ametryn (Evik) Herbicide Profile 3/85
CHEMICAL NAME: 2-ethylamino-4-(isopropylamino)-6-(methylthio)-s
TRADE NAME(S): Evik 80W (58)
FORMULATION(S): 50 and 80% WP (8b)
TYPE: Triazine herbicide
BASIC PRODUCER(S): Ciba-Geigy Corp.
P.O. Box 18300
Greensboro, NC 27419
STATUS: General use
PRINCIPAL USES: Ametryn is a selective herbicide for control of
broadleaf and grass weeds in pineapple, sugarcane, bananas and
plantains. It can also be used as a post-directed spray in corn and as
a potato vine desiccant. In addition, it can be used for total
vegetation control (58).
APPLICATION METHOD(S): Applications may be made preemergence,
postemergence, and post-directed, depending upon the crop. Ametryn has
considerable contact activity; therefore, postemergence treatments must
be directed on most crops. Under dry conditions a shallow
incorporation may increase the degree of weed control (58).
Important Weeds Controlled: Crotalaria, mustard, Dallisgrass,
cocklebur, lambsquarters, morningglory, velvetleaf, ragweed, panicum,
smartweed, shattercane, nutgrass, wiregrass, goosegrass, crabgrass, sow
thistle, purslane, pigweed, foxtail, and many others (8b).
Absorbed through the weed's root system as they germinate.
Therefore, weeds will emerge before dying. Considerable activity through
foliage contact. Mature weeds of certain species will be controlled by
post-emergence applications. Looks promising as an aquatic herbicide
II. PHYSICAL PROPERTIES
MOLECULAR FORMULA: C9 H19 N5 S (58)
MOLECULAR WEIGHT: 227.3 (58)
PHYSICAL STATE: White, crystalline (pure compound) (58)
ODOR: Odorless (24p)
MELTING POINT: 84 to 85 C (pure compound) (58)
VAPOR PRESSURE: 8.4 x 10-7 mmHg at 20 C (pure compound) (58)
SOLUBILITY: Soluble in water to 185 ppm at 20 C (56).
185 pmw water at 20 C (pure compound) (58).
III. HEALTH HAZARD INFORMATION
OSHA STANDARD: None established
NIOSH RECOMMENDED LIMIT: None established
ACGIH RECOMMENDED LIMIT: None established
A. ACUTE TOXICITY
DERMAL: LD50 = >10.2 gm/kg (ametryn 80% WP) (58).
Moderate skin irritation (rabbit, Evik 80W) (56).
LD50 = >3,100 mg/kg (rat); slight irritant to skin
of rabbits (62).
LD50 = >2,010 mg/kg (rabbit, Evik 80W) (24p).
Not a skin sensitizer (guinea pig, Evik 80W) (24p).
ORAL: LD50 = 1,750 mg/kg (rat, 80% WP) (58).
LD50 = 1,750 mg/kg (rat, technical ametryn) (56).
LD50 = 1,100 mg tech/kg (rat) (62).
LD50 = 1,950 mg/kg (rat, Evik 80W) (24p).
INHALATION: No deaths were recorded or untoward effects noted
among a group of albino rats exposed to ametryn
aerosol at >27 mg/l during a 4-hr exposure period
LC50 = >2.2 mg/l for 4 hours (rat, Evik 80W) (56).
EYES: Undiluted ametryn was mildly irritating to the eye of
the rabbit (58).
Nonirritant to rabbit eyes (62).
B. SUBACUTE AND CHRONIC TOXICITY:
In 2-yr feeding studies NEL: for rats 1,000 mg/kg diet (67 mg/kg
daily); for dogs 1,000 mg/kg diet (33 mg/kg daily) (62).
IV. ENVIRONMENTAL CONSIDERATIONS
Behavior In Or On Soils
1. Adsorption and leaching characteristics in basic soil types:
Ametryn is more readily adsorbed on muck or clay soils than
in soils of low clay or organic matter content, and is seldom
found below the upper few inches. The downward movement of
leaching is limited by its adsorption to certain soil
constituents and its comparatively rapid dissipation. The
adsorption of ametryn in soils is greater than with most
other commercial triazine herbicides, although this
adsorption is readily reversible under most conditions. It
has little lateral movement in soil except from erosion with
2. Microbial breakdown: Microbial action probably accounts for the
major breakdown of ametryn in the soil. Several soil
microorganisms have been reported to utilize it as a source
of energy and nitrogen. The effect of ametryn on these and
other organisms appears to be small, if at all.
