Unftxi Stztce
Environmental Protectson
Office of Pestlddce and Toxic Sut*t.nc
Office of Pestldde Programs ITS-766C)
Washington. DC 20460
Fact Sheet
Name of Chemical: Pheninedipham
Reason for Issuance: Registration Standard
Date Issued: March 30, 1987
Fact Sheet Number: 172
CAS Number:
OPP (Shaughnessy) Number:
Empirical Formula:
Trade Names:
Chemical Family:
Pesticide Type:
Year of Initial
Registrants of Technical
Phenmed ipham
C 16 H 1 6 N 2 0 4
Betanal®, GBP-1-127050®, Kemiphani®,
Morton EP-452®, Phenmediphame®,
Schering 4072®, Schering 4075®,
Schering 38584®, SN 38584®, Spinaid®.
Carban ilate
Schering AG, Nor-AM Chemical Co.
2. Use Patterns And Formulations
Application Sites:
Methods of Application:
Application Rates:
Types of- Formulations:
Terrestrial food uses (sugar beets,
table beets, spinach & spinach seed).
Applied posteinergence to foliage of
weeds and crops. Primarily applied
as broadcast or banded spray by
ground or aerial equipment.
Table beets, spinach: 0.5 to 1 lb,
sugar beets: 0.17 to 0.61 lb
(lb ai/Acre).
Emulsifiable concentrate EEC]
(8.0% and 15.9% a.i.)
1. Description of Chemical
The following chemical is covered by this Registration
Common name:
Chemical name:
Usual Carrier:

3. Science Findings
Phenmedipham did not induce neoplastic effects in chronic toxi-
city studies of rats. Except for weight changes in a 3 gene-
ration rat study, this chemical does not induce reproductive
effects in rats. This pesticide has shown low acute oral and
derrna]. toxicity in test animals. It is low in avian toxicity
and moderately toxic to fish and aquatic invertebrates.
It does not cause the destruction of habitat of animals or non-
target organisms.
Although the present data base for phenmedipham does not indicate
major toxicological concerns, there are still toxicology data
gaps: acute inhalation toxicity, primary eye irritation, primary
dermal irritation, dermal sensitization, subchronic dermal toxicity
(21-day), oncogenicity in two species, teratology in two species,
mutagenicity and general metabolism have not been characterized
for phenmedipham.
In addition, the environmental fate, metabolism in food crops,
metabolism in ruminants and poultry for this compound have not
been characterized.
Chemical Characteristics :
Phenmedipham is an odorless white to slightly colored powder at
room temperature. Its melting point is 140-144° C, and its
molecular weight is 300.3. Its water solubility is 3.1 mg/liter
in pH 4 water at 25°C.
Toxicological Characteristics :
Acute Oral: Toxicity Category IV - > 8,000 mg/kg (male &
female rats)
Acute Dermal: Toxicity Category III - > 4,000 mg/kg (male &
female rats)
Chronic Toxicity:
A rat chronic feeding study with phenmediphain showed a No-
Observable-Effect-Level (NOEL) for oncogenicity greater than
500 ppm (25 mg/kg), highest dose tested (HDT). Although an
increase in neoplastic findings was not observed in this study
up to and including a dosage level of 500 ppm (HDT), the
oncogenic potential of phenrnedipham cannot be ascertained in
the absence of a maximum tolerated dose. Therefore, this study
does not fulfill the data requirement for oncogenicity (rat).
Oncogenicity studies in two species are required. The body
weight gain changes noted in the high dose females during the
second year are minimal evidence of systemic toxicity (less
than 1O decrease). Therefore, the NOEL for systemic effects
is 100 ppm with a lowest observed effect level (LOEL) for
systemic effects at 500 ppm (HDT).

