Benfluralin

{{Chembox

| Verifiedfields = changed

| Watchedfields = changed

| verifiedrevid = 486406020

| ImageFile = Benfluralin.svg

| ImageSize = 150px

| PIN = N-Butyl-N-ethyl-2,6-dinitro-4-(trifluoromethyl)aniline

| OtherNames = Benefin; Benfluraline; α,α,α-Trifluoro-2,6-dinitro-N,N-ethylbutyl-p-toluidine

|Section1={{Chembox Identifiers

| CASNo = 1861-40-1

| CASNo_Ref = {{cascite|changed|??}}

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = 28224BUY6R

| PubChem = 2319

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| ChemSpiderID = 2229

| ChEBI_Ref = {{ebicite|changed|EBI}}

| ChEBI = 132878

| SMILES = [O-][N+](=O)c1cc(cc([N+]([O-])=O)c1N(CCCC)CC)C(F)(F)F

| InChI = 1/C13H16F3N3O4/c1-3-5-6-17(4-2)12-10(18(20)21)7-9(13(14,15)16)8-11(12)19(22)23/h7-8H,3-6H2,1-2H3

| InChIKey = SMDHCQAYESWHAE-UHFFFAOYAK

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| StdInChI = 1S/C13H16F3N3O4/c1-3-5-6-17(4-2)12-10(18(20)21)7-9(13(14,15)16)8-11(12)19(22)23/h7-8H,3-6H2,1-2H3

| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

| StdInChIKey = SMDHCQAYESWHAE-UHFFFAOYSA-N

}}

|Section2={{Chembox Properties

| C=13|H=16|F=3|N=3|O=4

| Appearance = Orange crystalline solid{{GESTIS|ZVG=490343}}

| Density = 1.338 g/mL

| MeltingPtC = 65.0 to 65.5

| MeltingPt_ref =

| BoilingPtC = 121 to 122

| BoilingPt_notes = at 0.6 mbar

| BoilingPt_ref =

| Solubility = 1 mg/L

| VaporPressure = 3.7 mPa (2010). ARS Pesticide Properties Database. U.S. Department of Agriculture. Retrieved from
https://app.knovel.com/hotlink/toc/id:kpARSPPD03/ars-pesticide-properties/ars-pesticide-properties

}}

|Section3={{Chembox Hazards

| MainHazards = Skin irritation; toxicity to aquatic life

| FlashPt =

| AutoignitionPt =

}}

}}

Benfluralin (or Benefin) is a herbicide of the dinitroaniline class. The mechanism of action of benfluralin involves pre-emergent inhibition of mitosis, root and shoot development,[http://www.globachem.com/Defaultb878.html?CID=7133&SLID=1#Benfluralin Agrochemicals] {{webarchive |url=https://web.archive.org/web/20120406170823/http://www.globachem.com/Defaultb878.html?CID=7133&SLID=1#Benfluralin |date=April 6, 2012 }}, Globachem same as trifluralin, from which benfluralin was developed in 1963.{{cite book |doi=10.1016/B0-12-369400-0/00987-X |chapter=Trifluralin |title=Encyclopedia of Toxicology |date=2005 |last1=Wallace |first1=David R. |pages=388–389 |isbn=978-0-12-369400-3 }}{{cite book |doi=10.1016/B978-0-12-823674-1.00008-0 |chapter=Herbicide mode of action |title=Herbicides |date=2021 |last1=Székács |first1=András |pages=41–86 |isbn=978-0-12-823674-1 }}

File:Registration of benfluralin USA.png

It is used to control grasses and other weeds. Annual use in the United States was approximately {{convert|700,000|lb|t}} in 2004,[http://www.epa.gov/oppsrrd1/REDs/factsheets/benfluralin_fs.pdf R.E.D. FACTS: Benfluralin] {{webarchive |url=https://web.archive.org/web/20110915205513/http://www.epa.gov/oppsrrd1/REDs/factsheets/benfluralin_fs.pdf |date=September 15, 2011 }}, United States Environmental Protection Agency down from {{convert|1,200,000|lb|t}} in 1974, when it was used more than paraquat.{{cite web |title=Pesticide Usage Survey of Agricultural, Governmental, and Industrial Sectors in the United States, 1974 |url=https://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=91012P4O.txt |website=epa.gov |publisher=EPA |date=1977}} Non-agricultural use includes domestic use, turf, golf courses, ornamentals, tree plantations, roads and paths. It is used on lettuce, alfalfa, clover, fruit, nuts, berries, and vineyards. Benfluralin's EU approval expired in 2023,{{cite news |title=Sowing Resilience: Industry Insights on Europe's Agri-input Challenges and Prospects |url=https://news.agropages.com/News/NewsDetail---49708.htm |work=Grainews |language=en}} leaving pendimethalin as the only EU-approved dinitroaniline.{{cite journal |last1=Giglio |first1=A |last2=Vommaro |first2=ML |title=Dinitroaniline herbicides: a comprehensive review of toxicity and side effects on animal non-target organisms. |journal=Environmental Science and Pollution Research International |date=November 2022 |volume=29 |issue=51 |pages=76687–76711 |doi=10.1007/s11356-022-23169-4 |pmid=36175724|pmc=9581837 |bibcode=2022ESPR...2976687G }}

Benfluralin is practically non-toxic. Chronic exposure may harm the liver and kidneys. No endocrine disruption is known. EPA modelling puts benfluralin water concentrations below any level of concern, and real life evidence shows benfluralin levels to be lower than predicted. {{cite web |title=R.E.D. Facts Benfluralin |url=https://www3.epa.gov/pesticides/chem_search/reg_actions/reregistration/fs_PC-084301_31-Jul-04.pdf |publisher=EPA |date=July 31, 2004|archive-url=https://web.archive.org/web/20240714140935/https://www3.epa.gov/pesticides/chem_search/reg_actions/reregistration/fs_PC-084301_31-Jul-04.pdf |archive-date=14 July 2024 }}

Benfluralin's soil half-life is moderate, 22-79 days, and volatilises quickly. It can bioaccumulate in fish, to whom it is very toxic. It is practically non-toxic to birds and bees.

After application, benefin must be inforporated into soil. It is usually applied at ~1.2 lb/ac (1.35 kg/Ha) active ingredient.{{cite web |title=Balan DF Product Label - 051908 V4D 08G09 |url=https://www.agrian.com/labelcenter/results.cfm?quicksearch=BALAN%20DF |website=www.agrian.com}}

Vapours of benefin can affect growing tobacco leaves, and exposed leaves are shortened, narrowed, thicker and distorted. Plant height is reduced, though more leaves sprout.{{cite journal |last1=Yamasue |first1=Yuji |last2=Worsham |first2=Arch D. |last3=Anderson |first3=Charles E. |title=Morphological and Anatomical Effects of Benefin Vapors on Tobacco (Nicotiana tabacum) |journal=Weed Science |date=1982 |volume=30 |issue=5 |pages=539–544 |doi=10.1017/S0043174500041126 |jstor=4043756 }}