*** Public Review Draft *** Guidance for Waiving Acute Dermal Toxicity Tests for Pesticide Technical Chemicals & Supporting Retrospective Analysis Issued By: Office of Pesticide Programs Office of Chemical Safety and Pollution Prevention United States Environmental Protection Agency Date of Issuance: September 2020 Unique ID: EPA 705-G-2020-3722 Docket ID: EPA-HQ-OPP-2016-0093 Related Authority: 7 U.S.C. 136 etseq. The overall purpose of this analysis is to address the utility of the acute dermal toxicity study for single technical chemicals in pesticide labelling, such as the signal word and precautionary statements as described in 40 CFR 156.64 and 40 CFR 156.70. Non-Binding Disclaimer: The contents of this guidance document do not have the force and effect of law and that the Agency does not intend to bind the public in any way and intends only to provide clarity to the public regarding existing requirements under the law or Agency policies. If the guidance document is binding because it is authorized by law or because the guidance is incorporated into a contract, the EPA will make that clear in the document. ------- Guidance for Waiving Acute Dermal Toxicity Tests for Pesticide Technical Chemicals & Supporting Retrospective Analysis 1.0 Introduction This guidance document follows upon the final dermal waiver guidance published in November 2016 for pesticide formulations. This document expands the potential for data waivers for acute dermal studies to single active ingredient technical chemicals (technical chemicals) used to formulate end user products. The reasoning and analysis in this dermal waiver guidance for technical chemicals is similar to what was presented in the 2016 guidance for end-use products. While more acute toxicity studies are submitted to OPP annually for formulated pesticide products than for technical chemicals, there is still the potential for animal and resource savings from waivers for technical chemical acute toxicity studies. Further, this guidance allows OPP to harmonize with the Pest Management Regulatory Agency (PMRA) of Canada, which published guidance1 on dermal waivers for both formulations and technical chemicals in 2017. OPP and the National Toxicology Program (NTP) Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM) have conducted a retrospective analysis of oral and dermal acute lethality studies that fit the regulatory context relevant for OPP, and considered the EPA pesticide categorization scheme, which uses acute study results (see 40 CFR 156.212 and OPP Label Review Manual2). The OPP/NICEATM analysis was designed to evaluate the relative consistency of the findings of paired oral and dermal studies for technical chemicals (Section 2.0). The Agency has used this analysis to support a policy statement in Section 5.0 to waive all acute lethality dermal studies for pesticide technical chemicals. The 2016 guidance focused on formulated pesticide product testing because ecological risk assessments for endangered and threatened species typically rely in part on acute studies for the technical chemical. After further consideration of these data needs, EPA has determined that the Agency is now able to provide waivers for acute dermal studies for technical chemicals. 2.0 Dataset for Analysis The Agency developed a dataset of rat acute oral and acute dermal LD5o studies for 249 active ingredients. The spreadsheet of data used in the analysis is provided in Dermal Data Spreadsheet for Pesticide Active Ingredient Technical Chemicals Final.xlsx, and is available in the docket3. The active ingredients include conventional pesticides, antimicrobials, and biopesticides across numerous chemical classes and Toxicity Categories (Appendix 1). Fumigants and rodenticides were excluded because of their 1 https://www.canada.ca/content/dam/hc-sc/documents/services/consumer-product-safety/reports- publications/pestirides-pest-management/policies-guidelines/science-policv-notes/2017/acute-dernnal-toxiritv- waiver-spn2017-03-eng.pdf 2 Chapter 7: https://www.epa.gov/sites/production/files/2018-04/documents/chap-07-mar-2018.pdf 3 https://www.regulations.gov/docket?D=EPA-HQ-QPP-2016-0093 Page 2 of 8 ------- physical forms and the types of exposures that would be anticipated; this policy does not apply to these types of pesticides. 