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cyfluthrin (Baythroid) Pesticide Petition Filing 4/98

[Federal Register: April 15, 1998 (Volume 63, Number 72)]
[Page 18411-18420]
>From the Federal Register Online via GPO Access []

[[Page 18411]]



[PF-801; FRL-5781-9]

Notice of Filing of Pesticide Petitions

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice.


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-801, must 
be received on or before May 15, 1998.
ADDRESSES: By mail submit written comments to: Public Information and 
Records Integrity Branch, Information Resources and Services Division 
(7502C), Office of Pesticides Programs, Environmental Protection 
Agency, 401 M St., SW., Washington, DC 20460. In person bring comments 
to: Rm. 119FF, 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. 1132 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    
Sidney Jackson (PM 5).........  Rm. 268, CM #2, 703-    1921 Jefferson  
                                 305-7610, e-            Davis Hwy,     
                                 mail:jackson.sidney@e   Arlington, VA  
Bipin Gandhi (PM 5)...........  Rm. 4W53, CS #2, 703-   Do.             
                                 308-8380, e-mail:                      

SUPPLEMENTARY INFORMATION: 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 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 support granting of the 
petition. Additional data may be needed before EPA rules on the 
    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-801] (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:

    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 file format or ASCII 
file format. All comments and data in electronic form must be 
identified by the docket number FRL-5781-9 and appropriate petition 
number. Electronic comments on 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 

Dated: April 1, 1998

    James Jones,

Director, Registration Division, Office of Pesticide Programs.

Summaries of Petitions

    Petitioner summaries of the pesticide petitions are printed below 
as required by section 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. Interregional Research Project

 PP 2E4101

    EPA has received a pesticide petition (PP 2E4101) from the 
Interregional Research Project Number 4 (IR-4), proposing pursuant to 
section 408(d) of the Federal Food, Drug and Cosmetic Act, 21 U.S.C. 
346a(d), to amend 40 CFR part 180 by establishing a tolerance for 
residues of the insecticide cyfluthrin, [cyano[4-fluoro-3-
phenoxyphenyl]-methyl-3-[2,2- dicloroethenyl]-2,2-
dimethylcyclopropanecarboxylate] in or on the raw agricultural 
commodity dried hops at 20.0 parts per million (ppm) and to remove the 
established tolerance for fresh hops at 4.0 ppm. EPA has determined 
that the petition contains data or information regarding the elements 
set forth in section 408(d)(2) of the Federal Food Drug and Cosmetic 
Act (FFDCA); however, EPA has not fully evaluated the sufficiency of 
the submitted data at this time or whether the data supports granting 
of the proposed tolerance. Additional data may be needed before EPA 
rules on the petition. This notice includes a summary of the petition 
prepared by Bayer Corporations (Bayer), the registrant.

A. Residue Chemistry

    1. Plant metabolism. The metabolism of cyfluthrin in plants is 
adequately understood. Studies have been conducted to delineate the 
metabolism of radiolabeled cyfluthrin in various crops all showing 
similar results. The residue of concern is cyfluthrin.

[[Page 18412]]

