United States
Environmental Protection
Agency
Office of Pesticides and Toxic Substances
Office of Pesticide Programs (TS-767C)
Washington, DC 20460 54Q/FS-89-D31
&EPA
Pesticide
Fact Sheet
Name Of Chemical: 2-(2-Methyl-4-chlorophenoxy)propionic
acid and its salts and esters
for ISSUanCe: Registration Standard
Date ISSUed: December 1988
Fact Sheet Number: 192
DESCRIPTION OF CHEMICAL
Chemical Names:
ANSI Common Names
2-(2-Methyl-4-chlorophenoxy)propionic
acid;
potassium 2-(2-methyl-4-chlorophenoxy)-
propionate;
diethanolamine 2-(2-methyl-4-
chlorophenoxy)-propionate;
dimethylamine 2-(2-methyl-4-
chlorophenoxy)-propionate;
isooctyl 2-(2-methyl-4-chlorophenoxy)-
propionate
MCPP (includes MCPP acid as well as the
MCPP potassium salt; MCPP diethanolamine
salt; MCPP dimethylamine salt; and
MCPP isooctyl ester)
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Other Common Names:
Principal Trade Names:
EPA (Shaughnessy) Code:
Chemical Abstracts
Service (CAS) Number:
Year of Initial
Registration:
Pesticide Type(s):
Chemical Family:
U.S. and Foreign
Producers:
Mecoprop
MCPP and Mecoprop
031501 (acid); 031503 (potassium salt);
031516 (diethanolamine salt); 031519
(dimethylamine salt), 031563 (isooctyl
ester).
7085-19-0 (acid)
1929-86-8 (potassium salt)
1432-14-0 (diethanolamine salt)
32351-70-5 (dimethylamine salt)
28473-03-2 (isooctyl ester)
1964 (potassium salt)
Herbicide; postemergence
Chlorinated phenoxy
Aceto Chemical Co., Inc.;
Akzo Zout Chemie Nederland;
Dow Chemical USA; Gilmore, Inc.;
A.H. Marks Co., Ltd.; Rhone-Poulenc
Ag Co.
USE PATTERNS AND FORMULATIONS
Registered Uses:
Principle'' Uses:
Formulations:
Terrestrial nonfood crop - Golf courses,
lawns, ornamental and sports turf, wide
area general indoor/outdoor treatments.
Aquatic nonfood crop - Drainage ditch
banks.
Forest trees - site preparation.
Ninety-six percent of the production
is used on turf, including lawns, sport
turf and commercial sod production. A
small percentage (1-4%) is used in
noncrop areas such as rights-of-way,
drainage ditch banks and forest site
preparation.
Granular, wettable powder, emulsifiable
concentrate, soluble concentrate/liquid,
pressurized liquid.
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Methods of Application: Foliar applications by ground equipment
including spreader, sprayer, pressure on
hose-end sprayer and pressurized
containers.
Application by air on specific
noncropland sites.
SCIENCE FINDINGS
Summary Science Statement: Virtually all data
reviewed were on MCPP acid. Data are needed for the
ester and each salt, with the exception of the
potassium salt, for which the data on the acid will
suffice, before the Agency can completely assess the
effects the forms of MCPP pesticides to organisms
and the environment.
The Agency's Office of Pesticide Programs (OPP) has
classified MCPP as a teratogen, based upon results of
a study in rats. Margins of safety may not be
adequate for some workers; additional data are
required to refine estimates of worker exposure. A
decision on the need for further regulatory action
will be made when these data have been submitted and
evaluated.
MCPP is stable to hydrolysis, had slow
photodegradation in water, and was very mobile in
sand, sandy loam, silt loam, and silty clay loam
soils. The submission of data are required for
terrestrial nonfood and aquatic nonfood uses for all
type formulations.
Freshwater fish toxicity data on MCPP acid is
incomplete, with a rainbow trout study that revealed
very low acute toxicity of MCPP acid of 124 ppm.
There were no acceptable acute freshwater aquatic
invertebrate data submitted.
