Potential Exposure
Pyrazole/phenylpyrazole/organofluor ine insecticide; veterinary medicine. Fipronil was intro duced into the United States in 1996 for use in animal
health and indoor pest control. It is the constituent of many
products for controlling a wide spectrum of domestic ani mal and residential pests. Banned for use in EU.
First aid
Give artificial respiration if victim is not breath ing. Do not use mouth-to-mouth method if victim ingested
or inhaled the substance; give artificial respiration with the
aid of a pocket mask equipped with a one-way valve or
other proper respiratory medical device. Administer oxygen
if breathing is difficult. Remove and isolate contaminated
clothing and shoes. In case of contact with substance,
immediately flush skin or eyes with running water for at
least 20 minutes. For minor skin contact, avoid spreading
material on unaffected skin. Keep victim warm and quiet.
Effects of exposure (inhalation, ingestion or skin contact)
to substance may be delayed. Ensure that medical person nel are aware of the material(s) involved and take precau tions to protect themselves.
Shipping
UN2588 Pesticides, solid, toxic, Hazard Class:
6.1; Labels: 6.1-Poisonous materials, Technical Name
Required. UN2902 Pesticide, liquid, toxic, n.o.s., Hazard
Class: 6.1; Labels: 6.1-Poisonous materials, Technical
Name Required.
Chemical Properties
White crystalline solid.
Chemical Properties
White SOlid
Waste Disposal
It is the responsibility of
chemical waste generators to determine the toxicity and
physical properties and of a discarded chemical and to
properly identify its classification and certification as a haz ardous waste and to determine the disposal method. United
States Environmental Protection Agency guidelines for the
classification determination are listed in 40 CFR Parts
261.3. Additionally, waste generators must consult and fol low all regional, national, state and local hazardous waste
laws to ensure complete and accurate classification and dis posal methods.
Uses
A broad spectrum insecticide which actively disrupts the CNS of contacted insects by blocking the passage of chloride ions through GABA receptors.
Uses
Fipronil is used for the control of a wide range of insect species in
rice, cereals, corn, cotton, top fruit, sugar beet, sugar cane, oilseed rape,
many vegetables and other high-value crops. It also has a veterinary use
as an ectoparasiticide.
Definition
ChEBI: 5-amino-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-[(trifluoromethyl)sulfinyl]-1H-pyrazole-3-carbonitrile is a member of the class of pyrazoles that is 1H-pyrazole that is substituted at positions 1, 3, 4, and 5 by 2,6-dichloro-4-(trifluoromethyl)phenyl, cyano, (trifluoromethyl)sulfinyl, and amino groups, respectively. It is a nitrile, a dichlorobenzene, a primary amino compound, a member of pyrazoles, a sulfoxide and a member of (trifluoromethyl)benzenes.
Agricultural Uses
Insecticide, Veterinary medicine: Not approved for use in EU countries. Fipronil
was introduced into the U.S. in 1996 for use in animal
health and indoor pest control. It is the constituent of many
products for controlling a wide spectrum of domestic animal and residential pests.
Trade name
BES® 602; CEASEFIRE®; CHIPCO®;
COMBAT®; FRONTLINE; MB-46030®; H&G®;
ICON®; MAXFORCE® ANT STATION; MAXFORCE®
ROACH STATION; REGENCY SOFION®; REGENT®;
REGENT® 500-FS; TERMIDOR® L VI-NIL
Pharmacology
Fipronil is a phenylpyrazole, the mode of action of which
is to inhibit nerve transmission in arthropods by blocking
γ -aminobutyric acid-gated chloride channels. Fipronil is
available as spray and spot-on formulations to control
fleas and ticks on cats and dogs. The adulticidal activity of
fipronil accounts for the majority of its activity, although
additional activity against flea eggs and larvae results
from the presence of fipronil on hairs and debris shed into
the environment from treated pets.
Autohistoradiography studies (11) into the cutaneous
distribution of 14C-fipronil in the cat and dog following
spot-on administration demonstrated that radioactivity
was restricted principally to the stratum corneum, the
viable epidermis, and the pilosebaceous units. Following
its slow release from sebaceous glands, fipronil migrates in
the sebum covering the skin and hairs by passive diffusion
and was shown to persist on hair for up to 2 months after
treatment.
Metabolic pathway
Through the abiotic degradation of fipronil in aqueous
solution and on the soil surface, 5-amino-3-
carbamoyl-1-[2,6-dichloro-4-(trifluoromethyl)-phenyl]-4-
[(trifluoromethyl)sulfinyl]pyrazole is the only hydrolysis
product detected. Fipronil in acidic aqueous solution
exposed under a xenon lamp degrades with the
concomitant appearance of 5-amino-3-cyano-1-[2,6-
dichloro-4-(trifluoromethyl)-phenyl]-4-
(trifluoromethyl)pyrazole and 5-amino-3-cyano-1-[2,6-
dichloro-4-(trifluoromethyl)phenyl]pyrazole-4-sulfonic
acid. Under field conditions, when fipronil is applied in
formulation, four metabolites which include one
product resulting from reduction on the sulfur atom of
fipronil are detected.
Degradation
Fipronil is stable in water at pH 5 and 7 but is slowly hydrolysed at pH 9
(DT50 28 days) to the amide (2). It undergoes rapid aqueous photolysis
with a DT50 of ﹤0.5 day. The major photodecomposition product in water
and on soil surfaces is desulfinyl-fipronil(3) which is formed by extrusion
of the SO group. A minor photoproduct in water, on soil and on plant
surfaces is the sulfonic acid (4). The mechanisms of these reactions are
discussed in a recent paper by Bobe et al. (1998).
Toxicity evaluation
Acute oral LD50 for rats: 100 mg/kg