In a dog chronic feeding study, phenmedipham showed a NOEL of
1000 ppm (25 mg/kg, HDT). Neoplastic findings were not observed
in this study up to and including a dosage level of 1 ,000 ppm
Major routes of exposure: Applicators (mixer/loader) handling
this pesticide.
Physiological & Biochemical C ra teristjcg :
Translocation: Phenmedipham is absorbed by the plant leaves and
translocated to other portions of the plant.
1echanism of pesticidal action: It is a strong inhibitor of the
Hill reaction in photosynthesis.
Metabolism & Persistej ce in Plants & Animals: The available
data are inadequate ttm evaluate the persistence of phenmedipharn
in plants and animals,
Environmental Chracterjstjcs
Available data are insufficient to fully assess the environmental
fate and potential exposure of humans and non-target organisms
to phenmedipham. Additional data are required to characterize
the potential for phenmedipham to reach ground water supplies.
Ecological Characteristics :
There is sufficient information to characterize pheninedipham as
having very low toxicity on an avian dietary basis for Bobwhite
quail and Mallard duck. However, an avian single-dose oral
toxicity study is required. There is sufficient acute toxicity
information to characterize technical phenmedipham as moderately
toxic to freshwater invertebrates and to both warm and cold
water fish. •In an acute contact study, phenmedipham was shown
to be very low in toxicity to honey bees.
(Low toxicity)
Avian dietary toxicity: Bobwhite quail - > 10,000 ppm
(8 day diet) Mallard duck - > 10,000 ppm
Freshwater fish toxicity: (Moderate toxicity)
(96-hour exposure in water) Bluegill - 3.98 ppm
Rainbow trout - 1.41 ppm
Aquatic invertebrate toxicity: (Moderate toxicity)
(48-hour exposure in water) Daphnia magna - 3.2 ppm.

Endangered species :
No endangered species labeling is required because of the low
to moderate toxicity of phenmedipharn products to avian and
aquatic species, and the fact that this pesticide will not
readily drift from the application sit s to endangered plants.
In addition, treated crops are not planted in the habitat of
these plants.
Tolerance Assessment
Sufficient data are available to ascertain the adequacy of the
established tolerances for residues of phenmedipham in or on
table beet roots and tops, sugar beet roots and tops, and spinach
(40 CFR 180.278).
Tolerances for Phenmedipham have been approved for the raw agri-
cultural commodities (RAC’s) listed below.
Crop Tolerance(ppin) Food Factor mg/day(1.Skg )
Beets 0.20 0.17 0.00052
Sugar, beet roots 0.10 3.64 0.00546
Sugar, beet tops 0.10 3.64 0.00546
Spinach 0.50 0.05 0.00038
The provisional acceptable daily intake (PADI) for phenmedipham
is based on a 104 week rat feeding study. The systemic NOEL for
for this study is 100 ppm (5 mg/kg). The systemic lowest observed
effect level (LOEL) is 500 ppm (25 mg/kg/day, HDT). There is
also a 104 week dog feeding study with a NOEL of greater than
1000 ppm (25 mg/kg, HDT). Utilizing a safety factor of 100, the
PADI was set at 0.050 mg/kg/day. This is equivilant to a maximum
permitted intake (MPI) of 3.00 mg/day for a 60 kg individual.
The theoretical maximum residue contribution (TMRC) for phenme-
diphain in the 4aily diet based on the total tolerances above and
a daily food intake of 1.5 kg is 0.0064 mg/day. Under these
conditions, 0.21% of the PADI has been utilized.
However, data gaps exist for plant and animal metabolism, analy-
tical methods, and storage stability. Processing studies are
required for sugar beets. Since the data required for individual
commodities are dependent on metabolism data, the Agency recommends
that metabolism data be obtained and submitted prior to any
required residue data.
There are Canadian tolerances of 0.10 ppm for phenmedipham residues
in or on sugar beets and tops but no tolerances on spinach and
table beets. There are no Mexican tolerances, Codex Maximum
Residue Levels, or exemptions for phenmedipham on sugar beets,
spinach and table beets.

