— uttioi ot Paiticidn ind Toxic Subcrincai Environ mental Prot.c1.on Wlc, of Pwiad. Progr.m, (TS-766C) A9*lcv Washington. DC 20460 540/FS-89-015 *>ER*\ Pesticide Fact Sheet Name of Chemical: diazinon Reason for Issuance: registration standard Date Issued: December i 988 Fact Sheet Number: 96.1 1. nreTRTFTICN CF chemical Ccmron Name: Diazinon Trade and Other Names: Spectracide, D.Z.N., Knox-Out EPA Shaughnessy Codes: 057801 Chanical Abstracts Service (CAS) Number: 333-41-5 ENT Registry Rimber: 19507 Year of Initial Registration: 1956 Pesticide Type: Insecticide Chanical Family: Organophosphate U.S. and Foreign Producers: Ciba-Geigy, Trans Chanic Industries Inc. , and Makliteshim Agan (America) Inc. 2. USE PATTERNS AND FTTfrULAJTfNS Application: Aerosols, sprays, pet collars, ear tags, dips, ground blast, aerial, and soil incorporation. Annual Usage: 10 million pounds active ingredient (1985 data). Predcminant Use(s): Agricultural, Heme and Garden uses. Types of Fornulations: Dusts, enulsifiable concentrates, granules, impregnated materials, liquids, microencapsulated, pressurized sprays, soluble concentrates, wettable pewders. ------- 2 3. SCHNZE FTTJnTM^ Sunmarv Science Statanent Diazinon is not oncogenic in the Fisher F344 rat or in the B6C3F1 mouse. Diazinon does not induce developmental toxicity in rats or rabbits at dose levels up to and including 100 mg/kg/day (highest dose tested). Based on acceptable laboratory data, technical diazinon is characterized as very highly toxic to waterfowl on an acute oral basis, with an LD50 of 6.38 mgAg for mallard ducks. Avian dietary studies characterized diazinon as highly toxic to upland game birds with a dietary LC50 of 245 pptn for bobwhite quail. Supplemental data characterize diazinon as very highly toxic to waterfowl with a dietary LC50 of less than 47 ppn for mallard ducks. End-use formulations of diazinon are characterized as very highly toxic to waterfowl, upland game birds and songbirds on acute oral and dietary basis. Technical diazinon and its end- use fonrulations are characterized as very highly toxic to aquatic organisms. It is considered highly toxic non-target insects. Diazinon degrades rapidly under aerobic, anaerobic, aquatic anaerobic and sterile soil conditions. Microbial degradation appears to be the major pathway for the degradation of diazinon. Hie most probable mechanism responsible for degradation under sterile and anaerobic soil conditions appears to be chemical hydrolysis in acidic soils. Supplemental hydrolysis data indicate that diazinon is stable with respect to hydrolysis at pH 7 and 9 but hydrolyzes in non-sters water with a pH of 5. The major soil degradate is oxypyrimidine. Oxypyrimidine is more persistent than diazinon under aerobic and sterile, anaerobic and anaerobic aquatic soil conditions. Diazinon with a 4 day EC50 of 4.14 mg/L and a 7 day ET50 of 3.7 mg/L is characterized as being moderately toxic to freshwater green alga. Diazinon caused greater than 25% detrimental effect in plant vigor in tomatoes, cucumbers, onions, and carrots. Diazinon caused a greater than 25% detrimental effect in seed germination in oats, tomatoes, and carrots. No detrimental effect was seen for seedling emergence. ------- 3 Ownical Qiaractjeristics of the Technical Riysical State: Liquid Color: Airiber and brown Odor: Mild, sweet, and aromatic MDlecular Weight and Fomtila: (304.3) C12H21N2°3PS Boiling Point: 83-84°*: at 0.002 mm Hg Vapor Pressure: 1.4 x 10_4nm at 20^ Density: 1.12 g/ml at 20°C Solubility in various solvents: In petroleum oils, 60 ppn in water at 25°C and 40 ppn in water at 20°c. ^¦^^^^1^^ xsLics Acute Oral: LD50= 618 rag/Tog* Acute Dermal: UD50 > 2000 mg/)cg* Primary Dermal Irritation: Not-irritating* Primary i^e Irritation: Non-irritating* Dermal Sensitization: Positive response in 10% of the human volunteers tested* Acute Inhalation: LC50=3.5 mg/L* Acute Delayed neurotoxicity: Data gap Subchroriic toxicity: Data gap Oncogenicity: {mouse and rat) Not oncogenic Chronic Feeding: Data gap Metabolism Data gap Teratogenicity: (Rabbit and Rat) No developmental toxicity at doses up to and including 100 mg/kg/day. * This information may not be applicable to all currently registered manufacturing use products (MUPs) of diazinon. The Agency is requiring additional toxicity studies to determine the toxicological similarities or dissimilarities of the registered MUPs. ------- 4 Reproduction: Data gap Mutagenicity: Data gap Maior routes of exposure Dermal, oral and inhalation Rivsiolocrical and Biochemical Qiaracteristics Mechanism of Pesticidal Action: Cholinesterase Inhibition Metabolism and Persistence in Plants and Animals: Data gap Envircumental Characteristics Diazinon