United State* Office of Pesticides and Toxic Substances
Environmental Protection Office of Pesticide Programs (TS-766C)
Agency Washington, DC 20460
&EPA Pesticide
Fact Sheet
Name of Chemical: Harmony 75 DF
Reason for Issuance: New Chemical Registration
Date Issued: ^n ~ £ ,i- -
FacfSheet Number: 152
1~ Description of Chemical
Generic Name: Methyl 3-[[[[(4-methoxy-6-methyl-l,3,5-trlazln-2-yl)
amlno] carbonyl]amlno]sulfonyl]-2-thlophencarboxylate
Common Name:
Trade Name: Harmony 75 DF
EPA Shaughnessy Code: 128845
Chemical Abstracts Service (CAS) Number: 79277-27-3
Year of Registration: 1988
Pesticide Type: Herbicide
Chemical Family: Sulfonylurea
U.S. Producer: E.I. DuPont DeNemours & Company
2. Use Pattern and Formulations
Application Sites: Terrestrial Food Crops
Major Crops Treated: Small grains (wheat and barley)
Types and Method of Application: Foliar, applied broadcast by
ground equipment or broadcast by aircraft. It is applied
postemergence in relation to the crop. A selective postemergence
herbicide for control of certain annual and perennial weeds.
Application Rates: 0.33 - 0.67 ounces active ingredient/A
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Types of Formulation: 75% water dispersible granule
Usual Carrier:
Wa t e r
3. Science Findings:
Summary Science Statement: All data are acceptable to the Agency.
DPX—M 6316 has low acute toxicity (Category III) for acute dermal,
primary eye irritation, and is less toxic (Category IV)
for all other forms of acute toxicity. It was not oncogenic
to rats or mice, not teratogenic to rabbit, and not mutagenic. It
is practically nontoxic to birds, fish, aquatic invertebates, and
honeybees. The pesticide and its degradates will leach in soil
and have the potential to contaminate groundwater at very low levels.
The nature of the residues in plants and animals are adequately
understood and adequate methodology is available for enforcement
of tolerances in wheat and barley grain and straw.
Chemical Characteristics:
Physical State:
Color: White
Odor: None
Crystalline solid
Melting Point: 176—178°C
Density: 1. 1 19g/cc
Solubility (25°C):
Water (pH 11.0)
(pH 5.0)
(pH 6.0)
24 milligrams 1 liter /1)
260 mg/i
2400 mg/i
Vapor Pressure:
Ac e toner
Acetonitrile
Ethanol
Methanol
He xane
Ethyl Acetate
Methylene Chloride
Xyl enes
2.7x10— 6 mm Hg/25°C
11.9 mg/i
7.3 mg/i
0.9 mg/i
2.6 mg/i
<0.1 mg/i
2.6 mg/i
27.5 mg/i
0.2 mg/i
Dissociation Constant: 4.0 (pKa of the acid)
Octanol/Water Partition Coefficient:
0.027
pH: 14.0 (slurry in water)
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Stability: Stable to metals and light. Decomposes on melting.
In solution the compound is very stable to methylene
chloride and ethyl acetate, moderately stable
in methanol, and relatively unstable in acetone
and acetonitrile. The photolytic half-life in an
aqueous solution is expected to be 1 to 5 days.
Toxicological Characteristics :
Acute Toxicology (Technical):
Acute Oral Toxicity greater than (>) 5000 milligrams/kilogram
(mg/kg)
(Rat) Toxicity Category tV
Acute Inhalation Toxicity > 7.9 mg/1/4 hour
(Rat) Toxicity Category III
Acute Derrnal Toxicity > 2000 mg/kg
(Rabbit) Toxicity Category III
Acute Toxicology (75% end—use formulation):
Acute Oral Toxicity > 5000 mg/kg
(rat) Toxicity Category P7
Acute Dermal Toxicity > 2000 mg/kg
(rabbit) Toxicity Category III
Primary eye Ii’ritation — Moderate Eye Irritant
(rabbit) Toxicity Category III
Skin Sensitization — Not a sensitzer
(guinea pig)
Major Routes of Exposure: The major routes of exposure are through
dermal and eye contact.
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Chronic Toxicology:
2-Year Feeding/Oncogenicity Study (Rats)
Systemic no—observable effect level (NOEL)= 1.25 mg/kg/day
Systemic lowest effect level (LEL)= 25 mg/kg/day
No—oncogenic effect noted at 125 mg/kg [ highest dose tested
(HD>)
18—Month Oncogenicity Study (Mice)
Systemic NOEL= 3.75 mg/kg/day
Systemic LEL= 112.5 mg/kg/day
No oncogenic effects noted at 1125 mg/kg/day (HDT)
1-Year Feeding (Dog)
NOEL = 18.75 mg/kg/day
LEL = 18.75 mg/kg/day
Teratology (Rat)
Maternal NOEL greater than (>) 725 mg/kgldayl(HDT)
Fetotoxic NOEL = 159 mg/kg/day
Fetotoxic LEL = 725 mg/kg/day
eratogenic NOEL = 159 mg/kg/day
Teratology (Rabbit)
Maternal NOEL = 158 mg/kg/day
Maternal LEL = 511 mg/kg/day
Teratogenic NOEL > 511 mg/kg/day(HDT)
2-Generation Reproduction (Rat)
Systemic and Reproduction NOEL > 125 mg/kg/day(HDT)
No reproductive effects seen at 125 mg/kg/day (HDT)
M tagenicity — Reverse Mutation Ass8ay In Salmonella — not mutagenic
with and without S-9.
