Environmental Protection Office of Pestiâde Progrann (TS-766C)
Agency Washington. DC 20460
- 540/FS—88—124
IEPA Pesticide
Fact Sheet
Name of Chemical: Glyphosate
Reason for Issuance: Registration Standard
Date Issued: June 1986
Fact Sheet Number: 173
1. Description of chemical
Generic name: N—(phosphonomethyl)glycine
Common name: Glyphosate
Trade names: Roundup, Rodeo, Roundup L&G, Polado, Shackle, Shackle C
EPA Shaughnessy Codes: Isopropylamine (IPA) salt of glyphosate 103601
Sodium Salt of glyphosate 103603
Chemical Abstracts Service (CAS) number: 38641—94—0
Year of initial registration: 1974
Pesticide type: Herbicide; Plant Growth Regulator
U.S. and foreign: Monsanto in the United States and GENP International
Corporation in Taiwan.
2. Use patterns and formulations
Application sites: Terrestrial food (soybeans, cotton, corn, sorghum,
wheat, vegetables, citrus fruits, pome fruits, pastures and alfalfa)
nonfood, noncrop, greenhouse nonfood, aquatic food and nonfood,
domestic outdoor and forestry.
Types and methods of applications: Postemergence spray to foliage of
the vegetation controlled before planting, after planting but prior
to crop emergence or as a directed spray in established crops.
Applied using ground equipment, hand—held, recirculating and shielded
sprayers, wiper applications and with aerial equ.ipment.
Pests controlled: Emerged annual and perennial grasses, broadleaf weeds,
and woody brush and trees.
Application rates: 0.3 to 1 .0 pound/acre active ingredient (lb/A ai)
to control annual weeds and grasses; 1.0 to 4.0 lb/ai to control
perennial weeds and grasses.
Types of formulations: 1.04 lb active ingredient (ai)/gal emulsifiable
concentrate (EC); 0.42, 3, and 4 lb ai/gal soluble concentrate/liquid
(SC/L); 5% and 6.6% ai SC/L; 0.5%, 0.96%, and 1% ai ready—to—use (RTtJ);
and 0.75% and 0.96% ai pressurized liquid (Pri).
Usual carrier: Water

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3. Science findings
Summary Science Statement
Glyphosate has low acute toxicity (Category III) for acute oral,
acute dermal, and primary eye irritation and is in Category IV for
primary skin irritation. it is not teratogenic to rats or rabbits
and is not mutagenic. The oncogenic potential is not fully defined
at this time. Repeat oncogenic studies are required in mice and rats.
Glyphosate is no more than slightly toxic to birds, aquatic
invertebrates, freshwater fish and marine/estuarine organisms. it
does pose a hazard to some endangered species.
Glyphosate is stable to hydrolsis and strongly adsorbed to the
soil and had a low potential to contaminate ground water.
Chemical characteristics:
The technical isopropylaxnirie salt is a white crystalline solid
with a melting point of 200 °C and a bulk density of 1 .74. It is
1% soluble in water at 25 °C, insoluble in ethanol, acetone, or
benzene. The technical sodium salt of glyphosate is a white crystalline
solid which decomposes at 140 °C with a bulk density of 30 pounds/cubic
food (lb/ft 3 ). It is soluble in water and insoluble in organic
solvents.
Glyphosate is corrosive to iron and galvanized steel. Spray
mixtures should not be held in galvanized or unlined steel tanks
(except stainless) for an extended period. Glyphosate solutions
should be mixed, stored, and applied on in stainless steel, aluminum,
fiberglass, plastic or plastic lined containers.
Toxicology characteristics:
Acute Toxicology
Acute Oral Toxicity — rat = 4320 milligrams/kilogram (mg/kg) for
males and females — Toxicity Category III
Acute Dermal Toxicity - rabbit — equal to or greater than (>) 794 mg/kg
for females > 5010 mg/kg for males -
Toxicity Category III
Primary Dermal Irritation — rabbit — Primary Irritation-Score (P.I.s.)
= 0.0/8 (24 hours)
Toxicity Category IV — Not an Irritant

