UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C.  20460

OFFICE OF           

PREVENTION, PESTICIDES

AND TOXIC SUBSTANCES

MEMORANDUM

	Date:	10/15/2007

	Subject:	Cyfluthrin and beta-Cyfluthrin.  Registration for Use on
Grasses, Alfalfa, and Seed Treatment Use on Sugar Beets.  Request for
Replacement of Individual Cereal Grain Tolerances with Crop Group
Tolerance for Cereal Grains (Except Rice), Crop Group 15, and
Replacement of Individual Tolerances on Forage and Stover/Straw of
Wheat, Corn, and Sorghum with Crop Group Tolerance for Forage, Fodder,
and Straw of Cereal Grains, Crop Group 16 (Except Rice).  Summary of
Analytical Chemistry and Residue Data.  

Petition Nos.	6E7058 (Grasses)

6F7160 (Sugar Beets)

7F7226 (Alfalfa)

7F7200 (Cereal Grains and Forage, Fodder, and Hay of Cereal Grains)

DP Number:	339413

PC Codes:	128831 - Cyfluthrin 

118831 - Beta Cyfluthrin

40 CFR 180.	436

Chemical Class:	Pyrethroid



	From:	Douglas Dotson, Ph.D., Chemist

		Registration Action Branch 2

		Health Effects Division (7509P)

	Through:	Dennis McNeilly, Chemist

		Registration Action Branch 2

		Health Effects Division (7509P)

		Richard Loranger, Ph.D., Branch Senior Scientist

		Registration Action Branch 2

		Health Effects Division (7509P)

	To:	Olga Odiott/George LaRocca, RM Team 13

		Insecticide Branch

		Sidney Jackson/Dan Rosenblatt, RM Team 05

		MUIERB

		Registration Division (7505P)

This document was originally prepared under contract by Dynamac
Corporation (1910 Sedwick Road, Building 100, Suite B, Durham NC 27713;
submitted 04/06/2007).  The document has been reviewed by the Health
Effects Division (HED) and revised to reflect current Office of
Pesticide Programs (OPP) policies.

Executive Summary

Cyfluthrin and beta-Cyfluthrin are pyrethroid insecticides registered to
Bayer CropScience for control of various insect pests on a wide variety
of crops.  Both compounds are mixtures of four diastereomers, Isomers
I-IV (see Table 1), with beta-cyfluthrin being enriched in Isomers II
and IV.  Permanent tolerances are established for residues of cyfluthrin
(40 CFR §180.436) in/on a wide variety of plant commodities at levels
ranging from 0.01 ppm in/on peanuts, tree nuts, and tuberous and corm
vegetables to 600 ppm in/on aspirated grain fractions.  Tolerances have
been established for alfalfa at 5.0 ppm and alfalfa hay at 10.0 ppm.  In
addition, tolerances with regional registration have been established
for grass forage (6 ppm) and hay (8 ppm).  Tolerances are also currently
in effect for animal commodities at levels ranging from 0.01 ppm in eggs
and poultry fat, meat, and meat byproducts to 30 ppm in milk fat.  The
Agency previously concluded that tolerances for cyfluthrin will also
cover beta-cyfluthrin provided that the use rates for beta-cyfluthrin
are ½ the use rates of cyfluthrin.

Although a tolerance of 4.0 ppm is currently in effect for stored cereal
grains, the registration was cancelled in 2004.  The tolerance was
allowed to remain in effect until the registered products cleared the
channels of trade.  Cyfluthrin is registered for foliar applications to
field corn, sweet corn, sorghum, and wheat.  As a result, tolerances are
in effect for the various commodities associated with these cereal
grains.  These tolerances include those for the forage, stover, straw,
and hay of field corn, sorghum, and wheat.

Interregional Research Project No. 4 (IR-4) submitted a petition (PP#
6E7058) proposing the use of cyfluthrin formulated as either a 2.0
lb/gal emulsifiable concentrate (EC) or 20% wettable powder (WP) and
beta-cyfluthrin formulated as a 1 lb/gal EC on grasses grown throughout
the U.S.  The proposed use is for a maximum of four broadcast foliar
applications using ground or aerial equipment at a rate of 0.044 lb
ai/A/application for cyfluthrin, for a total of 0.176 lb ai/A/season.
The proposed use rate for beta-cyfluthrin is ½ the rate of cyfluthrin. 
The proposed preharvest interval (PHI) is 0 days for grasses and 7 days
for mixed stands of grass and alfalfa.  In conjunction with this use,
IR-4 is proposing the following permanent tolerances for cyfluthrin:

Grass, forage, fodder and hay, group 17, forage 	13.0 ppm

Grass, forage, fodder and hay, group 17, hay	40.0 ppm

Bayer submitted a petition (PP# 7F7226) proposing an increased rate for
the use of cyfluthrin on alfalfa.  Tolerances are currently in effect
for alfalfa at 5.0 ppm and alfalfa hay at 10.0 ppm.    The proposed use
is for a maximum of eight broadcast foliar applications using ground,
aerial, or chemigation equipment at a rate of 0.044 lb ai/A/application,
for a total of 0.35 lb ai/A/season.  The proposed preharvest interval
and pre-grazing interval is 7 days.  The minimum retreatment interval is
5 days.  In conjunction with this use, Bayer is proposing the following
permanent tolerances for cyfluthrin:

Alfalfa, forage 	5.0 ppm

Alfalfa, hay	15.0 ppm

Bayer also submitted a petition (PP# 6F7160) proposing the use of a
multiple active ingredient (MAI) formulation containing 3.33 lb/gal of
clothianidin and 0.44 lb/gal of beta-cyfluthrin (Poncho Beta, EPA Reg.
No. 264-XXX) as a seed treatment for sugar beets.  This product is
formulated as a combination formulation of suspension concentrate and an
oil based emulsion, also known as a suspoemulsion.  The proposed use is
restricted to commercial seed treaters, and applications using equipment
for treating seeds at planting are prohibited.  The proposed use rate is
0.017 lb ai (8 g) of beta-cyfluthrin per 100,000 seeds.  This rate is
equivalent to 0.009-0.012 lb ai/A, based on typical planting rates of
53,000-72,000 seeds per acre.  In conjunction with this use, Bayer is
proposing the following permanent tolerances for cyfluthrin:

Beet, sugar, roots	0.09 ppm

Beet, sugar, dried pulp	11.0 ppm

Bayer submitted a petition (PP# 7F7200) proposing a crop group tolerance
for the Cereal Grains Crop Group, Except Rice (Crop Group 15).  Bayer
also proposed a tolerance for the Forage, Fodder, and Straw of Cereal
Grains Crop Group (Crop Group 16).  In conjunction with these uses,
Bayer is proposing the following tolerances for cyfluthrin:

Grain, Cereal; Crop Group 15 (except Rice)	4.0 ppm

Grain, Cereal, Forage, Fodder and Straw. Crop Group

16, (except Rice)	7.0 ppm

  

The nature of cyfluthrin residues in plants and animals is understood
based on adequate cotton, soybean, potato, apple, wheat, tomato, hen,
and cow metabolism studies.  Data from these studies indicate that the
major detectable residue is cyfluthrin, which metabolizes slowly with
little translocation.  In plants and animals, metabolism of cyfluthrin
involves hydrolysis of the ester linkage and hydroxylation of the
aromatic ring system.  The residue of concern for tolerance expression
and for dietary risk assessment in plants and animals is cyfluthrin per
se.

Adequate GC/electron capture detection (ECD) methods are available in
PAM Vol. II for enforcing tolerances for cyfluthrin residues in/on plant
and animal commodities.  In the current grass, alfalfa, and sugar beet
field trials, samples were analyzed using Bayer Method 108139-1 (GC/MS),
which has been previously reviewed by the Agency and deemed adequate for
data collection.  This method was also adequately validated in
conjunction with the analysis of samples from the grass, alfalfa, and
sugar beet field trials.  In grass, the validated LOQ for cyfluthrin
residues is 0.05 ppm, and the statistically calculated LOD is 0.014 ppm
for forage and 0.02 ppm for hay.  In alfalfa, the validated LOQ is 0.01
ppm for both forage and hay.  In sugar beet commodities, the validated
LOQ for cyfluthrin residues is 0.01 ppm.  The statistically calculated
LODs are 0.003 ppm for tops and roots and 0.0011-0.0018 ppm for
processed fractions.

Adequate storage stability data are available from numerous raw and
processed plant commodities indicating that cyfluthrin is stable in
frozen storage for up to 35-38 months.  These data support the current
grass and alfalfa field trials in which samples were stored frozen for
up to 16 months and 18 months, respectively.  These data also support
the current sugar beet field trials and processing study, as tops and
roots were stored frozen for ≤13.5 months and processed fractions were
stored frozen for <1 month.

The available grass field trial data are adequate and support the
proposed use on grasses.  The field trial data for the EC formulation of
cyfluthrin will support the same use for the WP formulation, as previous
studies indicate that the EC formulation results in higher residues than
does the WP formulation.  The field trial data for cyfluthrin also
support the use of beta-cyfluthrin, as the proposed use rate for
beta-cyfluthrin is ½ the proposed rate of cyfluthrin.

Following four broadcast foliar applications of cyfluthrin (EC) totaling
0.172-0.181 lb ai/A, residues of cyfluthrin were 3.79-10.4 ppm in/on
grass forage harvested on the day of the last application (0 DAT) and
6.30-33.1 ppm in/on grass hay harvested at 0 DAT.  Residues averaged
6.54 ppm in/on forage and 18.09 ppm in/on hay.  In the two residue
decline trials, average cyfluthrin residues declined steadily from 5.72
ppm in/on forage at 0 DAT to 2.52 ppm at 21 DAT.  In hay, residues
declined from 19.8 ppm at 0 DAT to 7.30 ppm at 21 DAT.  The available
data support tolerances of 12 ppm in/on forage and 50 ppm in/on hay of
the Grass Forage, Fodder, and Hay Group.

The available alfalfa field trial data are adequate and support the
proposed use on alfalfa.  

Twelve field trials were conducted to measure the magnitude of
cyfluthrin residues in/on alfalfa following two foliar spray
applications of BAYTHROID 2E to alfalfa at a target rate of
0.044 lb ai/A/application (0.043 to 0.047 lb ai/A/application) prior
to each of four cuttings.  The interval between applications was 5 to 9
days.  The highest cyfluthrin residue was 5.9 ppm in/on alfalfa forage
for all cuttings at commercial maturity at a PHI of 6 days (target PHI
is 7 days).  The maximum cyfluthrin residue in/on hay was 16.49 ppm
in/on alfalfa hay for all cuttings at commercial maturity at a PHI of
7 days.  The available data support tolerances of 5.0 ppm in/on alfalfa
forage and 13 ppm in/on alfalfa hay.  Because of the large number of
samples (94-96 for each RAC), the tolerance spreadsheet recommends
values that are lower than the highest residues.

The available sugar beet field trial data are adequate and support the
proposed seed treatment use. Although the field trials were conducted
using a MAI containing cyfluthrin rather than beta-cyfluthrin, the data
for cyfluthrin also support the use of beta-cyfluthrin, as the proposed
use rate for beta-cyfluthrin is ½ the rate of cyfluthrin used in the
field trials.  Following a seed treatment with cyfluthrin (1 lb/gal
suspoemulsion) at 0.035 lb ai/100,000 seeds, cyfluthrin residues at
normal crop maturity were <0.003-0.088 ppm in/on sugar beets roots, with
only 3 out of 24 root samples having residues at or above the LOQ of
0.01 ppm (0.01, 0.025, and 0.088 ppm).  Average cyfluthrin residues were
0.01 ppm in/on roots, and the highest average field trial (HAFT)
residues were 0.049 ppm.

The available wheat, field corn, sweet corn, and sorghum field trial
data are adequate and support separate tolerances for the various cereal
grain commodities.  Bayer proposed a tolerance of 4.0 ppm for the Cereal
Grains Crop Group, Except Rice (Crop Group 15).  This tolerance is
equivalent to the tolerance that was established based on the stored
grains uses.  The stored grains registrations have been cancelled,
however.  Because of differences in field trial values and harmonization
with Codex MRLs, different tolerances are being recommended for the
different cereal grains.  A tolerance of 0.15 is being recommended for
the grain of wheat, barley, oats, buckwheat, rye, and millet.  In order
to harmonize with the Codex MRL for maize, a tolerance of 0.05 ppm is
being recommended for field corn grain and for sweet corn, kernel plus
cob with husks removed.  A tolerance of 4.0 ppm is being recommended for
sorghum, grain.

