1.800.858.7378 npic@ace.orst.edu
We're open from 8:00AM to 12:00PM Pacific Time, Mon-Fri

Dicamba

Technical Fact Sheet

As of 2011, NPIC stopped creating technical pesticide fact sheets. The old collection of technical fact sheets will remain available in this archive, but they may contain out-of-date material. NPIC no longer has the capacity to consistently update them. To visit our general fact sheets, click here. For up-to-date technical fact sheets, please visit the Environmental Protection Agency's >webpage.

Molecular Structure -
Dicamba

Laboratory Testing: Before pesticides are registered by the U.S. EPA, they must undergo laboratory testing for short-term (acute) and long-term (chronic) health effects. Laboratory animals are purposely given high enough doses to cause toxic effects. These tests help scientists judge how these chemicals might affect humans, domestic animals, and wildlife in cases of overexposure.

Chemical Class and Type:

Physical / Chemical Properties:

Dicamba
Active Ingredient CASRN5 Form5,6 Vapor pressure5 Henry's constant4 Molecular weight5 Solubility in water (mg/L)5 Log Kow4 Koc5
Dicamba acid 1918-00-9 White to brown crystalline solid 4.5 x 10-3 Pa at 25 °C 1.0 x 10-4 Pa m3/mol-1 221.04 g/mole 4500 mg/L at 25 °C pH 5.0: -0.55
pH 6.8: -1.88
pH 8.9: -1.9
2
Dimethylamine salt 2300-66-5 Colorless to white crystalline powder 266.12 g/mole 720,000 mg/L

Uses:

Mode of Action:

Target Organisms

Non-target Organisms

Acute Toxicity:

Oral

TOXICITY CLASSIFICATION - DICAMBA
High Toxicity Moderate Toxicity Low Toxicity Very Low Toxicity
Acute Oral LD50 Up to and including 50 mg/kg
(≤ 50 mg/kg)
Greater than 50 through 500 mg/kg
(>50-500 mg/kg)
Greater than 500 through 5000 mg/kg
(>500-5000 mg/kg)
Greater than 5000 mg/kg
(>5000 mg/kg)
Inhalation LC50 Up to and including 0.05 mg/L
(≤0.05 mg/L)
Greater than 0.05 through 0.5 mg/L
(>0.05-0.5 mg/L)
Greater than 0.5 through 2.0 mg/L
(>0.5-2.0 mg/L)
Greater than 2.0 mg/L
(>2.0 mg/L)
Dermal LD50 Up to and including 200 mg/kg
(≤200 mg/kg)
Greater than 200 through 2000 mg/kg
(>200-2000 mg/kg)
Greater than 2000 through 5000 mg/kg
(>2000-5000 mg/kg)
Greater than 5000 mg/kg
(>5000 mg/kg)
Primary Eye Irritation Corrosive (irreversible destruction of ocular tissue) or corneal involvement or irritation persisting for more than 21 days Corneal involvement or other eye irritation clearing in 8 - 21 days Corneal involvement or other eye irritation clearing in 7 days or less Minimal effects clearing in less than 24 hours
Primary Skin Irritation Corrosive (tissue destruction into the dermis and/or scarring) Severe irritation at 72 hours (severe erythema or edema) Moderate irritation at 72 hours (moderate erythema) Mild or slight irritation at 72 hours (no irritation or erythema)
The highlighted boxes reflect the values in the "Acute Toxicity" section of this fact sheet. Modeled after the U.S. Environmental Protection Agency, Office of Pesticide Programs, Label Review Manual, Chapter 7: Precautionary Labeling. https://www.epa.gov/sites/default/files/2018-04/documents/chap-07-mar-2018.pdf

Dermal

Inhalation

Signs of Toxicity - Animals

Signs of Toxicity - Humans

Chronic Toxicity:

Animals

Humans

Endocrine Disruption:

Carcinogenicity:

Animals

Humans

Cancer: Government agencies in the United States and abroad have developed programs to evaluate the potential for a chemical to cause cancer. Testing guidelines and classification systems vary. To learn more about the meaning of various cancer classification descriptors listed in this fact sheet, please visit the appropriate reference, or call NPIC.

