Trifluralin
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| Names | |
|---|---|
| Preferred IUPAC name
2,6-Dinitro-N,N-dipropyl-4-(trifluoromethyl)aniline | |
| Other names
Treflan
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| Identifiers | |
3D model (JSmol)
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| ChEBI | |
| ChEMBL | |
| ChemSpider | |
| ECHA InfoCard | 100.014.936 |
| KEGG | |
PubChem CID
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| UNII | |
CompTox Dashboard (EPA)
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| Properties | |
| C13H16F3N3O4 | |
| Molar mass | 335.283 g·mol−1 |
| Appearance | Yellow crystals |
| Melting point | 46 to 47 °C (115 to 117 °F; 319 to 320 K) |
| Boiling point | 139 to 140 °C (282 to 284 °F; 412 to 413 K) (at 4.2 mmHg) |
| 0.0024 g/100 mL | |
| Hazards | |
| Lethal dose or concentration (LD, LC): | |
LD50 (median dose)
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>5000 mg/kg (rat, oral) |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Trifluralin is a commonly used pre-emergence herbicide. With about 14 million pounds (6,400 t) used in the United States in 2001[2], and 3–7 million pounds (1,400–3,200 t) in 2012[3], it is one of the most widely used herbicides. Introduced in 1964, Trifluralin was the first organofluorine compound used as an agrochemical.[4]
Trifluralin is generally applied to the soil to control annual grass and broadleaf weed species. It inhibits root development by interrupting mitosis and thus can control weeds as they germinate.[5] Trifluralin is also used in Australia, to be applied at 0.8-3.0 L/ha (for a 480 g/L formulation).[6]
Discovery
[edit]Selective herbicides were unavailable in the 1950s to protect soybean and cotton, (2,4-DNP could, but had to be exactingly applied lest it destroy the crops.) so Lilly Research Laboratories screened ~2000 compounds from 1958 to 1980 blindly looking for a result. Trifluralin was initially thought a failure, yet the plots stayed free of weeds weeks later.[4] Application by incorporation into the top soil instead was eight times more potent.[7] Pre-plant soil incorporation was a new technique at the time. It is unclear why trifluralin's exotic 4-trifluoromethyl was tested so early (1960), before commoner candidates. (e.g. fluoro, bromo, iodo)[4]
Environmental regulation
[edit]Trifluralin has been banned in the European Union since 20 March 2008, primarily due to high toxicity to aquatic life.[8]
Trifluralin is on the United States Environmental Protection Agency list of Hazardous Air Pollutants as a regulated substance under the Clean Air Act.[9]
Environmental behavior
[edit]Trifluralin breaks down into many products as it degrades, ultimately being incorporated into soil-bound residues or converted to carbon dioxide (mineralized). Among the more unusual behaviors of trifluralin is inactivation in wet soils. This has been linked to transformation of the herbicide by reduced soil minerals, which in turn had been previously reduced by soil microorganisms using them as electron acceptors in the absence of oxygen. This environmental degradation process has been reported for many structurally related herbicides (dinitroanilines) as well as a variety of explosives such as TNT and picric acid.[10]
Trifluralin has a long half-life in soil of ~180 days, but it is accepted at high application rates because of its low soil mobility and high volatility.[4] It is safe for mammals and chickens, even in large amounts.[11]
Trade names
[edit]- Trifluralin
- Treflan
- Trilin
- Trust
- Tri-4
- Edge
- Snapshot (formulation of isoxaben and trifluralin)
References
[edit]- ^ Merck Index, 11th Edition, 9598.
- ^ 2000-2001 Pesticide Market Estimates, United States Environmental Protection Agency
- ^ "Pesticides Industry Sales and Usage 2008 – 2012 Market Estimates" (PDF).
- ^ a b c d Epp, Jeffery B.; Schmitzer, Paul B.; Crouse, Gary D. (4 July 2017). "Fifty years of herbicide research: comparing the discovery of trifluralin and halauxifen-methyl". Pest Management Science. Retrieved 6 August 2024.
- ^ Grover, Raj; Wolt, Jeffrey D.; Cessna, Allan J.; Schiefer, H. Bruno (1997). "Environmental Fate of Trifluralin". Reviews of Environmental Contamination and Toxicology. Vol. 153. pp. 1–64. doi:10.1007/978-1-4612-2302-3_1. ISBN 978-1-4612-7492-6. PMID 9380893.
- ^ "Trifluralin 480 Leaflet" (PDF). 4farmers.com.au. 4Farmers Australia. Retrieved 28 May 2024.
- ^ Anderson, W. Powell; Richards, Anna Beth; Whitworth, J. Wayne (Jul 1967). "Trifluralin Effects On Cotton Seedlings". Weeds. 15 (3): 224–227. Retrieved 6 August 2024.
- ^ "European Union - Final Regulatory Action".
- ^ "Initial List of Hazardous Air Pollutants with Modifications". United States Environmental Protection Agency. 16 December 2015. Retrieved 16 December 2021.
- ^ Tor, Jason M.; Xu, Caifen; Stucki, Joseph M.; Wander, Michelle M.; Sims, Gerald K. (2000). "Trifluralin Degradation under Microbiologically Induced Nitrate and Fe(III) Reducing Conditions". Environmental Science & Technology. 34 (15): 3148–3152. Bibcode:2000EnST...34.3148T. doi:10.1021/es9912473.
- ^ Worth, H. M.; Anderson, R. C. (1965). "The toxicity of trifluralin, Treflan, an herbicide, to mammals and chickens". SWC. 18: 711–712.
External links
[edit]- Trifluralin in the Pesticide Properties DataBase (PPDB)