Fipronil
Encyclopedia
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 (GluCl) channels, components of the central nervous system. This causes hyperexcitation of contaminated insects' nerves and muscles. Specificity of fipronil on insects may come from a better efficacy on GABA receptor
, but also because GluCl channels do not exist in mammals.
es, the feces and carcass can contain sufficient residual pesticide to kill others in the same nesting site. In ant
s, 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 three days for ants and cockroaches.
Toxic baiting with fipronil has also been shown to be extremely effective in locally eliminating German wasp
s. All colonies within foraging range are completely eliminated within one week.
Wildlife impacts include the following:
Fipronil is also used as the active ingredient in flea control products for pets, field pest control for 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 noncompetitive inhibition.
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; generally benzodiazepine
use.
In May 2003, the Direction Générale de l'Alimentation du ministère de l'Agriculture indicated a case of bee mortality observed in southern France was related to fipronil acute toxicity. Toxicity was linked to defective seed treatment, which generated dust. In February 2003, the French Ministry of Agriculture decided to temporarily suspend the sale of BASF crop protection products containing fipronil in France. The seed treatment involved has since been forbidden. Fipronil was used in a broad spraying to control locusts in Madagascar in a program that began in 1997.
between 1985 and 1987, and placed on the market in 1993 under the US Patent No. US 5,232,940 B2. Between 1987 and 1996, fipronil was evaluated on more than 250 insect pests on 60 crops worldwide, and crop protection accounted for about 39% of total fipronil production in 1997. Since 2003, BASF
holds the patent rights for producing and selling fipronil-based products in many countries.
Fipronil, as marketed under the name Regent, is used against major lepidoptera
n and orthoptera
n pests on a wide range of field and horticultural crops and against coleopteran larvae in soils. It is also employed for cockroach
and ant
control under the trade names Goliath and Nexa, including in the US, where it is also used against pests of field corn
, golf courses and commercial lawn
(trade name Chipco Choice). It has been used under the trade name Adonis for locust
control in Madagascar
and in Kazakhstan
.
Fipronil effectively controls termite
pests, and was shown to be effective in field trials in Africa
and Australia
, where it is marketed under the name Termidor.
In 1999, 400,000 hectares were treated with Regent. It became the leading imported product in the area of rice
insecticide
s, the second biggest crop protection market after cotton
in China
. In the UK, provisional approval for five years has been granted for fipronil use as a public hygiene insecticide.
Fipronil is also the main active ingredient of Frontline, a treatment used in fighting tick
s and flea
s infestations in dog
s and cat
s.
, as well as bee
s, termite
s, rabbit
s, the fringe-toed lizard
and certain groups of gallinaceous birds
. It appears to reduce the longevity
and fecundity
of female braconid parasitoids. It is also highly toxic to many fish
, though its toxicity varies with species. Conversely, the substance is relatively innocuous to passerines, wildfowl and earthworm
s.
Few studies of effects on wildlife
have been conducted, but studies of the nontarget impact from emergency applications of fipronil as barrier sprays for locust control in Madagascar showed adverse impacts of fipronil on termites, which appear to be very severe and long-lived. There were also indications of adverse effects in the short term on several other invertebrate groups, one species of lizard (Mabuya elegans) and several species of birds (including the Madagascar bee-eater).
Nontarget effects on some insects (predatory and detritivorous beetle
s, some parasitic wasps and bees) were also found in field trials of fipronil for desert locust control in Mauritania
, and very low doses (0.6-2.0 g a.i./ha) used against grasshopper
s in Niger
caused impacts on nontarget insects comparable to those found with other insecticides used in grasshopper control. The implications of this for other wildlife and ecology of the habitat remain unknown, but appear unlikely to be severe.
among bees. It has been found by the Minutes-Association for Technical Coordination Fund in France that even at very low nonlethal doses for bees, the pesticide still impairs their ability to locate their hive, resulting in large numbers of forager bees lost with every pollen-finding expedition.
