Ur t«d Scatfc C -fice of P«rtlci. i *r I To k £ tear •»
En, perennial grassesl and nonflowering plants on sugarcane
and noncrop areas (such as rights-of-way)t, forestry sites (including Christmas
tree plantations i, site preparation^ and conifer release), ornamentals i,
established turf, and aquatic sites (ditchbanks).
Types of Formulations: 86.4Z asulam technical manufacturing-use product;
36.2Z end-use product formulated as a soluble concentrate/liquid
of the -sodium salt of Asulam (equivalent to 3.34 pounds of asulam
per gallon).
Types and Methods of Application: Surface and aerial spray and spot
treatment.
Application Rates: From 1.67 to 6.68 pounds active ingredient per acre
depending upon the use pattern and target weed species.
Usual Carrier: Water.
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3. Science Findinqs
Sumary Science Statement: Asulam poses a limited oncogenic risk fran
dietary and rker exposure. The pesticide is tentatively classified as a
Category C carcinogen (limited evidence of carcinogenicity in animals)
according to EPA’S Guidelines for Carcinogen Risk Assessment on the basis
of a rat oncogenicity study which showed a statistically significant
increase in benign adrenal gland pheochranocytanas in males at high dose
only, and also statistically significant increase in thyroid gland C—cell
carcinamas in low- and mid—dose males. Asularn did not produce a caTipound—
related statistically significant increase in tumors in a mouse oncogenicity
study. Available mutagenicity data are negative.
.imors were produced in only one strain and sex of rodent, and in only
a single experiment. Because of this rather limited evidence, quantifi-
cation of human risk is considered inappropriate.
Asulan did not induce teratogenic effects (birth defects) or im ir
reproductive ability.
Data are insufficient to fully assess the acute toxicity of asulam
to humans. However, available data on dermal and eye irritation and
sensitization indicate that asulam is not acutely toxic to humans.
In addition, data indicate that asulam is not acutely toxic to avian,
aquatic, or mariunalian species. Available data are insufficient to
ccsnpletely assess the environmental fate of asularn. Residues may carry
over to subsequent crops and asulam may possibly contaminate ground
water.
Chemical Characteristics :
Color: Cream to buff (tec* nical [ TI)
White (Pure Grade Active Ingredient [ PGAI])
Physical State: Powder (T)
Crystalline (PGA1)
Odor: Slight (T)
None (PGAI)
Melting Point: Approximately 135 °C (T)
(decanposes)
143 to 144 °C (PGAI)
(decanposes)
Solubility: Ethanol — 12.4 gflOO m
Methanol — 35.6 g/l00 mt
Acetone — 38.5 qjlOO mL
Methyl ethyl ketone — 34.5 qJlOO ml,
Dimethyl formamide — > 170 g/100 mL
ter — 0.425 g/100 ml,
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Octanol/Water
Partition
Coefficient:
0.30 at 0.01 m
0.76 at 0.001 w
1.76 at 0.0001 m
Toxicity characteristics:
Acute Effects 1 ! :
Primary Eye Irritation (Rabbit): Conjunctival irritation cleared by
day 7; no observed cornea] or iris irritation. Toxicity
Category III.
Primary Skin Irritation (Rabbit): No irritation. Toxicity Category
Iv.
Dermal Sensitization: Negative.
Subchronic Effects :
In a supplemental 6—month study dcx s were dosed at 60, 300, and
1500 mg/kg in the diet. Low-dose females and males and
females at high dose showed increased thyroid weights.
Relative thyroid/body ratio s increased in high—dose males
and females and, when canpa red to controls, high-dose males
and females showed lower mean body weight gain. The tentative
no—observed-effect level (NOEL) is 60 mg/kg/day. The study
may be upgraded if appropriate clinical measurement suni ary
tables and other data are submitted.
chronic Effects :
A 2—year feeding study in Charles River CD rats at doses of 0,
1000, 5000, and 25,000 ppm showed statistically significant
increases in benign adrenal gland pheochranocytanas in high—dose
males and also significant increases in thyroid gland C—cell
carcinanas in low- and mid—dose males. The systemic NOEL =
36 mg/kg/day (720 ppm) based on thyroid follicular hyperplasia
in mid— and high-dose males.
