UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

DEC 08 2011 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

MEMORANDUM 

SUBJECT: 

FROM: 

THRU: 

BEAD Case Level Chemical Profile for Registration Review: 

Cypermethrin (109702) and Zeta-Cypermethrin (129064) 

David Brassard, Senior Entomologist 

Donald Atwood, Ph.D., Entomologist 

Biological Analysis Branch 

. ~ 

kt/l;':~..Y 

Sepebr 

Science 

Haddad, 

Information 

Environmental 

and Analysis 

Protection 

Branch 

Specialist 1-,../ ~ 

Elizabeth Hill, Economist ~ Q) EconomIc AnalYSIS Branch . 

Biological and Economic Analysis Division (7503P) 

Diann Sims, Chief 

Science Information and Analysis Branch 

Economic 

Timothy Kiely, 

Analysis 

Chief 

Branch ~ tAA... ~ 

Biological and Economic Anal s Division 3P) 

TO: Dana Friedman, Chemical Review Manager 

Risk Management and Implementation Branch 2 

Pesticide Re-evaluation Division (7508P) 

Product Review Panel date: November 9, 2011 

INTRODUCTION 

The purpose of this document is to convey usage information and a broad overview of the pest 

management roles of pesticides that are beginning to undergo registration review. The 

anticipated audience consists of the team of EPA staff currently evaluating the registration status 

of cypermethrin (109702) and zeta-cypermethrin (129064), and eventually the general public. 

1 
This document builds upon the data already provided in the "Usage and Label Use Data 

Packages" that are also provided to Registration Review teams by BEAD. The document is 

based on information and data available. to BEAD as of September 15, 2011. 

Cypermethrin and zeta-cypermethrin are synthetic pyrethroid insecticides. Cypermethrin is a 

combination of 8 stereo isomers with percentage compositions ranging from 11-14%. Zetacypermethrin is an enriched enantiomer of cypermethrin consisting of the 4 stereo isomers at 

concentration of 24% each and the 4 less active stereo isomers at a concentration of 1 % each. 

The mode of action of cypermethrin and zeta-cypermethrin is as a fast-acting neurotoxin in 

insects. It is likely that the toxic action of pyrethroids is primarily due to their blocking action on 

some aspect of the synaptic function of the nerve axon. Since the analytical methods do not 

distinguish cypermethrin from zeta-cypermethrin, and the toxicological endpoints are the same, 

the Agency's human health risk assessment and environmental fate assessments consider both 

cypermethrin and zeta-cypermethrin. 

Agricultural products are restricted use. Residential, commercial, and industrial products are 

general use (can be purchased and applied by professional applicators or by residential 

applicators). 

The primary agricultural pests controlled with cypermethrin include: aphids, armyworms, bean 

leaf beetle, stinkbug (brown and green), plant bug, tarnished plant bug, cutworms, grasshopper, 

leafhopper, loopers, thrips, bollworm, tobacco budworm, and com earworm. The major 

agricultural pests controlled with zeta-cypermethrin include: aphids, armyworms, bean leaf 

beetle, flea beetle, Japanese beetle, stink bug (brown, green and rice), cutworms, grasshopper, 

leafhoppers, leafminers, loopers, Asiatic citrus psyllid, thrips, weevils, silverleafwhitefly, 

wireworms, bollworm, and com earworm. 

Numerous non-agricultural pests may be controlled with cypermethrin and zeta-cypermethrin. 

These include, but are not limited to: wood infesting insects (i.e. borers and termites), 

residential/structural pests (Pillbugs, earwigs, fleas, ticks, spiders, flies, beetles, ants, clothes 

moth, grain moth, carpet beetle, cockroaches, bedbugs, ants, etc.), and flying insects (wasps and 

bees). 