3. Loss from photodecomposition and/or volatilization:
Photodecomposition and/or volatilization of ametryn have not
been evaluated under field conditions, but it would be
expected to compare with prometryn in these respects.
4. Resultant average persistence at recommended rates: Research
results from most of the continental United States indicate
that the persistence of ametryn in soils compares quite
closely to prometryn. Under more tropical conditions of
Hawaii and Puerto Rico, however, ametryn not only gives
better postemergence and preemergence control of a wider
range of weeds, but its residual life in the soil is often
extended to several months, and may persist as long as
Esser, H.O., G. Dupuis, E. Ebert, C. Vogel, and G.J. Marco.
1975. S-triazines. In Herbicides. Chemistry,
Degradation, and Mode of Action. Ed. by P.C. Kearney and
D.D. Kaufman. Marcel Dekker, Inc., New York.
Gunther, F.A. and J.D. Gunther (Eds.) 1970. The triazine
herbicides. Residue Reviews. Vol. 32. 413 pp (58).
General toxicity to wildlife and fish: Toxicological
investigations concluded with bobwhite, quail, mallard ducks,
goldfish, Rainbow trout, bluegill sunfish and oyster have
shown ametryn to have a very low toxicity to these species (58).
Fish and wildlife - ametryn technical
Fish species 96-hr LC50 (ppm)
Rainbow trout 8.8
Bluegill sunfish 4.1
Bird Species 8-day Dietary LC50 (ppm)
Bobwhite quail 30,000
Mallard duck 23,000 (58).
V. EMERGENCY AND FIRST AID PROCEDURES
The chemical information provided below has been condensed from
original source documents, primarily from "Recognition and Management
of Pesticide Poisonings", 3rd ed. by Donald P. Morgan, which have been
footnoted. This information has been provided in this form for your
convenience and general guidance only. In specific cases, further
consultation and reference may be required and is recommended. This
information is not intended as a substitute for a more exhaustive
review of the literature nor for the judgement of a physician or other
If poisoning is suspected, do not wait for symptoms to develop.
Contact a physician, the nearest hospital, or the nearest Poison
KNOWN OR SUSPECTED ADVERSE EFFECTS: Some triazines are mildly
irritating to skin, eyes, and upper respiratory tract. Systemic
toxicity is unlikely unless very large amounts have been ingested (25).
No cases of poisoning in man have been reported from ingestion of
ametryn. Ataxia, dyspnea, muscular weakness, salivation, and loss of
reflexes in rats (58).
Irritation of eyes, skin, nose or throat may result from
overexposure to Evik 80W (24p).
SKIN CONTACT: WASH contaminated SKIN with soap and water (25).
INGESTION: INGESTIONS of SMALL amounts (less than 10 mg/kg body
weight) occurring less than an hour before treatment, are probably best
A. SYRUP OF IPECAC, followed by 1-2 glasses of water. Dose for
adults and children over 12 years: 30 ml. Dose for children
under 12 years: 15 ml.
B. ACTIVATED CHARCOAL - Administer 30-50 gm as a slurry in tap
water, after vomiting stops.
C. SODIUM or MAGNESIUM SULFATE, 0.25 gm/kg in tap water, as a
INHALATION: Remove from contaminated atmosphere. If symptoms
appear or person is unconscious, get medical attention (Evik 80W)
EYE CONTACT: FLUSH contaminated EYES with copious amounts of
fresh water for 15 minutes (25).
NOTES TO PHYSICIAN:
Evik 80W in an s-triazine herbicide. There is no specific
antidote if Evik 80W is ingested. If a large amount has been swallowed
and vomiting has not occurred, induce emesis or lavage stomach. After
lavage, a slurry of 30 to 50 gm activated charcoal in water can be left
in the stomach (24p).
INGESTIONS of LARGE amounts (more than 10 mg/kg) occurring less than an
hour before treatment, should probably be treated by gastric lavage:
A. INTUBATE stomach and ASPIRATE contents.
B. LAVAGE stomach with slurry of ACTIVATED CHARCOAL IN 0.9% saline.
Leave 30-50 gm activated charcoal in the stomach before
C. SODIUM SULFATE, 0.25 gm/kg in tap water, as a cathartic.
CAUTION: Hydrocarbons (kerosene, petroleum distillates) are
included in some formulations of these chemicals.
