Glyphosate - Chemical Profile 2/85
CHEMICAL name: Isopropylamine salt of N-(phosphonomethyl)glycine
TRADE name(S): Roundup (56)
FORMULATION(S): Roundup is sold as an aqueous solution of the
isopropylamine salt of glyphosate and wetting
BASIC PRODUCER(S): Monsanto Agricultural Products Co.
800 N. Lindberg Blvd.
St. Louis, MO 63166
STATUS: General use
PRINCIPAL USES: For control of many annual and perennial grasses and
broadleaf weeds plus many tree and woody brush species in cropland
and noncrop sites. A foliar-applied translocated herbicide, it may be
applied in spring, summer, or fall to undesirable vegetation by boom
equipment, hand-held and high volume rollers, and wipers throughout
the U.S. and, in some states, by aerial application equipment in
forestry. Roundup is nonselective and may be applied to undesirable
species in four ways in the culture of desirable species: (1) Prior
to the emergence of the following desirable species: alfalfa, edible
beans, grasses for seed production, green or English peas, and
turfgrasses. (2) Prior to emergence or within (as a directed spray
or spot treatment) a growing stand of the following desirable species:
apples, asparagus, barley, citrus, cotton, corn, grapes, nut crops,
cherries, oats, ornamentals, pears, sorghum (milo), soybeans,
sugarcane, and wheat. (3) Within established avocado groves. (4)
Through selective equipment in cotton or soybeans.
It may also be applied by conventional means or through selective
equipment for general weed control in noncrop areas such as industrial,
recreational, and public areas such as airports, ditch banks, dry
ditches and canals, fencerows, golf courses, highways, industrial plant
sites, rights-of-way, etc., and in farmstead weed control (56).
Weeds which can be effectively controlled by Roundup herbicide:
A. Annual grasses B. Annual broadleaves
Annual bluegrass Common lambsquarter
Crabgrass species Common ragweed
Downy brome Fleabane (Erigeron species)
Panicum species Giant ragweed
Field sandbur Kochia
Foxtail species Pennsylvania smartweed
Shattercane Prickly lettuce
Volunteer wheat Redroot pigweed
A. Perennial grasses B. Perennial broadleaves
Bermudagrass Canada thistle
Kentucky bluegrass Common mullein
(Poa species) Curly dock
Dallisgrass Field bindweed
Fescue species Hemp dogbane
Johnsongrass Milkweed (Asclepias
Paragrass Silverleaf nightshade
Quackgrass Swamp smartweed
Wirestem Muhly (55a)
II. PHYSICAL PROPERTIES
MOLECULAR FORMULA: C3 H8 NO5 P (glyphosate); C6 H17 N2 O5 P
MOLECULAR WEIGHT: 169.1 (glyphosate); 228.2 (glyphosate-mono
PHYSICAL STATE: Colorless crystals (pure compound, zwitterion
ODOR: None (pure chemical) (54)
MELTING POINT: 200 C (pure compound) (62)
VAPOR PRESSURE: Negligible (pure chemical) (54)
SOLUBILITY: At 25 C 12 g/l water (pure compound);
glyphosate-isopropylammonium is very soluble
in water (62).
III. HEALTH HAZARD INFORMATION
OSHA STANDARD: NA
NIOSH RECOMMENDED LIMIT: NA
ACGIH RECOMMENDED LIMIT: NA
A. ACUTE TOXICITY
DERMAL: MLD = >7940 mg/kg (rabbit, glyphosate); >7940 mg/kg
(rabbit, Roundup formulation) (54).
Nonirritating (rabbit, glyphosate); mild irritant
(rabbit, Roundup formulation) (54).
LD50 = >5000 mg a.i./kg, 3750 mg a.e. (as salt)/kg
ORAL: LD50 = 4320 mg/kg (rat, glyphosate); 4900 mg/kg
(rat, Roundup formulation) (54).
LD50 = 5600 mg a.i./kg, 4050 mg a.e. (as salt)/
kg (rat) (62).
INHALATION: LC50 = 3.28 mg/l for 4 hour aerosol exposure,
slightly toxic (rat) (55b).
Rats exposed for 4 hours to a concentration of
12.2 mg/liter of air survived with no abnormal
reactions. No relevant gross pathology was noted
when they were sacrificed and autopsied 10 days
later (Roundup formulation) (54).
EYES: (FHSA) Score = 18.4 on a scale of 110, moderately
irritating (rabbit) (55b).
Slightly irritating to rabbits' eyes (62).
B. SUBACUTE AND CHRONIC TOXICITY:
Technical material was fed to rats and dogs at dietary levels of
200, 600, and 2000 ppm for 90 days. No significant differences from
control animals were observed in mean body weight, food consumption,
behavioral reactions, mortality, hematology, blood chemistry, or
urinalyses. There were no relevant gross or histopathologic changes.
Two-year feeding studies to rats and dogs and rat production
studies at dietary levels of 30, 100, and 300 ppm have shown no adverse
Tests on the biologically active ingredient in this formulation
(glyphosate) showed that glyphosate did not cause any mutagenic,
carcinogenic, teratogenic (birth defects), adverse reproductive
changes, or neurotoxic effects (55b).
In 2-yr feeding trials on rats and dogs no ill-effect was observed
at 300 mg/kg diet (highest dose treated) (62).
IV. ENVIRONMENTAL CONSIDERATIONS
Toxicological investigations conducted with bobwhite quail, mallard
ducks, honey bees, rainbow trout, bluegills, and other species of fish
show that these species have an extremely high tolerance to glyphosate.