There were no acceptable data for toxicity of any
MCPP-formulations to nontarget plants, endangered
species, or nontarget insects.
It is possible that chlorinated dibenzo-p-dioxins or
dibenzofurans aay be formed during the manufacture of
MCPP. It is also possible that nitrosamines may be
formed during the manufacture or storage of the MCPP
amine salts. Thus, manufacturing process information
is required to assess the possibility of the
formation of these contaminants.
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Chemica1 Characteri s t i c s
Physical state:
Color:
Odor:
Molecular Weight:
Empirical Formula:
Boiling Point:
Vapor Pressure:
Melting Point:
Density, bulk:
Solubility:
Crystalline solid
White to light brown
Odorless
214. 7
ClOHllcl°3
Decomposes
1.4 x 10-5
Hg at 30°C
94°-95°C
0.6g/ml, dry uncompacted
0.06% in water at 20°C; readily soluble
in alcohol, benzene, acetone,
chlorinated hydrocarbons
before reaching boiling
mm Hg at 20°C; 4.7 x 10"
oint
mm
Toxicology Characteristics
Acute Toxicity
Acute Oral:
Acute Dermal:
Acute Inhalation:
Primary Dermal
Irritation:
Primary Eye
Irritation:
558 mg/kg
Toxicity Category*
III
Not lethal to rabbits
at 2 g/kg
Data gap
No dermal irritation
in rabbits exposed for
24 hours to abraded and
unabraded skin
Produces persistent
corneal opacities,
iritis, and conjunctival
III
IV
irritation in both
and unwashed eyes.
Data gap.
washed
Dermal Sensitization:
*For a--description of Toxicity categories, see 40 CFR 156.10
Delayed Neurotoxicitv: Data are not available. Testing is not
required because MCPP and its derivatives and metabolites are not
organophosphates or cholinesterase inhibitors.
Subchronic Toxicity; Oral exposure of rats to technical MCPP
caused increased creatinine levels in females and decreased
glucose levels in males at 27 mg/kg; increased relative kidney
weights in both sexes at 9 mg/kg and 27 mg/kg, respectively. The
NOEL was 3 mg/kg.
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Chronic Studies
Chronic toxicity; No data are available and none are
required because this pesticide does not have food uses.
Oncoaenicity; There were no data available nor are any
required.
Teratogenicitv & Developmental Toxicitv: In a rat study,
oral exposure to 125 mg/kq of MCPP on days 6-15 of gestation
caused increased intra-uterine deaths, decreased crown/rump
lengths, and an increased incidence of delayed or absent
ossification of the sternebrae. The NOEL was 50 mg/kg/day.
MCPP was not teratogenic in rabbits. A reproductive toxicity
study is not required.
Mutaaenicity
Gene Mutations. In a spot test, no increases in reverse
mutations in 4 strains of Salmonella were seen with or
without metabolic activati'on and no forward mutations to
streptomycin resistance were seen in S.CQelicolor A3(2) in
spot or standard plates, with or without activation.
Other Tests. MCPP caused an increase in sister chromatid
exchange after single oral doses of 470 and 3800 mg/kg in
Chinese Hamsters. Additional data are required.
Major Route of Exposure; Dermal.
Physiological and Biochemical Characteristics
MCPP is absorbed through leaves and roots and is trans-
located. It stimulates nucleic acid and protein synthesis
and affects the efficacy of enzymes, either stimulating or
inhibiting cell division.
Environmental Characteristics
Absorption and Leaching: Unaged MCPP is very mobile in
sand,--sandy loam, silt loam, and silty clay loam soils.
Absorption has been positively correlated with the organic
matter of the soils.
Hydrolysis; Technical MCPP at 51-52 ppm did not hydrolyze
during 31 days of incubation in sterile buffered solutions
(pH 5, 7, and 9) at 25'C ± 2'C.
Bioaccumulation: Available data indicate a low potential
of MCPP to bioaccumulate in fish.
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Ground Water; Available data indicate that MCPP is mobile in
many soils and may potentially leach to ground water.
