United States Office at Pectteidei and Toxic Sutactence*
Environmental Protection Office of Pesticide ProgrMns (TS-766C)
Agency Washington, DC 20460
540/FS-89-046
• v°/EPA Pesticide
Fact Sheet
Name Of Chemical: Cypermethrin
Reason for Issuance: Registration Update
Date Issued: January 3, 1939
Fact Sheet Number: 199
1. Description of Chemical
Generic Name: (jH/-)alpha-cyano-( 3-phenoxyphenyl) methyl ( + )-cis , trans-
3-(2,2-dichloroethenyl)-2,2-dimethyIcyclopropanecarboxylate *
[containing 14% 1S-cis-S, 1R-cis-R, IS-trans-S and iR-trans-R
and 11% IR-cis-S, IS-cis-R,. IR-trans-S and 1S-trans-R). . . .]
Common Name: Cypermethrin
Trade Names: Ammo"; Cymbush®; Demon®; Cynoff1"
Other Names: Barricade; CCN52;
Cymperator; Cyperkill; Folcord;
Kafil; Super; NRDC 149;
Siperin; Ripcord
EPA Shaughnessy Code: 109702
Chemical Abstracts Service (CAS) Number: 66841-24-5
Year of Initial Registration: 1984
Pesticide Type: Pyrethroid-like; Insecticide/Miticide
Chemical Family: Pyrethroid
Manufacturers: FMC Corporation; ICI Americas, Inc.;
Shell International Chemical Company, Ltd.
(London)
2. Use Patterns and Formulations
Application Rates: Applied to cotton, lettuce (head) and pecans at a
rate up to 0.1 pounds active ingredient per acre. It may also be
applied into overhead sprinkler irrigation water. Cypermethrin is
also applied by Pest Control Operators as a crack, crevice, and spot
spray treatment in and around areas including, but not limited to,
stores, warehouses, industrial buildings, houses, apartment buildings,
greenhouses, laboratories, and on vessels, railcars, buses, trucks,
trailers, and aircraft.
Also it may be used in nonfood areas of schools, nursing homes, hospitals,
restaurants, and hotels; and•food manufacturing, processing, and
servicing establishments; as barrier treatments; and as an insect
repellent for horses and ponies.
Usual Carrier: Water and oil
-------
-2-
Type of Formulations: 30.6%, 25.3%, and 36.6% emulsifiable concentrate
and 88% technical
Limitations:
o Registrations are being extended with an expiration date of
June 15, 1989. Tolerances expire December 31, 1989.
o RESTRICTED USE PESTICIDE - Extremely toxic to fish. For retail
sale to and use only by Certified Applicators, or persons under
their direct supervision, and only for those uses covered by the
Certified Applicator's Certification.
o REENTRY STATEMENTS - Do not treat areas while unprotected
humans or domestic animals are present in the treatment areas.
Do not allow entry into treated areas without protective clothing
until sprays have dried.
o Do not apply within 21 days of harvest.
o Do not graze livestock in treated orchards or cut treated cover
crops for feed.
o CROP ROTATION RESTRICTION - Do not plant 'rotational crops within
30 days of last application.
3. Science Findings
Cypermethrin, a pyrethroid, is extremely toxic to fish. It is highly
toxic to bees exposed to direct treatment on blooming crops or
weeds. Cypermethrin has a low toxicity to mammals. EPA's review of
the cypermethrin pond study indicated that the data, as presented,
were not adequate or scientifically complete to allow the Agency to
evaluate the actual impact that the use of cypermethrin would have
an aquatic life forms. Therefore, ICI/FMC must repeat this study.
The EPA Peer Review Committee completed its evaluation of cypermethrin
with respect to its oncogenic potential and concluded that the data
available for cypermethrin provide limited evidence of oncogenicity
for the chemical in female mice. According to EPA Guidelines for
Carcinogen Risk Assessment (Federal Register September 24, 1986),
the Committee classified cypermethrin as a weak Category C oncogen
(possible human carcinogen with limited evidence of carcinogenicity
in animals). That is, cypermethrin produced benign lung adenomas at
the highest dose level in only one sex and species of animal (female
mice) and was not considered strong enough to warrant a "quantitative
estimation of human risk."
Chemical/Physical Characteristics of the Technical Grade:
Physical State: Solid
-------
-3-
Color: Colorless crystals
Odor: Odorless
Molecular Weight: 416.3
Molecular Formula: C22H19°3NC12
Melting Point: 60 to 80 °C
Boiling Point: 170 to 195 °C
Density: 1.249 g CM3 at 20 °C
Vapor Pressure: 8 x 10~4 at 80 °C; 1 x 10~7 at 20 °C
Solubility in Various Solvents:
Water 4 ppb
Base as water
Acid as water
Propylene glycol insoluble (less than 0.5%)
Methanol very soluble (approx. 75%)
Acetone completely miscible
Cyclohexanone completely miscible
Hexane slightly soluble (7%)
Xylene completely miscible
Methylene dichloride completely miscible
Stability - as neat material: No detectable decomposition
at normal ambient temperatures
and for at least 3 months at
50 °C to date
- as dilute aqueous solution: Slowly hydrolyzes at
pH 7 and below.