It has moderate acute toxicity by the oral and inhalation routes in rats
. Dermal absorption in rats is less than 1% after 24 h and toxicity is considered to be low. It has been found to be very toxic to rabbits.
The photodegradate MB46513 appears to have a higher acute toxicity to mammals than fipronil itself by a factor of about 10.
Toxicity on humans has been tested in few studies, more commonly involving human cells which were used in carcinogenicity studies, but with no adverse effects. Yet, fipronil has been classified as a Group C (possible human) carcinogen based on an increase in thyroid
follicular cell tumors in both sexes of the rat. Furthermore, fipronil is considered slightly irritating to the skin
, while moderately irritating to the eyes in both humans and animals, and there is no evidence suggesting it may cause birth defects.
Two Top Spot products were determined by the New York State Department of Environmental Conservation
to pose no significant exposure risks to workers applying the product. However, concerns were raised about human exposure to Frontline spray treatment in 1996, leading to a denial of registration for the spray product. Commercial pet groomers and veterinarian
s were considered to be at risk from chronic exposure via inhalation and dermal absorption during the application of the spray, assuming they may have to treat up to 20 large dogs per day. Fipronil is not volatile
, so there is little likelihood of humans being exposed to this compound in the air.
Insecticide
An insecticide is a pesticide used against insects. They include ovicides and larvicides used against the eggs and larvae of insects respectively. Insecticides are used in agriculture, medicine, industry and the household. The use of insecticides is believed to be one of the major factors behind...
that disrupts the insect central nervous system by blocking the passage of chloride ions through the GABA receptor
GABA receptor
The GABA receptors are a class of receptors that respond to the neurotransmitter gamma-aminobutyric acid , the chief inhibitory neurotransmitter in the vertebrate central nervous system...
and glutamate-gated chloride (GluCl) channels, components of the central nervous system. This causes hyperexcitation of contaminated insects' nerves and muscles. Specificity of fipronil on insects may come from a better efficacy on GABA receptor
GABA receptor
The GABA receptors are a class of receptors that respond to the neurotransmitter gamma-aminobutyric acid , the chief inhibitory neurotransmitter in the vertebrate central nervous system...
, but also because GluCl channels do not exist in mammals.
Effects
Fipronil is a slow acting poison. When mixed with a bait, it allows the poisoned insect time to return to the colony or harborage. In cockroachCockroach
Cockroaches are insects of the order Blattaria or Blattodea, of which about 30 species out of 4,500 total are associated with human habitations...
es, the feces and carcass can contain sufficient residual pesticide to kill others in the same nesting site. In ant
Ant
Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than...
s, 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 three days for ants and cockroaches.
Toxic baiting with fipronil has also been shown to be extremely effective in locally eliminating German wasp
German wasp
The German wasp, or European wasp, Vespula germanica, is a wasp found in much of the Northern Hemisphere, native to Europe, northern Africa, and temperate Asia. It has been introduced and is well-established in many other places, including North America, South America , Australia and New Zealand...
s. All colonies within foraging range are completely eliminated within one week.
Wildlife impacts include the following:
- Fipronil is highly toxic to fish and aquatic invertebrates. Its tendency to bind to sediments and its low water solubility may reduce the potential hazard to aquatic wildlife.
- Fipronil is toxic to bees and should not be applied to vegetation when bees are foraging.
- Fipronil has been found to be highly toxic to upland game birds, but is practically nontoxic to waterfowl and other bird species. One of the metabolites of fipronil has a higher toxicity to birds than the parent compound itself.
Fipronil is also used as the active ingredient in flea control products for pets, field pest control for corn, golf courses and commercial turf.
It acts by binding to an allosteric
Allosteric regulation
In biochemistry, allosteric regulation is the regulation of an enzyme or other protein by binding an effector molecule at the protein's allosteric site . Effectors that enhance the protein's activity are referred to as allosteric activators, whereas those that decrease the protein's activity are...
site of GABAA receptors and GluCl receptor (of the insect), a form of noncompetitive inhibition.