Bayer proposed a tolerance of 7.0 ppm for the Forage, Fodder, and Straw
of the Cereal Grains Crop Group, Except Rice (Crop Group 16).  Forage
data are available for wheat, field corn, sweet corn, and sorghum.  The
data set for each commodity was entered into HED’s statistical
tolerance generator.  The generated tolerances for forage are as
follows:  wheat (4.0 ppm), field corn (3.0 ppm), sweet corn (25 ppm),
and sorghum (4.0 ppm).  The highest of these tolerances is that for
sweet corn, 25 ppm.  As a result, the recommended tolerance for the
Forage of the Cereal Grains Crop Group, except Rice, is 25 ppm.  The
term fodder has been replaced with the term stover.  Stover data are
available for field corn, sweet corn, and sorghum.  The data set for
each commodity was entered into HED’s statistical tolerance generator.
 The generated tolerances are as follows:  field corn (3.5 ppm), sweet
corn (30 ppm), and sorghum (3.5 ppm).  The highest of these tolerances
is that for sweet corn, 30 ppm.  As a result, the recommended tolerance
for the Stover of the Cereal Grains Crop Group, except Rice, is 30 ppm. 
Straw data are available for wheat only.  HED’s statistical tolerance
generator was used to calculate the recommended tolerance for straw
which was determined to be 7.0 ppm.  As a result, the recommended
tolerance for the Straw of the Cereal Grains Crop Group, except Rice, is
7.0 ppm.  Hay data are also available for wheat only.  HED’s
statistical tolerance generator was used to calculate the recommended
tolerance for hay which was determined to be 6.0 ppm.  As a result, the
recommended tolerance for the Hay of the Cereal Grains Crop Group,
except Rice, is 6.0 ppm. 

The available sugar beet processing study is adequate, and indicates
that cyfluthrin residues do not concentrate in refined sugar (<0.3x) or
molasses (<0.2x), but can concentrate in dried pulp (12x).  Based on
HAFT residues of 0.049 ppm in roots and the 12x processing factor, the
maximum expected residues in dried pulp would be 0.59 ppm, which
supports a tolerance of 1.0 ppm for dried pulp.

Tolerances for commodities processed from cereal grains are based on the
stored grains uses.  These processed commodities include wheat bran,
corn oil, rice bran, and rice hulls.  As the stored grain uses have been
cancelled, the tolerances for these processed commodities should now be
based on the currently registered applications.  The wheat bran
tolerance of 6.5 ppm should be decreased to 0.5 ppm.  The corn oil
tolerance of 30 ppm should be revoked altogether. The 0.05 ppm tolerance
for field corn grain will cover concentration of residues in corn oil. 
The only registered use on rice was the stored grain use.  As the stored
grain uses have been revoked, the tolerances for rice bran and rice
hulls should be revoked.

The following livestock feed items are associated with these tolerance
petitions:  grass forage, grass hay, alfalfa forage, alfalfa hay, sugar
beet dried pulp, sugar beet molasses, and the forage, stover, straw and
hay of cereal grains.  Based on recommended changes in tolerances for
cereal grain and grass commodities, along with the recent changes in
calculating livestock diets, the maximum dietary burden (MDB) for
cyfluthrin residues was recalculated to be 21.0 ppm for beef cattle,
27.1 ppm for dairy cattle, and 3.21 ppm for swine and poultry.  As the
MDB for poultry has not changed from earlier reviews, no changes in the
current tolerances on eggs and poultry tissues are required.  However,
tolerances for other livestock commodities were reassessed because of
the substantial reductions in the MDBs for cattle and swine.  Based on
the recalculated MDBs for beef cattle, dairy cattle, and swine, and the
residue data from the adequate cattle feeding study, tolerances for
milk, cattle, goat, hog, horse, and sheep commodities can be
substantially reduced. The available cattle feeding study data support
reducing the current livestock tolerances to 0.2 ppm for milk, 5.0 ppm
for milk fat, 2.0 ppm for cattle fat, 0.10 ppm for cattle meat and meat
byproducts, 0.05 ppm for meat and meat byproducts of goats, horses, and
sheep, 2.0 ppm for fat of goats, horses, and sheep, 0.01 ppm for meat
and meat byproducts of hogs, and 0.5 ppm for fat of hogs.

Regulatory requirements pertaining to rotational crops have been
fulfilled, and the rotational crop restrictions on the current labels
are adequate. 

  SEQ CHAPTER \h \r 1 Regulatory Recommendations and Residue Chemistry
Deficiencies

Aside from minor label revisions to the label for grasses, no major
deficiencies were noted in the subject petitions that would preclude
establishing permanent tolerances for cyfluthrin on grass forage, grass
hay, alfalfa forage, sugar beet roots, or sugar beet dried pulp.  No
major deficiencies were noted that would preclude increasing the alfalfa
hay tolerance.  HED  SEQ CHAPTER \h \r 1  recommends establishing
permanent tolerances for cyfluthrin at 12 ppm in/on forage and at 50 ppm
in/on hay of the Grass, Forage, Fodder, and Hay Group.  HED recommends
establishing a permanent tolerance for alfalfa forage at 5 ppm and
increasing the alfalfa hay tolerance from 5.0 to 13 ppm.  In addition,
HED  SEQ CHAPTER \h \r 1  recommends establishing permanent tolerances
for cyfluthrin at 0.10 ppm in/on sugar beet roots and at 1.0 ppm in
dried pulp.  These tolerance levels are also appropriate to cover the
proposed use of beta-cyfluthrin.  As discussed below, a separate section
is recommended in the CFR for beta-cyfluthrin tolerances.

 

•	The proposed label directions for grasses and alfalfa allow for
ultra-low volume aerial applications using a minimum of 1 qt/A of
vegetable oil as the carrier.  However, no residue data were submitted
supporting this type of use.  Therefore, this type of application should
be removed from the use directions.

HED does not object to the establishment of tolerances for field corn,
sweet corn, sorghum, or the equivalent of a crop subgroup tolerance for
wheat, barley, buckwheat, millet, oats, and rye.  HED also does not
object to the establishment of crop group tolerances for the forage,
fodder, hay and straw of cereal grains (except Rice).  The recommended
tolerances for the various cereal grain commodities are listed in Table
9.  As the stored grain registrations have been cancelled and crop group
tolerances are being established, changes need to be made to several
current tolerances.  The tolerance for wheat bran should be decreased
from 6.5 ppm to 0.5 ppm.  The tolerances for cattle meat and cattle meat
byproducts should be decreased from 0.40 ppm to 0.10 ppm.  The tolerance
for cattle fat should be decreased from 10 ppm to 2.0 ppm.  In addition,
the following tolerances should be revoked:  refined field corn oil,
rice bran, rice hulls, wheat forage, wheat hay, wheat straw, field corn
forage, field corn stover, popcorn stover, sweet corn forage, sweet corn
stover, sorghum grain forage, and sorghum grain stover.  See Table 9,
“Tolerance Summary for Cyfluthrin,” for the recommended tolerance
changes.

 

mixture comprising the enantiomeric pair
(R)-α-cyano-4-fluoro-3-phenoxybenzyl
(1S,3S)-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate and
(S)-α-cyano-4-fluoro-3-phenoxybenzyl
(1R,3R)-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate with
the enantiomeric pair (R)-α-cyano-4-fluoro-3-phenoxybenzyl
(1S,3R)-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate and
(S)-α-cyano-4-fluoro-3-phenoxybenzyl
(1R,3S)-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate] in or
on the following commodities:”

Revised Sections F should be submitted for the subject petitions
proposing separate tolerances for cyfluthrin and beta-cyfluthrin using
the commodity names and tolerance levels specified in Table 9.

HED also recommends that, at some point in the future, tolerances be
established for all food uses of beta-cyfluthrin (i.e., on those
commodities not included in the present actions).

Background

Cyfluthrin and beta-Cyfluthrin are related pyrethroid insecticides used
for the control of various Lepidopterous pests, beetles, lygus and plant
bugs, grasshoppers, leafhoppers, and white flies on a wide variety of
field, vegetable, tree fruit, and vine crops.  Both compounds are
mixtures of the same four diastereomers, Isomers I-IV, two in the cis
configuration (Isomers I and II) and two in the trans configuration
(Isomers III and IV).  Cyfluthrin is comprised of approximately equal
parts of Isomers I (25%), II (19%), III (34%) and IV (23%), whereas
beta-cyfluthrin is enriched in Isomers II (~35%) and IV (~62%), and
contains only minor amounts of Isomers I and III (<3% total).  Both
cyfluthrin and beta-cyfluthrin are registered to Bayer for use on a
variety of food/feed crops.

Permanent tolerances are established for residues of cyfluthrin in/on a
wide variety of plant commodities at levels ranging from 0.01 ppm in/on
peanuts, tree nuts, and tuberous and corm vegetables to 600 ppm in/on
aspirated grain fractions (40 CFR §180.436(a)(1)).  Tolerances have
been established for alfalfa at 5.0 ppm and alfalfa hay at 10.0 ppm.  In
addition, permanent tolerances with a regional registration have also
been established for cyfluthrin at 6 ppm in/on grass forage and 8 ppm
in/on grass hay (40 CFR §180.436(c)).  Cyfluthrin tolerances on animal
commodities are established at levels ranging from 0.01 ppm in eggs and
poultry fat, meat, and meat byproducts to 30 ppm in milk fat.  A
tolerance of 4.0 ppm is established for the cereal grains crop group
based on application of cyfluthrin to stored grains.  In 2004, HED
recommended that the tolerance for stored grains be revoked.  Tolerances
are also established for various animal feed items associated with the
cereal grains (i.e., forage, stover, hay, and straw).  In addition, a
tolerance of 0.05 ppm is established for cyfluthrin in animal feeds and
processed foods as a result of its use in food- and feed-handling
establishments (40 CFR §180.436(a)(2) and (a)(3)).  The tolerances for
cyfluthrin also cover the use of beta-cyfluthrin, although HED is now
recommending a separate section for beta-cyfluthrin as discussed above.

Both cyfluthrin and beta-cyfluthrin are currently registered for use on
grasses; however, this use is restricted to California, Idaho, Oregon,
and Washington State.  In one of the current petition (PP# 6E7058), IR-4
has proposed expanding the use on grasses to cover the entire U.S., and
establishing tolerances on forage and hay of the Grass, Forage, Fodder
and Hay Group (Group 17).

Bayer submitted a petition (PP# 7F7226) proposing an increased rate for
the use of cyfluthrin on alfalfa.  Tolerances are currently in effect
for alfalfa at 5.0 ppm and alfalfa hay at 10.0 ppm.    The proposed use
is for a maximum of eight broadcast foliar applications using ground,
aerial, or chemigation equipment at a rate of 0.044 lb ai/A/application,
for a total of 0.35 lb ai/A/season.  The proposed preharvest interval
and pre-grazing interval is 7 days.  The minimum retreatment interval is
5 days.

In another petition (PP#6F7160), Bayer is proposing a seed treatment use
for beta-cyfluthrin on sugar beets, as a component of a MAI formulation
that also contains clothianidin.  In conjunction with this use, Bayer is
proposing establishment of cyfluthrin tolerances on sugar beet roots and
dried pulp.  In petition number 7F7200, Bayer is proposing tolerances
for the Cereal Grains Crop Group (except Rice) as well as the Forage,
Fodder, and Straw of the Cereal Grains Crop Group (except Rice).

The nomenclature and physicochemical properties of cyfluthrin and
beta-cyfluthrin are presented below in Tables 1 and 2.

 

Table 1.	Cyfluthrin and β-Cyfluthrin Nomenclature.

