mecoprop (Chipco Turf Herb. MCPP) Herbicide Profile 12/88
EPA Pesticide Fact Sheet
Name of Chemical: 2-(2-Methyl-4-chlorophenoxy)propionic acid and its
salts and esters
Reason for Issuance: Registration Standard
Date Issued: December 1988
Fact Sheet Number: 192
1. DESCRIPTION OF CHEMICAL
- Chemical 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
- ANSI Common Names: MCPP (includes MCPP acid as well as the MCPP
potassium salt; MCPP diethanolamine salt; MCPP dimethylamine salt; and
MCPP isooctyl ester)
- Other Common Names: Mecoprop
- Principal Trade Names: MCPP and Mecoprop
- EPA (Shaughnessy) Code: 031501 (acid); 031503 (potassium salt);
031516 (diethanolamine salt); 031519 (dimethylamine salt), 031563
- Chemical Abstracts Service (CAS) Number: 7085-19-0 (acid); 1929-86-8
(potassium salt); 1432-14-0 (diethanolamine salt); 32351-70-5
(dimethylamine salt); 28473-03-2 (isooctyl ester)
- Year of Initial
- Registration: 1964 (potassium salt)
- Pesticide Type(s): Herbicide, postemergence
- Chemical Family: Chlorinated phenoxy
- U.S. and Foreign Producers: Aceto Chemical Co., Inc.; Akzo Zout
Chemie Nederland; Dow Chemical USA; Gilmore, Inc.; A.H. Marks Co.,
Ltd.; Rhone-Poulenc Ag Co.
2. USE PATTERNS AND FORMULATIONS
- Registered Uses: Terrestrial nonfood crop - Golf courses, lawns,
ornamental and sports turf, wide area general indoor/outdoor
- Aquatic nonfood crop - Drainage ditch banks.
- Forest trees - site preparation.
- Principle Uses: 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.
- Formulations: Granular, wettable powder, emulsifiable concentrate,
soluble concentrate/liquid, pressurized liquid.
- Methods of Application: Foliar applications by ground equipment
including spreader, sprayer, pressure on hose-end sprayer and
- Application by air on specific noncropland sites.
3. 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
may 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.
Physical state: Crystalline solid
Color: White to light brown
Molecular Weight: 214.7
Empirical Formula: CloHllC103
Boiling Point: Decomposes before reaching boiling point
Vapor Pressure: 1.4 x 10-5 mm Hg at 20 degrees C; 4.7 x 10 5 mm
Hg at 30 degrees C
Melting Point: 94-95 degrees C
Density, bulk: 0.6g/ml, dry uncompacted
Solubility: 0.06% in water at 20 degrees C; readily soluble in alcohol,
benzene, acetone, chlorinated hydrocarbons
Acute Toxicity Toxicity Category*
Acute Oral: 55% mg/kg III
Acute Dermal: Not lethal to rabbits III
at 2 g/kg
Acute Inhalation: Data gap
Primary Dermal No dermal irritation IV
Irritation: in rabbits exposed for 24 hours
to abraded and unabraded skin
Primary Eye Produces persistent corneal
Irritation: opacities, iritis, and conjunctival
irritation in both washed and unwashed eyes.
Dermal Sensitization: Data gap.
*For a description of Toxicity categories, see 40 CFR 156.10
- Delayed Neurotoxicity: 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.
- Chronic toxicity: No data are available and none are required because
this pesticide does not have food uses.
- Oncogenicity: There were no data available nor are any required.
- Teratogenicity & Developmental Toxicity: In a rat study, oral
exposure to 125 mg/kg 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.
- Gene Mutations. In a spot test, no increases in reverse
mutations in 4 strains of Salmonella were seen with or without
metabolic activation and no forward mutations to streptomycin
resistance were seen in S. Coelicolor 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 translocated. It
stimulates nucleic acid and protein synthesis and affects the efficacy
of enzymes, either stimulating or inhibiting cell division.
- 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 degrees C plus or minus 2 degrees C.
- Bioaccumulation: Available data indicate a low potential of MCPP to
bioaccumulate in fish.
- Ground water: Available data indicate that MCPP is mobile in many
soils and may potentially leach to ground water.
- Avian acute toxicity: 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
- 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 (LC50 = 124 ppm).
- Freshwater invertebrates toxicity: There were no acceptable
freshwater invertebrate studies submitted.
- Fish early lifestage and aquatic invertebrate life cycle toxicity:
There were no fish early lifestage nor aquatic invertebrate life cycle
- Nontarget plant toxicity: There were no acceptable nontarget plant
- Nontarget insects: There were no data on effects of MCPP to honeybees
and nontarget insects submitted.
- There were no reports of MCPP pesticide incidents.
4. 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 acid. Acceptable
data received on the MCPP acid will be generally acceptable for the
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
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.
5. LABELING REQUIREMENTS
- 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."
- 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
- Worker Reentry:
- "Do not reenter or permit workers to reenter treated areas until
sprays have dried or dusts have settled."
- Nontarget 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."
6. 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 Isooctyl Ester (5).
MCPP Due Date - From
Study Formulation Date of Standard
_____ ___________ ________________
Product Chemistry: All 9-12 months
Acute Oral, Dermal, 3, 4, 5 9 months
Irritation, Dermal Irritation
21-Day Dermal All 12 months
Teratogenicity 3, 4, 5 15 months
Mutagenicity 3, 4, 5 9 months
Chromosomal Aberration All 12 months
chromatid exchange) 3, 4, 5 12 months
Dermal Absorption All 9 months
Applicator Exposure All (protocols due in 6 months)
Foliar Dissipation All 27 months
Soil Dissipation All 27 months
Dermal Exposure All 27 months
Hydrolysis All 9 months
Water and Soil All 9 months
Aerobic Soil All 27 months
Anaerobic Aquatic 2, 4, 5 27 months
Aerobic Aquatic 2, 4, 5 27 months
Leaching and Ad-
sorption/Desorption All 12 months
Soil All 27 months
Aquatic (sediment) 2, 4, 5 27 months
Forestry 4 27 months
Irrigated Crops 2, 4, 5 39 months
Fish All 12 months
Organisms 2, 4, 5 12 months
Wildlife & Aquatic organisms:
Avian & Mammalian:
Acute Avian Oral 3, 4, 5 9 months
Upland Game Bird 3, 4, 5 9 months
Waterfowl 3, 5 9 months
Coldwater Fish TGAI 3, 4, 5 9 months
Coldwater Fish TEP 1, 3, 4, 5 9 months
Warmwater Fish TGAI All 9 months
Warmwater Fish TGAI 2, 4, 5 9 months
Invertebrates TGAI All 9 months
Invertebrates TEP 2, 4, 5 9 months
Nontarget Phytotoxicity - Tier II:
Emergence TGAI All 9 months
Vegetative Vigor TGAI All 9 months
Growth TGAI All 9 months
Honey Bee Contact TGAI 2, 3, 4, 5 9 months
7. CONTACT PERSON AT EPA
Mr. Richard Mountfort
Product manager (Team 23)
Registration Division (TS-767C)
Office of Pesticide Programs
Environmental Protection Agency
401 M St., SW
Washington, D.C. 20460
Crystal Mall #2
1921 Jefferson Davis Highway
Telephone number: (703) 557-1830
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