E X T O X N E T
Extension Toxicology Network
A Pesticide Information Project of Cooperative Extension Offices of
Cornell University, Michigan State University, Oregon State University, and
University of California at Davis. Major support and funding was provided
by the USDA/Extension Service/National Agricultural Pesticide Impact
Publication Date: 9/95
TRADE OR OTHER NAMES
Product names include Evik, Ametryne, Ametrex, Gesapax (1), G34162,
Trinatox-D (a combination with 2,4-D), Crisazina-Crisatrina Kombi (a
combination with atrazine)(2), Doruplant, Mebatryne, and Amephyt (3).
Ametryn is an unrestricted or General Use Pesticide (GUP). In Florida
and Texas, ametryn may be applied alone on grapefruit and orange trees. In
Florida, it may be applied with simazine for common bermuda grass and annual
grasses and broadleaf weeds. In Hawaii, a mixture with diuron may be used on
Ametryn, a member of the Triazine chemical family, is a herbicide which
inhibits photosynthesis and other enzymatic processes. It is used to control
broadleaf weeds and annual grasses in pineapple, sugarcane and bananas. It is
used on corn and potato crops for general weed control (1). It is also used as
a vine desiccant on dry beans and potatoes (3). Ametryn is available as an
emulsifiable concentrate, flowable wettable powder and a wettable powder.
Products containing ametryn should bear the SIGNAL WORD: CAUTION. The EPA
classifies it as Toxicity Class III, slightly toxic (2).
Ametryn is slightly toxic to humans. Symptoms of acute exposure to high
doses include nausea, vomiting, diarrhea, muscle weakness, and salivation (5).
Ametryn is moderately irritating to the eyes, skin, and respiratory tract.
The LD50 is the dose of ametryn which is lethal to half of the test
animals that ingest it. The oral LD50 of ametryn is 508 mg/kg for rats and 945
mg/kg for mice (13). The LC50 for rats that inhale ametryn for four hours is
greater than 2.2 mg/l of air (4). The dermal LD50 is greater than 3,100 mg/kg
for rats and 8,160 mg/kg for rabbits (13). Acute eye exposure in rabbits
causes a temporary irritation (9).
No information is currently available.
No information is currently available.
Studies have shown that ametryn is not mutagenic (7).
There is not adequate data to determine if ametryn can increase the risk
of cancer in humans (1, 8).
Animal studies indicate that consuming large amounts of ametryn over a
long period of time results in liver damage (1).
Fate in Humans and Animals
Excretion of ametryn is rapid. In rats, all but 2 to 7% is eliminated in
the urine and feces within 72 hours (12).
Effects on Birds
Ametryn is only slightly toxic to birds. The dietary LC50 (8 day) is
30,000 mg/kg for bobwhite quail and 23,000 mg/kg for mallard ducks (3).
Effects on Aquatic Organisms
Ametryn is moderately toxic to fish. The LC50 for rainbow trout exposed
for 96 hours is 8.8 mg/l. The LC50 for bluegill is 4.1 mg/l and for goldfish
it is 14.1 mg/l (2, 3). Ametryn is highly toxic to crustaceans and moderately
to highly toxic to mollusks (10).
Effects on Other Animals (Nontarget species)
Ametryn is only slightly toxic to bees (2).
Breakdown in Soil & Groundwater
Ametryn's half-life in soils, the amount of time it takes to degrade to
half of the original concentration, is 70 to 250 days, depending on the soil
type and weather conditions. Loss from the soil is principally by microbial
degradation (1, 3). Ametryn moves both vertically and laterally in soil due to
its high water solubility (11). Because it is persistent, it may leach as a
result of high rainfall, floods, and furrow irrigation (1).
In a study of surface and groundwater contaminants in the U.S, ametryn
was found in six states, in very few surface water samples and in 4% of the
groundwater samples. The maximum concentration found was 0.1 micrograms/l in
surface water and 450 micrograms/l in groundwater (7).
Breakdown in Vegetation
Ametryn is broken down into non-toxic substances by tolerant plants and,
to a lesser extent, by sensitive plants (3).
PHYSICAL PROPERTIES AND GUIDELINES
Ametryn is a colorless crystal. It is non-corrosive and is stable in
neutral and weak acid or basic solutions. However, it is hydrolyzed by
strongly acidic or basic solutions into an inactive derivative. It is
decomposed slowly by UV light (2).
|CAS #: ||834-12-8
|Chemical Name: ||2-(ethylamino)-4-isopropylamino-6-methyl-thio-s-triazine
|Melting point: ||84-85 degrees C (3)
|Solubility in water: ||185 mg/l at 20 degrees C. It dissolves readily in organic solvents including hexane, toluene, methanol, and acetone (3, 7).
|Partition Coefficient (octanol/water): ||Kow = 676 (3).
|HA: ||0.06 mg/l (lifetime); 8.6 mg/l (child) (11).
|DWEL: ||0.3 mg/l (11).
|LOEL: ||100mg/kg/day (6)
|NOAEL: ||10 mg/kg/day (11)
|RfD: ||0.0086 mg/kg/day (6, 11)
P.O. Box 18300
Greensboro, NC 27419-8300
Review by Basic Manufacturer:
Comments solicited: October, 1994
U.S. Environmental Protection Agency. 1989. Health Advisory Summary:
Ametryn. U.S. EPA. Washington, DC.
Meister, R. T. 1992. Farm Chemicals Handbook '92. Meister Publishing
Company. Willoughby, OH.
The Agrochemicals Handbook, Third Edition. 1994. Royal Society of
Chemistry Information Systems, Unwin Brothers Ltd., Surrey, England.
Farm Chemicals Handbook '94. 1994. Meister Publishing Company.
U.S. Environmental Protection Agency. 1994. Pesticide Poisoning Action
Guide for Agricultural Pesticides in the Midwest. EPA. Chicago, IL.
Hayes Jr., Wayland and Edward Laws, Jr., (eds.) 1991. Handbook of
Pesticide Toxicology. Academic Press, Inc. New York, NY.
U.S. EPA Office of Drinking Water. 1987. Ametryn Health Advisory.
EPA. Washington, D.C.
U.S. Department of Health and Human Services Agency for Toxic Substances
and Disease Registry. 1990. Draft Health Assessment Guidance Manual. U.S.
Department of Health and Human Services. Atlanta, GA.
U.S. Environmental Protection Agency. 1989. Toxchem No. 431 Document
#002372 and 002373. EPA. Washington, DC.
Briggs, Shirley. 1992. Basic Guide to Pesticides. Hemisphere
Publishing. Washington, DC.
Thomson, W. T. 1982. Agricultural Chemicals Book II Herbicides.
Thomson Publications. Fresno, CA.
U.S. Department of Health and Human Services. 1993. Hazardous
Substance Data Base. HHS. Washington, DC.
National Institute for Occupational Safety and Health (NIOSH). 1993.
Registry of Toxic Effects of Chemical Substances (RTECS). NIOSH. Cincinnati,