Compound	

Diastereomer I (1R,3R,αR + 1S,3S,αS; 1:1; cis)

Diastereomer II (1R,3R,αS + 1S,3S,αR; 1:1; cis)

Diastereomer III (1R,3S,αR + 1S,3R,αS; 1:1; trans)

Diastereomer IV (1R,3S,αS + 1S,3R,αR; 1:1; trans)

	Cyfluthrin:  Isomer I (23-27%), Isomer II (17-21%), Isomer III
(32-36%), and Isomer IV (21-25%)	beta-Cyfluthrin:  Isomer I (<2%),
Isomer II (30-40%), Isomer III (<3%), and Isomer IV (57-60%)

Common names	Cyfluthrin and beta-Cyfluthrin

Company experimental name	Baythroid, FCR1272

IUPAC names	Cyfluthrin:	(RS)-α-cyano-4-fluoro-3-phenoxybenzyl
(1RS,3RS;1RS,3SR)-3-(2,2-dichlorovinyl)-2,2-
dimethylcyclopropanecarboxylate

beta-Cyfluthrin:  enantiomeric pair
(R)-α-cyano-4-fluoro-3-phenoxybenzyl
(1S,3S)-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate and
(S)-α-cyano-4-fluoro-3-phenoxybenzyl
(1R,3R)-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate in
ratio 1:2 with the enantiomeric pair
(R)-α-cyano-4-fluoro-3-phenoxybenzyl
(1S,3R)-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate and
(S)-α-cyano-4-fluoro-3-phenoxybenzyl
(1R,3S)-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate

[These are the chemical names for the major isomers (II and IV)
comprising >95% of beta-cyfluthrin.]



CAS name	cyano(4-fluoro-3-phenoxyphenyl)methyl
3-(2,2-dichloroethenyl)-2,2-

dimethylcyclopropanecarboxylate

CAS registry number	68359-37-5

End-use products (EPs)	Cyfluthrin:	Baythroid® 2 (2 lb/gal EC; EPA Reg.
No. 264-745)

 	Renounce® 20WP (20% WP; EPA Reg. No. 264-784)

beta-Cyfluthrin:	Baythroid® XL (1 lb/gal EC; EPA Reg. No. 264-840)



Table 2.	Physicochemical Properties of Technical Grade Cyfluthrin.

Parameter	Value	Reference

Melting point/range (°C)	Isomer I: 57	Isomer II: 73-74

Isomer III: 65-66	Isomer IV: 101-102	MRID 40544902

pH	not measurable because of low solubility in water

	Density (g/mL at 20ºC)	1.28

	Water solubility  (μg/L at 20ºC)	Isomer I: 2.2	Isomer II: 1.9

Isomer III: 2.2	Isomer IV: 2.9

	Solvent solubility (g/L room temperature)	Methylene chloride >200
Toluene  >200

Hexane 10-20		Isopropanol 20-50

	Vapor pressure (20 or 25°C) 	7.2 x 10-9 Pa

	Dissociation constant, pKa	does not dissociate

	Octanol/water partition coefficient, Log(KOW)	Isomer I:  6	Isomer II:
5.9

Isomer III: 6	Isomer IV: 5.9

	UV/visible absorption spectrum	Absorption maxima:  primary: 196 nm,
secondary 275 nm

	

860.1200  Directions for Use

  SEQ CHAPTER \h \r 1 There are two cyfluthrin end-use products (EPs)
and one beta-cyfluthrin EP currently registered to Bayer for use on
food/feed crops.  The cyfluthrin EPs are a 2 lb/gal EC marketed under
the trade name Baythroid® 2 (EPA Reg. No. 264-745) and a 20% WP
marketed under the trade name Renounce® 20WP (EPA Reg. No. 264-784). 
The beta-cyfluthrin EP is a 1 lb/gal EC marketed under the trade name
Baythroid® XL (EPA Reg. No. 264-840).  Example use directions for the
proposed use on grasses were provided for each of these labels and are
summarized in Table 3.  Bayer proposed Baythroid® XL for use on the
cereal grains (except rice).  The use directions appearing on the label
are given in Table 3.

For the seed treatment of sugar beets, Bayer is proposing use of a MAI
formulation containing 3.33 lb/gal of clothianidin and 0.44 lb/gal of
beta-cyfluthrin formulated as a suspoemulsion.  A suspoemulsion is a
heterogeneous preparation consisting of a stable dispersion of the
active ingredient in the form of solid particles and fine globules in a
continuous water phase.  A copy of the proposed label was provided, and
the proposed use on sugar beet seeds is summarized in Table 3.

Table 3.  Summary of Directions for Use of Cyfluthrin and
beta-Cyfluthrin.

Applic. Timing, Type, and Equip.	Formulation

[EPA Reg. No.]	Applic. Rate 

(lb ai/A)	Max. No. Applic. per Season	Max. Seasonal Applic. Rate

(lb ai/A)	PHI

(days)	Use Directions and Limitations 1

Grasses (pasture/rangeland/grass for seed/grass for hay/grass in mixed
stands with alfalfa)

Broadcast foliar applications during crop development using ground or
aerial equipment	2 lb/gal  EC

[264-745]

20% WP

[264-784]	0.044	4	0.176	0

(7) 2	For aerial ultra-low volume application, apply in a minimum of 1.0
qt/A of vegetable oil.

	1 lb/gal EC

[264-840]	0.022

0.089



Alfalfa

Broadcast foliar applications during crop development using ground or
aerial equipment	2 lb/gal  EC

 [264-745]	0.044	8	0.35	7	For aerial ultra-low volume application, apply
in a minimum of 1.0 qt/A of vegetable oil.

Sugar Beets

Seed Treatment3	0.44 lb/gal suspoemulsion4

[264-XXX]	0.017 lb/100,000 seeds	1	0.009-0.0125	NS	All seed treated with
this product must be conspicuously colored at the time of treatment.

Do not use treated seed for food, feed or oil processing.  



Wheat, Barley, Buckwheat, Millet, Oats, Rye, and Triticale

Broadcast foliar applications during crop development using ground or
aerial equipment	1 lb/gal EC

[264-840]	0.019	2	0.038	30	For aerial ultra-low volume application,
apply in a minimum of 1.0 qt/A of vegetable oil.

Field Corn, Popcorn, Seed Corn, Teosinte

Broadcast foliar applications during crop development using ground or
aerial equipment	1 lb/gal EC

[264-840]	0.022	4	0.088	21

Grain,

Stover

0 Forage

	For aerial ultra-low volume application, apply in a minimum of 1.0 qt/A
of vegetable oil.

Sweet Corn Foliar Applications

Broadcast foliar applications during crop development using ground or
aerial equipment	1 lb/gal EC

[264-840]	0.022	10	0.22	0	For aerial ultra-low volume application, apply
in a minimum of 1.0 qt/A of vegetable oil.

Sweet Corn Soil Applications

Apply in water or liquid pop-up fertilizer at planting	1 lb/gal EC

[264-840]	0.022	1	0.022	N/A	Apply in a minimum of 2 GPA of total mix
volume when applied in water

Sorghum Foliar Applications

Broadcast foliar applications during crop development using ground or
aerial equipment	1 lb/gal EC

[264-840]	0.022	3	0.066	14	For aerial ultra-low volume application,
apply in a minimum of 1.0 qt/A of vegetable oil.

1  Rotational crops may be replanted as soon as practical after the last
application.  Maximum seasonal use rates resulting from combined use of
cyfluthrin and beta-cyfluthrin products are not to exceed the specified
maximum seasonal application rate for cyfluthrin.

2  The 7-day PHI is for applications to mixed stands of grass and
alfalfa.

3  For use only in liquid or slurry seed treating equipment by
commercial seed treaters.  Do not use in farm equipment for seed
treatment at the time of planting.

4  This formulation is a suspo-emulsion, which is a heterogeneous
preparation consisting of a stable dispersion of the active ingredient
in the form of solid particles and fine globules in a continuous water
phase.  It is an MAI that also contains 3.33 lb/gal of clothianidin.

5  Maximum field use rate based on seeding rates of ~53,000-72,000 seeds
per acre.

Conclusions.  The proposed label directions for grasses and alfalfa are
adequate and, with the exception of the ultra-low volume application,
are supported by the available field trial data using the 2 lb/gal EC
formulation of cyfluthrin.  The field trial data will also support the
use of the 20% WP formulation of cyfluthrin.  Side-by-side tests
comparing the EC and WP formulations on numerous crops are available
indicating that residues resulting from application of the EC are equal
to or greater than residues resulting from the application of the WP
(DP# 290921, Y. Donovan, 12/6/04).  In accordance with an earlier Agency
decision (2/2006), the data from the cyfluthrin 2 lb/gal EC also support
the use of beta-cyfluthrin at ½ the use rate of cyfluthrin. 

In addition, the inclusion of applications to mixed stands of grass and
alfalfa is allowable as the labels include separate use directions for
both grass and alfalfa at the same use rate and the more restrictive
7-day PHI for alfalfa is specified for mixed stands.  However, no data
were submitted supporting the ultra-low volume application to grasses
and alfalfa; therefore, this type of application should be removed from
the labels.  

The proposed label directions for sugar beets are adequate and are
supported by the available field trial data.  Although the field trials
were conducted using seeds treated with a similar MAI containing
cyfluthrin, the proposed use rate for beta-cyfluthrin is ½ the rate of
cyfluthrin used in the field trials.

The proposed label directions for cereal grains (except rice) are
adequate and, with the exception of the ultra-low volume application,
are supported by the available field trial data using the 2 lb/gal EC
formulation of cyfluthrin.  The field trial data will also support the
use of the 20% WP formulation of cyfluthrin.  In accordance with an
earlier Agency decision (2/2006), the data from the cyfluthrin 2 lb/gal
EC also support the use of beta-cyfluthrin at ½ the use rate of
cyfluthrin.

860.1300 Nature of the Residue - Plants

The Agency previously concluded that the nature of the residues of
cyfluthrin in plants is adequately understood based on plant metabolism
studies on cotton, soybeans, potatoes, apples, wheat, and tomatoes. 
Data from those studies show the major detected residue is parent
cyfluthrin, which metabolizes slowly with little translocation.  The
residue of concern in plants is cyfluthrin per se.

The nature of the residue was similar in all plant matrices.  Parent
comprised 38-98% of the TRR in cotton, soybeans, potatoes, and apples
(PP# 4F3046, 5/18/84, K. Arne and PP# 5G3307, 12/23/85, L. Propst), and
in wheat and tomato (PP# 9F3731/ 9H5574, H. Fonouni, 11/17/89).  Other
metabolites generally comprised <10% of the TRR.  These metabolites
include FPBalc, FPBald, FPBacid, FPBamide, FPB methyl ester, and
4'-OH-FPBacid, which arise from hydrolysis of the ester linkage and
hydroxylation of the aromatic ring system.

860.1300 Nature of the Residue - Livestock

The Agency previously concluded that the nature of the residues of
cyfluthrin in animals is adequately understood based on livestock
metabolism studies on poultry and cows.  The residue of concern in
animals is cyfluthrin per se.

In lactating cows and laying hens, parent comprised 56-100% of the TRR
in cow tissues and milk, 28-56% of the TRR in poultry muscle, fat, skin
and eggs, and 9-12% of the TRR in poultry liver and kidney.  Other
metabolites; FPBalc, FPBald, FPBacid, and 4'-OH-FPBacid, comprised 0-43%
of the TRR in cow tissues and milk, and 0-19% of the TRR in poultry
tissues and eggs (PP# 4F3046, 5/18/84, K. Arne, PP# 4G2976, 2/23/84, R.
Loranger, and PP# 9F3731/ 9H5574, H. Fonoumi, 11/17/89).

860.1340 Residue Analytical Methods

  SEQ CHAPTER \h \r 1 Adequate GC/ECD methods are available in PAM Vol.
II for enforcing tolerances for cyfluthrin residues in/on plant
commodities (Method 85823) and animal commodities (Method 85883).  The
limit of detection for cyfluthrin in both methods is 0.01 ppm in the
plant and animal commodities tested.  This method does not distinguish
between cyfluthrin and beta-cyfluthrin.

