified as a Group C chemical (possible human 
carcinogen) based upon urinary bladder tumors in mice; assignment of a 
Q* has not been recommended.

    6. Animal metabolism. The metabolism of bifenthrin in animals is 
adequately understood. Metabolism studies in rats with single doses 
demonstrated that about 90% of the parent compound and its hydroxylated 
metabolites are excreted.

    7. Metabolite toxicology. The Agency has previously determined that 
the metabolites of bifenthrin are not of toxicological concern and need 
not be included in the tolerance expression.

    8. Endocrine disruption. To date, no special studies investigating 
potential estrogenic or other endocrine effects of bifenthrin have been 
conducted. However, no evidence of such effects were reported in the 
standard battery of required toxicology studies which have been 
completed and found acceptable. Based on these studies, FMC Corporation 
concludes that there is no evidence to suggest that bifenthrin has an 
adverse effect on the endocrine system.

C. Aggregate Exposure

    1. Dietary exposure--i. Food. Tolerances have been established for 
the residues of bifenthrin, in or on a variety of raw agricultural 
commodities including: hops; strawberries; corn grain, forage, and 
fodder; cottonseed; and livestock commodities of cattle, goats, hogs, 
horses, sheep, poultry, eggs and milk. Pending tolerances for 
artichokes, the crop group cucurbit vegetables, the crop subgroup 
edible-podded legume vegetables and subgroup succulent shelled pea and 
bean, eggplant, citrus, raspberries, sweet corn, canola, and the 
subgroup head and stem brassica also exist. For the purposes of 
assessing the potential dietary exposure for the existing and pending 
tolerances, FMC has utilized available information on anticipated 
residues, monitoring data and percent crop treated as follows:

    ii. Acute exposure and risk. Acute dietary exposure risk 
assessments are performed for a food-use pesticide if a toxicological 
study has indicated the possibility of an effect of concern occurring 
as a result of a 1-day or single exposure. For the purposes of 
assessing acute dietary risk for bifenthrin, the maternal NOAEL of 1.0 
mg/kg/day from the oral developmental toxicity study in rats was used. 
The maternal LOAEL of this study of 2.0 mg/kg/day was based on tremors 
from day 7-17 of dosing. This acute dietary endpoint was used to 
determine acute dietary risks to all population subgroups. Available 
information on anticipated residues, monitoring data and percent crop 
treated was incorporated into a Tier 3 analysis, using Monte Carlo 
modeling for commodities that may be consumed in a single serving. 
These assessments show that the MOEs are greater than the EPA standard 
of 100 for all subpopulations. The 99.9th percentile of exposure for 
the overall U.S. population was estimated to be 0.005278 mg/kg/day (MOE 
of 189). The 99.9th percentile of exposure for all infants < 1-year old 
was estimated to be 0.006255 mg/kg/day (MOE of 159). The 99.9th 
percentile of exposure for nursing infants < 1-year old was estimated 
to be 0.004280 mg/kg/day (MOE of 233). The 99.9th percentile of 
exposure for non-nursing infants < 1-year old was estimated to be 
0.005812 mg/kg/day (MOE of 172). The 99.9th percentile of exposure for 
children 1 to 6 years old (the most highly exposed population subgroup) 
was estimated to be 0.009578 mg/kg/day (MOE of 104). Therefore, FMC 
concludes that the acute dietary risk of

[[Page 27265]]

bifenthrin, as estimated by the dietary risk assessment, does not 
appear to be of concern.

    iii. Chronic exposure and risk. The acceptable RfD is 0.015 mg/kg/
day, based on a NOAEL of 1.5 mg/kg/day from the chronic dog study and 
an uncertainty factor of 100. The endpoint effect of concern were 
tremors in both sexes of dogs at the L0AEL of 3.0 mg/kg/day. A chronic 
dietary exposure/risk assessment has been performed for bifenthrin 
using the above RfD. Available information on anticipated residues, 
monitoring data and percent crop treated was incorporated into the 
analysis to estimate the Anticipated Residue Contribution (ARC). The 
ARC is generally considered a more realistic estimate than an estimate 
based on tolerance level residues. The ARC are estimated to be 0.000356 
mg/kg bwt/day and utilize 2.4% of the RfD for the overall U. S. 
population. The ARC for children 7-12 years old and children 1-6 years 
old (subgroups most highly exposed) are estimated to be 0.000558 mg/kg 
bwt/day and 0.001008 mg/kg bwt/day and utilizes 3.7% and 6.7% of the 
RfD, respectively. Generally speaking, the EPA has no cause for concern 
if the total dietary exposure from residues for uses for which there 
are published and proposed tolerances is less than 100% of the RfD. 
Therefore, FMC concludes that the chronic dietary risk of bifenthrin, 
as estimated by the dietary risk assessment, does not appear to be of 
concern.