USE SITES 

Agricultural Use Sites 

Cypermethrin Use Sites 

Crop Group Site + Crops 

Vegetable, root and tuber, group 01 Carrot 

Vegetable, bulb, group 03 Garlic, leek, onion, shallot 

Vegetable, leafy, except Brassica, Lettuce (leaf and head), spinach, chinese spinach 

group 04 

Vegetable, Brassica leafy, group 05 Broccoli, broccoli raab, chinese broccoli, brussels sprouts, cabbage, 

cauliflower, collards, kale, kohlrabi, mustard greens, mustard spinach, rape 

greens 

2 
Nut, tree, group 14 Pecan 

Grain, cereal, group 15 Com 

Oilseed crop, group 20 Cotton 

No group name, group 99 Chinese mustard 

+Cypermethrin is not registered for entire crop group, crop group names are included for hierarchical reference 

purposes only 

Zeta-cypermethrin Use Sites 

Crop Group Site Crops 

Vegetable, root and tuber, group 01 Arracacha, arrowroot, artichoke (chinese and jerusalem), beet (garden 

and sugar), carrot, cassava, celeriac, chayote, chicory, chufa, dasheen, 

ginseng, horseradish, leren, parsley, parsnip, potato, radish, rutabaga, 

salsify (black and spanish), skirret, sweet potato, tanier, taro, turnip, yam 

(true and bean) 

Vegetable, leaves of root and tuber, Garden beet, burdock, cassava, chicory 

group 02 

Vegetable, bulb, group 03 Garlic, leek, onion (bulb and green), shallot 

Vegetable, leafy, except brassia, group Leafy amaranth, arugula, cardoon, celery, celtuce, chervil, 

04 chrysanthemum (edible leaved and garland), com salad, cress (garden 

and upland), dandelion, dock, endive, .florence fennel, lettuce (head and 

leaf), orach, parsley, purslane (garden and winter), radicchio, rhubarb, 

spinach (including Chinese, New Zealand, and vine), swiss chard, 

tampala 

Vegetable, brassica leafy, group 05 Broccoli, broccoli raab, chinese broccoli, brussels sprouts, cabbage 

(including bok choy, mustard, and napa), cauliflower, collards, kale, 

kohlrabi, mustard greens, mustard spinach, rape greens 

Vegetable, legume, group 06 Bean (adzuki, broad, dry, kidney, lablab, lima, moth, mung, navy, pinto 

rice, runner, snap, succulent, tepary, urd, wax, and yardlong), catjang, 

chickpea, cowpea, guar, jackbean, lentil, lupi, pea (black-eyed, crowder, 

dry, dwarf, English, garden, green, pigeon, snow, southern, succulent, 

sugar snap), soybean 

Vegetable, foliage oflegume, group Soybean, forage 

07 

Vegetables, fruiting, group 08 Eggplant, groundcherry, okra, pepino, pepper (bell, non-bell, sweet nonbell), tomatillo, tomato 

Vegetable, cucurbit, group 09 Balsam pear, cantaloupe, chayote, cucumber, chinese cucumber, gherkin, 

edible gourd, melon, muskmelon, pumpkin, squash (summer and winter), 

watermelon, Chinese waxgourd 

Fruit, citrus, group 10 Calamondin, citron, citrus, grapefruit, kumquat, lemon, lime, satsuma 

mandarin, orange (sour and sweet), pummelo, tangelo, tangerine 

Fruit, pome, group 11 Apple, crabapple, loquat, pear, oriental pear, quince 

Fruit, stone, group 12 Apricot, cherry (sweet and tart), nectarine, peach, plum, japanese plum, 

prune 

Berry and small fruit, group 13 Blackberry, blueberry, currant, elderberry, gooseberry, grape, 

huckleberry, loganberry, raspberry 

Nut, tree, group 14 Almond, beechnut, butternut, cashew, chestnut, chinquapin, hazelnut, 

brazil nut, hickory nut, macadamia nut, pecan, walnut 

3 
Grain, cereal, group 15 Corn (field, pop, and sweet), millet, wild rice, grain sorghum, triticale, 

wheat 

Grain, cereal, forage, fodder and Field corn, grass hay, millet, rice, sorghum, wheat 

straw, group 16 

Grass, forage, fodder and hay, group Bahiagrass, bentgrass, bermudagrass, bluegrass, big bluestem, 

