Unftxi Stztce Environmental Protectson Agency Office of Pestlddce and Toxic Sut*t.nc Office of Pestldde Programs ITS-766C) Washington. DC 20460 540/FS—88—118 VEPA Pesticide 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 Registration: Registrants of Technical Products: Phenmed ipham 3-methoxycarbonylaminophenyl -3-methylcarbanilate 13684-63—4 098701 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 Herbicide 1970 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.) Water 1. Description of Chemical The following chemical is covered by this Registration Standard: Common name: Chemical name: Usual Carrier: ------- -2- 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). ------- —3- 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 (HDT). 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. ------- -4- 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. ------- —5— 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. ------- -6- - - 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 plants. - - 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.” ------- —7— 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 Metabolism) Residue Analytical Methods Storage Stability Residue Studies on Crops, Processed Food/Feed Commodities 158.135 81-3 81-4 81-5 81-6 82-2 83-2 83-3 84-2 85-1 158. 130 161-1 161—2 1 62-2 163-1 164—1 165—1 165-4 Toxicology: Acute Inhalation Toxicity (Rat) Primary Eye Irritation Toxicity (Rabbit) Primary Dermal Irritation (Rabbit) Dermal Sensitization (Guinea pig) Subchronic Dermal (21-day) Oncogencity (Two species) (Mouse) (Rat) Teratogenicity (Two species) Mutagenicity Metabolism Environmental Fate Hydrolysis 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. 1 71—4 171—4 1 71—4 October 30, 1988 July 30, July 30, April 30, 1988 1988 1 989 Hay 30, 1988 June 30, 1991 July 30, 1988 April 30, 1988 April 30, 1989 ------- |