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Primary Eye Irritation — rabbit - P.I.S. = 12.6/110 at 1 hour
Toxicity Category III — Mild Irritant
Acute Inhalation or Derma]. Sensitization studies have not been
submitted and are being required.
Major routes of exposure
The primary potential for exposure from SC/L formulation is
during mixing and loading where both dermal and ocular exposure may
occur via splashing. Inhalation and dermal exposure may occur during
application of the liquid ready—to—use (RTU) and pressurized liquid.
Information from the Agriculture Department of Food and Agriculture
reported incidence of worker poisonings and illness during mixing,
loading and application from exposure to glyphosate. Most illnesses
or poisonings were due to skin or eye irritation. The Agency is
requiring “Worker Safety Rules” including protective clothing to
reduce exposure of workers to glyphosate.
Chronic Feeding/Oncogenicjty Studies
In the mouse chronic feeding study non—neoplastic changes noted in
male mice included centrilobular hypertrophy and necrosis of hepatocytes,
chronic interstitial nephritis, and proximal tubule epithelial cell
basophilla and hypertrophy in females. The no—observable effect
level (NOEL) for non—neoplastic chronic effects was the mid dose,
5000 parts per million (ppm).
In the rat chronic feeding study no effects of treatment on the
incidence of non-neoplastic lesions were noted. The NOEL for this
study was 31 mg/kg/day.
The 1-year chronic feeding study in dogs indicated an apparent
decrease in the absolute and relative weights of pituitaries from mid-
and high-dose dogs. Additional data have been requested to better
assess this apparent effect. The tenative NOEL is 20 mg/kg/day,
pending submission of requested data.
The oncogenic potential of glyphosate is not fully understood at
this time. A review of the mouse oricogenicity study noted a slight
increase in renal tubular adenomas. Upon review by the Toxicology
Branch Ad Hoc Oncogenicity Committee and the Science Advisory Panel,
the Agency concluded that the mouse study was not adequate to define
the oncogenic potential of glyphosate. A review of the rat oncogenicity
study determined that a maximum tolerated dose had not been reached;
therefore, the rat study was also inadequate to determine oncogenic
potential. The Agency has required that the mouse and rat oncogenicity
studies be repeated.

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Subchronic Toxicology Studies
No acceptable subchronic feeding studies are available for
technical glyphosate. No additional studies are required because the
rat chronic feeding and 1—year dog studies discussed above fulfill
these requirements.
An acceptable 21-day dermal study in rabbits is available for
glyphosate. The NOEL for this study was 1000 mg/kg/day. The only
effect noted was slight edema and erythema of the skin at 5000 mg/kg/day
(highest dose tested).
Teratology and Reproduction Studies
A teratology study in rats indicated no evidence of teratology
up to 3500 mg/kg/day (highest dose tested). A fetotoxic and maternal
toxic NOEL for this study is 1000 mg/kg/day.
A teratology study in rabbits indicated rio evidence of teratology
up to 350 mg/kg/day (highest dose tested). The maternal toxic NOEL
is 175 mg/kg/day and the fetotoxic NOEL is 350 mg/kg/day for this
study.
A three—generation rat reproduction Study indicated no effects
on fertility or reproductive parameters up to 30 mg/kg/day (highest
dose tested). The NOEL for systemic effects is 10 mg/kg/day.
No additional teratology or reproduction studies are required
for glyphosate.
Mutagenicity Studies
Glyphosate was negative in all mutagenicity studies submitted to
satisfy the Agency’s requirements for gene mutation, chromosomal
aberrations and primary DNA damage. No additional mutagenicity studies
are required.
Metabolism
Available rat metabolism studies are not adequate to fulfill
Guidelines requirements, therefore repeat studies are required.
N-Ni troso Glyphosate
The Agency has determined that technical glyphosate contains
N—nitroso glyphosate (NNG) as a contaminant at levels of 0.1 ppm or
less. The Agency has determined that testing of nitroso contaminants
will normally be required only in those cases in which the level of