In the current grass, alfalfa, and sugar beet field trials as well as
the sugar beet processing study, samples were analyzed for residues of
cyfluthrin using Bayer Method 108139-1 (GC/MS), which was developed for
determining residues of cyfluthrin in a wide variety of plant matrices. 
This method was previously reviewed by the Agency and deemed adequate
for data collection (D290921, Y. Donovan, 12/16/04).  The method was
adequately validated on grass, alfalfa, and sugar beet commodities in
conjunction with the analysis of field trial and processing study
samples.  For a discussion of analytical methods used for cereal grain
commodities, see Memo, D290921, Y. Donovan, 12/16/2004.

For Method 108139-1, residues are extracted from homogenized samples
with methanol:1.2 N HCl (4:1, v:v) and filtered, and the
[2H6]-cyfluthrin internal standard is added.  The extract is
concentrated to an aqueous remainder, diluted with water, and
partitioned with acetone:dichloromethane (1:2, v/v).  Residues in the
resulting organic phase are filtered through anhydrous sodium sulfate,
concentrated, and reconstituted in hexane.  Residues are further
purified using a Florisil column eluted sequentially with hexane and
hexane:acetone (9:1, v/v).  Residues in the final eluate are
concentrated to dryness, redissolved in toluene, and analyzed by GC/MS. 
Residues of cyfluthrin (m/z 207) are quantified using the 2H6-cyfluthrin
(m/z 216) as an internal standard.  The validated LOQ for cyfluthrin
residues in grass forage and hay is 0.05 ppm, and the statistically
calculated LOD is 0.014 ppm for forage and 0.020 ppm for hay.  The LOQ
for cyfluthrin in alfalfa forage and hay is 0.01 ppm.  The validated LOQ
for cyfluthrin residues is 0.01 ppm for all sugar beet commodities, and
the statistically calculated LODs are 0.003 ppm for tops and roots and
0.0011-0.0018 ppm for processed fractions.  This method does not
distinguish between cyfluthrin and beta-cyfluthrin.

860.1360 Multiresidue Methods

Data pertaining to the recovery of cyfluthrin using FDA's multiresidue
methods were submitted (Mobay Report 94892; MRID 40355901).  These
multiresidue screening data were forwarded to FDA (PP#4F3046, M.
Bradley, 12/4/87).  The FDA Pestrack Data Base (PAM Vol. I, Appendix,
dated 11/6/90) indicates that complete recovery has been obtained for
cyfluthrin using FDA multiresidue methods.

860.1380 Storage Stability

Storage stability data are available from numerous raw and processed
commodities indicating that cyfluthrin is stable in frozen storage for
up to 35-38 months (D198397, J. Garbus, 5/25/95; D290921, Y. Donovan,
12/16/04).  The available studies include storage stability data on
lettuce, potato tubers, dried potato peel, and sugarcane molasses. 
These data support the current grass and alfalfa field trials in which
samples were stored frozen for up to 16 months and 18 months,
respectively.  These data also support the maximum storage intervals for
sugar beet tops and roots from the field trials (13.5 months) as well as
for roots (13 months) and processed fractions (<1 month) from the
processing study.

860.1400 Water, Fish, and Irrigated Crops

This guideline requirement is not relevant to the current petition as
the proposed use on grasses is non-aquatic.

860.1460 Food Handling

This guideline requirement is not relevant to the current petition as no
new uses are being proposed for food/feed handling establishments.

860.1480 Meat, Milk, Poultry, and Eggs

The dietary burdens for cyfluthrin residues in livestock diets were
recently calculated in conjunction with petitions for use of cyfluthrin
on a number of crops and crop groups (D290921, Y. Donovan, 12/16/04). 
The calculated MDBs under these earlier petitions were 158 ppm for beef
and dairy cattle, 3.2 ppm for poultry and 123 ppm for swine.  These high
levels of dietary exposure were driven largely by the 600 ppm tolerance
for aspirated grain fractions resulting from the post-harvest use of
cyfluthrin on stored grains.  Subsequent to the 12/16/2004 review of Y.
Donovan, the post-harvest uses for cyfluthrin on stored grains were
cancelled.  The Agency recommended a number of future changes to
tolerances on raw and processed cereal grain commodities, once the
products registered for this use clear the channels of trade (D321638,
Y. Donovan, 7/15/05).  Changes were also recommended for future
tolerances on livestock commodities. 

After these recommendations were made, HED revised its guidance on
calculating potential residues in livestock diets and has updated the
types and percentages of feedstuffs listed in Table 1 of Guideline
860.1000 (draft memo 10/2006).  Therefore, the potential dietary burden
of cyfluthrin for livestock has been recalculated using the recommended
changes to tolerances for grain commodities, the recommended tolerances
for the forage and hay of grass and alfalfa, and the recent guidance on
constructing a reasonably balanced diet for livestock.  The dietary
exposure of livestock to cyfluthrin residues was recalculated to be 21.0
ppm for beef cattle, 27.1 ppm for dairy cattle, and 3.21 ppm for swine
and poultry (Table 4).  The MDBs for cattle and swine were substantially
reduced, and there was no effect on the dietary exposure of poultry.

The only livestock feedstuffs associated with the sugar beet tolerance
petition are sugar beet dried pulp and molasses.  As cyfluthrin residues
in dried pulp and molasses are substantially lower than in the
feedstuffs they would replace in the calculated diets, the proposed use
on sugar beets will not increase the MDB of livestock for cyfluthrin
residues.

 

Table 4.   Calculation of Maximum Dietary Burdens of Cyfluthrin Residues
to Livestock.

Feedstuff	Dietary Component	% Dry Matter1	% Diet1	Established/
Recommended Tolerance (ppm)	Dietary Contribution (ppm)2

Beef Cattle

Grass, hay	R	88	15	50	8.5

Sorghum, grain	CC	86	75	4.0	3.5

Grain, aspirated fraction	CC	85	5	150 3	8.8

Cotton, undelinted seed	PC	88	5	1.0	0.06

TOTAL BURDEN	100

20.9

Dairy Cattle

Grass, hay	R	88	40	50	22.7

Grass, forage	R	25	5	12	2.40

Sorghum, grain	CC	86	40	4.0	1.86

Corn, field, grain	CC	88	5	0.05	0.003

Cotton, undelinted seed	PC	88	10	1.0	0.12

TOTAL BURDEN	100

27.1

Poultry and Swine

Sorghum, grain	CC	NA	80	4.0	3.2

Soybean seed	CC	NA	20	0.03	0.006

TOTAL BURDEN	100

3.21

1	Potential dietary burdens for livestock were determined using recent
Agency guidance on calculating reasonably balanced livestock diets
(draft memo, 10/2006).

2	Contribution = ([tolerance /% DM] X % diet) for beef and dairy cattle;
contribution = ([tolerance] X % diet) for poultry and swine. 

3	Based on tolerance reduction (to 150 ppm) for aspirated grain
fractions (D321368, Y. Donovan, 7/15/05).

An adequate ruminant feeding study is available (D216660, J. Garbus,
3/17/96) in which dairy cows were dosed orally for up to 28 days with
cyfluthrin at levels equivalent to 15, 50, or 150 ppm in the diet. 
These dose levels are equivalent to 0.72x, 2.4x and 7.2x the MDB for
beef cattle and 0.55x, 1.8x and 5.5x the MDB for dairy cattle.  Residues
of cyfluthrin in milk and tissues from the feeding study are listed in
Table 5.  The maximum cyfluthrin residue in milk from the 50 ppm dose
group (1.8x MDB) was 0.27 ppm.  The maximum cyfluthrin residues in
tissues from the 50 ppm dose group (2.4x MDB) were, <0.01 ppm in liver,
0.07 ppm in kidney and muscle, and 3.30 ppm in fat.  Based on the MDBs
for beef and dairy cattle, the estimated residues at a 1x feeding level
would be 0.15 ppm in milk (3.75 ppm in milk fat), <0.01 ppm in liver,
0.029 ppm in kidney and muscle, and 1.4 ppm in fat.  These residue
levels support reducing the current livestock tolerances to 0.05 ppm for
meat and meat byproducts of goats, horses, and sheep, and 2.0 ppm for
fat of goats, horses, and sheep.  Tolerances for cattle commodities need
to consider the additional residues from dermal uses as discussed below.

Cyfluthrin is also registered as a pour-on (dermal) application to
cattle (Cyclence Pour-On Insecticide).  The current tolerances for
cattle commodities and milk include the residue contribution from the
pour-on application.  As the stored grain uses have been cancelled,
however, the cattle commodity tolerances need to be reassessed.  The
registrant submitted the results of two studies in which residues in
milk and tissues were measured after pour-on applications were made to
cattle (MRIDs 41555702 and 41555703).  The residue levels that were
found in the tissues and milk are listed in the cyfluthrin Metabolism
Assessment Review Committee briefing memo (J. Morales, 8/12/96).  The
greatest residue value in milk was found 1.3 days after the third
application at 0.9 mg ai/kg body weight.  The residue value was 0.039
ppm.  When this number is added to the dietary residue value of 0.15
ppm, the total maximum expected residue in milk is 0.19 ppm.  Whole milk
is approximately 4% milk fat, so the maximum expected residue in milk
fat would be 4.7 ppm.  The tolerance for whole milk should therefore be
reduced from 1.0 ppm to 0.20 ppm, and the tolerance for milk fat should
be reduced from 30 ppm to 5.0 ppm.  The greatest residue value in meat
was found after the fifth application at 0.9 mg ai/kg body weight.  The
residue value was 0.022 ppm.  When this number is added to the dietary
residue value of 0.029 ppm, the total maximum expected residue in beef
meat is 0.051 ppm.  The tolerance for cattle meat should therefore be
reduced from 0.40 ppm to 0.10 ppm.  The greatest residue value in fat
was found after the fifth application at 0.9 mg ai/kg body weight.  The
residue value was 0.24 ppm.  When this number is added to the dietary
residue value of 1.4 ppm, the total maximum expected residue in beef fat
is 1.64 ppm.  The tolerance for cattle fat should therefore be reduced
from 10 ppm to 2.0 ppm.  The greatest residue value in kidney was found
after the fifth application at 0.9 mg ai/kg body weight.  The residue
value was 0.023 ppm.  When this number is added to the dietary residue
value of 0.029 ppm, the total maximum expected residue in beef kidney is
0.052 ppm.  The greatest residue value in liver was found after the
fifth application at 0.9 mg ai/kg body weight.  The residue value was
0.0015 ppm.  When this number is added to the dietary residue value of
<0.01 ppm, the total maximum expected residue in beef liver is 0.0115
ppm.  Based on the maximum expected residues in kidney and liver, the
tolerance for cattle meat byproducts should be reduced from 0.40 ppm to
0.10 ppm.  

Although the current petition is for grass, and grass commodities are
not fed to swine, other regulatory changes have substantially reduced
the potential dietary exposure of swine; therefore, the tolerances for
hog commodities were also reassessed.  Based on the MDB for swine (3.21
ppm), the dose levels in the cattle feeding study are equivalent to
4.7x, 15.6x, and 47x the MDB for swine.  Considering the residue data
from the 15 ppm dose level (4.7x) of the cattle feeding study, the
estimated residues at a 1x feeding level for swine would be <0.01 ppm in
liver, kidney, and muscle, and 0.29 ppm in fat.  Based on these residue
levels, and considering that cyfluthrin residues were detected in kidney
and muscle from the 50 ppm dose group (15.6x), the available data
support reducing the current tolerances to 0.01 ppm for meat and meat
byproducts of hogs and 0.5 ppm for fat of hogs.

As the potential dietary exposure of poultry to cyfluthrin residues (3.2
ppm) has remained unchanged from earlier evaluations of livestock
tolerances, no reassessment of poultry tolerances is required.  The
current tolerances of 0.01 ppm for cyfluthrin residues in eggs and
poultry tissues are adequate.  The recommended revised tolerances for
animal commodities are listed in Table 8.