    2. Analytical method. Adequate analytical methodology (gas liquid 
chromatography with an electron capture detector) is available for 
enforcement purposes. The methodology was successfully validated by 
EPA's Beltsville laboratory in support of tolerances on cottonseed. The 
enforcement methodology has been submitted to the Food and Drug 
Administration for publication in the Pesticide Analytical Manual Vol. 
II (PAM II). Because of the long lead time for publication of the 
method in PAM II, the analytical methodology is being made available in 
the interim to anyone interested in pesticide enforcement when 
requested from Calvin Furlow, Public Response and Program Resource 
Branch, Field Operations Division (7502C), Office of Pesticide 
Programs, U.S. Environmental Protection Agency, 401 M St., SW., 
Washington, DC 20460. Office location and telephone number: Rm. 119FF, 
CM #2, 1921 Jefferson-Davis Hwy., Arlington, VA 22202, (703) 305-5232.
    The established tolerances for residues of cyfluthrin in/on eggs, 
milks, fat, meat and meat by-products of cattle, goats, hogs, horses, 
sheep and poultry are adequate to cover secondary residues resulting 
from the proposed use as delineated in 40 CFR 180.6(a)(2).
    3. Magnitude of residues. Import tolerances for cyfluthrin are 
presently established on fresh hops at 4.0 ppm and on dried hops at 
20.0 ppm. IR-4 has conducted field trials in Washington, Oregon and 
Idaho in order to support expansion of the tolerances to include the 
domestic production of hops in the United States.
    The residue data submitted to the EPA by IR-4 consist of three 
trials, one each in Washington, Oregon and Idaho. In each trial, hops 
were planted in three plots, two treated and one untreated. Cyfluthrin 
(Baythroid 2) was applied by foliar (ground) application at a rate of 
0.05 pounds(lb) active ingredient(ai)/acre(A) to one plot and 0.1 lb 
ai/A to another. Five separate applications were made with an interval 
of 7-days between the last application and harvest.
    Residues of cyfluthrin were detected in all treated samples from 
each trial and no interferences were detected in samples from control 
plots. The residue data are consistent for each trial. Cyfluthrin 
applied at 0.05 lb ai/A was detected from 0.44 to 0.78 ppm on fresh 
hops and from 1.83 to 2.36 ppm on dried hops. At 0.10 lb ai/A, residues 
were detected at 1.10 to 2.70 ppm on fresh hops and 3.76 to 7.57 ppm on 
dried hops.