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nitroso compounds exceeds 1 .0 ppm (See “Pesticide Contaminates with
N—nitroso Compound; Proposed Policy 45 FR 42854 (June 25, 1980)”].
No data are required on N—nitroso glyphosate because the amount of
N—nitroso glyphosate is less than 1 .0 ppm.
Plant Metabolite - Aminomethylphosphonic Acid
The Agency has determined that the inetabolite aminomethylphosphonic
acid (AMPA) is formed on plants in amounts that can range as high as
28 percent of total residue in the plant. Acceptable acute toxicology
studies and a 90-day subchronic feeding study are available for this
metabolite. The available data do not suggest that this compound
poses any hazard distinct from that of the parent compou.nd. The need
for additional testing on this compound will be assessed after
submission of an acceptable rat metabolism study with glyphosate.
Physiological and Biochemical Behavior Characteristics
Foliar Absorption: Readily absorbed through foliage and
translocated throughout the plant.
Translocation: Translocated from treated areas to untreated
shoots and roots.
Mechanism of Pesticidal Action: Inhibition of amino acid biosynthesis
resulting in a reduction of protein synthesis and inhibition of
growth.
Metabolism and Persistence in Plants: Metabolism occurs via
N—methylation and ultimately yields N—methylated glycines and
phosphonic acids. Parent compound and its metabolite AMPA
are considered to be residues of concern in pJ .. nts.
Metabolism and Persistence in Animals: Glyphosate and AMPA have
been identified in the tissues, urine, arid feces of rats and
rabbits; liver of poultry, swine, and cattle; and the kidney
of swine and cattle.
Environmental Characteristics:
Adsorption and leaching in basic soil types: strongly adsorbed
to the soil and very little leaching.
Microbial Breakdown: Microbial breakdown is the major cause of
decomposition of glyphosate in soil. Depending on soil and
microfloral population types, varying rates of decomposition
occur.
Loss from photodecomposition and/or volatizatiori: Negligible
losses via either route.

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Bioaccumulation - Low potential to bioaccumulate in edible and
visceral tissue of catfish or whole body tissue of clams.
Potential to Contaminate Ground Water: Low potential to contaminate
ground water because glyphosate is tightly bound to the soil.
Ecological Characteristics:
Avian Acute Oral Toxicity: Bobwhite quail > 2000 mg/kg
Avian Subacute Dietary Toxicity: Mallard duck > 4640 ppm
Bobwhite quail > 4640 ppm
Avian Reproduction Stzi dies: }lallard duck > 1000 ppm
Bobwhite quail > 1000 ppm
Acute Toxicity to Freshwater Fish: Bluegill sunfish = 120 mg/L
Rainbow trout = 86 mg/L
Chronic Toxicity to Freshwater Fish: Fathead minnow with a
maximum threshold concentration (MATC) > 25.7 mg/L
Acute Toxicity to Freshwater Lnvertebrates: Daphnia magna = 780 ppm
Chironomus plurnosus = 55 ppm
Chronic Toxicity to Freshwater Invertebrates: Daphnia magna MATC
> 50 < 96 mg/L
Acute Toxicity to Marine/Estuarine Organisms: Grass shrimp = 281 ppm
Fiddler Crab = 934 ppm
Atlantic Oyster > 10 mg/L
These data indicate that glyphosate is no more than slightly
toxic to birds on an acute or dietary basis and will not cause avian
reproduction impairment.
The available data indicate that glyphosate is practically
nontoxic to both coldwater and warrnwater fish, no more than slightly
toxic to freshwater invertebrates, grass shrimp, fiddler crab or
Atlantic oyster.
Hazard to Endangered Species
Minimal hazard is expected to aquatic endangered species.
Previous consultations with Office of Endangered Species have
resulted in jeopardy opinions and labeling for crops (alfalfa,
apples, barley, corn, cotton, pears, and wheat), rangeland and
pastureland, silvicultural sites, aquatic sites, and noncropland
use. Labeling is being imposed to reduce the risk to endangered
species.