3.0 Comparison of Toxicity Category Between Oral and Dermal Studies As shown in the blue boxes in Table 1 below, for 167 of the 249 technical chemicals, the paired oral and dermal studies provide the same Toxicity Category. For 80 chemicals, the oral study provides a lower (i.e., more potent) category than the dermal study (grey boxes). Table 1. Results of comparison analysis for oral & dermal technical chemical acute studies Rat Dermal Hazard Category (mg/kg) Rat Oral Hazard Category (mg/kg) EPA 1 <50 EPA II >50 - <500 EPA III >500 - <5000 EPA IV >5000 EPA 1 <200 1 0 0 EPA II >200 - <2000 6 1 0 EPA III >2000 - <5000 4 40 0 EPA IV >5000 ŠJ 6 22 Total 22 62 137 28 For 2 chemicals, the dermal study provides a lower (i.e., more potent) Category than the oral study (yellow boxes). One chemical (xylenol) had a Toxicity Category II for dermal (LD50: 1040 mg/kg), and Toxicity Category III for oral (LD5o: 3200 mg/kg) (i.e., a more potent Category for dermal compared to oral) and one chemical, dichlorvos (DDVP), in the dataset has a Toxicity Category I for dermal (LD5o: 75 mg/kg) and a Toxicity Category II for oral (LD5o56 mg/kg). EPA's Label Review Manual4 provides information on how acute toxicity information is used in pesticide labeling, including the hazard statements, signal word, first aid, and precautionary statements that appear on technical labels. The results from all six acute toxicity tests are considered, and the lowest category determines the signal word, whereas the other precautionary/first aid statements are determined by the category for each endpoint. Acute studies are primarily used by the Agency to determine the appropriate level of Personal Protective Equipment (PPE), hazard labeling, first aid, and precautionary statements for all product labels. 4 https://www.epa.gov/pesticide-registration/label-review-manual Page 3 of 8 ------- 4.0 Discussion - Implications of Retrospective Analysis on Utility of Acute Dermal Technical Product Lethality Studies The overall purpose of this analysis is to address the utility of the acute dermal toxicity study for single technical chemicals in pesticide labelling, such as the signal word and precautionary statements as described in 40 CFR 156.64 and 40 CFR 156.70. To this end, this analysis includes a large number of technical chemicals (249) from numerous chemical classes representing conventional pesticides, antimicrobials, and biopesticides. This guidance expands upon the work of the dermal waiver guidance published in November 2016 for pesticide formulations. For 67% of the 249 technical chemicals, the results of both oral and dermal acute toxicity studies fall within the same Toxicity Category. For 32% of the chemicals, the oral study falls within a lower (i.e., more protective) Toxicity Category; thus, for 99% of the chemicals in the analysis, if the dermal study had not been available, and labelling had been based only on the Toxicity Category for the oral acute toxicity study, the labelling requirements would have been equally or more protective. For the two remaining chemicals (less than 1%), as noted above, factors other than the dermal acute toxicity may influence labelling requirements. In some cases, dermal irritation/corrosion studies or risk management decisions based on other factors may result in label requirements more protective than what would otherwise be required based on acute oral toxicity alone. When all these sources of information are considered together, in most cases, the dermal acute toxicity study for technical chemicals provides little to no added value in regulatory decision making. 5.0 Waiver Guidance The Agency believes this retrospective analysis fully supports the conclusion that waivers may be granted for acute dermal toxicity studies for pesticide technical chemicals except for fumigants and rodenticides which were excluded because of their physical forms and the types of exposures that would be anticipated. Waivers may be accepted for fumigants and rodenticides but on a case by case basis with appropriate scientific rationale. Applicants should submit formal waiver requests as part of their registration application through existing processes and cite this guidance. The Agency maintains the ability to request acute dermal toxicity data on a case by case