Table 5.	Residues of Cyfluthrin in Milk and Tissues of Dairy Cattle
Dosed Orally for 28 Consecutive Days at Levels Equivalent to 15, 50, and
150 ppm in the Diet. 1

Commodity	Cyfluthrin Residues (ppm)

	15 ppm dose group	50 ppm dose group	150 ppm dose group

Milk	Day 7	0.07, 0.07, 0.08	0.20, 0.21, 0.26	0.49, 0.50, 0.68

	Day 14	0.06, 0.07, 0.10	0.20, 0.24, 0.27	0.41, 0.56, 0.89

	Day 21	0.04, 0.05, 0.07	0.16, 0.20, 0.22	0.50, 0.65, 0.96

	Day 28	0.06, 0.06, 0.06	0.08, 0.13, 0.16	0.43, 0.44, 0.49

Liver	<0.01, <0.01, <0.01	<0.01, <0.01, <0.01	<0.01, 0.01, 0.03

Kidney	<0.01, <0.01, 0.01	<0.01, 0.02, 0.07	0.02, 0.05, 0.07

Muscle	<0.01, <0.01, 0.01	0.02, 0.03, 0.07	0.04, 0.05, 0.11

Fat	0.98, 1.15, 1.36	2.18, 2.58, 3.30	3.99, 6.49, 9.94

1	Data from D216660, J. Garbus, 3/17/96.

860.1500 Crop Field Trials

Grasses

46795801.der

IR-4 submitted crop field trials supporting the use of cyfluthrin (EC)
on grasses across the U.S.    SEQ CHAPTER \h \r 1 The results from this
study are discussed below and summarized in Table 6.

Table 6.	Summary of Residue Data from Crop Field Trials with Cyfluthrin
(2 lb/gal EC).

Crop matrix	Total Applic. Rate  (lb ai/A)	PHI (days)	Residue Levels
(ppm)



	n	Min.	Max.	HAFT 1	Median (STMdR)	Mean (STMR)	Std. Dev.

Grasses (proposed use = 0.178 lb ai/A total application rate, 0-day PHI)

Forage	0.172-0.181	0	24	3.79	10.40	9.39	6.02	6.54	1.77

Hay	0.173-0.180	0	24	6.30	33.10	31.90	15.50	18.09	7.42

1  HAFT = Highest average field trial result.

In 12 field trials conducted in Zones 1, 2, 3, 4, 5, 8, 10, 11, and 12
during 2004, cyfluthrin (2 lb/gal EC) was applied to a variety of
grasses (fescue, Bermuda, and bluegrass) as four broadcast foliar
applications during vegetative development at rates of 0.042-0.046 lb
ai/A/application and RTIs of 4-6 days, for a total of 0.172-0.181 lb
ai/A.  Applications were made using ground equipment in volumes of 12-22
gal/A, and did not include the use of any spray adjuvants.  Single
control and duplicate treated samples of forage and hay were cut at each
test site at 0 DAT, and at two sites, duplicate treated samples were
harvested at 0, 7, 14, and 21 DAT to assess residue decline.  Forage
samples were immediately placed in frozen storage, and hay samples were
field-dried for 2-20 days prior to collection.  Samples were stored
frozen for up to 485 days, an interval that is supported by available
storage stability data.  

Bayer Method 108139-1 (GC/MS), which was used to determine residues of
cyfluthrin in/on grass forage and hay, was adequately validated in
conjunction with the analysis of field trial samples.  The validated LOQ
for cyfluthrin residues is 0.05 ppm in/on both forage and hay, and the
calculated LOD is 0.014 ppm for forage and 0.020 ppm for hay.

Following four broadcast foliar applications of cyfluthrin (EC) totaling
0.172-0.181 lb ai/A, residues of cyfluthrin at 0 DAT were 3.79-10.40 ppm
in/on 24 samples of grass forage and 6.30-33.10 ppm in/on 24 samples of
grass hay.  Average residues were 6.54 ppm in/on forage and 18.09 ppm
in/on hay at 0 DAT.  In the two residue decline trials, average
cyfluthrin residues declined steadily from 5.72 ppm in/on forage at 0
DAT to 2.52 ppm at 21 DAT.  In hay, residues declined from 19.8 ppm at 0
DAT to 7.30 ppm at 21 DAT.

Conclusions.  The available field trial data are adequate.  The number
and geographic distribution of the field trials are adequate, and the
appropriate samples were collected at the proposed PHI.  The samples
were analyzed using an adequate analytical method and the sample storage
intervals are supported by the available storage stability data.  

The available field trial data support the use of up to four broadcast
foliar applications of cyfluthrin (EC) to grasses grown throughout the
U.S. at a maximum single application rate of 0.044 lb ai/A, with a
minimum RTI of 5 days, for a maximum of 0.178 lb ai/A/season.  The data
also support a 0-day PHI for cutting of both forage and hay.  The
available data support tolerances of 50 ppm on grass hay and 12 ppm on
grass forage. 

These field trial data also support the use of the WP formulation on
grass, as previous side-by-side tests on numerous crops using EC and WP
formulations of cyfluthrin have shown that use of the EC formulation
typically results in higher crop residues than use of the WP.  Also, in
accordance with an earlier Agency decision (2/2006), the current field
trial data for cyfluthrin (EC) support the use of beta-cyfluthrin at a
maximum of 0.022 lb ai/A/application for a total of 0.089 lb
ai/A/season.

Alfalfa

47144101.der

Bayer CropScience submitted crop field trials supporting the use of
cyfluthrin (EC) on alfalfa.    SEQ CHAPTER \h \r 1 The results from this
study are discussed below and summarized in Table 7.

TABLE 7.	Summary of Residue Data from Alfalfa Field Trials with
Cyfluthrin.

Commodity	Total Applic. Rate1

 (lb ai/A)	PHI

(days)	Residue Levels   (ppm) 2



	n	Min.	Max.	HAFT 3	Median

(STMdR)	Mean

(STMR)	Std. Dev.

Field Trial Data

Alfalfa Forage	0.087-0.091	5-8	96	0.011	5.882	5.65	1.495	1.792	1.1

Alfalfa Hay	0.087-0.091	5-8	94	1.802	16.494	15.27	4.172	4.734	2.4

1	Total application rate is for the two applications preceding each of
the four cuttings.

2	Half the limit of quantitation was used if the residue was less than
the LOQ.

3	HAFT = Highest Average Field Trial.

Twelve field trials were conducted to measure the magnitude of
cyfluthrin
[cyano(4-fluoro-3-phenoxyphenyl)methyl-3-(2,2-dichloroethenyl)-2,2-dimet
hylcyclopropane-carboxylate] residues in/on alfalfa following two foliar
spray applications of BAYTHROID 2E to alfalfa at a target rate of
0.044 lb ai/A/application (0.043 to 0.047 lb ai/A/application) prior
to each of four cuttings.  The interval between applications was 5 to 9
days.  BAYTHROID 2E is an emulsifiable concentrate formulation
containing 240 g ai/L (2.0 lb ai/gal).  For all trials, the first
application prior to each of the four cuttings (applications 1, 3, 5,
and 7) was made at BBCH growth stages 24 to 61 (BBCH 24:  four side
shoots visible; BBCH 61:  10% of flowers open or 10% of plants in bloom)
or when the plants were 12 to 15 inches in height.  There were no
adjuvants added to the spray mixture.  All applications were made using
ground-based equipment.

In each of the field trials, duplicate composite samples of both alfalfa
forage and hay were collected at each of four cuttings at commercial
maturity at a pre-harvest interval (PHI) of 5 to 8 days after the
application just preceding cutting (applications 2, 4, 6, and 8). 
Single composite samples of both alfalfa forage and hay were collected
at the first cutting from the control plots when the forage and hay were
at commercial maturity, 5 to 8 days following the last treatment to the
corresponding treated plot.

The residue of cyfluthrin was quantitated in alfalfa forage and hay by
gas chromatography/mass spectrometry (GC/MS) using a stable isotopically
labeled internal standard.  The limit of quantitation (LOQ) for
cyfluthrin residue was 0.01 ppm for both alfalfa forage and hay.

The registrant has submitted storage stability studies on several
different crops.  Residues were stable for at least 19 months in all of
these studies.  The alfalfa forage and hay analyzed in this study were
held in frozen storage for a maximum of 18 months prior to extraction.

The HAFT cyfluthrin residue was 5.65 ppm in/on alfalfa forage (37% dry
matter) for all cuttings at commercial maturity at a PHI of 6 days
(target PHI is 7 days).  The maximum cyfluthrin residue was 5.88 ppm
in/on alfalfa forage (37% dry matter) for all cuttings at commercial
maturity at a PHI of 6 days.  The HAFT cyfluthrin residue was 15.27 ppm
in/on alfalfa hay (74% dry matter) for all cuttings at commercial
maturity at a PHI of 7 days (target PHI is 7 days).  The maximum
cyfluthrin residue was 16.49 ppm in/on alfalfa hay (74% dry matter) for
all cuttings at commercial maturity at a PHI of 7 days.

Sugar Beets

47007809.der

Bayer submitted field trials depicting the use of cyfluthrin (1 lb/gal
suspoemulsion) as a seed treatment on sugar beets.    SEQ CHAPTER \h \r
1 The results from these trials are discussed below and summarized in
Table 8. 

Table 8.	Summary of Residue Data from Sugar Beet Field Trials with
Cyfluthrin (Suspo-Emulsion)

Crop matrix	Total Applic. 1 Rate (lb ai/A) 	DAP 2	Residue Levels (ppm) 3



	n	Min.	Max.	HAFT 4	Median (STMdR)	Mean (STMR)	Std. Dev.

Sugar beet (proposed use = 0.017 lb ai/100,000 seeds) 5

Roots	0.019-0.025	109-179	24	<0.01	0.088	0.049	0.01	0.01	0.018

Tops

	24	<0.01	<0.01	0.01	0.01	0.01	N/A

1	Use rate for cyfluthrin was 0.035 lb ai/100,000 seeds; field use rate
was calculated based on actual seeding rates.

2	DAP = days after planting; no PHI is proposed as the application is a
seed treatment.

3	The validated LOQ for cyfluthrin is 0.01 ppm in/on sugar beet roots
and tops, and the statistically calculated LOD is 0.003 ppm for both
roots and tops.    For calculating the median, mean, and standard
deviation, the LOQ was used for residue values of <LOQ.

4	HAFT = Highest Average Field Trial.

5	Proposed use rate is for beta-cyfluthrin, and is equivalent to
0.009-0.012 lb ai/A.

Twelve sugar beet field trials were conducted in Zones 5, 7, 8, 9, 10,
and 11 during 2004.  For each test, sugar beet seeds were treated using
a commercial Hege 11 Seed Treater with a suspoemulsion formulation
containing both cyfluthrin (1 lb/gal) and clothianidin (4 lb/gal). 
Seeds were treated at a rate equivalent to 0.035 lb of cyfluthrin per
100,000 seeds.  Based on the actual seeding rates used in the field
trials (52,870-71,320 seeds/A), this rate was equivalent to 0.019-0.025
lb ai cyfluthrin/A.  Single control and duplicate treated samples of
sugar beet roots and tops were harvested from each trial at the earliest
possible commercial maturity, 109-179 DAP.  Samples were stored frozen
for up to 13.5 months prior to analysis, an interval supported by
available storage stability data.

Bayer Method 108139-1 (GC/MS), which was used to determine cyfluthrin
residues in/on sugar beet roots and tops, was adequately validated in
conjunction with the analysis of field trial samples.  The validated LOQ
for cyfluthrin residues is 0.01 ppm in/on both roots and tops, and the
calculated LOD is 0.003 ppm for both matrices.

Following a seed treatment with cyfluthrin (suspoemulsion) at 0.035 lb
ai/100,000 seeds, cyfluthrin residues at normal crop maturity were
non-detectable (<0.003 ppm) in/on all 24 samples of sugar beet tops and
<0.003-0.088 ppm in/on 24 samples of sugar beet roots.  Only 3 out of 24
root samples had residues above the LOQ of 0.01 ppm (0.01, 0.025, and
0.088 ppm).  Average residues were 0.01 ppm in/on tops and roots, and
the HAFT residues were 0.049 ppm for roots and 0.01 ppm for tops.  Sugar
beet tops are no longer a regulated feedstuff (revised Table 1, memo
10/2006). 