Hydrolyzes more
rapidly at pH 9.
Slow photodegradation
in sterile solution
in sunlight (< 10%
in 32 days).
Toxicology Characteristics of the Technical Grade:
o Acute Oral LD5g - Rat: LD50 = 247 (187-326) mg/kg (males)
LD50 = 309 (150-500) mg/kg (females)
o Acute Dermal LD5Q - Rabbit: LD5Q > 2460 mg/kg
o Primary Dermal Irritation - Rabbit: PIS = 0.71
(not irritating)
o Primary Eye Irritation - Rabbit: Mild irritation
o Skin Sensitization - Guinea Pig: May cause allergic
skin reactions
o Subchronic Oral - Rat: NOEL of 75 ppm for pharma-
cological effects. NOEL of 150 ppm for toxic effects.
-------
-4-
o Chronic Toxicity - Rat: NOEL = 150 ppm
LEL = 1500 ppm (HOT)
o Oncogenicity - 24-Month Mouse: Positive neoplastic
response in lung tissue. Increased incidence of benign
adenomas in females (only), statistically significant
at 1600 ppm (HOT). No evidence of oncogenicity in
the rat at up to 1500 ppm (HDT).
o Teratogenicity - Rabbit: Not teratogenic at 30 mg/kg/day.
(HDT).
- Rat: Not teratogenic at 70 mg/kg/day (HDT).
o Reproduction - 3-Generation Rat: NOEL for adverse repro-
ductive effects = 750 ppm (HDT), NOEL for systemic
effects = 50 ppm, LEL = 150 ppm (decreased body weight
gain in maturing pups).
o Mutagenicity - Ames Test: Not mutagenic.
o Mutagenesis - Host-Mediated Assay: Not mutagenic at
50 mg/kg.
o Mutagenesis - Dominant Lethal: Not mutagenic at 25 mg/kg.
Physiological and Biochemical Characteristics:
The mode of action in biological systems is stomach and contact
exhibiting neurotoxicological characteristics typical of pyrethroid
insecticides. Slight repellent effect.
Foliar Absorption - N/A.
Translocation - N/A.
Environmental Characteristics:
Adequate data are sufficent to define the fate of cypermethrin in
the environment. Cypermethrin is stable to hydrolysis, with an
estimated T 1/2 exceeding 50 days at environmentally expected
temperatures and pH values. Cypermethrin is extremely stable to
photolysis in water with an estimated T 1/2 exceeding 100 days at
environmentally expected temperatures and pH values. Photoproducts
produced included DCVA, 3-phenoxybenzaldehyde, and 3-phenoxybenzoic
acid. Cypermethrin photodegrades rapidly on soil surfaces (T 1/2:
8 to 16 days) to many photoproducts, the major ones identified as
3-phenoxybenzoic acid and compound XIV. Cypermethrin degrades in
soil under laboratory conditions. The rate is more rapid on
sandy clay and sandy loam soils than on clay soils and more rapid
on soils lower in organic matter content and cation exchange
capacity under all aerobic conditions. The T 1/2 in aerobic
-------
-5-
soils ranged from 2 to 8 weeks. In sterile aerobic soils,
cypennethrin degraded with a T 1 /2 of 20 to 25 weeks indicating
that microbes play a signicant role in soil degradation.
Cypennethrin degraded more slowly under anaerobic or waterlogged
conditions with the major metabolite 3-phenoxybenzoic acid produced.
Under aerobic conditions the major metabolites produced were DCVA
and 3-phenoxybenzoic acid. Cypermethrin does not leach signifi-
cantly in soil. It has a low solubility in water (0.2 ppm) and,
consequently, high adsorption characteristics. The leaching
potential for its degradates may be higher. Under field conditions,
runoff of cypermethrin has been shown to occur to some degree and
was probably due to physical transport of the solid particles via
erosion. Cypermethrin itself degrades rapidly in the field with
a T 1 /2 of 4 to 1 2 days. The persistence of the major aerobic
soil metabolites is not known. Both accumulation and depuration
of cypermethrin residues will occur in trout and catfish. Bio-
concentration factors of approximately 1200X were calculated in
rainbow trout in a f lowthrough study. , The data requirement for
accumulation of cypermethrin in rotational crops has not been
satisfactorily completed.