Reproductive or Teratogenic Effects:

Animals

Humans

Fate in the Body:

Absorption

Distribution

Metabolism

Excretion

Medical Tests and Monitoring:

Environmental Fate:

Soil

Water

Air

Plants

Indoor

Food Residue

Ecotoxicity Studies:

Birds

Fish and Aquatic Life

Terrestrial Invertebrates

Regulatory Guidelines:

Date Reviewed: January 2012

Please cite as: Bunch, T. R; Gervais, J. A.; Buhl, K.; Stone, D. 2012. Dicamba Technical Fact Sheet; National Pesticide Information Center, Oregon State University Extension Services.. https://npic.orst.edu/factsheets/archive/dicamba_tech.html.

References:

  1. Kamrin, M. A. Phenoxy and benzoic acid herbicides. Pesticide Profiles: Toxicity, Environmental Impact, and Fate; CRC Press: Boca Raton, FL, 1997; pp 319-322, 332-334.
  2. Reigart, J. R.; Roberts, J. R. Recognition and Management of Pesticide Poisoning, 5th ed.; U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, U.S. Government Printing Office: Washington, DC, 1999; pp 94-96.
  3. Correction to the Amendments to the Dicamba RED; U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, U.S. Government Printing Office: Washington, DC, 2009.
  4. Tomlin, C. D. S. The Pesticide Manual, A World Compendium, 15th ed.; Bristish Crop Protection Countil: Surrey, UK, 2009; pp 323-325.
  5. Senseman, S. A. Herbicide Handbook, 9th ed.; Weed Science Society of America: Lawrence, KS, 2007; pp 336-338.
  6. Database of Hazardous Materials Chemical Datasheet - Dimethlyamine Dicamba; National Oceanic and Atmospheric Administration, Office of Response and Restoration: Silver Spring, MD, 2011.
  7. Kelley, K. B.; Riechers, D. E. Recent developments in auxin biology and new opportunities for auxinic herbicide research. Pestic. Biochem. Physiol. 2007, 89 (1), 1-11.
  8. Caux, P. Y.; Kent, R. A.; Tache, M.; Grande, C.; Fan, G. T.; MacDonald, D. D. Environmental fate and effects of dicamba: a Canadian perspective. Rev. Environ. Contam. Toxicol. 1993, 133, 1-58.
  9. Bradberry, S. M.; Proudfoot, A. T.; Vale, J. A. Poisoning Due to Chlorophenoxy Herbicides. Toxicol. Rev. 2004, 23 (2), 65-73.
  10. González, N. V.; Soloneski, S.; Larramendy, M. L. The chlorophenoxy herbicide dicamba and its commercial formulation Banvel® induce genotoxicity and cytotoxicity in Chinese hamster ovary (CHO) cells. Mutat. Res. 2007, 634 (1-2), 60-68.
  11. Peixoto, F.; Vicente, J. A. F.; Madeira, 11. V. M. C. The herbicide dicamba (2-methoxy-3,6-dichlorobenzoic acid) interacts with mitochondrial bioenergetic functions. Arch. Toxicol. 2003, 77 (7), 403-409.
  12. Edson, E. F.; Sanderson, D. M. Toxicity of the herbicides, 2-methoxy-3,6-dichlorobenzoic acid (dicamba) and 2-methoxy-3,5,6- trichlorobenzoic acid (tricamba). Food Cosmet. Toxicol. 1965, 3, 299-304.
  13. Gaines, T. B.; Linder, R. E. Acute Toxicity of Pesticides in Adult and Weanling Rats. Toxicol. Sci. 1986, 7 (2), 299-308.
  14. Yeary, R. A. Miscellaneous Herbicides, Fungicides, and Nematocides. Small Animal Toxicology, 2nd ed.; Peterson, M. E.; Talcott, P. A., Eds.; Saunders Elsevier: St. Louis, MO, 2006; p 738.
  15. Lorgue, G.; Lechenet, J.; Riviere, A. Clinical Veterinary Toxicology; Blackewell Science: Osney Mead, Oxford, 1996; pp 90-91.