    iv. Drinking water. Laboratory and field data have demonstrated 
that bifenthrin is immobile in soil and will not leach into ground 
water. Other data show that bifenthrin is virtually insoluble in water 
and extremely lipophilic. As a result, FMC concludes that residues 
reaching surface waters from field runoff will quickly adsorb to 
sediment particles and be partitioned from the water column. Further, a 
screening evaluation of leaching potential of a typical pyrethroid was 
conducted using EPA's Pesticide Root Zone Model (PRZM3). Based on this 
screening assessment, the potential concentrations of a pyrethroid in 
ground water at depths of 1 and 2 meters are essentially zero < 0.001 
parts per billion (ppb). Surface water concentrations for pyrethroids 
were estimated using PRZM3 and Exposure Analysis Modeling System 
(EXAMS) using standard EPA cotton runoff and Mississippi pond 
scenarios. The maximum concentration predicted in the simulated pond 
was 0.052 ppb. Concentrations in actual drinking water would be much 
lower than the levels predicted in the hypothetical, small, stagnant 
farm pond model since drinking water derived from surface water would 
normally be treated before consumption. Based on these analyses, the 
contribution of water to the dietary risk estimate is negligible. 
Therefore, FMC concludes that together these data indicate that 
residues are not expected to occur in drinking water.

    v. Non-dietary exposure. Analyses were conducted which included an 
evaluation of potential non-dietary (residential) applicator, post-
application and chronic dietary aggregate exposures associated with 
bifenthrin products used for residential flea infestation control and 
agricultural/commercial applications. The aggregate analysis 
conservatively assumes that a person is concurrently exposed to the 
same active ingredient via the use of consumer or professional flea 
infestation control products and to chronic level residues in the diet. 
In the case of potential non-dietary health risks, conservative point 
estimates of non-dietary exposures, expressed as total systemic 
absorbed dose (summed across inhalation and incidental ingestion 
routes) for each relevant product use category (i.e., lawn care) and 
receptor subpopulation (i.e., adults, children 1-6 years and infants < 
1-year) are compared to the systemic absorbed dose NOAEL for bifenthrin 
to provide estimates of the MOEs. Based on the toxicity endpoints 
selected by EPA for bifenthrin, inhalation and incidental oral 
ingestion absorbed doses were combined and compared to the relevant 
systemic NOAEL for estimating MOEs.

    In the case of potential aggregate health risks, the above 
mentioned conservative point estimates of inhalation and incidental 
ingestion non-dietary exposure (expressed as systemic absorbed dose) 
are combined with estimates (arithmetic mean values) of chronic average 
dietary (oral) absorbed doses. These aggregate absorbed dose estimates 
are also provided for adults, children 1-6 years and infants < 1-year. 
The combined or aggregated absorbed dose estimates (summed across non-
dietary and chronic dietary) are then compared with the systemic 
absorbed dose NOAEL to provide estimates of aggregate MOEs.

    The non-dietary and aggregate (non-dietary + chronic dietary) MOEs 
for bifenthrin indicate a substantial degree of safety. The total non-
dietary (inhalation + incidental ingestion) MOEs for post-application 
exposure for the lawn care product evaluated was estimated to be > 
194,000 for adults, 52,400 for children 1-6 years old and 56,700 for 
infants < 1-year. The aggregate MOE (inhalation + incidental oral + 
chronic dietary, summed across all product use categories) was 
estimated to be 2,664 for adults, 653 for children 1-6 years old and 
1,042 for infants (< 1-year). It can be concluded that the potential 
non-dietary and aggregate (non-dietary + chronic dietary) exposures for 
bifenthrin are associated with substantial margins of safety.

D. Cumulative Effects

     In consideration of potential cumulative effects of bifenthrin and 
other substances that may have a common mechanism of toxicity, FMC 
Corporation concludes that there are currently no available data or 
other reliable information indicating that any toxic effects produced 
by bifenthrin would be cumulative with those of other chemical 
compounds, thus only the potential risks of bifenthrin have been 
considered in this assessment of its aggregate exposure. FMC intends to 
submit information for EPA to consider concerning potential cumulative 
effects of bifenthrin consistent with the schedule established by EPA 
in the Federal Register of August 4, 1997 (62 FR 42020) (FRL-5734-6) 
and other EPA publications pursuant to the Food Quality Protection Act.

E. Safety Determination

    1. U.S. population. The established RfD is 0.015 mg/kg/day, based 
on a NOAEL of 1.5 mg/kg/day from the chronic dog study and an 
uncertainty factor of 100. Available information on anticipated 
residues, monitoring data and percent crop treated was incorporated 
into an analysis to estimate the ARC for 26 population subgroups. The 
ARC is generally considered a more realistic estimate than an estimate 
based on tolerance level residues. The ARC are estimated to be 0.000356 
mg/kg bwt/day and utilize 2.4% of the RfD for the overall U.S. 
population. The ARC for children 7-12 years old and children 1-6 years 
old (subgroups most highly exposed) are estimated to be 0.000558 mg/kg 
bwt/day and 0.001008 mg/kg bwt/day and utilizes 3.7% and 6.7% of the 
RfD, respectively. Generally speaking, the EPA has no cause for concern 
if the total dietary exposure from residues for uses for which there 
are published and proposed tolerances is less than 100% of the RfD. 
Therefore, FMC concludes that the chronic dietary risk of bifenthrin, 
as estimated by the aggregate risk assessment, would not exceed the 
Agency's level of concern.

