INDAZIFLAM (Alion,™ Specticle™ and Esplanade™) BEWARE: IS THIS the ROUNDUP WEED KILLER ALTERNATIVE?

INF ORMATION F OR AC TION

INDAZIFLAM (Alion,™ Specticle™ and Esplanade™) BEWARE: IS THIS THE ROUNDUP WEED KILLER ALTERNATIVE?

EDITOR’S NOTE. This factsheet is based on a review of U.S. Environmental ChemicalWATCH Summary Stats Protection Agency (EPA) reports, New York State Department of Environmental Chemical Name: Indaziflam; N-[(1R,2S)-2,3-dihydro-2,6-dimethyl-1H- Conservation reviews, and the Australian inden-1-yl]-6-[(1RS)-1fluoroethyl]-1,3,5-triazine-2,4-diamine Pesticides and Veterinary Medicines Authority assessment. CAS Registry Number: 950782-86-2 Trade Names: Alion™, Specticle™ and Esplanade™ SUMMARY Toxicity Rating: Toxic. Indaziflam (N-[(1R,2S)-2,3-dihydro-2,6- dimethyl-1H-inden-1-yl]-6-[(1RS)- Signal Words: Caution, Warning. 1fluoroethyl]-1,3,5-triazine-2,4-diamine) is a pre-emergent and post-emergent Health Effects: Neurotoxicity, adverse effects on thyroid at low doses. weed killer with a broad spectrum of Higher doses affect sexual organs and reproduction. action against annual grasses and broad- Environmental Effects: Highly toxic to aquatic and terrestrial plants. leaf plants. It was originally registered by Bayer CropScience in 2010 under a conditional registration for residential areas. Since then, its uses have been effects observed on the thyroid in rat the chlorotriazines (e.g., atrazine). expanded to citrus, tree nuts, grapes, studies indicate a potential for endocrine Indaziflam is registered for appli- sugarcane, and more. This review disruption. Indaziflam shows no evidence cation to residential and commercial identifies inadequacies in study design, of carcinogenicity, according to EPA. areas (lawns, ornamentals, and hard- species tested for reproductive toxicity, As an herbicide, indaziflam is extreme- scapes including patios, walkways, etc.), and endocrine disruption. EPA issued ly toxic to aquatic and terrestrial plants. turf (parks, cemeteries, golf courses, an emergency exemption to expand Adverse impacts to nontarget plants are sod farms, sports fields, and commer- uses in 2018 through 2020 on forage expected from all of the labeled uses. cial lawns), field-grown ornamentals, and grass, fodder, and hay grown on Data for indaziflam are inadequate to and Christmas trees, commercial nursery rangeland and pastures. Despite its fully assess chronic toxicity to fish, chronic and landscape plantings, and forestry high cost and the lack of data to eval- toxicity to estuarine/marine invertebrates, sites. Food use sites include woody uate it, some look at indaziflam as a and endocrine disruption in fish and trees, shrubs, vine fruits, and nuts. potential alternative to glyphosate birds. Without data or sufficient evidence Indaziflam products include, in addi- (Roundup).1 to demonstrate otherwise, an unaccept- tion to products containing concentra- Indaziflam’s primary mode of action able risk to fish, aquatic invertebrates, tions of indaziflam alone, products that is inhibition of seedling emergence and and birds is presumed. also contain diquat dibromide, isopro- root development, by inhibiting cellulose pylamine salt of glyphosate, synthetic biosynthesis (CB Inhibitor). Originally GENERAL amorphous silica, for homeowner use not registered for food production, uses Indaziflam is a fluoroalkyltriazine to control annual grasses and broad- now include woody trees, shrubs, and herbicide, part of the broader triazine leaf weeds. There are indaziflam formu- vining fruits and nuts. herbicide family. It differs from other lations with the herbicides 2,4-D, di- In mammals, the nervous system is triazine herbicides in having a fluoro- camba, mecoprop, and penoxsulam. the major target for toxicity, and adverse ethyl group in place of a chloride in

1 D. Chiotti, L. Ritter, D. Schlenk, C. Wilen, and K. Schiff, 2020. Alternatives to Glyphosate for Vegetation Management in Los Angeles County: A technical report. Southern California Coastal Research Project. SCCWRP Technical Report #1103. http://ftp.sccwrp.org/pub/download/DOCUMENTS/TechnicalReports/1103_ GlyphosateAlternativesPanel.pdf.