degrades rapidly under aerobic, anaerobic, aquatic anaerobic and sterile soil conditions. The major soil degradate is oxypyrimidine. Oxypyrimidine is more persistent than diazinon under aerobic and sterile, anaerobic and anaerobic aquatic soil conditions. Diazinon's potential to contaminate groundwater is unkncwn. Ecological Characteristics Avian acute toxicity: 3.2 mg/kg (Red-winged blackbird)-Very highly toxic 6.3 mg/kg (Mallard duck) -Very highly toxic 10 mg/kg (Botwhite quail) -Very highly toxic Avian dietary toxicity: < 47 ppn (Mallard duck) -Highly toxic 245 ppn (Bobwhite quail) -Highly toxic Freshwater fish acute toxicity: Want-water DC50 = 136 ug/L (Bluegill sunfish) -Highly toxic Coldwater DC50 = 90 ug/L (Rainbow Trout) -Very highly toxic Marine fish acute toxicity: LC50 = 1400 ug/L (Sheepshead minnow) -{"tiderately toxic Freshwater invertebrate toxicity: 1X50 = 0.2 mg/L (QanroaEUS fasciatus)-Verv highly toxic Marine invertebrate toxicity: Data gap Non-Target Insects: LD50 =0.22 ug/bee (contact: Honey Bees)-Highly toxic LD50 = 0.2 ug/bee (oral: Honey Bees) -Highly toxic ------- 5 TOLEKAMZE ASSES3€NT Tolerances have been established for residues of diazinon in a variety of raw agricultural commodities, in meat, fat arid meat byproducts (40 CFR 180.153), food additives (40 CFR 185.1750) ana in food handling estab- lishments (40 CFR 185.1750), and feed handling/processing establishments (40 CFR 186.1750). Itolerances for residues of diazinon are currently expressed as residues of diazinon ESC S£- Codex FRL's, Canadian, and Mexican tolerances have been established for many of diazinan*s registered uses. Compatibility of these tolerances to that of U.S. tolerances cannot be determined until all additional metabolism and residue studies are available. Based chi inhibition of plasma cholinesterase observed in a 90 day rat feeding study a NCXL of 0.009 mg/kg/day was established. A provisional acceptable daily intake (FM)I) has been established at 0.00009 mgAg/day utilizing an uncertainty factor of 100. *me FM)I is provisional because the existing data base on diazinon is lacking chronic feeding studies, and a multi-generation reproduction study. 4. Required Unique Labeling o Restricted use Statement for all commercial outdoor uses (e.g., turf, and agricultural). o Restricted use Statement for residential products in toxicity category I or II,(danger or warning). o Homeowner Protection Statements for indoor and outdoor application. o Institutional use Protection Statements for hospitals and schools. o Feed and Food Handling Establishments statements. o Worker Protection Statanents for Toxicity Categories I, II and III end- use formilations. o 24-Hour Interim Reentry Interval (ccnmercial and greenhouse use). ------- 6 5. Sunroarv of Regulatory Positions o The Agency is deferring a decision at this time on whether to place diazinon into Special Review for its potential hazard to avian species resulting fran its use on agricultural crops, cm turf and other grassy sites (e.g., athletic fields, recreational parks, home lawns). o Hie Agency is classifying all conmercial outdoor uses (agricultural crops, ornamentals, and turf) of diazinon for restricted use, based upon its known toxicity to birds and aquatic species. o All diazinon aid-use products that are in Tbxicity Category I or II (IWCER or WAPNING) and bear product labeling that directly recommends residential use or reasonably can be interpreted to permit residential use are classified for restricted use. Such products may be used only by certified applicators or persons under their direct supervision. In the past, the Agency has allowed these types of products to be labeled , "For Agricultural Use Only" or "For FCO Use Only" in an attempt to limit use to conmercial or trained applicators. However, these statemaits are unenforceable. o The Agency will is requiring the following testing of a series of typical end use products: acute oral, acute dermal, primary dermal irritation, primary eye irritation, dermal sensitization, and acute inhalation if appropriate. The Agency will reserve alternative product formulations testing, pending submission and review of toxicity testing on the stabilized technical diazinon products (manufacturing use products). o The U.S. Fish and Wildlife Service, Division of Endangered Species and Habitat Conservation (DESCH) has determined that certain uses of diazinon, including uses on corn and sorghun may jeopardize the continued existence of endangered species. Based on this determination, BESHC specified reasonable and prudent alternatives to avoid jeopardizing the continued existence of the identified species by these uses. EFA is developing a program to