Ecological Effects Characteristics;
o Avian acute oral LDso ~ Mallard Duck: > 4640 mg/kg
o Avian dietary LC5Q - Mallard Duck and Bobwhite Quail:
LC50 > 20,000 ppm
o Avian reproduction - Mallard Duck and Bobwhite Quail:
NOEL > 50 ppm (HOT)
o Fish acute 96-hour UC^Q - Rainbow Trout = 0.82 ppb
o Fish acute 96-hour "LC^Q - Bluegill Sunfish = 1 .78 ppb
o Aquatic invertebrate acute LCso - Daphnia magna =0.26 ppb
Tolerance Assessments:
Section 408 tolerances under the Federal Food, Drug, and Cosmetic Act
are established until December 31, 1989 for residues of the
insecticide cypermethrin [(+/-) alpha-cyano-( 3-phenoxyphenyl)
methyl (_+-cis, trans-3-(2, 2-dichloroethenyl)-2 panecarboxylate]
and its metabolites* 3-PB Acid and DCVA in or on the following
raw agricultural commodities:
Commodity ppm
Cattle, fat 0.05
Cattle, meat 0.05
Cattle, meat byproducts 0.05
-------
-6-
Commodity ppm
Cottonseed 0.5
Goats, fat 0.05
Goats, meat 0.05
Goats, meat byproducts 0.05
Hogs, fat 0.05
Hogs, meat 0.05
Hogs, meat byproducts 0.05
Horses, fat 0.05
Horses, meat ' 0.05
Horses, meat byproducts . 0.05
Lettuce (head) 10.00
Milk 0.05
Pecans* 0.05
Sheep, fat 0.05
Sheep, meat 0.05
Sheep, meat byproducts 0.05
The acceptable daily intake (ADI) is calculated to be 0.01 mg/kg/day
based on a dog study with a NOEL of 1.0 mg/kg/day and using a
safety factor of 100. The maximum permissible intake (MPI) is
calculated to be 0.60 mg/kg/day for a 60-kg person. Published
tolerances result in a"theoretical maximum residue contribution
(TMRC) of 0.002773 mg/kg bwt/day. The existing TMRC is equivalent
to 27.7 percent of the ADI. No additional data are required to
support the current crop tolerances listed in 40 CFR 180.418.
4. Summary of Regulatory Position and Rationale
Adequate data are available to assess the acute and chronic toxicological
effects of cypermethrin to humans. The Agency's review of the field
study (§72-7) found that the data, as presented, were not scientifically
adequate nor sufficiently complete to allow the Agency to evaluate
the actual impact that the use of cypermethrin would have on aquatic
life forms. ICI/FMC disagreed with the Agency's conclusion and will
submit additional information necessary in order for the Agency to
complete the risk assessment.
On the basis of this information, EPA seriously considered whether to
issue new conditional registrations for cypermethrin. Based on the
information submitted, on January 3, 1989 the Agency issued new
conditional registrations of cypermethrin which will expire on June 15,
1989.
The Agency issued these new conditional registrations for this short
period of time to ICI and FMC in light of their agreement to:
a. Submit all data generated in the course of the cypermethrin
Alabama pond study pertaining to runoff and residues in water
and sediment to the Agency by January 1989.
-------
-7-
b. Submit all other data now in existence and not previously
submitted to the Agency, as well as all other data generated
in the future in the course of the cypermethrin Alabama pond
study, as soon as is practical.
c. Conduct an aquatic mesocosm study (a simulated 2-year field
study) for which EPA will develop and provide the protocol no
later than April 15, 1989, in case ICI/FMC do not persuade
EPA that the current cypermethrin pond study is acceptable.
d. Within 30 days of receipt of an EPA protocol for an aquatic
mesocosm study, provide the Agency with written unconditional
acceptance .of the protocol and an unconditional commitment to
conduct the study through completion. For any modification
of the protocol to be valid, it must be agreed to by EPA
within the above-mentioned 30-day period.
EPA has concluded that the continual use of cypermethrin for this short
period of time will not cause a significant increase in the risk of
adverse effects to the environment.
The Delaney Clause in section 409 of the Federal Food, Drug, and Cosmetic
Act bars the establishment of food additive regulations for substances
which induce cancer in man or test animals. Since cypermethrin has
been found to produce'an oncogenic response in test animals, no 409
tolerances will be granted. Cypermethrin as parent does not leach
significantly in soil. At this time, there are no concerns for
ground water contamination.
5. Summary of Major Data Gaps
Simulated and/or actual field study (§72-7)
6. Contact Person at EPA
George T. LaRocca
Product Manager (15)
Insecticide-Rodenticide Branch
Registration Division (H7504C)
Office of Pesticide Programs
Environmental Protection Agency
401 M Street SW.
Washington, DC 20460
Office location and telephone number:
Room 211, Crystal Mall #2
1921 Jefferson Davis Highway
Arlington, VA 22202
Phone: (703) 557-2400
DISCLAIMER: The information presented in this Pesticide Fact Sheet is for
informational purposes only and may not be used to fulfill data requirements
for pesticide registration and reregistration.
-------
&EPA
United States \
Environmental Protection Agency'
Office of Pesticide Program (H7502C)
PMSD. Information Services Branch
401 M Street. SW.
Washington. DC 20460
Official Business
Penalty for Private Use S300
First-Class Bulk
Postage and Fees Paid
EPA
Permit No. G-35 t
------- |