  16. Beasley, V. R.; Arnold, E. K.; Lovell, R. A.; Parker, A. J. 2,4-D toxicosis. I: A pilot study of 2,4-dichlorophenoxyacetic acid- and dicambainduced myotonia in experimental dogs. Vet. Hum. Toxicol. 1991, 33 (5), 435-40.
  17. Campbell, S. M.; Grimes, J.; Jaber, M.; Beavers, J. B. An Acute Oral Toxicity study with the Northern Bobwhite. Unpublished Project no. 131-179A, 1993, submitted to U.S. Department of Agriculture, by Sandoz Agro, Des Plaines, IL, prepared by Wildlife International Ltd., Easton MD. EPA MRID No. 42918001. Dicamba - Human Health and Ecological Risk Assessment - Final Report; U.S Department of Agriculture, Forest Health Protection: Arlington, VA, 2004.
  18. Dicamba: HED Chapter of the Reregistration Eligibility Decision Document; U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, U.S. Government Printing Office: Washington, DC, 2005.
  19. Espandiari, P.; Thomas, V. A.; Glauert, H. P.; O'Brien, M.; Noonan, D.; Robertson, L. W. The Herbicide Dicamba (2-Methoxy-3,6- dichlorobenzoic Acid) Is a Peroxisome Proliferator in Rats. Fundam. Appl. Toxicol. 1995, 26 (1), 85-90.
  20. Dicamba (3,6-dichloro-o-anisic acid); Pesticide Tolerance. Fed. Reg. 1999, 64 (3), 759-769.
  21. Samanic, C.; Rusiecki, J.; Dosemeci, M.; Hou, L.; Hoppin, J. A.; Sandler, D. P.; Lubin, J.; Blair, A.; Alavanja, M. C. R. Cancer Incidence among Pesticide Applicators Exposed to Dicamba in the Agricultural Health Study. Environ. Health Perspect. 2006, 114 (10).
  22. EFED Reregistration Chapter For Dicamba/Dicamba Salts; U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, U.S. Government Printing Office: Washington, DC, 2005.
  23. Greenlee, A. R.; Ellis, T. M.; Berg, R. L. Low-Dose Agrochemicals and Lawn-Care Pesticides Induce Developmental Toxicity in Murine Preimplantation Embryos. Environ. Health Perspect. 2004, 112 (6).
  24. Oehler, D. D.; Ivie, G. W. Metabolic fate of the herbicide dicamba in a lactating cow. J. Agric. Food Chem. 1980, 28 (4), 685-689.
  25. Tye, R.; Engel, D., Distribution and excretion of dicamba by rats as determined by radiotracer technique. J. Agr. Food Chem. 1967, 15 (5), 837-40.
  26. Makary, M. H.; Street, J. C.; Sharma, R. P. Pharmacokinetics of dicamba isomers applied dermally to rats. Pestic. Biochem. Physiol. 1986, 25 (2), 258-263.
  27. Mukherjee, M.; Muraleedharannair, P.; Karmakar, U. K.; Datta, B. K.; Sar, T. K.; Chakraborty, A. K.; Bhattacharya, A.; Choudhury, A.; Mandal, T. K. Toxicokinetics and recovery studies of dicamba dimethyl amine salt in goats following single oral administration. J. Sci. Food Agric. 2010, 90 (2), 257-266.
  28. Roberts, T. R. Metabolic Pathways of Agrochemicals Part 1 - Herbicides and Plant Growth Regulators; The Royal Society of Chemistry: Cambridge, UK, 1998; pp 148-150.
  29. Kutz, F. W.; Cook, B. T.; Carter-Pokras, O. D.; Brody, D.; Murphy, R. S. Selected pesticide residues and metabolites in urine from a survey of the U.S. general population. J. Toxicol. Environ. Health 1992, 37 (2), 277-91.
  30. Harris, S. A.; Villeneuve, P. J.; Crawley, C. D.; Mays, J. E.; Yeary, R. A.; Hurto, K. A.; Meeker, J. D. National study of exposure to pesticides among professional applicators: an investigation based on urinary biomarkers. J. Agric. Food Chem. 2010, 58, 10253-10261.