basis. The Agency anticipates allowing the waiver in most cases, however, a determination that a waiver request is unacceptable will be made upon consultation with the Agency's relevant internal peer review groups (e.g., Hazard and Science Policy Committee (HASPOC) and Chemistry and Acute Toxicity Science Advisory Committee (CATSAC)) and/or OPP's science advisor. Page 4 of 8 ------- Appendix 1. List of Active Ingredients in the Retrospective Analysis l,3-Dibromo-5,5- dimethylhydantoin 1-Decanol 2.3-Dichlorobenzoic acid- methyl ester 2,4,4-Trimethylpentene 2.4-D, sodium salt 2,4-Dichlorophenoxyacetic acid (2,4-D) 2-Ethylhexanoic acid 2-Methyl-4-chlorophenoxy acetic acid (MCPA) 2-Methyl-4- chorophenoxybutyric acid (MCPB) 2-Phenylphenol 4-(2,4- Dichlorophenoxy)butyric acid (2,4-DB) 4,4-Dimethyloxazolidine 4,6-dinitro-o-cresol (DNOC) 4-Chloro-3-cresol Abamectin a-Cll-15-sec-alkyl-omega- hydroxypoly(oxy-l,2- ethanediyl) Acephate Acetochlor Acibenzolar-S-methyl (CGA 245704) Aclonifen Alachlor Aldicarb Alpha cypermethrin Ametryn Amidosulfuron aminopyralid (xde-750) Ammonium bromide Ammonium chloride Ammonium sulfate Antimycin-a asana (esfenvalerate) Atrazine Azinphos-methyl bcs-aal0717 herbicide (indaziflam) Benalaxyl Benalaxyl-M Benfuracarb Bentazone bifenthrin Bispyribac-sodium Bitertanol (KWG 0599) Bromoxynil Bromuconazole Buprofezin Butralin Captan Carbaryl Carbofuran Carbosulfan Chlorfenapyr Chloridazon Chlorpropham Chlorpyrifos Cinidon ethyl Citral Clodinafop-propargyl Clomazone Copper as elemental Copper carbonate, basic Benfluralin Copper compounds ------- Cupric oxide Cuprous oxide Cyclanilide Cyfluthrin Cymoxanil Cypermethrin Cyproconazole technical Cyprodinil Cyromazine Daminozide Deltamethrin Diazinon Dicamba Dichloroisocyanuric acid, sodium salt, dihydrate Dichlorprop-P Dichlorvos Diclofop-Methyl Dimethachlor Dimethenamid Dimethoate Dimethomorph Dimethoxane Dinocap Dinoterb Diquat Disulfoton (S 276) Diuron dpx-kjm44 herbicide (aminocyclopyrachlor- methyl) emamectin benzoate Endosulfan Epoxiconazole Ethephon Ethoprophos Ethoxysulfuron Famoxadone Fenamiphos Fenarimol Fenhexamid Fenitrothion Fenoxaprop Fenpropidin Fenpropimorph Fenpyroximate Fenthion Ferric phosphate Flonicamid insecticide Fluazinam Flufenacet flufenpyr-ethyl-s-3153 flumethrin Fluopicolide Fluopyram Fluoxastrobin Fluroxypyr Flurprimidol Flusilazole Flutolanil Folpet Forchlorfenuron Formetanate Fosthiazate Fuberidazole Furfural Glufosinate Glyphosate Glyphosate trimesium Haloxyfop-R Imazalil initium fungicide (ametoctradin) lodosulfuron loxynil Page 6 of 8 ------- ipconazole Iprodione Isoproturon kixor herbicide (saflufenacil) Lavandulyl senecioate l-Cyhalothrin Lindane Linuron Magnate (imazalil) Malathion Maleic hydrazide mem 437 (fipronil) mepp-p (mecoprop) Mecoprop Mecoprop-P mecoprop-p acid Mepiquat Mesosulfuron-methyl Metalaxyl-M Metamitron Metazachlor Methamidophos Methiocarb Methomyl Methoxyfenozide Metrafenone Metribuzin metsulfuron methyl Milbemectin Mitin FF mkh 3586 (amicarbazone) Molinate Monolinuron Nipacide cmx (chloroxylenol) nni-0001 (flubendiamide) Nonanoic acid (CGA- 133205 Technical) Oxazolidine-E Oxydemeton-methyl Paraquat Parathion Parathion-methyl Penconazole Penflufen tc Penthiopyrad Permethrin Pethoxamid Phorate Phosalone Phosmet Phosphides Pirimicarb Pirimiphos-methyl Potassium silicate Procymidone Profenofos Propamocarb Propiconazole Propineb Propoxycarbazone sodium Prosulfocarb Prosulfuron pyrasulfotole Pyrazophos Pyridalyl Pyridate Pyrimethanil Pyroxasulfone Quinoclamine reldan f (chlorpyrifos- methyl) rotam imidacloprid Salicylic acid Page 7 of 8 ------- Sedaxane Thiabendazole Trichlorfon Sethoxydim Simazine Sodium ferric ethylenediaminetetraacet ate Sodium fluoride Spinosad Spiromesifen Spirotetramet Sulfur sumione (metofluthrin) tebuconazole fungicide (tebuconazole) Tecnazene Terbuthylazine Tetraconazole Thiacloprid Thiamethoxam Thidiazuron Thiencarbazone-methyl Thiodicarb Thiram Thymol Tolclofos-methyl Tolyfluanid tpth (fentin) Tralkoxydim Triadimenol Triallate Triazamate Tribenuron methyl Tributyltin benzoate Triclopyr Trinexapac Triphenyltin Hydroxide Triticonazole Tritosulfuron Undecylenic acid Urea, sulfate (1:1) Vinclozolin xde-742 (pyroxsulam) Xemium fungicide (fluxapyroxad) Xylenol Zinc pyrithione Ziram Zoxamide Page 8 of 8 ------- |