B. Toxicological Profile

    The data base for cyfluthrin is essentially complete. Data lacking 
but desirable are an acute neurotoxicity study in rats and a 90-day 
neurotoxicity study in rats. Although these data are lacking, Bayer 
believes the available toxicity data are sufficient to support the 
proposed tolerance and these missing data will not significantly change 
its risk assessment. Bayer has committed to submit the acute 
neurotoxicity study and the 90-day neurotoxicity study.
    1. Acute toxicity. Results of acute toxicity tests show an acute 
oral lethal dose (LD<INF>50</INF>) grater than or equal to 16.2 
milligram (mg)/ kilogram (kg), a dermal (LD<INF>50</INF>) >5,000 mg/kg, 
inhalation lethal concentration (LC<INF>50</INF> greater than or equal 
to 0.468 mg/liter(L), primary eye irritation and primary dermal 
irritation show toxicity categories III and IV, respectively. Dermal 
sensitization tests conducted show that cyfluthrin is not a dermal 
    2. Genotoxicty. Mutagenicity tests were conducted, including 
several gene mutation assays (reverse mutation and recombination assays 
in bacteria and a Chinese hamster ovary(CHO)/HGPRT assay); a structural 
chromosome aberration assay (CHO/sister chromatid exchange assay); and 
an unscheduled DNA synthesis assay in rat hepatocytes. All tests were 
negative for genotoxicity.
    3. Reproductive and developmental toxicity. An oral developmental 
toxicity study in rats with a maternal and fetal no-observed effect 
level (NOEL) of 10 mg/kg/day (highest dose tested). An oral 
developmental toxicity study in rabbits with a maternal NOEL of 20 mg/
kg/day and a maternal lowest effect level (LEL) of 60 mg/kg/day, based 
on decreased body weight gain and decreased food consumption during the 
dosing period. A fetal NOEL of 20 mg/kg/day and a fetal LEL of 60 mg/
kg/day were also observed in this study. The LEL was based on increased 
resorptions and increased postimplantation loss.
    A developmental toxicity study in rats by the inhalation route of 
administration with a maternal NOEL of 0.0011 mg/l and a LEL of 0.0047 
mg/l, based on reduced mobility, dyspnea, piloerection, ungroomed coats 
and eye irritation. The fetal NOEL is 0.00059 mg/l and the fetal LEL is 
0.0011 mg/l, based on sternal anomalies and increased incidence of 
runts. A second developmental toxicity study in rats by the inhalation 
route of administration has been submitted to the Agency. A 3-
generation reproduction study in rats with a systemic NOEL of 2.5 mg/
kg/day and a systemic LEL of 7.5 mg/kg/day due to decreased parent and 
pup body weights. The reproductive NOEL and LEL are 7.5 mg/kg/day and 
22.5 mg/kg/day respectively.
    4. Subchronic toxicity. In a 28-day oral toxicity study in rats, 
cyfluthrin demonstrated a NOEL of 20 mg/kg/day. The lowest-observed-
effect level (LOEL) was 80 (40) mg/kg/day in both sexes based on 
clinical signs of nerve toxicity, decreases in body weight gain, and 
changes in liver and adrenal weights. The high dose was 80 mg/kg/day 
during the first and third weeks and 40 mg/kg/day during the second and 
fourth weeks.
    In a six month dog feeding study established a NOEL at 5 mg/kg/day 
for male and females. The LOEL for this study was 15 mg/kg/day for both 
sexes, based on neurological effects (hindlimb abnormalities) and 
gastrointestinal disturbances.
    A 21-day repeated dose dermal toxicity study, male and female rats 
were treated with cyfluthrin by dermal occlusion at target doses of 0, 
100, 340, or 1,000 mg/kg/day for 6 hours/day (average actual dose 
levels were 0, 113, 376 or 1,077 mg/kg/day). No mortality was observed, 
and there were no treatment-related effects on body weight, 
ophthalmology, organ weights, clinical biochemistry, or hematology. The 
LOEL for dermal effects was 376 mg/kg/day for male and female Sprague-
Dawley rats based on gross and histological skin lesions. The NOEL for 
dermal effects was 113 mg/kg/day. The LOEL for systemic effects was 
1,077 mg/kg/day based on decreased food consumption, red nasal 
discharge and urine staining. The NOEL for systemic effects was 376 mg/
    5. Chronic toxicity. A 12-month chronic feeding study in dogs with 
a NOEL of 4 mg/kg/day. The LEL for this study is established at 16 mg/
kg/day, based on slight ataxia, increased vomiting, diarrhea and 
decreased body weight.
    A 24-month chronic feeding/carcinogenicity study in rats showed a 
NOEL of 2.5 mg/kg/day and LEL of 6.2 mg/kg/day, based on decreased body 
weights in males, decreased food consumption in males, and inflammatory 
foci in the kidneys in females.
    6. Carcinogenicity. A 24-month carcinogenicity study in mice was 
conducted. There were no carcinogenic effects observed under the 
conditions of the study.
    A 24-month chronic feeding/carcinogenicity study in rats was 
conducted. There were no carcinogenic effects observed under the 
conditions of the study.

[[Page 18413]]

    Cyfluthrin has been classified as a Group E chemical (evidence of 
non-carcinogenicity for humans) by the Agency. The classification was 
based on a lack of convincing evidence of carcinogenicity in adequate 
studies with two animal species, rat and mouse.
    7. Animal metabolism. A metabolism study in rats showed that 
cyfluthrin is rapidly absorbed and excreted, mostly as conjugated 
metabolites in the urine, within 48 hours. An enterohepatic circulation 
was observed.
    8. Ednocrine effects. No special studies investigating potential 
estrogenic or endocrine effects of cyfluthrin have been conducted. 
However, the standard battery of required studies has been completed. 
These studies include an evaluation of the potential effects on 
reproduction and development, and an evaluation of the pathology of the 
endocrine organs following repeated or long-term exposure. According to 
Bayer no endocrine effects were noted in any of the studies.