17 buffalograss, canary grass (annual and reed), dallisgrass, foxtail (creeping 

and meadow), rangeland grass, indiangrass, lovegrass, orchardgrass, 

pangolagrass, pasture, sudangrass, timothy 

Animal feed, nongrass, group 18 Alfalfa, clover, crownvetch, kudzu, lespedeza, lupin, sweet lupin, 

sainfoin, trefoil, velvetbean, vetch, milk vetch 

Herbs and spices, group 19 Borage, chervil, fennel, marigold, mustard, poppy 

Oilseed crop, group 20 Canola, castorbean, cotton, crambe, flax, jojoba, lesquerella, 

meadowfoam, rapeseed, safflower, sesame, sunflower 

No group name, group 99 Asparagus, Chinese mustard, peanut, sugarcane, tea 

Non-Agricultural Use Sites 

Cypennethrin and zeta-cypennethrin may be used in a wide variety of non-agricultural sites 

including but not limited to: ornamental plants/greenhouses, kennels/livestock facilities, 

residential sites (i.e. homes, hotels, hospitals), structural termiticide treatments, transportation 

facilities (i.e. railroad, bus, aircraft), and commercial/industrial food storage and/or production 

facilities, utility right-of-ways, and sanitation (dumps and sewers). 

COMMON FORMULATIONS AND APPLICATION METHODS 

Cypennethrin is fonnulated as pressurized liquid, wettable powder, emulsifiable concentrate, 

soluble concentrate, pressurized liquid, and ready-to-use solution. Zeta-cypennethrin is 

fonnulated as a dust, granular, impregnated material, emulsifiable concentrate, flowable 

concentrate, soluble concentrates and as a ready-to-use solution. 

USAGE 

Agricultural Usage 

Cypennethrin was first registered in 1984 by FMC Corporation, which also subsequently 

registered the isomer enriched zeta-cypennethrin in 1992. The Reregistration Eligibility 

Decision (RED) Document for cypennethrin was signed in June 2006. 

Based on private market usage data from 1998-2010, usage for cypennethrin averaged 

approximately 100,000 pounds active ingredient (a.i.) for 1.6 million acres treated. Usage for 

zeta-cypennethrin averaged approximately 90,000 pounds a.i. for 3.7 million acres treated. 

Between 2005 and 2010, cypennethrin was typically applied one time per year at a rate of 0.06 

pounds a.i. per acre, while zeta-cypennethrin was typically applied one time per year at a rate of 

4 
0.02 pounds a.i. per acre. Figures 1 presents usage in pounds a.i. for both cypermethrin and zetacypermethrin during the 1998-2010 timeframe. Usage for cypermethrin remained fairly steady 

between 1998 and 2003, but usage spiked from 2003 to 2005, and decreased sharply from the 

peak in 2005 to 2007 where use has remained fairly steady through 2010. The large increase in 

cypermethrin usage from 2003 to 2005 was due to heavy infestations of plant bugs, stink bugs, 

and cotton bollworms on cottop. Usage for zeta-cypermethrin peaked in 2002, and remained 

fairly steady between 2004 and 2010 as shown in Figure 1 (proprietary Data, 1998-2010). 

FIGURE 1. Cypermethrin & Zeta-Cypermethrin Usage in Pounds Active Ingredient 

1998 -2010 

<i. 

III 

o 

Z 

::) 

o 

0. 

250,000 -r------------------

~ cypermethrin 

_ zeta-cypermethrin 

?JCO ?JO) D() D'\. D'" D"'> ~ D" Dfo t$- _t:lCO DO) ~ ~ ~ ",(J ~ ",(J ",(J ",(J ",(J ",(J ",(J ",\oJ ",(J ",() 

YEARS 

Source: Proprietary Data, 1998 -2010 

Figure 2 presents the top crops for cypermethrin in 1998-2000, as compared to the top crops in 

2008-2010, based on pounds ofa.i. used. Average annual use in pounds a.i. applied for the 

1998-2000 timeframe was similar to the average annual use in the 2008-2010 timeframe. In 

1998-2000, cotton (68%) and lettuce (16%) were the highest uses with pecans, onions, sorghum 

following with 4% each. The "other" category of crops (the remaining 4%) includes garlic, com, 

broccoli and cauliflower. In 2008-2010, the top crops were cotton (57%) and soybeans (19%), 

followed by peanuts (10%), pecans (8%), and the "other" category of crops (6%) which include 

cabbage, sorghum, garlic, rice, onion and lettuce. Use on lettuce has fallen in absolute terms 

from its high in 1998 to almost no use in 2010, while use on peanuts and pecans have increased 

in absolute terms from 1998 to 2010. Cotton use in pounds a.i. applied has fallen slightly in 

absolute terms between the two time periods. (Proprietary Data, 1998-2010). 