Ecological Characteristics
Avian acute toxicitv; MCPP acid has been shown to have an
acute oral LD50 of 700 mg/kg to the bobwhite quail and is
considered to be of low toxicity.
Avian dietary toxicity: Studies on MCPP acid indicate LC50
values of >5620 ppm and 5000 ppm for the mallard and the
bobwhite quail, respectively. These values are considered
practically nontoxic to avian species on subacute basis.
Freshwater fish acute toxicity: MCPP acid has very low
toxicity to the rainbow trout (LC5Q =124 ppm).
Freshwater invertebrates toxicity: There were no
acceptable freshwater invertebrate studies submitted.
Fish early lifestage and Aquatic invertebrate life cycle
toxicitv; There were no fish early lifestage nor aquatic
invertebrate life cycle, studies submitted.
Nontarget plant toxicity: There were no acceptable
nontarget plant studies submitted.
Nontaraet insects; There were no data on effects of MCPP
to honeybees and nontarget insects submitted.
Pesticide Incidents
There were no reports of MCPP pesticide incidents.
SUMMARY OF REGULATORY POSITION
1. Special review; The Agency is deferring a decision on
initiating a Special Review of MCPP based on teratogenicity
until data needed to refine worker exposure estimates have been
submitted and evaluated.
2. Restricted Use: The Agency will not restrict the use of MCPP
products at this time.
3. Special Data Requirements: The Agency is requiring a
submission of special studies to refine exposure estimates to
workers. These data will be used to assess the teratogenic risk
posed by MCPP to workers or other persons exposed to MCPP.
4. Basic Data Requirements; The Agency is requiring data
specific to the amines and the ester formulations as well as the
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acid. Acceptable data received on the MCPP acid will be
generally acceptable for the potassium salt.
5. Groundwater concerns: MCPP has the potential to contaminate
groundwater because it is mobile in many mineral soils. Studies
to evaluate the potential of MCPP and its metabolites to
contaminate groundwater are required. A groundwater statement
is required (see labeling section below).
6. Reentry requirement: Reentry data are required because of
the potential teratogenic risk and because some use patterns
involve post-treatment tasks that could result in dermal
exposures of workers to MCPP residues. Workers are not permitted
to reenter treated areas until sprays have dried and dusts have
settled (see labeling section below).
7. Protective clothing requirement; The Agency is requiring
mixers/loaders and applicators to use protective clothing and
equipment. See the protective clothing statement in the labeling
section below.
•
8. Endangered species regulatory position: There has been no
determination that MCPP acid or any MCPP formulation would
affect endangered animal or plant species.
9. Dibenzo-p-dioxins/Dibenzofurans: The Agency is requiring
submission of manufacturing process data on MCPP to assess the
possibility of contamination by dibenzo-p-dioxins or
dibenzofurans.
10. Nitrosamines; The Agency is requiring chemical analysis of
products containing MCPP amine salts for possible nitrosamine
contamination.
11. Data for Immediate Review; The Agency has identified data
which will be reviewed as soon as they are received: product
chemistry; environmental fate; dermal absorption, applicator
exposure and reentry; toxicity on the amine salts and ester; and
Tier II phytoxicity.
LABELING-^REOUIREMENTS
Statements for Manufacturing-Use Products
"Do not discharge effluent containing this product into
lakes, streams, ponds, estuaries, oceans or public waters
unless this product is specifically identified and
addressed in an NPDES permit. Do not discharge effluent
containing this product to sewer systems without previously
notifying the sewage treatment plant authority. For
guidance, contact your State Water Board or Regional Office
of the EPA."
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Statements for End-Use Products
Ground Water Contamination; "Although highly mobile, in
general phenoxy herbicides such as MCPP are not
sufficiently persistent to reach ground water from use as
specified on product labels. Most cases of ground water
contamination involving phenoxy herbicides have been
associated with mixing/loading and disposal sites. Caution
should be exercised when handling MCPP at such sites to
prevent contamination of water supplies."
Protective Clothing; "Mixer/loader and applicators must
wear long pants, long sleeve shirts, and gloves. Persons
applying liquid MCPP products such as sprays are required
to use goggles to cover their eyes."