Conclusions.  The available field trial data are adequate.  The number
and geographic distribution of the field trials are adequate, and the
appropriate samples were collected at normal crop maturity.  The samples
were analyzed using an adequate analytical method and the sample storage
intervals are supported by the available storage stability data.  The
available data support the use of cyfluthrin (suspoemulsion) as a seed
treatment for sugar beets at a rate of 0.035 lb ai/100,000 seeds, or the
use of beta-cyfluthrin at a rate of 0.017 lb ai/100,000 seeds.  The
residue data on roots support a tolerance of 0.10 ppm.  For both roots
and tops, most of the field trial values were below the LOQ.  As a
result, HED’s statistical tolerance generator was not used to
determine tolerances.

Cereal Grains Except Rice (Crop Group 15)

A tolerance of 4.0 ppm is currently in effect for the Cereal Grain Crop
Group (Group 15).  This tolerance covers residues resulting from stored
grain uses as well as from foliar applications.  In 2004, HED
recommended that the stored grain uses be cancelled (Memo, D290921, Y.
Donovan, 12/16/2004).  As it would take time for the products used on
stored grains to clear the channels of trade, HED recommended that RD
not cancel the registrations for the stored grains uses until the
products had cleard the channels of trade (Memo, D321638, Y. Donovan,
7/15/2005).  HED has reviewed field trial data for foliar applications
to wheat, field corn, sweet corn, and sorghum. The reviews were prepared
between 1989 and 2004.

Field trial data for foliar applications to wheat were submitted and
reviewed in the memorandum D290921 of Y. Donovan (12/16/2004).  In this
memorandum, HED recommended that the cereal grain crop group tolerance
of 4.0 ppm be revoked and that a tolerance of 0.2 ppm be established for
wheat grain.  HED currently uses a statistical tolerance generator to
determine recommended tolerances.  The statistically generated tolerance
for wheat grain is 0.15 ppm.  As a result, HED recommends that the wheat
grain tolerance be established at 0.15 ppm rather than 0.2 ppm.  This
0.15 ppm tolerance should be extended to the following cereal grains: 
barley, buckwheat, millet, oats, and rye.  

Field trial data for field corn have been submitted and reviewed. 
Cyfluthrin is registered for use on field corn for at-planting soil
applications (Memo, D171140, M. Nelson, 3/8/93) as well as for foliar
applications (Memo, D250002, Y. Donovan, 8/15/2002).  It was concluded
that the existing corn grain tolerance of 0.01 ppm was adequate to cover
the existing at-planting use plus the proposed foliar uses.  In 2002,
HED did not recommend harmonizing the field corn grain tolerance with
the Codex MRL of 0.05 ppm because a tolerance of 4.0 ppm was pending as
a result of the stored grain use.  The stored grain registrations have
been cancelled, however.  As a result, HED now recommends that the field
corn grain tolerance be harmonized with the Codex MRL.  Therefore, HED
recommends in favor of a tolerance of 0.05 ppm for field corn grain. 
The recommended tolerances for animal feed items associated with field
corn are discussed in the following section, Forage, Fodder, and Straw
of Cereal Grains Group (Crop Group 16).

Field trial data for sweet corn were evaluated in HED reviews prepared
by H. Fonouni (11/17/89) and J. Garbus (D198397, 5/26/95).  A tolerance
of 0.05 ppm was established for sweet corn, kernel plus cob with husks
removed.  This tolerance is currently in effect and is equivalent to the
Codex MRL of 0.05 ppm for maize.  HED recommends that this tolerance
remain in effect.  Tolerances are also in effect for sweet corn forage
and stover.  HED’s recommendations concerning these tolerances are
discussed in the following section, Forage, Fodder, and Straw of Cereal
Grains Group (Crop Group 16).

In 1996, HED recommended in favor of a tolerance of 4.0 ppm for residues
in sorghum grain resulting from foliar applications (Memo, D220494, G.
Otakie, 3/5/96).  In 2004, HED recommended that the sorghum grain
tolerance be re-established based on its pre-harvest uses (D290921, Y.
Donovan, 12/16/2004).  This tolerance is equivalent to the cereal grain
crop group tolerance being cancelled, i.e., 4.0 ppm.  It is the current
policy of HED to recommend tolerances that are generated using HED’s
“Guidance for Setting Pesticide Tolerances Based on Field Trial
Data.”  The recommended tolerance for sorghum grain based on this
guidance is 3.5 ppm.  The recommended tolerances for animal feed items
associated with sorghum are discussed in the following section, Forage,
Fodder, and Straw of Cereal Grains Group (Crop Group 16).

Rice is a member of the cereal grains crop group.  As the 4.0 ppm
tolerance resulting from the stored grain use is being revoked, a
tolerance for rice grain will no longer be in effect.  There are no
registrations for foliar application of cyfluthrin to rice.

 

Forage, Fodder, and Straw of Cereal Grains Group Except Rice (Crop Group
16)

Field trial data have been submitted for wheat forage, fodder, and straw
(D290925, Y. Donovan, 12/16/2004), field corn forage and fodder
(D250002, Y. Donovan, 8/15/2002), sweet corn forage and stover (H.
Fonouni, 11/17/89 and J. Garbus, D198397, 5/26/95), and sorghum forage
and stover (D220494, G. Otakie, 3/5/96).  The data were reviewed in the
specified memos and deemed to be adequate.  Tolerances were established
based on these data and these tolerances are currently in effect.  These
tolerances include the following:  wheat forage (5.0 ppm), wheat hay
(6.0 ppm), wheat straw (6.0 ppm), field corn forage (3.0 ppm), field
corn stover (6.0 ppm), popcorn stover (6.0 ppm), sweet corn forage (15
ppm), sweet corn stover (30 ppm), sorghum grain forage (2.0 ppm), and
sorghum grain stover (5.0 ppm).  The registrant has requested tolerances
for Crop Group 16, the Forage, Fodder, and Hay of the Cereal Grains
(Except Rice) Group.  The registrant proposed one tolerance for the
entire crop group, 7.0 ppm.

Forage

Forage field trial data are available for wheat, field corn, sweet corn,
and sorghum.  The individual field trial values that were obtained for
the forage of each commodity were entered into HED’s statistical
tolerance generator to determine what the recommended tolerance for each
one would be.  These tolerances are as follows:  wheat (4.0 ppm), field
corn (3.0 ppm), sweet corn (25 ppm), and sorghum (4.0 ppm).  The highest
of these four values is that for sweet corn, 25 ppm.  Forage data were
collected in 1988 (MRID 41001607) and 1990 (MRID 42864604).  The values
that were obtained are as follows (in ppm, ascending order):  2.97,
3.04, 3.08, 3.73, 6.54, 6.84, 7.50, 7.71, 7.73, 8.59, 9.89, 10.5, 11.6,
12.0, 13.6, and 53.2.  J. Garbus, in his memo, D198397 (5/26/95), stated
that HED considered the 53.2 ppm value to be aberrant.  HED recommended
in favor of a tolerance of 15 ppm for sweet corn forage and this
tolerance is still in effect.  The mean of the forage field trial values
(including the 53.2 ppm value) is 10.5 ppm with a standard deviation of
11.9.  The high value is 3.6 standard deviations from the mean. 
Therefore, HED is in agreement with the previous determination that the
value is aberrant.  When the remaining 15 field trial values were
entered into HED’s statistical tolerance generator, the recommended
tolerance that was obtained was 25 ppm.  As a result, the recommended
tolerance for the forage of the Cereal Grains Crop Group (Except Rice)
is 25 ppm.  Although residues differ by more than 5x among the forages,
HED considers a crop group tolerance to be appropriate, as only
livestock feeds are involved.    

Stover

Stover field trial data are available for field corn, sweet corn, and
sorghum.  The individual field trial values that were obtained for the
stover of each commodity were entered into HED’s statistical tolerance
generator to determine what the recommended tolerance for each one would
be.  These recommended tolerances are as follows:  field corn (3.5 ppm),
sweet corn (30 ppm), and sorghum (3.5 ppm).  The highest of these four
values is that for sweet corn, 30 ppm.  As a result, the recommended
tolerance for the stover of the Cereal Grains Crop Group Except Rice is
30 ppm.  A tolerance of 30 ppm is currently in effect for sweet corn
stover.  This tolerance should be extended to the stover of the other
cereal grains (except rice).    

Hay

The only commodity for which hay field trial data are available is wheat
(D290921, Y. Donovan, 12/16/2004).  The recommended tolerance for hay
was determined using HED’s statistical tolerance generator.  This
tolerance is 6.0 ppm and should be applied to the hay of the Cereal
Grains Crop Group Except Rice.  

Straw

The only commodity for which straw field trial data are available is
wheat (D290921, Y. Donovan, 12/16/2004).  The recommended tolerance for
straw was determined using HED’s statistical tolerance generator. 
This tolerance is 7.0 ppm and should be applied to the straw of the
Cereal Grains Crop Group Except Rice.

As crop group tolerances are being established for the forage, stover,
hay, and straw of the cereal grains commodities, the individual
tolerances that are currently in effect should be revoked.  These
tolerances include the following:  wheat forage (5.0 ppm), wheat hay
(6.0 ppm), wheat straw (6.0 ppm), field corn forage (3.0 ppm), field
corn stover (6.0 ppm), popcorn stover (6.0 ppm), sweet corn forage (15
ppm), sweet corn stover (30 ppm), sorghum grain forage (2.0 ppm), and
sorghum grain stover (5.0 ppm).  

860.1520 Processed Food and Feed

Grass

There are no regulated processed commodities associated with grass.

Sugar Beets

47007810.der

For the sugar beet processing study, sugar beet seeds were treated with
a suspoemulsion formulation containing both cyfluthrin (1 lb/gal) and
clothianidin (4 lb/gal), and the treated seeds were planted at a field
site in Minnesota during 2004.  The application rate for cyfluthrin was
0.176 lb ai/100,000 seeds (5x rate), which is equivalent to 0.094 lb
ai/A based on the actual seeding rate used at the field site (52,900
seeds/A).  Single bulk control and treated samples of sugar beet roots
were harvested at normal commercial maturity, 147 DAP, and placed in
frozen storage.  After approximately 13 months of storage, roots were
processed into molasses, refined sugar, and dried pulp using simulated
commercial procedures.  Root samples were stored frozen for
approximately 13 months prior to analysis, and the frozen processed
commodities were analyzed within 1 month of collection.  These storage
intervals are supported by the available storage stability data.

Bayer Method 108139-1 (GC/MS), which was used to determine cyfluthrin
residues in/on sugar beet roots and processed fractions, was adequately
validated in conjunction with the analysis of processing study samples. 
The validated LOQ for cyfluthrin residues is 0.01 ppm in/on roots and
all processed fractions, and the statistically calculated LODs are 0.003
ppm in roots and 0.0011-0.0018 ppm in sugar beet processed fractions.

Following the seed treatment (5x cyfluthrin rate), cyfluthrin residues
in/on sugar beet roots (RAC) at commercial maturity were 0.0054 ppm,
which is below the LOQ, but above the LOD.  Residues were not detected
in refined sugar (<0.0018 ppm) and molasses (<0.0011 ppm), but were
quantifiable in dried pulp (0.064 ppm).

eet processing study is adequate.  Using all values ≥LOD for each
commodity, the processing factors were calculated to be <0.3x for
refined sugar, <0.2x for molasses, and 12x for dried pulp.

Cereal Grains Crop Group Except Rice

In 2004, HED recommended in favor of a tolerance of 0.5 ppm for wheat
bran.  That tolerance was based on the highest average field trial value
(HAFT) of 0.17 ppm and a concentration factor of 1.6x.  The recommended
tolerance was 0.5 ppm.  A tolerance of 6.5 ppm was in effect because of
the stored grains use.  As the stored grains use has been cancelled, HED
recommends that the current tolerance of 6.5 ppm for wheat bran be
revoked and that the previously recommended tolerance of 0.5 ppm be
established.