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Tolerance Assessment
40 CFR 180.364 Glyphosate, tolerances for residues.
Tolerances are established for combined residues of
glyphosate(N-(phosphonomethyl)glycine) and its metabolite
aminomethyiphosphonic acid resulting from the application of
isopropylamine salt of glyphosate in or on the following raw
agricultural commodities:
Parts per
Commodity million
Alfalfa 200
Alfalfa, fresh and hay 0.2
Almonds, hulls 1
Asparagus 0.2
Avocados 0.2
Bahiagrass 200.0
Bermudagrass 200.0
Bluegrass 200.0
Bromegrass 200.0
Citrus fruits 0.2
Clover 200.0
Coffee beans 1
Cotton, forage 15
Cotton, hay 15
Cottonseed 15
Cranberries 0.2
Fescue 200.0
Forage grasses 0.2
Forage legumes (except soybeans and —
peanuts) 0.4
Grain crops 0.1 (N)
Grapes 0.2
Grasses, forage 0.2 (N)
Guavas 0.2
Leafy vegetables 0.2 (N)
Mangoes 0.2
Nuts 0.2
Orchardgrass 200.0
Papayas 0.2
Peanuts 0.1
Peanut, forage 0.5
Peanut, hay - 0.5
Peanut, hulls 0.5
Pineapple 0.1
Pistachio nuts 0.2

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Pome fruits 0.2
Root crop vegetables 0.2 (N)
Ryegrass 200.0
Seed and pod vegetables 0.2 (N)
Seed and pod.vegetables, forage 0.2 (N)
Seed and pod vegetable, hay 0.2 (N)
Soybeans 6
Soybeans, forage 15
Soybeans, hay 15
Stone fruit 0.2
Timothy 200.0
Wheatgrass 200.0
Tolerances are established for combined residues of glyphosate
(N-(phosphonomethyl)glycine) and its metabolite aminomethyiphosphonic
acid resulting from application of glyphosate isopropylamine salt for
herbicidal purposes in or the sodium sesqui salt for plant growth
regulator purposes in or on the following raw agricultural commodities:
Parts per
Commodity million
Cattle, kidney 0.5
Cattle, liver 0.5
Fish 0.25
Goats, kidney 0.5
Goats, liver 0.5
Hogs, kidney 0.5
Hogs, liver 0.5
Horses, kidney 0.5
Horses, liver 0.5
Poultry, kidney 0.5
Poultry, liver 0.5
Sheep, kidney 0.5
Sheep, liver 0.5
Sugarcane 2.0
Tolerances are established for the combined residues of glyphosate
(N-phosphonomethylglycine) and its metabolite aminomethyiphosphonic
acid, resulting from the use of irrigation water containing residues
of 0.5 ppm following applications on or around aquatic sites, at 0.1
ppm on the crop groupings, citrus, cucurbits, forage grasses, forage
legumes, fruiting vegetables, grain crops, leafy vegetables, nuts,
pome fruits, root crop vegetables, seed and pod vegetables, stone
fruit and the individual commodities cottonseed, hops, and avocados.
Where no tolerances are established at higher levels from other uses
of glyphosate in or on the subject crops, the higher tolerances should
also apply to residues from the aquatic uses cited in this paragraph.