5 
FIGURE 2. Comparison of Use on Top Crops for Cypermethrin (1998-2000 vs. 2008-2010) 

Sorghum 

(Milo) 

4% 

1998-2000 

------

Average (1998-2000) 77,000 Ibs. a.i 

Source: Proprietary Data, 1998-2010 

2008-2010 

Average (2008-2010) 76,000 Ibs. a.i 

Figure 3 presents the top crops for zeta-cypennethrin in 1998-2000, as compared to the top crops 

in 2008-2010, based on pounds a.i. used. Average annual use in pounds a.i. applied for the 

1998-2000 timeframe was much lower than the average annual use in the 2008-2010 timeframe. 

In 1998-2000, cotton (87%) and lettuce (7%) were the top crops followed by onions and pecans 

at 3% each. In 2008-2010, soybeans (22%), oranges (13%) and lettuce (9%) were the top crops 

followed by alfalfa, com, and cotton, all at 8%. The "other" category accounted for 22% of the 

remaining use and include over 30 crops but sugar beets, winter wheat, dry beans and peas, 

grapefruit and onions make up the majority of the other crops usage (Proprietary Data, 1998-

2010). 

6 
FIGURE 3. Comparison of Use on Top Crops for Zeta-Cypermethrin (1998-2000 vs. 2008-

2010) 

1998-2000 2008-2010 

Sweet Corn 

Average (1998-2000) 43,000 Ibs. a.i Average (2008-2010) 108,000 Ibs a.i. 

Source: Proprietary Data, 1998-2010 

Use ofzeta-cypermethrin on oranges has increased specifically in the 2009-2010 timeframe from 

almost no use before 2009 due to the registration of zeta-cypermethrin on oranges in 2008. Use 

on soybeans in pounds a.i. has increased in absolute terms from 2004 through 2010 with the 

highest use in 2009. Lettuce use in pounds a.i. has increased in absolute terms from 1998 

through 2010 with highest use on lettuce in 2005. Cotton use in pounds a.i. has decreased in 

absolute terms between the two time periods as shown above. 

Figure 4 presents the states with the highest pounds a.i. used for cypermethrin from 1998-2000, 

as compared to the states with the highest pounds a.i. used from 2008-2010. In 1998-2000, 

Georgia was the state with the highest use (20%), followed by Texas (19%), California (14%), 

and Louisiana (12%). Other states (18%) include Arkansas, South Carolina, Alabama, North 

Carolina, Tennessee, and Missouri. In 2008-2010, the state with the highest use was again 

Georgia (27%), followed by Louisiana (20%), and Mississippi (16%), and the "other" states 

accounted for (10%) and included South and North Carolina, Florida, California, and Missouri. 

7 
FIGURE 4. Comparison of States with Highest Use for Cypermethrin (1998-2000 vs. 2008-

2010) 

1998-2000 

MISSISSIPPI 

Source: Proprietary Data, 1998-2010 

TENNESSEE 

5% 

6% 

TeXAS 

6% 

2008-2010 

Figure 5 presents the states with the highest pounds a.i. used for zeta-cypermethrin from 1998-

2000, as compared to the states with the highest pounds a.i. used from 2008-2010. Arkansas was 

the state with the highest use (21%) followed by Missouri (16%), and Texas (11%), with the 

"other" states (26%) being Louisiana, California, Arizona, Oklahoma, Alabama, and Florida. 

In 2008-2010, Florida (18%) was the state with the highest use, followed by California (12%), 

and Missouri, Illinois, and Texas each at 6%. The "other" states accounted for 33% of use and 

included Iowa, Minnesota, Arkansas, Montana, Tennessee, Washington, and Indiana. 

8 
FIGURE 5. Comparison of States with Highest Use for Zeta-Cypermethrin (1998-2000 vs. 

2008-2010) 

1998-2000 

9% 

Source: Proprietary Data, 1998-2010 

Non-Agricultural Usage 

NORTH 

CAROLINA 

2008-2010 

3% NEBRASKAARIZONA 

4% 4% 

6% 

5% 

In terms of non-agricultural usage, data are available only for cypermethrin usage by pest control 

operators and lawn care operators, and for uses such as landscape, nursery/greenhouse, and food 

handling establishments. Generally, over the reported years (2000 through 2008), the majority of 

use was by pest control operators which used more than 500,000 pounds a.i. in 2000, and more 

than 400,000 pounds a.i. in 2003, which is substantially more use than the agricultural use of 

cypermethrin. Use by lawn care operators was approximately 11,000 pounds a.i. in 2006, while 

food handling establishments used approximately 3,000 pounds a.i. in 2005, and close to 4,000 

pounds a.i. in 2008 (Kline & Co., Inc. 2000-2008) 

BIOLOGICAL ASPECTS RELEVANT TO CVPERMETHRIN & ZETACYPERMETHRIN 

There are no reports of resistance, plant health claims, or public health issues associated with 

either cypermethrin or zeta-cypermethrin. 