Reported Pesticide Incidences
The Pesticide Incident Monitoring System (PIMS) does not have
any incident involving phenmedipham at this time.
4. Summary of Regulatory Positions & Rationale :
- - The Agency has determined that phenrnedipharn does not exceed any
of the risk criteria for adverse effects in 40 CFR, Section 154.7
at the present time. Available data indicate that phenmedipham
does not promote neoplastic findings in chronic toxicity studies
of rats. Except for weight changes in a 3-generation rat study,
this compound does not induce reproductive effects in rats. It
does not pose a risk of serious acute injury to humans, domestic
animals or non-target organisms and, it does not cause the
destruction of habitat of non-target organisms.
-- The Agency has determined that certain toxicological studies
are required to support the reregistration of phenmedipham
products: acute inhalation, primary eye irritation, primary
dermal irritation, dermal sensitization, subchronic dermal toxicity
(21-day), oncogenicity in two species, teratology in two species,
mutagenicity and metabolism studies.
-- The Agency has determined that present precautionary statements
for persons handling or applying phenmedipharn products are suff i-
cient for the labels of manufacturing-use and end-use products.
Available data indicate that phenmedipham causes low oral (Category
IV) and dermal (Category III) toxicities in test animals. There-
fore, the labeling of these products contain statements that
caution persons applying or handling this compound, give first
aid instructions, and require the use of precautionary measures
to ensure safe handling of the pesticide products.
- - The Agency has determined that reentry intervals for workers
are not required for phenmedipham products. The low acute toxi-
city of this chemical does not warrant significant concern about
exposure of workers reentering treated areas, according to the
criteria in 40 CFR Part 158.140.
-- At this time, the Agency will defer action on ground water
issues until receipt and evaluation of environmental fate data.
-- The Agency is requiring labeling which warns of potential
hazards to aquatic organisms. Available acute toxicity data
indicate that phenmedipham is moderately toxic to fish and
aquatic invertebrates.
--The available data indicate that this pesticide, when applied
at recommended rates, does not present unreasonable hazards to
birds. Existing studies on this compound indicate that its die-
tary toxicity to birds is very low.

- - The Agency has determined that specific labeling to mitigate
potential hazards to endangered species are not required.
Available data indicate that phenmedipham exhibits low toxicity
to avian species, and moderate toxicity to fish and aquatic
invertebrates. Crops treated with this pesticide are not planted
in the habitat of endangered plants. Also , this chemical will
not readily drift from its application sites to the endangered
- - The Agency will not require phytotoxicity data.
Phenmedipham has low volatility and will not readily drift from
its application sites to non-target plants and it has limited
terrestrial use on minor crops.
5. Precautionary Statements
a. Manufacturing-Use Product Statements
All phenmediphan products intended for formulation into
end-use products must bear the following statements:
“This pesticide is toxic to fish and aquatic organisms.
Do not discharge effluent containing this product into
lakes, streams, ponds, estuaries, oceans, or public
water unless this product is specifically identified and
addressed in an NPDES permit. Do not discharge effluent
containing this product into sewer systems without
previously notifying the sewage treatment plant authority.
For guidance contact your State Water Board or Regional
Office of the EPA.”
b. End-Use Product Statements
The following precautionary statements must appear on all
EP labels:
“This pesticIde is toxic to fish and aquatic organisms.
Do not apply directly to water or wetlands (swamps, bogs,
marshes, and potholes). Drift and runoff from treated areas
may be hazardous to fish and aquatic organisms in adjacent
aquatic sites. Do not contaminate water by cleaning
of equipment or disposal of wastes.”

6. Summary of Major Data Gaps
158.120 Product Chemistry data are required during 1987.
158.125 Residue Chemistry:
171-4 Nature of Residue (Plant & Animal
Residue Analytical Methods
Storage Stability
Residue Studies on Crops, Processed
Food/Feed Commodities
158. 130
1 62-2
Acute Inhalation Toxicity (Rat)
Primary Eye Irritation Toxicity
Primary Dermal Irritation (Rabbit)
Dermal Sensitization (Guinea pig)
Subchronic Dermal (21-day)
Oncogencity (Two species)
Teratogenicity (Two species)
Environmental Fate
Photodegradation in Water
Anaerobic Soil Metabolism
Mobility Studies (Leaching &
Adsorp t ion/Desorpt ion)
Soil Dissipation
Rotational Crops (Confined)
Accumulation in Fish
January 30, 1988
January 30, 1988
January 30, 1988
January 30, 1988
April 30, 1988
January 30, 1988
January 30, 1988
July 30, 1989
April 30, 1988
July 30, 1989
July 30, 1990
April 30, 1988
158.145 Wildlife and Aquatic Organisms
71-1 Avian Oral Toxicity
7. Contact Person at EPA
January 30, 1988
Robert J. Taylor, PM-25
Office of Pesticide Programs, EPA
Registration Division (TS-767C)
401 H Street, S.W.
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 or reregistration.
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