An acceptable field corn processing study was submitted and reviewed by
Y. Donovan (D250002, 8/15/2002).  Residues of cyfluthrin were below the
LOQ of 0.01 ppm in all six samples of grain treated at 5.7x the proposed
application rate.  Residues were not measured in the processed
commodities.  It was concluded that residues in processed commodities
would not exceed 0.01 ppm.  The current corn oil tolerance of 30 ppm was
established in conjunction with the stored grains uses.  As the stored
grain uses have been cancelled, the field corn refined oil tolerance
should be revoked.  The corn grain tolerance of 0.05 ppm will be high
enough to cover residues in field corn, refined oil.

Tolerances are currently in effect for rice bran (6.0 ppm) and hulls (18
ppm).  Rice is a member of the cereal grains crop group.  The bran and
hulls tolerances result from the stored grains use.  As the 4.0 ppm
tolerance resulting from the stored grain use is being revoked, the
tolerances for rice bran and hulls should also be revoked.  There are no
registrations for foliar application of cyfluthrin to rice.

  SEQ CHAPTER \h \r 1 860.1650 Submittal of Analytical Reference
Standards

Analytical reference standards for both cyfluthrin and beta-cyfluthrin
are available at the EPA National Pesticide Standards Repository.

860.1850/860.1900 Confined and Field Accumulation in Rotational Crops

Rotational crop data supporting planting as soon as practical were
reviewed by EFED in 1989/1990 based on correspondence provided by RD. 
Although there were questions about storage stability of residues in
wheat forage, the registrant provided information on stored potato and
soybean leaves to resolve the issue.  In a letter from George LaRocca
(RD) to Mobay Chemical Corporation dated 5/9/90, the labeling bearing
the proposed rotational crop statement (i.e., planting as soon as
practical) was accepted.  Pyrethroids show very little uptake of the
parent compounds into rotational crops.  Cyfluthrin’s plantback
interval, “as soon as practical,” is consistent with that of the
other pyrethroids.

Because of the presence of clothianidin in the proposed MAI formulation,
the rotational crop restrictions on the proposed label are actually more
restrictive than those on the labels for products containing only
cyfluthrin or beta-cyfluthrin.  Therefore, the proposed rotational crop
restrictions are adequate to cover the beta-cyfluthrin component of the
MAI. 

860.1550 Proposed Tolerances

HED has determined that cyfluthrin per se is the residue of concern for
both tolerance enforcement and risk assessment.  Permanent tolerances
are established for residues of cyfluthrin in/on a wide variety of plant
commodities at levels ranging from 0.01 ppm in/on peanuts, tree nuts,
and tuberous and corm vegetables to 600 ppm in/on aspirated grain
fractions (40 CFR §180.436(a)(1)).  Cyfluthrin tolerances on animal
commodities are established at levels ranging from 0.01 ppm in eggs and
poultry fat, meat, and meat byproducts to 30 ppm in milk fat.  In
addition, a tolerance of 0.05 ppm is established for cyfluthrin in
animal feeds and processed foods as a result of its use in food- and
feed-handling establishments (40 CFR §180.436(a)(2) and (a)(3)). 
Permanent tolerances with a regional registration have also been
established for cyfluthrin at 6 ppm in/on grass forage and 8 ppm in/on
grass hay (40 CFR §180.436(c)).  The tolerances for cyfluthrin also
cover similar uses of beta-cyfluthrin, although HED now recommends that
a separate section be established for the beta-cyfluthrin tolerances.   
SEQ CHAPTER \h \r 1 The tolerances proposed for grass forage and hay by
the petitioner are listed in Table 9, along with the Agency’s
recommended tolerance levels. 

The recommended tolerance levels for grass forage and hay were
determined using recent Agency Guidance (Guidance for Setting Pesticide
Tolerances Based on Field Trial Data SOP), as residues in all samples of
forage and hay were above the LOQ.  The appropriate tolerances for grass
forage and hay were determined to be 12 and 50 ppm, respectively
(Attachment 2).

The recommended tolerance levels for alfalfa forage and hay were also
determined using recent Agency Guidance (Guidance for Setting Pesticide
Tolerances Based on Field Trial Data SOP), as residues in all samples of
forage and hay were above the LOQ.  The appropriate tolerances for
alfalfa forage and hay were determined to be 5.0 and 13 ppm,
respectively (Attachment 2).

As the majority of the sugar beet root samples (21 out of 24) had
residues <LOQ, HED’s statistical tolerance generator was not used to
determine the recommended tolerance.  The recommended tolerance of 0.10
ppm for roots is based on the maximum residues detected in roots (0.088
ppm).  No tolerance is required for sugar beet tops, as sugar beet tops
are no longer a regulated livestock feedstuff.  The results from the
sugar beet processing study indicate that separate tolerances are not
required for sugar and molasses, as cyfluthrin residues did not
concentrate in these fractions.  However, cyfluthrin residues
concentrated by 12x in dried pulp.  Based on HAFT residues of 0.049 ppm
in roots and the 12x processing factor, the maximum expected residues in
dried pulp would be 0.59 ppm, which supports a tolerance of 1.0 ppm for
dried pulp.

Bayer proposed a tolerance of 4.0 ppm for the Cereal Grains Crop Group,
Except Rice (Crop Group 15).  This tolerance is equivalent to the
tolerance that was established based on the stored grains uses.  The
stored grains registrations have been cancelled, however.  Because of
differences in field trial values and harmonization with Codex MRLs,
different tolerances are being recommended for the different cereal
grains.  A tolerance of 0.15 is being recommended for the grain of
wheat, barley, oats, buckwheat, rye, and millet.  In order to harmonize
with the Codex MRL for maize, a tolerance of 0.05 ppm is being
recommended for field corn grain and for sweet corn, kernel plus cob
with husks removed.  A tolerance of 4.0 ppm is being recommended for
sorghum, grain.

Bayer proposed a tolerance of 7.0 ppm for the Forage, Fodder, and Straw
of the Cereal Grains Crop Group, Except Rice (Crop Group 16).  Forage
data are available for wheat, field corn, sweet corn, and sorghum.  The
data set for each commodity was entered into HED’s statistical
tolerance generator.  The highest of these tolerances is that for sweet
corn, 25 ppm.  As a result, the recommended tolerance for the Forage of
the Cereal Grains Crop Group, except Rice, is 25 ppm.  The term fodder
has been replaced with the term stover.  Stover data are available for
field corn, sweet corn, and sorghum.  The data set for each commodity
was entered into HED’s statistical tolerance generator.  The highest
of these tolerances is that for sweet corn, 30 ppm.  As a result, the
recommended tolerance for the Stover of the Cereal Grains Crop Group,
except Rice, is 30 ppm.  Straw data are available for wheat only. 
HED’s statistical tolerance generator was used to calculate the
recommended tolerance for straw which was determined to be 7.0 ppm.  As
a result, the recommended tolerance for the Straw of the Cereal Grains
Crop Group, except Rice, is 7.0 ppm.  Hay data are also available for
wheat only.  HED’s statistical tolerance generator was used to
calculate the recommended tolerance for hay which was determined to be
6.0 ppm.  As a result, the recommended tolerance for the Hay of the
Cereal Grains Crop Group, except Rice, is 6.0 ppm.   

Considering the recommended changes in tolerances for grain commodities,
the new tolerances for grass forage and hay, and recent regulatory
changes in calculating livestock diets, the MDB for cyfluthrin residues
was recalculated to be 20.9 ppm for beef cattle, 27.1 ppm for dairy
cattle, and 3.21 ppm for swine and poultry.  As the calculated dietary
exposure of poultry has not changed from earlier reviews, no changes in
the current tolerances on eggs and poultry tissues are required. 
However, tolerances of other livestock commodities were reassessed based
on the substantial reductions in the MDBs for cattle and swine.

Based on the calculated MDBs for beef cattle (20.9 ppm), dairy cattle
(27.1 ppm) and swine (3.21 ppm) and the residue data from the adequate
cattle feeding study, tolerances on milk, cattle, goat, hog, horse, and
sheep commodities can be substantially reduced.  The available data
support reducing the current livestock tolerances to 0.2 ppm for milk,
5.0 ppm for milk fat, 0.10 ppm for meat and meat byproducts of cattle,
0.05 ppm for meat and meat byproducts of goats, horses, and sheep, 2.0
ppm for fat of cattle, goats, horses, and sheep, 0.01 ppm for meat and
meat byproducts of hogs, and 0.5 ppm for fat of hogs.

With regard to international MRLs for cyfluthrin, harmonization of the
proposed tolerances is not an issue for grass forage, grass hay, sugar
beet roots, and sugar beet dried pulp, as there are no established for
proposed Canadian, Mexican or Codex MRLs for cyfluthrin residues on
grass or sugar beet commodities (See Attachment 1).

The recommended tolerances in Table 9 should be established for both
cyfluthrin and beta-cyfluthrin.

Table 9. 	Tolerance Summary for Cyfluthrin.

Commodity	Established Tolerance (ppm)	Proposed Tolerance (ppm)
Recommended Tolerance (ppm)	Comments; Correct Commodity Definition

Grass, forage, fodder and hay, group 17, forage	6.0 1	13.0	12	Adequate
grass field trial data are available.



Grass, forage, fodder and hay, group 17, hay	8.0 1	40.0	50

	Alfalfa, forage	-	5.0	5.0	Adequate alfalfa field trial data are
available.



Alfalfa, hay	10.0	15.0	13

	Beet, sugar, roots	-	0.09	0.10	Adequate field trial data are available

Beet, sugar, dried pulp	-	11	1.0	Maximum expected residues are 0.59 ppm
based on HAFT residues of 0.049 ppm and a 12x processing factor for
dried pulp.

Grain, cereal; Crop Group 15 (except Rice)	4.0	4.0	0.15	Wheat grain,
barley grain, buckwheat grain, millet grain, oat grain, rye grain

Grain, cereal; Crop Group 15 (except Rice)	4.0	4.0	0.05	Corn, field,
grain

Grain, cereal; Crop Group 15 (except Rice)	4.0	4.0	0.05	Corn, sweet,
kernel plus cob with husks removed

Grain, cereal; Crop Group 15 (except Rice)	4.0	4.0	3.5	Sorghum, grain,
grain

Wheat, bran	6.5	-	0.5	Stored grain uses have been revoked

Corn, field, refined oil	30.0	-	-	The field corn, grain tolerance will
cover residues in corn oil

Rice, bran	6.0	-	-	Stored grain uses have been revoked

Rice, hulls	18.0	-	-	Stored grain uses have been revoked

Grain, cereal, forage, fodder and straw, Crop Group 16 (except Rice)	-2
7.0	25	Grain, cereal, forage, fodder, and hay, group 17, forage, except
Rice

Grain, cereal, forage, fodder and straw, Crop Group 16 (except Rice)	- 3
7.0	30	Grain, cereal, forage, fodder, and hay, group 17, stover, except
Rice

Grain, cereal, forage, fodder and straw, Crop Group 16 (except Rice)	- 4
7.0	7.0	Grain, cereal, forage, fodder, and hay, group 17, straw, except
Rice

Grain, cereal, forage, fodder and straw, Crop Group 16 (except Rice)	- 5
7.0	6.0	Grain, cereal, forage, fodder, and hay, group 17, hay, except
Rice

Wheat, forage	5.0	-	-	Crop group tolerance is being established for
Forage of Grain, Cereal, except Rice (Crop Group 16)

Corn, field, forage	3.0	-	-

	Corn, sweet, forage	15	-	-

	Sorghum, grain, forage	2.0	-	-

	Corn, field, stover	6.0	-	-	Crop group tolerance is being established
for Stover of Grain, Cereal, except Rice (Crop Group 16)

Corn, pop, stover	6.0	-	-

	Corn, sweet, stover	30.0	-	-

	Sorghum, grain, stover	5.0	-	-

	

Wheat, hay	6.0	-	-	Crop group tolerance is being established for Hay of
Grain, Cereal, except Rice (Crop Group 16)

Wheat, straw	6.0	-	-	Crop group tolerance is being established for Straw
of Grain, Cereal, except Rice (Crop Group 16)

Cattle, fat	10	NA	2.0	Based on the recalculated MDBs for beef cattle
(20.9 ppm), dairy cattle (27.1 ppm) and swine (3.21 ppm) and the residue
data from the available cattle feeding study, tolerances for livestock
commodities can be substantially reduced.