    For the overall U.S. population, the calculated MOE at the 95th 
percentile

[[Page 27266]]

was estimated to be 719; 386 at the 99th percentile; and 189 at the 
99.9th percentile. For all infants < 1-year old, the calculated MOE at 
the 95th percentile was estimated to be 531; 186 at the 99th 
percentile; and 159 at the 99.9th percentile. For nursing infants < 1-
year old, the calculated MOE at the 95th percentile was estimated to be 
1,478; 528 at the 99th percentile; and 233 at the 99.9th percentile. 
For non-nursing infants < 1-year old, the calculated MOE at the 95th 
percentile was estimated to be 470; 189 at the 99th percentile; and 172 
at the 99.9th percentile. For the most highly exposed population 
subgroup, children 1-6 years old, the calculated MOE at the 95th 
percentile was estimated to be 347; 225 at the 99th percentile; and 104 
at the 99.9th percentile. Therefore, FMC concludes that there is 
reasonable certainty that no harm will result from acute exposure to 
bifenthrin.

    2. Infants and children--i. General. In assessing the potential for 
additional sensitivity of infants and children to residues of 
bifenthrin, FMC considered data from developmental toxicity studies in 
the rat and rabbit, and a 2-generation reproductive study in the rat. 
The developmental toxicity studies are designed to evaluate adverse 
effects on the developing organism resulting from pesticide exposure 
during prenatal development to one or both parents. Reproduction 
studies provide information relating to effects from exposure to the 
pesticide on the reproductive capability of mating animals and data on 
systemic toxicity. The Federal Food, Drug, and Cosmetic Act (FFDCA) 
section 408 provides that EPA may apply an additional margin of safety 
for infants and children in the case of threshold effects to account 
for pre- and postnatal toxicity and the completeness of the data base.

    ii. Developmental toxicity studies. In the rabbit developmental 
study, there were no developmental effects observed in the fetuses 
exposed to bifenthrin. The maternal NOAEL was 2.67 mg/kg/day based on 
head and forelimb twitching at the LOAEL of 4 mg/kg/day. In the rat 
developmental study, the maternal NOAEL was 1 mg/kg/day, based on 
tremors at the LOAEL of 2 mg/kg/day. The developmental (pup) NOAEL was 
also 1 mg/kg/day, based upon increased incidence of hydroureter at the 
LOAEL (2 mg/kg/day). There were 5/23 (22%) litters affected (5/141 
fetuses since each litter only had one affected fetus) in the 2 mg/kg/
day group, compared with zero in the control, 1, and 0.5 mg/kg/day 
groups.

    According to recent data (1992-1994) for this strain of rat, 
incidence of distended ureter averaged 11% with a maximum incidence of 
90%.

    iii. Reproductive toxicity study. In the rat reproduction study, 
parental toxicity occurred as decreased bwt at 5.0 mg/kg/day with a 
NOAEL of 3.0 mg/kg/day. There were no developmental (pup) or 
reproductive effects up to 5.0 mg/kg/day HDT.

    iii. Pre- and postnatal sensitivity-a. Pre-natal. Since there was 
not a dose-related finding of hydroureter in the rat developmental 
study and in the presence of similar incidences in the recent 
historical control data, the marginal finding of hydroureter in rat 
fetuses at 2 mg/kg/day (in the presence of maternal toxicity) is not 
considered a significant developmental finding. Nor does it provide 
sufficient evidence of a special dietary risk (either acute or chronic) 
for infants and children which would require an additional safety 
factor.

    b. Postnatal. Based on the absence of pup toxicity up to dose 
levels which produced toxicity in the parental animals, there is no 
evidence of special post-natal sensitivity to infants and children in 
the rat reproduction study.

    c. Conclusion. Based on the above, FMC concludes that reliable data 
support use of the standard 100-fold uncertainty factor, and that an 
additional uncertainty factor is not needed to protect the safety of 
infants and children. As stated above, aggregate exposure assessments 
utilized less than 10% of the RfD for either the entire U.S. population 
or any of the 26 population subgroups including infants and children. 
Therefore, it may be concluded that there is reasonable certainty that 
no harm will result to infants and children from aggregate exposure to 
bifenthrin residues.

F. International Tolerances

     There are no Codex, Canadian, or Mexican residue limits for 
residues of residues of bifenthrin in or on the subject commodities.
[FR Doc. 99-12482 Filed 5-18-99; 8:45 am]
BILLING CODE 6560-50-F