Dicamba

Dicamba[1]
Names
Preferred IUPAC name
3,6-Dichloro-2-methoxybenzoic acid
Other names
3,6-Dichloro-o-anisic acid
Dianat
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.016.033 Edit this at Wikidata
KEGG
UNII
  • InChI=1S/C8H6Cl2O3/c1-13-7-5(10)3-2-4(9)6(7)8(11)12/h2-3H,1H3,(H,11,12) checkY
    Key: IWEDIXLBFLAXBO-UHFFFAOYSA-N checkY
  • InChI=1/C8H6Cl2O3/c1-13-7-5(10)3-2-4(9)6(7)8(11)12/h2-3H,1H3,(H,11,12)
    Key: IWEDIXLBFLAXBO-UHFFFAOYAV
  • Clc1ccc(Cl)c(c1OC)C(=O)O
Properties
C8H6Cl2O3
Molar mass 221.03 g·mol−1
Appearance White crystalline solid
Density 1.57
Melting point 114 to 116 °C (237 to 241 °F; 387 to 389 K)
"low"[2]
Solubility in acetone 810 g/L
Solubility in ethanol 922 g/L
Hazards
GHS labelling:[3]
GHS05: CorrosiveGHS07: Exclamation mark
Danger
H302, H318, H412
P273, P280, P305+P351+P338
Flash point 199 °C (390 °F; 472 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Dicamba (3,6-dichloro-2-methoxybenzoic acid) is a selective systemic herbicide first registered in 1967.[4] Brand names for formulations of this herbicide include Dianat, Banvel, Diablo, Oracle and Vanquish. This chemical compound is a chlorinated derivative of o-anisic acid.[5] It has been described as a "widely used, low-cost, environmentally friendly herbicide that does not persist in soils and shows little or no toxicity to wildlife and humans."[6]

Despite its success in improving crop yields, dicamba has attracted controversy. According to the United States Environmental Protection Agency (EPA), dicamba's primary ecological risk is for non-target terrestrial plants from exposure through spray drift, whereby dicamba inadvertently migrates to non-targeted neighboring areas, damaging those plants.[7][8]

In 2016, dicamba was approved for use in the United States over GMO dicamba-resistant crops created by Monsanto. Dicamba came under significant scrutiny due to its tendency to spread from treated fields into neighboring fields, causing damage.[9] The controversy led to litigation, state bans and additional restrictions over dicamba use.

  1. ^ Merck Index, 11th Edition, 3026.
  2. ^ Cite error: The named reference Ullmann was invoked but never defined (see the help page).
  3. ^ Record of Dicamba in the GESTIS Substance Database of the Institute for Occupational Safety and Health, accessed on 2023-12-12.
  4. ^ "Reregistration Eligibility Decision for Dicamba and Associated Salts - US EPA" (PDF). 8 June 2006.
  5. ^ "Dicamba (Banvel) Herbicide Profile 10/83, Pesticide Management Education Program". Cornell University.
  6. ^ Cite error: The named reference Weeks was invoked but never defined (see the help page).
  7. ^ "Dicamba". United States Environmental Protection Agency. 16 February 2023.
  8. ^ "Dicamba". United States Environmental Protection Agency. 16 February 2023. Archived from the original on 23 December 2023.
  9. ^ Revealed: Monsanto predicted crop system would damage US farms The Guardian, 2020