Worker Reentry;
"Do not reenter or permit workers to reenter treated areas
until sprays have dried or dusts have settled."
Nontaraet Plant Species; •
Aquatic uses;
"Drift or run-off may adversely affect nontarget plants.
Do not apply directly to water except as specified on this
label. Do not contaminate water when disposing of
equipment washwaters."
Nonaquatic uses:
"Drift or run-off may adversely affect nontarget plants.
Do not apply directly to water or wetlands (swamps, bogs,
marshes and potholes). Do not contaminate water when
disposing of equipment washwaters."
SUMMARY OF DATA GAPS
The following data are required as specified. Uses of MCPP
potassium salt may be supported with data on either the salt or
MCPP acid. Codes for the different formulations are MCPP Acid
(1), Potassium Salt (2), Diethanolamine (3), Dimethylamine (4),
and Isooefeyl Ester (5).
MCPP Due Date - From
Study Formulation Date of Standard
Product Chemistry; All 9-12 months
Toxicology;
Acute Oral, Dermal, 3, 4, 5 9 months
Inhalation, Eye
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Irritation, Dermal
Irritation and
Sensitization
Subchronic
21-Day Dermal All
Chronic
Teratogenicity 3, 4, 5
Mutagenicity 3, 4, 5
Chromosomal Aberration All
Other (sister
chromatid exchange) 3, 4, 5
Special Testing
Dermal Absorption All
Applicator Exposure All
Reentry Protection; *
Foliar Dissipation All
Soil Dissipation All
Dermal Exposure All
Environmental Fate;
Hydrolysis All
Photodegradation
Water and Soil All
Metabolism
Aerobic Soil All
Anaerobic Aquatic 2, 4, 5
Aerobic Aquatic 2, 4, 5
Mobility
Leaching and Ad-
sorption/Desorption All
Dissipation
Soil All
Aqoatic (sediment) 2, 4, 5
Forestry 4
Accumulation
Irrigated Crops 2,4,5
Fish All
Aquatic Nontarget
Organisms 2, 4, 5
12 months
15 months
9 months
12 months
12 months
9 months
(protocols due
in 6 months)
27 months
27 months
27 months
9 months
9 months
27 months
27 months
27 months
12 months
27 months
27 months
27 months
39 months
12 months
12 months
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Wildlife & Aquatic Organisms:
Avian &
Acute Avian Oral
Avian Subacute
Upland Game Bird
Waterfowl
3, 4, 5
3, 4, 5
3, 5
9 months
9 months
9 months
Acniatic Organism;
Freshwater Fish
Coldwater Fish TGAI
Coldwater Fish TEP
Warmwater Fish TGAI
Warmwater Fish TGAI
Freshwater
Invertebrates TGAI
Invertebrates TEP
Plant Protection:
Nontarget Phytotox-
icitv - Tier II;
Seed Germina-
tion/Emergence TGAI All
Vegetative Vigor TGAI All
Aquatic Plant
Growth TGAI
Nontarget Insect;
Honey Bee Contact TGAI
3, 4, 5
1, 3, 4, 5
All
2, 4, 5
All
2, 4, 5
All
2, 3, 4, 5
9 months
9 months
9 months
9 months
9 months
9 months
9 months
9 months
9 months
9 months
CONTACT PERSON AT EPA; Mr. Richard Mountfort
--*•- Product manager (Team 23)
Fungicide-Herbicide Branch
Registration Division (TS-767C)
Office of Pesticide Programs
Environmental Protection Agency
401 M St., SW
Washington, D.C. 20460
Physical Location; Crystal Mall #2
1921 Jefferson Davis Highway
Arlington, VA
Telephone number: (703) 557-1830
10
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DISCLAIMER: The information in this Pesticide Fact Sheet is a
summary only and may not be used to satisfy data requirements
for pesticide registration and reregistration. The complete
Registration Standard for the pesticide may be obtained from the
National Technical Information Service. Contact the Product
Manager listed above for further information.
11
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