A 18 month oncogenicity study in Carworth CI—l mice at doses of
0, 1500 and 5000 ppm showed a statistically significant positive
trend for undifferentiated sarcana of the skin and subo.itis in males.
However, these tumors were not considered ccrnpound—related because:
1) they occurred only at the high dose in low incidence (4/46),
2) the incidence was not statistically significant though showed
/ See 40 CFR 162.10 for discussion of toxicity categories and canpanion
labeling reguir rents.
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a positive trend and 3) a parasitic skin infection was present
whi;h could have been re1at d to the occurrence of skin turrors.
The Ag3ncy is reguiring a r pe t mouse oncogenicity study
since 1) the maximum tolerated dose (MID) was not achieved, 2)
two doses rather than three specified in Guidelines were used,
and 3) evidence that the test animals were in poor health
demonstrated by chronic kidney inflammation and parastic
infect ion.
Develc ental Toxicity :
Rabbits were dosed with 0, 150, 300, and 750 mg/kg/day asulam in
the diet. The OEL was 750 mg/kg/day (highest dose tested).
Rats were dosed with 0, 50, 1000, and 1500 rrrg/kajday. The
OEL was 1500 mg/kg/day (highest dose tested). Not teratogenic.
Two-Generation Reproduction — Rat :
Charles River CD rats were a ninistered 0, 1000, 5000, and
25,000 ppm asulam in the diet. At 5000 and 25,000 ppm there
were fewer live births per litter and also slightly lower
fertility index in F 1 parents (second generation). The NOEL
for reproductive effects is 1000 ppm. Did not impair
reproductive ability.
Mutaqenicity :
A cell transformation assay was negative. A provisionally acceptable
study was negative for dcxninant lethal effects.
Physioloqical and Biochemical Behavior Characteristics :
Foliar Absorption: Applied after emergence, asulam is readily
absorbed.
Translocation: Asulam may be taken up either by roots or leaves
and moves to other parts of the plant.
Mechanisn of Pesticidal Action: In the meristematic regions of
plants (the growing points are areas of rapidly dividing cells
at the tip of the stem, root, or branch), asulam interferes
with the process of cell division and expansion.
Environmental Characteristics :
Available data are insufficient to assess the environmental fate of
asulam.
Persistence and Absorption: Asulam appears to be resistant to
hydrolysis. It is degraded in soil under aerobic conditions
with half-life apparently frm one to several days with most
of degraded material bound to soil. Under anaerobic (flooded)
conditions, the amount of bound residues appears to decrease
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and degradation rates decrease.
Leaching: Asulam appears to be mobile to very mobile in sand,
loamy soil, loam and clay loam soil. In soil columns both
the parent cmpound and degradates leached and were found as
19 to 88 percent of the applied material in the column
leachates.
Crcp Rotation: Available data indicate that residues may occur
in crops grown in areas treated in prior years with asulam.
Environmental Fate and Surface and Ground Water Contamination Concerns:
Ability of asulam residues to carry over to subs uent crcps
will be fully evaluated when the r uired cr rotation data
are subuitted. Asulam may possibly contaminate ground ter.
Additional data are reguired before the Agency can fully
assess the potential for ground water contamination.
Ecoloqical Characteristics :
Avian Acute Oral Toxicity (40% formulation): > 4000 mjkg
(mallard duck, partridge, pheasant, and pigeon)
(> 1600 nv/kg when adjusted to 100% asulam).
Avian Subacute Dietary Toxicity (60% formulation):
(pheasant and mallard duck)
(> 45,000 ppn when adjusted to 100% asulain).
Freshwater Fish Acute Toxicity:
Bluegill sunfish (technical): >
Rainbow trout (60% formulation):
Channel catfish (60% formulation):
Beneficial Insects Acute Contact Study (Honey Bees): 1.28 percent
mortality at 36.26 micrograms per bee.
Available data suggest that asulam is practically nontoxic to birds,
warrnwater fish, and estuarineMarine species, and relatively
nontoxic to honey bees. Asulam is not expected to pose a
hazard to nontarget organi ns; however, additional data are
required to be certain.
180 ppm
> 5000 ppn
> 5000 ppm
Freshwater Invertebrate Acute Toxicity (Daphnia):
Estuarine and Marine Invertebrate Acute Toxicity:
> 75,000 n
27 p n.