HISTORY OF BEAD ASSESSMENTS FOR CYPERMETHRIN & ZETACYPERMETHRIN 

According to the BEAD Official Records Database, there have been no previous cypermethrin 

assessments conducted by BEAD, nor does the EPA Section 18 Action Database indicate that 

any requests have been made to the agency. 

BEAD has reviewed multiple zeta-cypermethrin emergency exemptions for grasshopper control 

in North Dakota, including a reoccurring emergency request for use on flax and single-year 

requests for use on mustard, pasturegrass, and rangeland. Emergency requests have also been 

9 
made by Texas for the control of Diaprepes root weevil in· commercial and residential citrus 

groves. Since these requests, zeta-cypermethrin has been registered for use on all of these crops 

(i.e., citrus, flax, mustard, and pasture grass and rangeland). BEAD concludes that these 

registrations are an indication of the importance of zeta-cypermethrin for pest control on these 

crops. The registration of zeta-cypermethrin for use on oranges in 2008 appears to be of 

particular importance, with this use accounting for 13% oftotal pounds a.i. applied from 2008 to 

2010 (see Figure 3). Refer to Attachment 1 for an overview of EPA zeta-cypermethrin 

emergency exemption records (EPA, 2011; BEAD Official Records). 

DATA NEEDS RELEVANT TO BEAD'S FUTURE WORK ON CYPERMETHRIN & 

ZETA-CYPERMETHRIN 

Obtaining additional information on the use and usage of cypermethrin in kennels and livestock 

facilities would improve future BEAD assessments of the importance of cypermethrin & zetacypermethrin and may be required as part of the registration review of this pesticide. 

REFERENCES 

1998-2010, Proprietary Data 

EPA. 2011. Section 18 Actions. Accessed July 12,2011 Online: 

http://cilmbl.epa.gov/oppref/section18/search.cfm 

Kline & Co., Inc. 2000-2008 

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ATTACHMENT 1 

Table A-I: History of Section 18 Requests for Zeta-Cypermethrin Located in the EPA 

Section 18 Action Database 

BEAD Official 

Received Response DP Barcode 

Site Pest Applicant Date Date Status Number 

No record of a 

BEAD 

assessment 

CITRUS GROVES CRISIS being 

(COMMERCIAL) DIAPREPES TEXAS 4/25/2007 4/25/2007 APPROVED conducted 

DIAPREPES 

CITRUS TREES ROOT WITH-

(RESIDENTIAL) WEEVIL TEXAS 3/14/2007 4/25/2007 DRAWN 338303 

No record of a 

BEAD 

assessment 

GRASSHOPP NORTH being 

FLAX ER DAKOTA 5/7/2007 5/15/2007 ISSUED conducted 

Source: EPA (2011); BEAD OfficIal Records. 

Table A-2: Section 18 Assessments in BEAD Official Records Database for ZetaC ;yperme th· rm N t R d 0 ecor e m d· th e c EPA A ti on D t b a a ase 

Document BEAD Official DP 

Site Pest Applicant Date Barcode Number 

FLAX GRASSHOPPERS NORTH DAKOTA 6/6/2002 284857 

FLAX GRASSHOPPERS NORTH DAKOTA 8/19/2003 291406 

FLAX GRASSHOPPERS NORTH DAKOTA 6/18/2004 303169 

FLAX GRASSHOPPERS NORTH DAKOTA 6/18/2005 3432N-0 

MUSTARD GRASSHOPPERS NORTH DAKOTA 7/13/2004 304220 

PASTUREGRASS AND 

RANGELAND GRASSHOPPERS ARKANSAS 5/27/2004 302020 

Source: EPA (2011); BEAD Official Records. 

11