- Acute oral (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; generally benzodiazepine
Benzodiazepine
A benzodiazepine is a psychoactive drug whose core chemical structure is the fusion of a benzene ring and a diazepine ring...
use.
In May 2003, the Direction Générale de l'Alimentation du ministère de l'Agriculture indicated a case of bee mortality observed in southern France was related to fipronil acute toxicity. Toxicity was linked to defective seed treatment, which generated dust. In February 2003, the French Ministry of Agriculture decided to temporarily suspend the sale of BASF crop protection products containing fipronil in France. The seed treatment involved has since been forbidden. Fipronil was used in a broad spraying to control locusts in Madagascar in a program that began in 1997.
Historical use
Fipronil was discovered and developed by Rhône-PoulencRhône-Poulenc
-History of the company:The Company was founded in 1928 through the merger of Société des Usines Chimiques du Rhône from Lyon and Établissements Poulenc Frères from Paris founded by Étienne Poulenc, a 19th century Parisian apothecary and brought to prominence by his second and third sons Emile...
between 1985 and 1987, and placed on the market in 1993 under the US Patent No. US 5,232,940 B2. Between 1987 and 1996, fipronil was evaluated on more than 250 insect pests on 60 crops worldwide, and crop protection accounted for about 39% of total fipronil production in 1997. Since 2003, BASF
BASF
BASF SE is the largest chemical company in the world and is headquartered in Germany. BASF originally stood for Badische Anilin- und Soda-Fabrik . Today, the four letters are a registered trademark and the company is listed on the Frankfurt Stock Exchange, London Stock Exchange, and Zurich Stock...
holds the patent rights for producing and selling fipronil-based products in many countries.
Fipronil, as marketed under the name Regent, is used against major lepidoptera
Lepidoptera
Lepidoptera is a large order of insects that includes moths and butterflies . It is one of the most widespread and widely recognizable insect orders in the world, encompassing moths and the three superfamilies of butterflies, skipper butterflies, and moth-butterflies...
n and orthoptera
Orthoptera
Orthoptera is an order of insects with paurometabolous or incomplete metamorphosis, including the grasshoppers, crickets and locusts.Many insects in this order produce sound by rubbing their wings against each other or their legs, the wings or legs containing rows of corrugated bumps...
n pests on a wide range of field and horticultural crops and against coleopteran larvae in soils. It is also employed for cockroach
Cockroach
Cockroaches are insects of the order Blattaria or Blattodea, of which about 30 species out of 4,500 total are associated with human habitations...
and ant
Ant
Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than...
control under the trade names Goliath and Nexa, including in the US, where it is also used against pests of field corn
Field corn
Field corn is maize of varieties that are not, in the United States, grown primarily for consumption as human food in the form of fresh kernels. More than 98% of corn-growing land in the U.S...
, golf courses and commercial lawn
Lawn
A lawn is an area of aesthetic and recreational land planted with grasses or other durable plants, which usually are maintained at a low and consistent height. Low ornamental meadows in natural landscaping styles are a contemporary option of a lawn...
(trade name Chipco Choice). It has been used under the trade name Adonis for locust
Locust
Locusts are the swarming phase of short-horned grasshoppers of the family Acrididae. These are species that can breed rapidly under suitable conditions and subsequently become gregarious and migratory...
control in Madagascar
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
and in Kazakhstan
Kazakhstan
Kazakhstan , officially the Republic of Kazakhstan, is a transcontinental country in Central Asia and Eastern Europe. Ranked as the ninth largest country in the world, it is also the world's largest landlocked country; its territory of is greater than Western Europe...
.
Fipronil effectively controls termite
Termite
Termites are a group of eusocial insects that, until recently, were classified at the taxonomic rank of order Isoptera , but are now accepted as the epifamily Termitoidae, of the cockroach order Blattodea...
pests, and was shown to be effective in field trials in Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
and Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, where it is marketed under the name Termidor.