Strong adsorption to soils is evidenced in part by low
phytotoxicity produced by soil applications. Glyphosate leaching is
Microbiological degradation is the major cause of decomposition of
glyphosphate in soil. Depending on soil and microfloral population
types, varying rates of decomposition occur, producing for example,
from 10 to 60% 14CO2 from glyphosate - C14 over growing season time
periods or less. Normally the half life is less than 60 days.
Negligible loss from photodecomposition and/or volatilization.
Glyphosate is relatively nonpersistent in soil and offers little or no
preemergent activity; thus it appears that crops can be planted or
seeded directly into treated areas following application. Soil
residues usually are near or below 10% of that applied within a growing
Environmental Toxicity Information:
96-hr TL50 Bluegill: 14 mg/l, slightly toxic
96-hr TL50 Carp: 3.9 ppm, moderately toxic
96-hr TL50 Trout: 11 mg/l, slightly toxic
96-hr LC50 Catfish: 16 mg/l, slightly toxic
96-hr LC50 Crayfish: >1000 ppm, practically nontoxic
96-hr LC50 Fathead minnow: 9.4 mg/l, moderately toxic
48-hr LC50 Daphnia: 5.3 mg/l, moderately toxic
Carp contained in a static pond were unaffected at any time during
the 90-day observation period by exposure to an aerial application of
Roundup herbicide at the intended use level. Tissue residue analyses
indicated that glyphosate will not bioaccumulate (55b).
LC50 (8-d) for quail and ducks was >4640 mg a.i./kg diet. LC50
(96-hr) is: for trout 86 mg a.i./l, 8.2 mg a.e. (as salt)/kg; for
bluegill 120 mg/l, 10.5 mg a.e. (as salt)/kg (62).
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 sub-
stitute for a more exhaustive review of the literature nor for the
judgement of a physician or other trained professional.
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: Irritant to eyes and respiratory
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 treated by: 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 (25).
EYE CONTACT: Flush contaminated eyes with copious amounts of
fresh water for 15 minutes (25).
NOTES TO PHYSICIAN:
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 withdrawing
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 precautions:
(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
GENERAL: Flash Point (TCC): >200 F. Water-based formulation,
Special Firefighting Procedures: None.
Unusual Fire and Expolosion Hazards: None (55b).
EXTINGUISHER TYPE: In case of fire, use water spray, foam, dry
chemical or CO2 (55b).
Tank mixtures with residual type herbicides, such as substituted
ureas, triazines, or others may reduce activity of glyphosate. Other
combinations with foliage absorbed herbicides such as paraquat,
dalapon, MSMA, phenoxy, or other hormone type herbicides may modify or
lower action of glyphosphate. Corrosive to iron and galvanized steel.
Do not hold spray mixtures in galvanized or unlined steel tanks (except
stainless) for extended periods. Following application clean sprayer
parts by flushing with water (54).
VIII. PROTECTIVE MEASURES
STORAGE AND HANDLING: Formulations of glyphosate are quite stable under
temperatures up to 140 F, however will freeze at -20 F, but will go
back into solution upon thawing. Does not require heated facilities.
Handle with care, avoid contact with eyes, avoid spray drift to
desirable vegetation. Mix store, and apply glyphosate solutions in
stainless steel, aluminum, fiberglass, plastic, or plastic-lined steel
PROTECTIVE CLOTHING: During mixing or pouring operations or other
activities in which eye contact with undiluted Roundup herbicide is
likely to occur, splash goggles should be worn.
In cases in which prolonged or repeated skin contact with Roundup
herbicide may occur, long-sleeved shirt, long pants and rubber or
plastic gloves are recommended. Clothing soaked with Roundup solution
should be promptly removed and laundered before reuse (55b).
PROTECTIVE EQUIPMENT: Respiratory protection is not required for
normal use and handling. During periods of abnormal exposure to heavy
spray or mist, use a NIOSH approved dust/mist respirator (55b).
IX. PROCEDURES FOR SPILLS AND LEAKS
IN CASE OF EMERGENCY, CALL, DAY OR NIGHT
PESTICIDE TEAM SAFETY NETWORK/CHEMTREC
Open dumping is prohibited.
This product (Roundup), spray mixture or rinsate that cannot be
used or chemically reprocessed should be disposed of in a landfill
approved for pesticides.
Triple rinse container and offer for recycling, reconditioning, or
disposal in approved landfill.
Consult federal, state, or local disposal authorities for
additional or alternative requirements.
Avoid skin and eye contact.
Soak up small amounts with absorbent clays (kitty litter, oil dri,
Sweep or scoop up spilled material and dispose of in approved
Wash down surfaces (floors, truck beds, streets, etc.) with
detergent and water soluion (55b).
X. LITERATURE CITED
25. Morgan, D.P. 1982. Recognition and management of pesticide
poisonings, 3rd ed. U.S. Environmental Protection Agency,
Washington, DC. 120 pp.
54. Weed Science Society of America, Herbicide Handbook Committee.
1979. Herbicide handbook of the weed science society
of America, 4th ed. Weed Science Society of America,
Champaign, IL. 479 pp.
55a. Monsanto Agricultural Products Company. 1978. Guide for
Roundup herbicide. St. Louis, MO.
55b. Monsanto Company. 1982. Material safety data: Roundup
herbicide. St. Louis, MO.
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.
62. The Pesticide Manual: A World Compendium, 7th ed. 1983. C.R.
Worthing, ed. The British Crop Protection Council, Croydon,
England. 695 pp.