Ingestion of very LARGE AMOUNTS may cause CNS
depression. In this case, IPECAC IS CONTRAINDICATED.
Also, gastric intubation incurs a risk of HYDROCARBON
PNEUMONITIS. For this reason observe the following
(1) If the victim is unconscious or obtunded and
facilities are at hand, insert an ENDOTRACHEAL TUBE
(cuffed, if available) prior to gastric intubation.
(2) Keep victim's HEAD BELOW LEVEL OF STOMACH during
intubation and lavage (Trendelenburg, or left
lateral decubitus, with head of table tipped
downward). Keep victim's head turned to the left.
(3) ASPIRATE PHARYNX as regularly as possible to remove
gagged or vomited stomach contents.
INGESTIONS occurring MORE THAN an HOUR before treatment are probably
best treated only by ACTIVATED CHARCOAL, 30-50 gm, and SODIUM or
MAGNESIUM SULFATE, 0.25 gm/kg, as described above.
There are no specific antidotes for these chemicals. Because
manifestations of toxicity do occasionally occur in peculiarly
predisposed individuals, MAINTAIN CONTACT with victim for at least 72
hours so that unexpected adverse effects can be treated promptly (25).
VI. FIRE AND EXPLOSION INFORMATION
Compatible with most other pesticides and fertilizers when used at
normal rates. Noncorrosive under normal use conditions (58).
VIII. PROTECTIVE MEASURES
STORAGE AND HANDLING: Store in a cool, dry place. Very stable over
several years of shelf-life and only slight sensitivity to natural
light and extreme temperatures (58). Shelf life of at least 5 years
when stored in a dry place (Evik 80W) (56).
Keep out of reach of children. Harmful or fatal if swallowed.
Avoid contamination of food or feed, inhalation of dust, contact with
eyes, contact with skin and breathing spray mist. Do not contaminate
domestic or irrigation water supplies or lakes, streams or ponds (58).
PROTECTIVE CLOTHING: Skin contact with the powder should be prevented
through the use of rubber gloves and clothing consistent with good
pesticide handling practice. Eye contact with powder should be avoided
through the use of chemical safety glasses or goggles (Evik 80W) (24p).
PROTECTIVE EQUIPMENT: This material should be handled in a well
ventilated area. Where adequate ventilation is not available, wear a
Conflo II (MSA) or other approved pesticide respirator (Evik 80W)
IX. PROCEDURES FOR SPILLS AND LEAKS
IN CASE OF EMERGENCY, CALL, DAY OR NIGHT
PESTICIDE TEAM SAFETY NETWORK/CHEMTREC
Make sure all personnel involved in spill cleanup follow good
industrial hygiene practices.
Small spills can be handled routinely. Cover the spill with an
absorbent material such as vermiculite or sawdust to prevent dust.
Sweep up the material and place in an appropriate chemical waste
container. Seal container and dispose of in an approved landfill.
Wash the spill area with a saturated solution of sodium carbonate and a
strong detergent. Flush the spill area with water to remove any
Do not reuse container. Destroy by burning in a safe place.
Disposal of material, spill residues, wash water and containers
must be by methods consistent with local, state and federal health and
environmental regulations (Evik 80W) (24p).
X. LITERATURE CITED
8b. Thomson, W.T. 1981. Agricultural chemicals - book 2:
herbicides. Revised ed. Thomson Publications, Fresno, CA.
24p. Ciba-Geigy Corporation, Agricultural Division. 1982. Safety
data sheet: Evik 80W. Greensboro, NC.
25. Morgan, D.P. 1982. Recognition and management of pesticide
poisonings, 3rd ed. U.S. Environmental Protection Agency,
Washington, DC. 120 pp.
56. Farm Chemicals Handbook, 70th ed. 1984. R. T. Meister, G. L.
Berg, C. Sine, S. Meister, and J. Poplyk, eds. Meister
Publishing Co., Willoughby, OH.
58. Weed Science Society of America, Herbicide Handbook Committee.
1983. Herbicide handbook of the weed science society of
America, 5th ed. Weed Science Society of America, Champaign,
IL. 515 pp.
62. The Pesticide Manual: A World Compendium, 7th ed. 1983. C.R.
Worthing, ed. The British Crop Protection Council, Croydon,
England. 695 pp.