Fiddler crab:
Grass shrimp:
> 100 ppn
> 100 ppm
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4. Tolerance Assessment
Tolerances have been cstablished for residues of asularn in or on the raw
agricultural comodity sugarcane at 0.1 ppm (40 CFR 180.360).
No Mexican tolerance or Codex Alimentarius Canmission Maximum Residue
Limits have been established for residues of asulam. A negligible
residue tolerance is in effect in Canada for asulain residues in or on
flax.
The Agency is unable to canplete a full tolerance reassessment because
the available asulam toxicology and residue data do not fully supExrt
the established tolerance. There are data gaps for metabolism in
animals, residue analytical method,’and magnitude of residue in su rcane.
The acceptable daily intake (ADI) is a way of expressing the amount of
a substance that the Agency believes, on the basis of the results of data
fran animal studies and the application of “safety” or “uncertainty” factors,
may safely be ingested by humans without risk of adverse health effects. The
ADI is expressed in terms of milligrams (mg) of the substance per kilogram
(kg) of body weight per day (mg/kg/day).
The Agency has calculated a provisional acceptable daily intake (PADI) of
0.05 mg/kg/day for asulam on the basis of missing data and on a 2—generation
reproductive effects study with a reproductive NOEL of 50 mg/kg/day (1000
but no t’OEL for syst nic effects and a 1000—fold safety factor.
The established tolerances for asulam have a theoretical maximum residue
contribution (mRC) of 0.0001837 mg/kg/day, id utilizes 0.3673 percent
of the PADI.
5. Summary of Requlatory Position and Rationale
Special Review Status: EPA will not place asulam into Special Review
because none of the risk criteria for initiating Special Review has
been met.
Registration of New Uses of Asulam: The Agency will issue registrations
for substantially similar asulam products. However, new uses will be
approved only on a case—by-case basis after considering the effects on
the IWC, the MPI (Maximum Permissible Intake), and the onccxgenic
risks.
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Unique Label Precautionary Statements:
nd-Use Products
ENVIRONME AL HAZARDS
Do not apply directly to water or wetlands (swamps,
bogs, lagoons, marshes, or potholes). Do not
clean equi ent or dispose of ui nent washwater in
a manner that will contaminate water resources.
CROP ROTATI(1 STATEMEt T
Do not rotate with any crop ihich is not registered
for use with Asulam for one year following the last
application of this ch iical.
CRCP USE ST TEMENFS
Do not treat sugarcane within 90 days of harvest. Do
not graze or feed sugarcane forage and fodder to livestock.
6. Sumarl of Malor Data Gaps (Data R uired and Due Date )
Product Chenis try
(All) August 1988 and
February 1.989
Residue Chemistry
Animal Metaboli n August 1989
Residue Analytical Methods August 1989
Magnitude of Residues August 1989 and
February 1990
Environmental. Fate
Hydrolysis November 1988
Photodegradatiori (water, soil) Noverr er 1988
Aerobic and Anaerobic Soil Metaboli n May 1.990
Aerobic and Anaerobic Pquatic Metaboli n May 1990
Leach in; and Adsorption/Desorption February 1989
Small—Scale Prospective Field Lead ing Study May 1988
Field Dissipation (aquatic sediment and forestry) May 1990
Rotational Crops (confined and field) May 1991 and April 1992
Irrigated Crops May 1991
Toxicology
Acute Toxicity November 1988
Subchronic Toxicity (21—day dermal) February 1989
Mutagenicity (Ames test and dircznosomal aberration) November 1988 and
February 1989
General Metabo1i n February 1990
Oncogenicity (mouse) April 1992
**Date protocols are due. After acceptance, the Agency will, provide
timeframes for sutinission of the reports.
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Ecological Effects
Freshwater Fish LC 50 (coidwater fish) Nov ber 1988
Acute LC 50 Estuarine and Marine
Organi ns (oyster study) 1bve iber 1988
Acute LC 50 Freshwater Invertebrates February 1989
7. Contact Person at EPA
Richard F. !kxintfort
U.S. Envirorinental Protection Agency
TS- 767C
401 M Street J.
Washington, DC 20460
(703) 557—1830
DISCLAIMER: The information presented in this Pesticide Fact Sheet is for
information purposes only and may not be used to fulfill data requiranents
for pesticide registration and reregistration.
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