PESTICIDES AND YOU WINTER 2019–2020 www.BeyondPesticides.org HUMAN HEALTH RISK waters. Indaziflam is not volatile and Reproductive toxicity has been observed The nervous system is the major target therefore it is not likely to be transported in mammals. Parental effects include for toxicity in mammals. Evidence of neu- via atmospheric processes. Indaziflam tremors in females, decreased body rotoxicity (e.g., decreased motor activity, degradates are more mobile than weights and body weight gains, de- clinical signs, and neuropathology) was the parent, and were detected in field creased food consumption, and effects observed in rats and dogs, in acute, studies at the deepest depths sampled on kidneys in males. Offspring effects subchronic, and chronic toxicity studies. —particularly the degradate FDAT, include decreased body weights, body Organs affected by indaziflam in which is mobile to highly mobile. weight gains, and secondary delays in mice and rats include the kidney, liver, sexual maturation. Evidence of repro- thyroid, stomach, seminal vesicles, and EFFECTS ON NONTARGET ductive toxicity includes delayed sexual ovaries. Adverse effects on the thyroid PLANTS AND ANIMALS maturation. Results of available toxicity indicating potential endocrine disrup- Aquatic Organisms studies on terrestrial invertebrates tion include increased thyroid stimulat- Indaziflam is categorized as highly toxic indicate that indaziflam in short-term ing hormone (TSH) and thyroid histopa- to freshwater and estuarine/marine fish, exposures is practically nontoxic to thology. Chronic exposures also led to moderately toxic to highly toxic to estuarine honey bees and earthworms, but toxic atrophied small seminal vesicles (pro- invertebrates, and slightly toxic to mod- to earthworms in extended exposures. duce semen) in male rats and glandular erately toxic to freshwater invertebrates Seedling emergence and vegetative erosion/necrosis in the stomach and on an acute exposure basis. Subchronic vigor in terrestrial plants are affected blood-filled ovarian cysts/follicles in toxicity studies are only available for by indaziflam at application rates female mice. freshwater fish and invertebrates using much lower than the registered uses. Developmental toxicity is evidenced by the species P. promelas and D. magna, Thus, evidence indicates that adverse decreased fetal weight with decreased respectively. The one chronic freshwater effects can be expected to nontarget maternal body weight gain and food fish toxicity endpoint used in this assess- terrestrial plants and birds. A screening consumption. Decreased pup weight ment was based on fry (young fish), level assessment does not predict direct and delays in sexual maturation were survival, total length, and dry weight, risk to mammals. Direct adverse effects observed in offspring in the rat two- with sublethal effects immediately preced- on terrestrial invertebrates are uncertain. generation reproductive toxicity study, ing mortality at the highest concentrations along with clinical signs of toxicity, tested. Of the parameters assessed in UNCERTAINTIES AND DATA GAPS at a dose causing parental toxicity. the one submitted invertebrate life cycle EPA used the fathead minnow early-life Indaziflam shows no evidence of study, indaziflam inhibits both parental stage test results to characterize chronic carcinogenicity in the two-year dietary (F0) growth and reproduction. Effects toxicity for fish. This is inappropriate rat and mouse bioassays. All genotoxic- to offspring (F1) were not evaluated. because EPA estimated the risk to be ity studies that were conducted on indazi- Results of aquatic plant toxicity studies based on a chronic no effect value higher flam were negative. Testing in acute of technical grade indaziflam indicate than the acute lethality value, indicating lethality studies with indaziflam resulted that this pesticide is extremely toxic to that the fathead minnow used for the in low toxicity via the oral (Category III), aquatic plants. Risk Quotients (RQs) acute study is less sensitive than other dermal (Category III), and inhalation for all vascular aquatic plants exceed fish species. In addition, the study did (Category IV) routes of exposure. Indazi- the agency’s aquatic plant risk Level of not address reproduction endpoints, flam was not an irritant to eyes (Toxicity Concern (LOC) by up to two orders of and actual measured concentrations Category IV) or skin (Toxicity Category magnitude. Risks to aquatic plants are in the aquatic tests were improperly IV), and was not a skin sensitizer. expected across all of the proposed determined. EPA should require that Despite the evidence of endocrine uses evaluated. these tests be repeated. disruption, EPA reduced the required In addition, degradate toxicity data Endocrine disrupting (thyroid and additional margin of safety from 10X on aquatic vascular and nonvascular reproductive) effects observed in rat studies safety factor to 1X. plants indicate that indaziflam-olefin warrant Tier II Endocrine Disruptor Screen- and indaziflam-hydroxyethyl are of equal ing Program tests, which have not been ENVIRONMENTAL FATE or similar toxicity to the parent indaziflam. conducted. Indaziflam and its principal degradate, Indaziflam-hydroxyethyl, FDAT, and fluoroethyldiaminotraizine (FDAT), have triazine indanone demonstrate toxicity CONCLUSION a potential to leach to groundwater. to these same taxa at magnitudes The statutory standard requiring suffi- Indaziflam is expected to be moderately 2–7 times less than the parent. cient data to demonstrate indazifam mobile to mobile in soil, moderately will not pose any unreasonable adverse persistent to persistent in aerobic soil, Terrestrial Organisms effects on the environment has not persistent in anerobic soil, and persistent Indaziflam is categorized practically been met, so all registrations should in aerobic and anaerobic aquatic nontoxic to birds and mammals on an be suspended until these data are avail- environments. Indaziflam is subject acute oral basis and (and to birds on able and fully assessed to confirm to aqueous photolysis in clear shallow a subacute dietary exposure basis). otherwise.