Cattle, meat	0.4	NA	0.10

	Cattle, meat byproducts	0.4	NA	0.10

	Goat, fat	10	NA	2.0

	Goat, meat	0.4	NA	0.05

	Goat, meat byproducts	0.4	NA	0.05

	Hog, fat	10	NA	0.5

	Hog, meat	0.4	NA	0.01

	Hog, meat byproducts	0.4	NA	0.01

	Horse, fat	10	NA	2.0

	Horse, meat	0.4	NA	0.05

	Horse, meat byproducts	0.4	NA	0.05

	Milk	1.0	NA	0.2

	Milk, fat	30	NA	5.0

	Sheep, fat	10	NA	2.0

	Sheep, meat	0.4	NA	0.05

	Sheep, meat byproducts	0.4	NA	0.05

	

NA = not applicable

1 Regionally restricted tolerances for grass grown in CA, OR, ID and WA.

2 Forage tolerances are established for wheat (5.0 ppm), field corn (3.0
ppm), sweet corn (15 ppm), and sorghum (2.0 ppm)

3 Stover tolerances are established for field corn (6.0 ppm), popcorn
(6.0 ppm), sweet corn (30 ppm), and sorghum (5.0 ppm)

4 A Straw tolerance is established for wheat (6.0 ppm)

5 A hay tolerance is established for wheat (6.0 ppm)

.

References

CB Nos.:  5039-5041 and 5242-5243, PP# 9F3731/9H5574.  Baythroid ®
(Cyfluthrin) in/on Various Raw and Processed Agricultural Commodities. 
Evaluation of Analytical Methodology and Residue Data, H. Fonouni,
11/17/89.

D198397 and D198399, PPs# 3F4309/3H5686, Cyfluthrin in/on Alfalfa,
Sunflowers, Sweet Corn and Soybeans.  Evaluation of Analytical Methods
and of Residue Data, J. Garbus, 5/25/95.

D216660, D216662, D220082 and D220083, PP#5F4475/5H5717: EPA Reg. No.
3125-XXX. (TEMPO 2E) Cyfluthrin (Chemical No.128831) in/on Stored Cereal
Grains and Aspirated Grain Fractions. Evaluation of Analytical Methods
and of Residue Data, J. Garbus, 3/17/96.

D290921,   SEQ CHAPTER \h \r 1 Cyfluthrin.  Petitions for Tolerances on
Various Crops and Crop Groups.  Summary of Analytical Chemistry and
Residue Data.  Petition Numbers: 2F6445, 2F6479, 1F6290, 1E6318, 3E6583,
and 3E6776, Y. Donovan, 12/6/04.

D321638,   SEQ CHAPTER \h \r 1 Cyfluthrin.  Addendum to HED’s Memo of
12/16/04, D290921, “Summary of Analytical Chemistry and Residue Data. 
Petition Numbers: 2F6445, 2F6479, 1F6290, 1E6318, 3E6583, and 3E6776,”
Y. Donovan, 12/16/04.

  SEQ CHAPTER \h \r 1 Attachments:  

Attachment 1 - International Residue Limit Status Sheet

Attachment 2 - Tolerance Assessment Calculations

Attachment 1.  International Residue Limit Status Sheet

INTERNATIONAL RESIDUE LIMIT STATUS

Chemical Name: cyano(4-fluoro-3-phenoxyphenyl) methyl 3-(2,2-dichloro
ethenyl)-2,2-dimethyl cyclopropane- carboxylate	Common Name: Cyfluthrin
X Proposed tolerance

 Reevaluated tolerance

 Other	Date: 4/05/07

Codex Status (Maximum Residue Limits)	U. S. Tolerances

 No Codex proposal step 6 or above

X No Codex proposal step 6 or above for the crops requested 	Petition
Number: 6E7058

DP Number: 331951

 No Limits

X No Limits for the crops requested	 No Limits

X No Limits for the crops requested

Residue definition: Cyfluthrin	Residue definition:  Cyflutrin

Crop(s)	MRL (mg/kg)	Crop(s)	MRL (mg/kg)

Milk, fat	15	Algodonero (cotton)	0.50

Fat of cattle, goats, hogs, horses, poultry and sheep	5	Chile (peppers)
0.5

Milk	0.5	Jitomate (tomatoes)	0.2

Meat and meat by-products of cattle, goats, hogs, horses, poultry and
sheep	0.4	Maiz (corn)	0.01

Eggs	0.01	Papa (potatoes)	0.1



Soya (soybeans)	0.1

Notes/Special Instructions:





Attachment 2.  Tolerance Assessment Calculations.

The Agency’s Guidance for Setting Pesticide Tolerances Based on Field
Trial Data was utilized for determining appropriate tolerance levels on
grass forage and hay as well as most of the cereal grain commodities. 
The datasets used to establish tolerances for cyfluthrin residues on
grass and cereal grain commodities consist of field trial data
representing applications of the appropriate formulations at
approximately 1x the maximum proposed use rates.  As specified by the
Guidance for Setting Pesticide Tolerances Based on Field Trial Data SOP,
the field trial application rates were within 25% of the maximum label
application rate, and the PHIs are consistent with the appropriate stage
of maturity and the proposed PHIs for each commodity.  The residue
values used to calculate the tolerances are provided in Tables II-1 and
II-2

The application rates to grass, alfalfa, and cereal grains were 1x the
maximum proposed use rate for cyfluthrin.  The application rates for
cyfluthrin are twice as high as the application rates for
beta-cyfluthrin.  The tolerance levels for cyfluthrin apply to
beta-cyfluthrin as well.

Most of the field and sweet corn grain field trial samples had residues
that were below the LOQ of 0.01 ppm.  The sweet corn data were submitted
in MRID 41001607, “Baythroid – Magnitude of the Residue on Sweet
Corn and Sweet Corn Processed Products,” 1988.  Thirteen samples of
kernel plus cobs with husks removed were analyzed.  Eleven of these
samples had residues that were below the LOQ.  Of the other two samples,
one had a residue value of 0.01 ppm and the other had a residue value of
0.02 ppm.  Field corn data were submitted in MRID 44629605, “Baythroid
2 – Magnitude of the Residues in Field Corn, Lab Project No.:
BD19CO05/108115,” 1998.  Sixty-eight samples were analyzed and
residues were below the LOQ in all 68.  As a result, the tolerance
spreadsheet was not used to determine the recommended tolerance.  For
field corn grain and sweet corn, kernel plus cob with husks removed, the
recommended tolerance was harmonized with the Codex MRL for maize of
0.05 ppm.

 



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昀Ĵ瑹㞂@咊ЀCrop:	Grass Forage	Grass Hay

PHI:	0 days

App. Rate:	0.172-0.181 lb ai/A	0.173-0.180 lb ai/A

Submitter:	IR-4

MRID Citation:	MRID 4795801

	Residues	Residues

	6.01	22.1

	9.02	25.1

	5.92	18.8

	6.23	24.1

	5.43	12.6

	10.4	33.1

	3.82	10.1

	8.03	15.3

	5.85	12.8

	8.7	26.8

	4.36	15.6

	3.79	6.3

	6.55	21.7

	8.57	28.9

	5.96	18.2

	6.51	24

	4.99	12.6

	8.38	30.7

	5	11

	9.33	15.3

	6.03	15

	6.71	10.6

	5.77	15.4

	5.72	7.98





Table II – 2.  Field Trial Values

Wheat Grain

(ppm)	Wheat Hay

(ppm)	Wheat Straw

(ppm)	Sorghum Grain

(ppm)	Sweet Corn Forage

(ppm)	Sweet Corn Stover

(ppm)

0.046	2.29	2.18	0.77	6.54	1.67

0.062	2.60	4.99	0.30	11.6	2.11

0.019	2.48	3.98	3.48	3.73	1.90

0.028	3.29	3.40	0.22	9.89	4.96

0.026	1.88	1.60	0.07	13.6	5.61

0.034	2.23	1.55	0.38	7.5	0.53

0.058	2.82	2.28	0.13	3.08	3.64

0.058	2.14	1.01

8.59	1.42

0.024	1.76	1.02

6.84	21.6

0.022	1.98	0.87

12.0	28.4

0.092	3.81	0.93

10.5	22.6

0.082	2.87	0.96

7.71

	0.033	3.52	0.59



	0.039	5.72	0.54



	0.155	2.24	1.64



	0.180	2.48	1.94



	0.040	2.65	0.91



	0.040	2.84	0.88



	0.026	2.79	1.21



	0.024	3.10	2.07



	0.074	2.10	0.61



	0.096	2.03	0.63



	0.017	2.49	1.55



	0.011	3.12	1.63



	0.014	2.86	1.12



	0.017	4.14	1.15



	0.047	3.22	1.88



	0.068	2.76	2.03



	0.058	3.96	1.59



	0.050	3.50	1.18



	0.025	2.69	5.08



	0.029	2.89	4.38



	0.027	3.90	1.19



	0.023	4.44	1.02



	0.087	2.66	3.68



	0.094	2.85	3.44



	0.049	1.59	2.29



	0.029	1.48	2.26



	0.035	1.53	1.32



	0.037	1.64	2.04



	



Table II – 2.  Field Trial Values

Sugar Beet Roots (ppm)	Sugar Beet Tops (ppm)	Alfalfa Forage

(ppm)	Alfalfa Forage

Cont’d. (ppm)	Alfalfa Hay

(ppm)	Alfalfa Hay

Cont’d. (ppm)

<0.003	<0.003	1.340	1.835	4.374	5.954

0.009	<0.003	0.930	1.988	4.854	5.926

0.004	<0.003	2.588	2.438	5.033	5.994

0.004	<0.003	2.119	2.260	5.696	5.429

<0.003	<0.003	1.492	2.324	5.890	16.494

0.003	<0.003	1.327	2.456	5.235	14.055

0.009	<0.003	2.752	4.412	4.506	4.220

0.025	<0.003	1.839	4.605	3.893	4.001

0.009	<0.003	1.509	1.194	4.373	4.238

0.009	<0.003	1.574	1.202	4.178	4.651

0.010	<0.003	1.095	2.465	2.507	1.993

0.088	<0.003	1.077	2.096	2.588	2.425

0.005	<0.003	0.647	0.917	1.802	3.321

<0.003	<0.003	0.614	1.251	2.114	3.485

<0.003	<0.003	1.060	1.858	2.522	4.182

0.006	<0.003	1.487	1.856	2.513	3.778

0.013	<0.003	0.710	1.468	5.513	3.657

0.003	<0.003	0.609	1.256	5.120	4.081

<0.003	<0.003	4.650	1.588	4.277	3.797

<0.003	<0.003	5.434	2.114	3.502	3.910

<0.003	<0.003	0.389	1.498	13.034	3.740

<0.003	<0.003	0.011	1.551	11.321	4.101

0.004	<0.003	5.882	1.296	3.362	5.412

<0.003	<0.003	5.412	1.270	3.922	4.933



1.206	1.266	4.714	3.711



1.052	1.263	4.566	3.557



1.732	1.074	3.289	6.958



1.684	1.187	3.645	6.943



1.151	2.492	6.688	10.543



1.211	2.529	6.612	10.660



2.569	3.714	3.637	4.166



2.129	3.396	3.161	3.915



1.098	1.468	4.111	4.715



1.114	1.491	4.006	4.644



1.648	1.254	2.351	3.760



1.220	1.658	2.664	3.786



0.903	1.732	2.068	5.216



1.233	1.483	2.162	5.117



0.682	2.002	5.605	4.502



0.543	1.913	5.676	4.551



1.743	2.257	4.768	3.556



1.884	2.519	4.772	3.569



1.722	1.351	3.590	2.871



1.559	1.421	3.991	3.177



1.225	1.054	4.402	5.166



1.292	1.329	3.646	6.110



1.429	2.816	3.954



	1.539	1.992	3.800

	

Cyfluthrin and beta-Cyfluthrin	Summary of Analytical Chemistry and
Residue Data	Barcode:  D339413

 PAGE   

Page  PAGE   2  of   NUMPAGES  34 

Cyfluthrin and beta-Cyfluthrin	Summary of Analytical Chemistry and
Residue Data	Barcode:  D339413

Page  PAGE   34  of   NUMPAGES  34 