  31. Altom, J. D.; Stritzke, J. F. Degradation of dicamba, picloram, and four phenoxy herbicides in soils. Weed Sci. 1973, 21 (6), 556-60.
  32. Krueger, J. P.; Butz, R. G.; Cork, D. J. Aerobic and anaerobic soil metabolism of dicamba. J. Agric. Food Chem. 1991, 39 (5), 995-999.
  33. Smith, A. E. Breakdown of the herbicide dicamba and its degradation product 3,6-dichlorosalicylic acid in prairie soils. J. Agric. Food Chem. 1974, 22 (4), 601-5.
  34. Ochsner, T. E.; Stephens, B. M.; Koskinen, W. C.; Kookana, R. S. Sorption of a Hydrophilic Pesticide. Soil Sci. Soc. Am. J. 2006, 70 (6), 1991-1997.
  35. Scifres, C. J.; Allen, T. J.; Leinweber, C. 35. L.; Pearson, K. H. Dissipation and phytotoxicity of dicamba residues in water. J. Environ. Qual. 1973, 2 (2), 306-9.
  36. Pesticides in Ground Water Database: A Compilation of Monitoring Studies: 1971-1991 National Summary; U.S Environmental Protection Agency, Office of Prevention, Pesticides, and Toxic Substances, U.S. Government Printing Office: Washington, DC, 1991.
  37. Kolpin, D. W., Barbash, J. E., Gilliom, R. J. Pesticides in Ground Water of the United States, 1992-1996. Ground Water 2000, 38 (6), 858- 863.
  38. Behrens, R.; Lueschen, W. E. Dicamba Volatility. Weed Sci. 1979, 27 (5), 486-493.
  39. Aulagnier, F.; Poissant, L.; Brunet, D.; Beauvais, C.; Pilote, M.; Deblois, C.; Dassylva, N. Pesticides measured in air and precipitation in the Yamaska Basin (Québec): Occurrence and concentrations in 2004. Sci. Total Environ. 2008, 394 (2-3), 338-348.
  40. Kearney, P. C.; Kaufman, D. D. Herbicides : chemistry, degradation, and mode of action, 2nd ed.; Marcel Dekker, Inc.: New York, 1975; pp 563-570.
  41. Chang, F. Y.; Born, W. H. V. Dicamba Uptake, Translocation, Metabolism, and Selectivity. Weed Sci. 1971, 19 (1), 113-117.
  42. Al-Khatib, K.; Parker, R.; Fuerst, E. P. Foliar absorption and translocation of dicamba from aqueous solution and dicamba-treated soil deposits. Weed Technol. 1992, 6 (1), 57-61.
  43. Lemley, A. T.; Hedge, A.; Obendorf, S. K.; Hong, S.; Kim, J.; Muss, T. M.; Varner, C. J. Selected Pesticide Residues in House Dust from Farmers' Homes in Central New York State, USA. Bull. Environ. Contam. Toxicol. 2002, 69 (2), 155-163.
  44. Ward, M. H.; Lubin, J.; Giglierano, J.; Colt, J. S.; Wolter, C.; Bekiroglu, N.; Camann, D.; Hartge, P.; Nuckols, J. R. Proximity to Crops and Residential Exposure to Agricultural Herbicides in Iowa. Environ. Health Perspect. 2006, 114 (6), 893-897.
  45. Pesticide Data Program Annual Summary, Calendar Year 2008; United States Department of Agriculture, Agricultural Marketing Service: Washington, DC, 2009.
  46. Pesticide Data Program Annual Summary, Calendar Year 2009; United States Department of Agriculture, Agricultural Marketing Service: Washington, DC, 2011.
  47. Total Diet Study Market Baskets 1991-3 through 2003-4; U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Offie of Food Safety: College Park, MD, 2004.
  48. Fink, R. Eight-day dietary LC50 - Mallard duck. Unpublished Report no. 107-150, 1977, submitted to Council Directive EU Review Programme, by Novartis Crop Protection AG, Basel, Switzerland, prepared by Wildlife International Ltd., Easton, MD. Dicamba Volume 3 Annex B9: Ecotoxicology Draft Assessment Report; Council Directive EU Review Programme: Denmark, 2007.
