Fipronil

Chembox new
Name = Fipronil
ImageFile = Fipronil structure.png ImageFile1 = fipronil.jpg
ImageName = Fipronil
IUPACName = 5-amino-1- [2,6-dichloro-4-(trifluoromethyl)phenyl] -4-
(trifluoromethylsulfinyl)-1H-pyrazole-3-carbonitrile
OtherNames = Fipronil
Fluocyanobenpyrazole
Termidor
Section1 = Chembox Identifiers
CASNo = 120068-37-3
SMILES = ClC1=C(N2N=C(C#N)C(S(C(F)(F)F)=O)=C2N)C(Cl)=CC(C(F)(F)F)=C1
Section2 = Chembox Properties
Formula = C₁₂H₄Cl₂F₆N₄OS
MolarMass = 437.15 g/mol
Density = 1.477-1.626 g/cm³
MeltingPt = 200.5 °C

Fipronil is a broad spectrum insecticide that disrupts the insect central nervous system by blocking the passage of chloride ions through the GABA receptor and glutamate-gated chloride channels (GluCl), components of the central nervous system. This causes hyperexcitation of contaminated insects' nerves and muscles. Insect specificity of fipronil may come from a better efficacy on GABA receptor but also on the fact that GluCl does not exist in mammals. [Raymond-Delpech V, Matsuda K, Sattelle BM, Rauh JJ, Sattelle DB (2005) Ion channels: molecular targets of neuroactive insecticides. "Invert Neurosci": 1-15.]

Fipronil is a slow acting poison. When mixed with a bait it allows the poisoned insect time to return to the colony or haborage. In cockroaches the feces and carcass can contain sufficient residual pesticide to kill others in the same nesting site. In ants, the sharing of the bait among colony members assists in the spreading of the poison throughout the colony. With the cascading effect, the projected kill rate is about 95% in 3 days for ants and cockroaches.

Toxic baiting with Fipronil has also been shown to be extremely effective in locally eliminating German wasps (yellowjackets). All colonies within foraging range are completely eliminated within one week. [cite web | url = http://www.inta.gov.ar/bariloche/ssd/nqn/ecologiadeinsectos/pdfs/Sackmann%20et%20al%202001.pdf | title = Successful Removal of German Yellowjackets (Hymenoptera: Vespidae) by Toxic Baiting. | author = Paula Sackmann, Mauricio Rabinovich and Juan Carlos Corley J. Econ. Entomol.| pages = 94(4):811-816 | date = 2001 ] Beneficial insects, such as honeybees, are not affected by this method as they are not interested in the bait.

Fipronil is used as the active ingredient in Frontline Top Spot at about 9.8% concentration, and is used together with (S)-methoprene (8.8%) in Frontline Plus, a topical flea and tick control commonly used on dogs and cats. It kills adult fleas before they lay eggs. It is also the active ingredient in Over N Out season long fire ant control product.

After a local application of Frontline, fipronil is slightly absorbed (approx. 15%) through the skin. Low levels of fipronil may be detected in the plasma, with a very high variability between dogs. [cite web | url = http://www.vmd.gov.uk/espcsite/Documents/120391.doc | title = Summary of Product Characteristics for Frontline Spot On Dog | author = Veterinary Medicines Directorate | date = 2004 ]

It is also the active ingredient of Regent, now marketed by BASF, which also sells Fipronil under the brand name Termidor for use as a conventional barrier treatment for termites and also as a dust to be blown into termite tunnels. In the US, ant Fipronil based gels are sold under the MaxForce brand (mfg. Bayer), and under the Combat brand (mfg. Dial Corp). Both brands carry .001% Fipronil by weight as the active ingredient. Agricultural products include Chipco Choice for use against pests of field corn, golf courses and commercial turf.

It acts by binding to an allosteric site of GABAA receptors and GluCl receptor (of the insect), a form of non-competitive inhibition.

:Acute oral LD50 (rat) 97 mg/kg:Acute dermal LD50 (rat) >2000 mg/kg

In animals and humans, fipronil poisoning is characterized by vomiting, agitation, and seizures, and can usually be managed through supportive care and early treatment of seizures. [cite web | url = http://books.google.com/books?id=NgMX__L3q40C&pg=PA503&lpg=PA503&dq=fipronil+bioaccumulate+dogs&source=web&ots=wqru1o-r27&sig=9PmjC1Y4foBmQo_Y2NaXB7Eijs0#PPA503,M1 | title = Veterinary Toxicology | author = Ramesh C. Gupta | date = 2007 | pages = 502-503 ] [Mohamed F, Senarathna L, Percy A, Abeyewardene M, Eaglesham G, Cheng R, Azher S, Hittarage A, Dissanayake W, Sheriff MH, Davies W, Buckley NA, Eddleston M., Acute human self-poisoning with the N-phenylpyrazole insecticide fipronil--a GABAA-gated chloride channel blocker, J Toxicol Clin Toxicol. 2004;42(7):955-63)] This risk may be associated with the withdrawal of the MaxForce tick management product. [cite web | url = http://www.swarthmore.edu/Documents/administration/crumwoods/Deer_Management_Plan_April_2007.pdf | title = Deer Management Plan for the Crum Woods of Swarthmore College | author = Natural Resource Consultants, Inc. | pages = 40 | date = Mar 2007 ]

In May 2003, the DGAL (Direction Générale de l'Alimentation du ministère de l'Agriculture ) indicated a case of bee mortality observed in Southern France related to Fipronil acute toxicity. Intoxication was linked to defective seed treatment, which generated dust. The seed treatment involved has since been forbidden.Fact|date=November 2007

References

External links

* [http://npic.orst.edu/factsheets/fipronil.pdf Fipronil Fact Sheet - National Pesticide Information Center]
* [http://www.pesticideinfo.org/Detail_Chemical.jsp?Rec_Id=PC35768 Fipronil Toxicity & Regulatory Info - PANNA PesticideInfo database]