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21 CFR 193.235 Glyphosate.
Tolerances are established for the combined residues of the
herbicide glyphosate and the metabolites as indicated when present
the therein as a result of the herbicide application to growing crops.
1. Glyphosate. (N—(phosphonomethyl)glycine] and its metabolite
aminomethyiphosphonic acid resulting from the application of the
isopropylamine salt of glyphosate for herbicidal purposes and/or
the sodium sesqui salt for plant growth regulator purposes.
Foods Parts Per Million
—Molasses, sugarcane 30.0
2. Glyphosate (N-(phosphonomethyl)glycjne] and its metabolite
aminomethyiphosphonic acid resulting from the application of the
isopropylam.ine salt of glyphosate for herbicidal purposes.
Foods Parts Per Million
Oil, palm 0.1
Olives, imported 0.1
Tea, dried 1.0
Tea, instant 4.0
21 CFR 561 .253 Glyphosate
A feed additive regulation is established permitting the combined
residues of the herbicide glyphosate (N—(phosphonomethyl)glycine) and
its metabolite aminomethylphosphonic acid in or on the following feed
commodities:
Feeds Part Per Million
Citrus pulp, dried 0.4
Soybean hulls 20.0
Canadian tolerances have been established for residues of
glyphosate in or on carrots, sugarbeets, lettuce, cabbage, beans,
peas, soybeans, citrus, pome fruits, stone fruits, grapes, cereals,
grasses, and forage legumes) at 0.1 ppm.
. he tolerance assessment indicated several changes in tolerance
listin - are needed and several crops and processed commodities require
additional residue data. Refer to the Regulatory Position and
Rationale for listings of crops and changes needed.

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The acceptable daily intake (ADI) for glyphosate is currently
based on the finding of renal tubular dilation in F3b pups in the rat
three—generation reproduction study. The NOEL for this effect was
10 mg/mg/day. Using a hundredfold safety factor, the ADI for glyphosate
is 0.1 mg/kg/day, which is equivalent to a maximum permissible intake
(MPI) of 6.0 mg/day in a 60 kg individual. Existing tolerances produce
a theoretical maximum residue contribution (TMRc) of 1 .4238 mg/day
from a 1 .5 kg diet which occupies 23.73 percent of the ADI.
Reported Pesticide Incidents
Most of the pesticide incidents reported involve illnesses of
workers due to skin or eye irritation during mixing, loading, or
ground application of glyphosate. Symptoms include derma]. irritation,
nausea or dizziness.
4. Summary of Regulatory Position and Rationale
A review of the data available indicate that no risk criteria
listed in 40 CFR 154.7 have been exceeded for glyphosate. A repeat
of the mouse and rat oncogenicity studies is required to fully detail
the oncogenic potential of glyphosate.
The Agency will issue registrations for substantially similar
products and will issue significant new uses on a case—by—case basis.
Information available is adequate to assess any potential risk from
issuance of new uses or new products.
The Agency is not imposing a ground water advisory statement for
glyphoste because the potential of glyphosate to contaminate ground
water is very low.
The Agency is not requiring a reentry interval or reentry data
for glyphosate because glyphosate has a low toxicity and the “Worker
Safety Rules” required are believed to reduce any risk to workers
from exposure to glyphosate during mixing, loading, or application of
glyphos ate.
The Agency is requiring that labeling on all end-use products
containing glyphosate bear “Worker Safety Rules” including protective
clothing (face shield or goggles, chemical resistant gloves, apron,
and shoes, shoe coverings or boots) to be worn when mixing, loading,
applying the pesticide, or when handling concentrate.
The Agency is imposing endangered species labeling for crops
(alfalfa, apples, barley, cotton, pears, and wheat), rangeland and
pastureland, silvicultural sites, aquatic sites, and noncrop].and
areas to protect plant and animal species in Jeopardy from application
of glyphosate. The Agency will notify the registrants when these
statements are to appear on the labeling.