Mutagenicity — Gene—Mutation—No increase in mutation frequency was
seen at the highest dose tested of 7 nm the limit of solubility.
Mutagenicity — DNA synthesis/rat hepatocytes in nitro—material
did not induce signficant increase in unscheduled DNA synthesis
(UDS) in primary cultures.
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Physiological and Biochemical Behavior Characteristics:
Foliar Absorption: Rapid
Translocation: Translocated within the plant
Mechanism of Pesticidal Action: Selectively inhibit acetolactate
s ynthas e.
Metabolism and Persistence In Plants: In plants DPX-M6316 degrades
into thiophene and triazine containing entities which appear to
be stable and behave as sugars.
Bioaccumulation: Not expected to bioaccumulate in fish.
Environmental Characteristics:
Absorption and Leaching: In unaged column leaching studies,
DPX-M6316 showed a high propensity to move in all soil types
tested (sandy loam, loamy sand, silt and silt loam). In
aged column leaching studies, residues were very mobile in
silt loam soil with parent compound and DPX-M6316 acid
represnting a major fraction of the leachate. The triazine
amine degrades and has a high potential to leach. Because
of its potential to leach, the triazine amine has a potential
to contaminate groundwater, but because of the low application
rate rapid degradation and single application/season, the
levels would be very low.
Microbial breakdown: Degrades rapidly in the field via microbial
degradation. Aerobic soil metabolism study indicates the
DPX—M6316 is degraded to CO 2 via several metabolites in 2-6
days. The triazine am’ine peaked at 15% of the total residues.
The anaerobic metabolism study indicated a similar pattern
hut at a slower rate.
Loss from Photodecomposition and/or volatilization : Does not
volatilize. Degrades rapidly in the field via photolysis.
Exposure of Humans and Nontarget Organisms to Chemical or Degradate:
Because of the low toxicity from oral, dermal and inhalation
(toxicity category IV, III, and III) and since the chemical is not
a skin sensitizer, the risk to humans from exposure should be
minimal. Nontarget organisms are not likely to be adversely
affected by use of DPX—M6316 because of its low toxicity to birds,
fish, and invertebrates.
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Exposure During Reentry: Because of low acute toxicity and cultural
practices for wheat and barley (little or no reason for field
workers to enter field after application) reentry data or
labeling are not required.
Ecological Characterists:
Avian Oral Acute Toxicity with Mallard Ducks: > 2510 mg/kg
Avian Dietary Toxicity with Bobwhite quail:> 5620 mg/kg
Mallard Ducks: > 5620 mg/kg
Acute Aquatic Toxicity with Rainbow Trout: > 100 mg/kg
Bluegill Sunfish> 100 mg/kg
Acute Toxicity to Invertebrates: > 1000 mg/kg
Acute Toxicity to Honey Bee:> 12.5 mg/kg
Available data indicate that DPX—M6316 is practically non—toxic to
birds, fish, aquatic invertebrates, and honey bees.
Endangered Species: The available data indicate that the proposed
use of DPX—M6316 is unlikely to pose a hazard to endangered
aquatic or avian species. There may be some hazard to endangered
plants.
Tolerance reassessment: Tolerances are established for residues
of the herbicide DPX-M6316 (methyl 3— [ [ [ [ —methoxy—6—methyl—1,3,5
Triazin—2-yl) amino]carbonyl] amino] sulfonyl]—2—thiophencarboxylate)
in or on the following raw agricultural commodities (Lb CFR 180.Lb39).
Commodities Parts Per Million
barley, grain 0.05
barley, straw 0.1
wheat, grain 0.05
wheat, straw 0.1
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The acceptable daily intake (ADI) based on the 2-year rat feeding
study (NOEL of 1.25 mg/kg/day) and using a safety factor of 100
Is calculated to 0.013 mg/kg/day. The theoretical maximum residue
contribution (TMRC) from these tolerances is calculated to be
0.000073 mg/kg body weight/day, which occupies approximately
0.6 of the ADI. There are no other published tolerances for
this chemical.
Reported Pesticide Incidents: There are no reported pesticide
Incidents for the chemical.
Lj Summary of Regulatory Position and Rationale
The Agency has decided that the data submitted in support
of the registration request is acceptable and fulfills the
guidelines requirements. Therefore, the Agency has accepted
the use of DPX—M6316 for control of weeds in wheat and barley.
The Agency has determined that DPX—M6316 and its degradates
have a potential to leach and therefore contaminate groundwater.
Therefore the Agency is requiring a small scale groundwater
monitoring study, methodology to determine DPX—M6316 and Its
degradates In groundwater, and an anaerobic soil metabolism
study using radiolabeled material with labeling on the triazine
moiety.
5. Summary of Data Gaps
Small scale prospective groundwater monitoring study.
Methodology to determine DPX-M6316 and its degradates in water.
Anaerobic soil metabolism study with radlolabelled triazine
moiety.
6. Contact Person at EPA : Robert J. Taylor
Office of Pesticide Programs, EPA
Registration Division (TS—767C)
1 01 M Street, S.W.
Washington, D.C. 20L 160
Phone: (703) 557—1800
Disclaimer: The information in this Pesticide Fact Sheet is
a summary only and may not be used to fulfill data requirements
for pesticide registration and reregistration.
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