United Stvtes Office of Pesticides «nd Toxic Subctinc*i
Environment*! Protection Office of Pesticide Programs (TS-766C)
Agency Wnhington. DC 2O46O
vvEPA Pesticide
Fact Sheet
Name of Chemical: f
Reason for Issuance: REGISTRATION STANDARD
Date Issued: OCT 1987
Fact Sheet Number: 14?
1. DESCRIPTION OF CHEMICAL
- Generic Name: N'-(2,4-dimethylphenyl)-N-[[(2,4-dimethyl=
phenyl)imino Jmethyl]-N-methylmethanimidamide
- Common Name: Amitraz
- Trade Name: Baam, Taktic
- EPA Shaughnessy Code: 106201
- Chemical Abstract Service (CAS) Number: 33089-61-1
- Year of Initial Registration: 1975
- Pesticide Type: Insecticide/Acaricide
- Chemical Family: Diamidides
- U.S. Producer: Nor-Am Chemical Company
2. USE PATTERNS AND FORMULATIONS
- Application sites: pears
- Types and methods of applications: aerial and ground
application as a spray
- Application rates: 0.75 Ib active ingredient (ai)/A
to 1.5 Ib ai/A
- Usual Carriers: Confidental business information
3. SCIENCE FINDINGS
- In summary, amitraz is a diamidide compound of moderate
mammalian acute toxicity but has been shown to be carcino-
genic in mice. The Agency has concluded that amitraz is
a borderline C/D carcinogen. Other toxicology studies do
not demonstrate other significant chronic effects.
Amitraz's behavior in the environment is not well defined.
Its acute toxicity to birds is low, although it may affect
reproduction, it is moderately toxic to aquatic species.
Additional studies are being required for environmental
fate and ecological effects.
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Chemical Characteristics
— Technical amitraz is a straw colored crystalline solid.
Its melting point is 86—87°C.
— It is extreme] y soluble in xylene and acetone and is very
insoluble in water.
- Am traz is relatively stable to heat, however the stability
of amitraz in water is poor. Additional data are being
required in order to determine the sensitivity of amitraz
to metal ions and metal.
Toxicology Characteristics
— Acute oral: 523 mg/kg, Toxicity Category III.
- Acute dermal: >200 mg/kg, Toxicity Category II.
— Primary Eye Irritation: Non—irritating, Toxicity Category IV
- Acute Inhalation: 2.40 mg/i, Toxicity Category III.
— Primary Skin Irritation: Nonirritant, Toxicity Category IV.
- Skin Sensitization: Not a sensitizer.
— Major Routes of Exposure: Human exposure from amitraz
applications is greatest from mixing and loading of pesticide
formulation and applying it. Exposure can be reduced by the
use of goggles or face shield and gloves and other protective
clothing.
— Neurotoxicity: Amitraz is not expected to be a delayed
neurotoxin because it is neither an organophosphate or an
analog of a neurotoxic compound.
— Oncogenicity: A 2—year rat feeding and oncogenicity study
was negative at 200 ppm. An 80-week mouse oncogenicity
study demonstrated an increase in lymphoreticular tumors
in female mice but not in males at 400 ppm. A 2-year
mouse oncogenicity study demonstrated an increase in
hepátocellular tumors in female mice at the 400 ppm level.
The 2—year mouse study was referred to the Agency’s Cancer
Assessment Group (CAG) for evaluation. CAG determined,
based on the weight of the evidence, that amitraz is in
the lower portion of the Group C M range. The SAP concluded
that amitraiz should be classified as a Group D, (not
classifiable as to human carcinogenicity) because they
believed the weight of the evidence was inadequate to clearly
categorize the oncogenic potential of amitraz. The Agency
has reassessed its own position in light of the SAP position
and has now concluded thaLamitraz is a borderline Class C/D
carcinogen.
— Metabolism: Available data suggest that amitraz is not
readily absorbed in tissues and is excreted in the urine.
— Teratology: A teratology study in the rat was negative at
12 mg/kg body wecght (but). A teratology study in the rabbit
was negative at 25 mg/kg but. -
— Reproduction: A 3—generation rat reproduction study was
negative at 15 ppm.
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- Mutagenicity: Available data show amitraZ to be negative
in the gene mutation, host mediated and dominant lethal
test systems. Additional negative mutagenic studies were
conducted in the Mouse Lymphoma Mutation Assay, Ames
Bacterial Mutagenicity Test and in Unscheduled DNA
Synthesis in Human Embryonic Cells.
Physiological and Biochemical Characteristics
— Mechanism of action: Amitraz causes depression of
hypothalamic function.