reduce or eliminate exposure to these species to a point where use does not result in jeopardy. PR Notices 87-4 and 87-5, which specified labeling requirements designed to reduce or eliminate exposure to endangered species, have been withdrawn. The Agency will issue a notice of arty necessary regulatory actions when the program is developed. o The Agency will require each registrant of a manufacturing use product to submit the following toxicity studies on their current fonrulations: acute oral, acute denial, acute inhalation, primary dermal irritation, primary eye irritation, dermal sensitization, and a 6-week rat feeding study. The Agency may require additional toxicity testing based upon its evaluation of these studies. o The Agency will iupose a 24-hour interim reentry interval for all conmercial uses of diazinon (greenhouses, agricultural). o The Agency is revising worker safety and protective equipment statements for end use products containing diazinon. ------- 7 o The Agency is not imposing a ground water contamination advisory statement for diazinon products at this time. The Agency will assess the potential of diazinon for groundwater contamination after receipt and review of environmental fate data and will determine whether regulatory action is necessary. o The Agency is inposing additional statements for all end-use products intended for use in and around the heme. o The Agency has determined that diazinon products must bear revised and updated labeling for hazards to norrtarget species. o The Agency will propose tolerance revocation for rutabagas, red chicory tops, and dandelions (40 CFR 180.153). o Residue data must be sutmitted and tolerances must be proposed for corn fodder and forage, and either sorghum forage and fodder, or wheat forage, hay and straw, and soybean straw and hay. o For the following crops; sorghum fodder and forage, soybean straw ar*3 hay, and sugarcane forage, the registrant is given the choice of developing and submitting data in support of tolerances, or of adding label restrictions aganist the feeding and grazing of treated crops to livestock. Each registrant most inform the Agency by 90 days of receipt of this Registration Standard which option he chooses. If he selects the label restrictions, labeling sutmitted at the 9 month deadline must include the grazing/feeding restrictions. o The Agency will not grant any significant new tolerances or any sigificant new food uses for diazinon until the required residue chemistry and toxicology studies have been sutmitted and reviewed. o The Agency is not requiring additional residue data to support the established tolerances for diazinon in or on guar beans and coffee beans. o The Agency will revise caimodity definitions for certain raw agricultural ccmrodities listed in 40 CFR 180.153. a) Tolerance listing "peas with pods (determined on peas after renoving any shell present when marketed)" will be revised to read, "peas, succulent". b) Tolerance listing "bean forage" will be revised to read, "bean vines". c) the tolerance listing for "wheat forage and straw" was omitted frcm listing and will read "wheat forage and straw 0.05 ppn". o The connon name "diazinon" will appear before the chenical name on the pesticide label, rebels must be revised to reflect this. o Petroleum distillates and xylene based solvents mast be declared as inert ingredients. ------- 8 o The Agency has identified certain data that will receive inmediate review wi sutmitted; 158.240 Residue Chemistry - Plant and Animal Metabolism - Special Storage Stability (EUP) 158.290 Environmental Fate - Hydrolysis - Fhotolysis 158.340 Toxicology - Acute Toxicity Studies (MUP) - 6 week Feeding study (MUP) - Neurotoxicity study (MUP) - Acute Toxicity Studies (HP) 158.490 Ecological Effects (all) 6. Sumarv of Maior Data Gaps Timeframe Ranges Toxicology 12-50 Months BTvirormental Fate/Exposure 9-39 Manths Ecological effects 9-30 Months Residue Chemistry 18-24 Months prnrftv-f 9-12 Months ------- 9 7. gamer fepxn at eta George LaRocca Product Manager (15) Insecticide Rodenticide Branch Registration Division (TS-767C) Office of Pesticide Programs Elrviromental Protection Agency 401 M Street, S. W. Washington, D. C. 20460 Office location and telephone ntsnber: Roan 204, Crystal Mall #2 1921 Jefferson Davis Hi^way Arlington, VA 22202 (703) 557-2400 DISCLAIMER: Bie information in this Pesticide Fact Sheet is a summary only and is not to be used to satisfy data requirements for pesticide registration and reregistration. Hie ccnplete Registration Standard for the pesticide may be obtained fran the National Technical Information Service. Contact the Product Manager listed above for further information. ------- |