  49. Campbell, S.; Beavers, J. Technical Dicamba: An Acute Oral Toxicity Study with the Mallard Duck. Unpublished Lab Project no. 131-184A, 1993, submitted to U.S. Environmental Protection Agency, by Wildlife International. Ltd. EPA MRID 42774106. EFED Reregistration Chapter For Dicamba/Dicamba Salts; U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, U.S. Government Printing Office: Washington, DC, 2005.
  50. Touart, L. W. Avian acute oral LD50 Mallard duck. Unpublished Report no. MRID 0046180, 1983, submitted to the U.S. Environmental Protection Agency. EFED Reregistration Chapter For Dicamba/Dicamba Salts; U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, U.S. Government Printing Office: Washington, DC, 2005.
  51. Gutenson, O. Avian Acute Oral LD50 Bobwhite quail. Unpublished Report no. MRID 261466, 1987, submitted to the U.S. Environmental Protection Agency. EFED Reregistration Chapter For Dicamba/Dicamba Salts; U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, U.S. Government Printing Office: Washington, DC, 2005.
  52. Avian acute oral LD50 Bobwhite quail. Unpublished Report no. ACC263863, submitted to the U.S. Environmental Protection Agency. EFED Reregistration Chapter For Dicamba/Dicamba Salts; U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, U.S. Government Printing Office: Washington, DC, 2005.
  53. Rainbow Trout. Dimethylamine salt of dicamba. Unpublished Report no. MRID 00263000, submitted to the U.S. Environmental Protection Agency. EFED Reregistration Chapter For Dicamba/Dicamba Salts; U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, U.S. Government Printing Office: Washington, DC, 2005.
  54. Woodward, D. F. Acute toxicity of mixtures of range management herbicides to cutthroat trout. J. Range Manage. 1982, 35 (4), 539-40.
  55. Touart, L. W. 55. Bluegill sunfish. Dimethylamine salt of dicamba. Unpublished Report no. MRID 00046183, 1983, submitted to the U.S. Environmental Protection Agency. EFED Reregistration Chapter For Dicamba/Dicamba Salts; U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, U.S. Government Printing Office: Washington, DC, 2005.
  56. Touart, L. W. Rainbow trout. Sodium salt of dicamba. Unpublished Report no. MRID 00029623, 1983, submitted to the U.S. Environmental Protection Agency. EFED Reregistration Chapter For Dicamba/Dicamba Salts; U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, U.S. Government Printing Office: Washington, DC, 2005.
  57. Touart, L. W. Bluegill sunfish. Sodium salt of dicamba. Unpublished Report no. MRID 00022539, 1983, submitted to the U.S. Environmental Protection Agency. EFED Reregistration Chapter For Dicamba/Dicamba Salts; U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, U.S. Government Printing Office: Washington, DC, 2005.
  58. Acute toxicity of potassium salt of dicamba to Bluegill Sunfish. Unpublished Report no. MRID 258983, 1985, submitted to the U.S. Environmental Protection Agency. EFED Reregistration Chapter For Dicamba/Dicamba Salts; U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, U.S. Government Printing Office: Washington, DC, 2005.