C. Aggregate Exposure

    1. Dietary exposure. In examining aggregate exposure, FFDCA section 
408 requires that EPA take into account available and reliable 
information concerning exposure from the pesticide residue in the food 
in question, residues in other foods for which there are tolerances, 
residues in ground water or surface water that is consumed as drinking 
water, and other non-occupational exposures through pesticide use in 
gardens, lawns, or buildings (residential and other indoor uses). 
Dietary exposure to residues of a pesticide in a food commodity are 
estimated by multiplying the average daily consumption of the food 
forms of that commodity by the tolerance level or the anticipated 
pesticide residue level. The Theoretical Maximum Residue Contribution 
(TMRC) is an estimate of the level of residues consumed daily if each 
food item contained pesticide residues equal to the tolerance. In 
evaluating food exposures, EPA takes into account varying consumption 
patterns of major identifiable subgroups of consumers, including 
infants and children. The TMRC is a ``worst case'' estimate since it is 
based on the assumptions that food contains pesticide residues at the 
tolerance level and that 100% of the crop is treated by pesticides that 
have established tolerances. If the TMRC exceeds the Reference Dose 
(RfD) or poses a lifetime cancer risk that is greater than 
approximately one in a million, EPA attempts to derive a more accurate 
exposure estimate for the pesticide by evaluating additional types of 
information (anticipated residue data and/or percent of crop treated 
data) which show, generally, that pesticide residues in most foods when 
they are eaten are well below established tolerances.
    2. Food. Under a petition to establish tolerances for cyfluthrin in 
or on citrus (PP 4F4313 and FAP 4H5687, the EPA has recently performed 
a chronic dietary exposure/risk assessment for cyfluthrin using a RfD 
of 0.025 mg/kg body weight(bwt)/day, based on a NOEL of 50 ppm (2.5 mg/
kg bwt/day) and an uncertainty factor of 100. The NOEL was determined 
in a 2-year rat feeding study. The endpoint effects of concern were 
decreased body weights in males and inflammation of the kidneys in 
females at the LEL of 6.2 mg/kg/day. This dietary exposure/risk 
assessment estimated the current dietary exposure for the U.S. 
population resulting from established tolerances, including the current 
4 ppm tolerance on fresh hops, is 0.002907 mg/kg/bwt day. This 
represents 11.6% of the RfD. The exposure to children (1-6 years old), 
the subgroup population exposed to the highest risk was 0.00662 mg/kg/
bwt/day or 26.4% of the RfD. The current action will increase the 
exposure to 0.003266 mg/kg/bwt day or 13% of the RfD for the U.S. 
population and 0.006622 mg/kg/bwt day or 26.4% or the RfD for children 
(1-6 years old). Generally speaking, 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 the RfD. Therefore, 
Bayer concludes that the chronic dietary risk of cyfluthrin, as 
estimated by the dietary risk assessment, does not appear to be of 
    3. Drinking water. Cyfluthrin is immobile in soil, therefore, will 
not leach into ground water. Additionally, due to the insolubility and 
lipophilic nature of cyfluthrin, any residues in surface water will 
rapidly and tightly bind to soil particles and remain with sediment, 
therefore, Bayer does not anticipate dietary exposures to cyfluthrin 
from drinking water.
    4. Non-dietary exposure. Non-occupational exposure to cyfluthrin 
may occur as a result of inhalation or contact from indoor residential, 
indoor commercial, and outdoor residential uses. Reliable data to 
determine aggregate exposures from these sources are currently not 
available. However, determinations of worst case exposure from 
inhalation in indoor settings (continuous exposure at saturation vapor 
concentration) indicated that adequate margins of safety existed even 
under these conditions. Since this evaluation greatly overestimated 
exposure, the contribution to aggregate exposure from inhalation in 
normal uses would be expected to be negligible. Estimations of outdoor 
residential exposure have been required for cyfluthrin in a data call-
in issued in 1995. These data are being generated by the Outdoor 
Residential Exposure Task Force (ORETF). However, available data show 
that the acute dermal toxicity of cyfluthrin is very low, with the 
LD<INF>50</INF> being greater than 5,000 mg/kg, the highest dose 
tested. Sub-acute (21-day) dermal toxicity data showed only localized 
(skin) effects at higher level exposures (1,000 mg/kg/day and 340 mg/
kg/day). Other than skin effects at these high exposure levels, no 
effects were observed at any exposure levels, the highest level tested 
being 1,000 mg/kg/day. The use rate for cyfluthrin on residential turf 
is 1 g (1,000 mg) active ingredient per 1,000 square feet which would 
indicate that potential exposures would be well below levels tested. In 
addition, the localized skin effects seen at the prolonged higher 
exposures in animal tests have not been reported for non-occupational 
exposures to cyfluthrin in currently accepted uses, indicating that 
exposures are below the threshold of any observable effects. Indoor 
uses are limited to areas with little or no contact, so exposures would 
be expected to be even less. Thus, the dermal route of exposure does 
not appear to be significant and the contribution to aggregate exposure 
from dermal contact would be expected to be negligible.