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The Agency is imposing a label restriction prohibiting the
rotation of food or feed crops in glyphosate—treated soils unless
glyphosate is registered for use on those crops. This restriction
will be in effect until requested crop rotational data are sutinitted
and reviewad.
The Agency is imposing a label restriction prohibiting the use
of glyphosate on rice fields in which crayfish and catfish are incl .x ed
in cultural practice to ensure that catfish and crayfish harvested
for human food are not exposed to residues of glyphosate.
The Agency is imposing label restrictions prohibiting the use of
water containing glyphosate fran rice cultivation for irrigation of
food or feed crops not appearing on the glyphosate label or use of
water fran glyphosate—treated ponds for irrigation purposes for 24 hours
after treatment. The restrictions are to ensure that food or feed
crops not having tolerances are not exposed to residues of glyphosate.
The Agency is requiring that additional residue data and/or
information be submitted on the following raw agricultural ccii n dities:
parsnips; turnips, turnip greens; onions; cranberries; sorghum grain;
asparagus; coffee; rnangoes; peanuts, peanut forage, hay and hulls;
and su arcane. Additional residue data and/or information are required
on the following processed calln-vDditles: potato granules, chips, and
dried potatoes; processed caiircdities of si.x arLeets (dehydrated pulp,
rrolasses, and refined sugar); dried citrus pulp; prunes; processed
products of grapes; corn oil (cruide and refined); corn—milled
products; alfalfa seed; processed olives and olives. Additional
residue data and/or information are required on the following crop
groups: root and tuber vegetables; leaves of root and tuber vegetables;
beib vegetables group; fruiting vegetables (except cucurbits) group;
citrus fruit group; snail fruits and berries group; and cereal grains
group. All other registered food or feed crops are adequately supported
yj residue data.
The Agency is requiring that a grazing restriction prohibiting
the feeding of sugarcane forage or pineapple forage be added to the
label. Alternatively, a petition proposing tolerances for stx arcane
forage and pineapple forage with supporting data be subnitted.
The Agency is requiring the following changes in the tolerance
regulations: 1) the established tolerances on crop groups: root crop
vegetables, seed and pods vegetables, and leafy vegetables should be
deleted and tolerances established for the individual m nters of the
groups, 2) amend the entry “nuts” to read “tree nuts”, 3) the existing
tolerances for alfalfa, clover, and forage legurres should be deleted
and separate tolerances for glyphosate and AMPA of 100 ppit established

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for residues of forage and hay of nongrass animal feed, 4) the existing
tolerances for forage legumes should be deleted and separate tolerances
of 0.2 ppm should be established in or on legume vegetables (except
soybeans) and the foliage of legume vegetables, except soybean forage
and hay, 5) the established tolerances for forage grasses, grasses,
forage; bahiagrass, bermudagrass, bluegrass, bromegrass, fescue,
ozchardgrass, ryegrass, timothy and wheat grass should be deleted and
a separate tolerance of 100 ppm for residues in or on grass forage
and hay be established. These changes are based on new tolerance
expressior s (Refer to 40 CFR 180.34).
The Agency will raise the tolerance for instant tea from 4 ppm
to 7 ppm because processing studies available support a tolerance of
7 ppm.
The tolerances for cottonseed hay and forage must be cancelled
because cottonseed hay is not considered a raw agricultural commodity
of cotton and a grazing restriction exists.
Additional data are required on crops treated with irrigation
water containing residues of glyphosate. Once these data are submitted,
the crop groupings presently listed in Section (c) of 180.364 must be
deleted and tolerances based on requested field irrigation tests must
be established for glyphosate residues in or on members of the current,
appropriate crop groups and all major irrigated crops which are not
included in a crop group such as cottonseed, sugarcane, peanuts, etc.
5. Summary of Major Data Gaps
Product Chemistry 6-12 Months
Repeat of Mouse and Rat Oncogenic Studies 50 Months
Environmental Fate Studies 9—50 Months
Residue Chemistry Data 18—24 Months
6. Contact Person at EPA
Robert J. Taylor
Office of Pesticide Programs, EPA
Registration Division (TS—767C)
401 M Street SW.
Washington, DC 20460
Phone: (703) 557—1800
Disclaimer : The information presented in this Pesticide Fact Sheet is for
informational purposes only and may not be used to fulfill data requirements
for pesticide registration and reregistration.

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