  59. Bond, C. E.; Fortune, J. D.; Young, F. Results of Preliminary Bioassays with Kurosal SL and Dicamba. The Progressive Fish-Culturist 1965, 27 (1), 49-51.
  60. Daphnia. Dimethylamine salt of dicamba. Unpublished Report no. MRID 00028283, 1983, submitted to the U.S. Environmental Protection Agency. EFED Reregistration Chapter For Dicamba/Dicamba Salts; U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, U.S. Government Printing Office: Washington, DC, 2005.
  61. Daphnia. Sodium salt of dicamba. Unpublished Report no. MRID 00233292, submitted to the U.S. Environmental Protection Agency. EFED Reregistration Chapter For Dicamba/Dicamba Salts; U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, U.S. Government Printing Office: Washington, DC, 2005.
  62. Aquatic Invertebrate Acute Toxicity. Daphnia magna. Unpublished Report no. MRID ACC263863, submitted to the U.S. Environmental Protection Agency. EFED Reregistration Chapter For Dicamba/Dicamba Salts; U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, U.S. Government Printing Office: Washington, DC, 2005.
  63. Zucker, E. Banvel CN-10-6471 Potassium Formulation. Acute Toxicity of CN-10-6471 to Daphnia magna. Unpublished Report no. MRID 258983, 1985, submitted to the U.S. Environmental Protection Agency. EFED Reregistration Chapter For Dicamba/Dicamba Salts; U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, U.S. Government Printing Office: Washington, DC, 2005.
  64. Sanders, H. O. Toxicities of Some Herbicides to Six Species of Freshwater Crustaceans. J. Water Pollut. Control Fed. 1970, 42 (8), 1544- 1550.
  65. Johnson, C. R. Herbicide toxicities in some Australian anurans and the effect of subacute dosages on temperature tolerance. J. Linn. Soc. London, Zool. 1976, 59 (1), 79-83.
  66. Cullimore, D. R. The in vitro sensitivity of some species of Chlorophyceae to a selected range of herbicides. Weed Res. 1975, 15 (6), 401-406.
  67. Design for the Environment Program Alternatives Assessment Criteria for Hazard Evaluation; U.S. Environmental Protection Agency, Office of Prevention, Pesticides, and Toxic Substances, U.S Government Printing Office: Washington, DC, 2010; p 26.
  68. Morton, H. L.; Moffett, J. O.; Macdonald, R. H. Toxicity of Herbicides to Newly Emerged Honey Bees. Environ. Entomol. 1972, 1, 102-104.
  69. Effect of 3,6-Dichloro-2methyoxybenzoic acid on Apis mellifera Mortality; U.S. Environmental Protection Agency, Office of Prevention, Pesticides, and Toxic Substances, Office of Pesticide Programs, Environmental Fate and Effects Division, U.S. Government Printing Office: Washington, DC, 2000.
  70. Stevenson, J. H. The Acute Toxicity of Unformulated Pesticides to Worker Honey Bees (Apis mellifera L.). Plant Pathol. 1978, 27 (1), 38-40.
  71. 2011 Edition of the Drinking Water Standards and Health Advisories; EPA 820-R-11-002; U.S. Environmental Protection Agency, Office of Water, U.S. Government Printing Office: Washington, DC, 2011.
  72. WHO. Acceptable daily intakes, acute reference doses, short-term and long-term dietary intakes, recommended maximum residue limits and supervised trials median residue values recorded by the 2010 meeting; World Health Organization, Food and Agriculure Organization of the United Nations: Rome, Italy, 2010.
Facebook Twitter Youtube