D. Cumulative Effects

    In consideration of potential cumulative effects of cyfluthrin and 
other substances that have a common mechanism of toxicity, Bayer 
concludes that there are currently no available data or other reliable 
information indicating that any toxic effects produced by cyfluthrin 
would be cumulative with those of other chemical compounds; thus only 
the potential risks of cyfluthrin have been considered in this 
assessment of its aggregate exposure.

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 it can be concluded that total aggregate exposure to 
cyfluthrin from all current uses as well as the proposed tolerance will 
utilize little more than 13% of the RfD for the U.S. population. EPA 
generally has no concerns for exposures below 100% of

[[Page 18414]]

the RfD, because the RfD represents the level at or below which daily 
aggregate exposure over a lifetime will not pose appreciable risks to 
human health. Thus, it can be concluded that there is a reasonable 
certainty that no harm will result from aggregate exposure to 
cyfluthrin residues.
    2. Infants and children. In assessing the potential for additional 
sensitivity of infants and children to residues of cyfluthrin, the data 
from developmental studies in both rat and rabbit and a 2-generation 
reproduction study in the rat can be considered. The developmental 
toxicity studies evaluate any potential adverse effects on the 
developing animal resulting from pesticide exposure of the mother 
during prenatal development. The reproduction study evaluates any 
effects from exposure to the pesticide on the reproductive capability 
of mating animals through 2-generations, as well as any observed 
systemic toxicity.
    FFDCA section 408 provides that EPA may apply an additional safety 
factor for infants and children in the case of threshold effects to 
account for pre- and post- natal effects and the completeness of the 
toxicity database. Based on current toxicological data requirements, 
the toxicology database for cyfluthrin relative to pre- and post-natal 
effects is complete. The NOELs observed in the developmental and 
reproduction study are equivalent or higher than the NOEL from the 2-
year rat feeding study, used with a 100 fold uncertainty factor to 
establish the reference dose. Therefore, Bayer believes that an 
additional uncertainty factor is not warranted and that the RfD at 
0.025 mg/kg/day is appropriate for assessing aggregate risk to infants 
and children.
    Using the conservative exposure assumptions described above, 
cyfluthrin residues resulting from established tolerances, including a 
tolerance of 20 ppm on dry hops, would utilize 26.4% of the RfD for 
children (1-6 years old), the subgroup population exposed to the 
highest risk. Generally, EPA has no cause for concern if the exposure 
is less than 100% of the RfD. Therefore, based on the completeness and 
the reliability of the toxicity data and the conservative exposure 
assessment, Bayer concludes that there is a reasonable certainty that 
no harm will result to infants and children from aggregate exposure to 
the residues of cyfluthrin, including all anticipated dietary exposure 
and all other non-occupational exposures.

F. International Tolerances

    A Codex maximum residue levels (MRLs) or 20 ppm has been 
established for residues of cyfluthrin on dried hops.

[FR Doc. 98-9395 Filed 4-14-98; 8:45 am]