— Metabolism and persistance in plants and animals: The
metabolism of amitraz in plants has not been adequately
described. Additional data are required. Data pertaining
to the metabolism of amitraz in food producing animals are
not required because there are no finite tolerances esCab—
lished for amitraz residues on crops involving livestock
feed items.
Environmental Characteristics
— Available data are insufficient to fully assess the
environmental fate of amitraz. Data gaps exist for all
required studies.
— The available data do suggest that amitraz can leach
slowly in certain soils. Data are required to assess
amitraz’s environmental fate and ability to leach
through soils.
Ecological Characteristics
— Avian acute oral ( CD 5 0 ) toxicity: 788 mg/kg for bobwhite
quail (slightly toxic).
- Avian dietary (LC 50 ) toxicity: 7000 ppm for mallard duck
(slightly toxic).
- Avian reproduction: No observable effect level (NOEL) is
<40 ppm. A new study is required to demonstrate a NOEL.
— Freshwater fish acute (LC 50 ) toxicity: cold water species
(rainbow trout)——0.74 ppm for technical; warm water species
(bluegill)-—l.34 ppb for technical.
— Aquatic freshwater invertebrates toxicity: Daphnia—-35.O ppb.
— Additional data are required to fully characterize the
ecological effects of amitraz.
Required Unique Labeling Summary
All manufacturing—use and end—use amitraz products
must bear appropriate labeling as specified in 40 CFR 162.10.
In addition to the above, the following information must
appear on the labeling:
— Manufacturing—use_products must state that they are intended
for formulation into other manufacturing—use products or
end—use products only for use on pears, cattle and hogs.
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— The Agency is removing the Restricted Use Classification
for amitraz since the weight of the evidence is inadequate
to clearly catagorize the oncogenic potential of amitraz.
will specify the reason (oncogenicity).
- A reentry interval of 24 hours will continue to be required
for the pear use until data requi red by the standard are
received and evaluated.
— Worker protection statements will be required for all end—use
amitraz products.
Tolerance Assessment
— The Agency is unable to complete a full tolerance assessment
because the metabolism of amitraz in plants has not been
adequately described.
— The available data support the established tolerances for
pears, cattle and hogs.
— Established tolerances are published in 40 CFR 180.287 and
they are:
Commodity Parts Per Million
Pears 3.0
Apples 0.0
Cattle, fat 0.1
Cattle, meat byproducts (mbyp) 0.3
Cattle, meat 0.05
Milk 0.03
Goats, fat 0.0
Goats, mbyp 0.0
Goats, meat 0.0
Hogs, fat 0.3
Hogs, mbyp 0.3
Hogs, meat 0.05
Hogs, kidney and liver 0.2
Horses, fat 0.0
Horses, mbyp 0.0
Horses, meat 0.0
Sheep, fat 0.0
Sheep, mbyp 0.0
Sheep, meat 0.0
— The Agency established the above zero tolerances to reflect,
in part, its conclusion of the Rebuttable Presumption Against
Registration (RPAR) (1979) not to permit the use of amitraz
on apples and therefore not to permit residues in apples or
meat producing animals which consume apple processing waste.
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— The acceptable daily intake (ADI) for amitraz is
0.0025 mg/kg/day based on a 2-year dog study with a NOEL of
10 ppm and a safety factor of 100. The maximum permitted
intake (MPI) (based on a 60 kg person) is 0.15 mg/day. The
published tolerances provide a theoretical maximum residue
contribution (TMRC) to the daily diet of 0.0723 mg/day
for an average 1.5 kg daily diet) which accounts for 48.20%
of the ADI.
4. SUMMARY OF REGULATORY POSITION AND RATIONALE
— The Agency has determined that it should continue to allow
the registration of amitraz for use on pears, cattle and
hogs. Other uses will be considered on a case—by—case. ., basis.
— The toxicology data base for amitraz is complete. The
Agency’s has determined that amitraz should be classified
as a Group C/D carcinogen.
— Available data are insufficient to fully assess the environ-
mental fate of and the ecological effects from amitraz.
Data are required to determine if amitraz will contaminate
ground water.
5. SUMMARY OF MAJOR DATA GAPS
— The full complement of environmental fate data requirements
including studies on degradation (hydrolysis and
photolysis), soil metabolism, mobility, dissipation, and
accumulation
— An avian reproduction study
— A plant metabolism study
CONTACT PERSON AT EPA
Dennis [ -I. Edwards, Jr.
Product Manager (12)
Insecticide—Rodenticide Branch
Registration Division (TS—767)
Office of Pesticide Programs
Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
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