In 1999, 400,000 hectares were treated with Regent. It became the leading imported product in the area of rice
Rice
Rice is the seed of the monocot plants Oryza sativa or Oryza glaberrima . As a cereal grain, it is the most important staple food for a large part of the world's human population, especially in East Asia, Southeast Asia, South Asia, the Middle East, and the West Indies...
insecticide
Insecticide
An insecticide is a pesticide used against insects. They include ovicides and larvicides used against the eggs and larvae of insects respectively. Insecticides are used in agriculture, medicine, industry and the household. The use of insecticides is believed to be one of the major factors behind...
s, the second biggest crop protection market after cotton
Cotton
Cotton is a soft, fluffy staple fiber that grows in a boll, or protective capsule, around the seeds of cotton plants of the genus Gossypium. The fiber is almost pure cellulose. The botanical purpose of cotton fiber is to aid in seed dispersal....
in China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
. In the UK, provisional approval for five years has been granted for fipronil use as a public hygiene insecticide.
Fipronil is also the main active ingredient of Frontline, a treatment used in fighting tick
Tick
Ticks are small arachnids in the order Ixodida, along with mites, constitute the subclass Acarina. Ticks are ectoparasites , living by hematophagy on the blood of mammals, birds, and sometimes reptiles and amphibians...
s and flea
Flea
Flea is the common name for insects of the order Siphonaptera which are wingless insects with mouthparts adapted for piercing skin and sucking blood...
s infestations in dog
Dog
The domestic dog is a domesticated form of the gray wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The dog may have been the first animal to be domesticated, and has been the most widely kept working, hunting, and companion animal in...
s and cat
Cat
The cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests...
s.
Ecological toxicity
Fipronil is highly toxic for crustaceans, insects and zooplanktonZooplankton
Zooplankton are heterotrophic plankton. Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word "zooplankton" is derived from the Greek zoon , meaning "animal", and , meaning "wanderer" or "drifter"...
, as well as bee
Bee
Bees are flying insects closely related to wasps and ants, and are known for their role in pollination and for producing honey and beeswax. Bees are a monophyletic lineage within the superfamily Apoidea, presently classified by the unranked taxon name Anthophila...
s, termite
Termite
Termites are a group of eusocial insects that, until recently, were classified at the taxonomic rank of order Isoptera , but are now accepted as the epifamily Termitoidae, of the cockroach order Blattodea...
s, rabbit
Rabbit
Rabbits are small mammals in the family Leporidae of the order Lagomorpha, found in several parts of the world...
s, the fringe-toed lizard
Fringe-toed lizard
Fringe-toed lizards are reptiles of the genus Uma in the family Phrynosomatidae. They are adapted for life in sandy deserts.-Description:...
and certain groups of gallinaceous birds
Galliformes
Galliformes are an order of heavy-bodied ground-feeding domestic or game bird, containing turkey, grouse, chicken, New and Old World Quail, ptarmigan, partridge, pheasant, and the Cracidae. Common names are gamefowl or gamebirds, landfowl, gallinaceous birds or galliforms...
. It appears to reduce the longevity
Longevity
The word "longevity" is sometimes used as a synonym for "life expectancy" in demography or known as "long life", especially when it concerns someone or something lasting longer than expected ....
and fecundity
Fecundity
Fecundity, derived from the word fecund, generally refers to the ability to reproduce. In demography, fecundity is the potential reproductive capacity of an individual or population. In biology, the definition is more equivalent to fertility, or the actual reproductive rate of an organism or...
of female braconid parasitoids. It is also highly toxic to many fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
, though its toxicity varies with species. Conversely, the substance is relatively innocuous to passerines, wildfowl and earthworm
Earthworm
Earthworm is the common name for the largest members of Oligochaeta in the phylum Annelida. In classical systems they were placed in the order Opisthopora, on the basis of the male pores opening posterior to the female pores, even though the internal male segments are anterior to the female...
s.
Few studies of effects on wildlife
Wildlife
Wildlife includes all non-domesticated plants, animals and other organisms. Domesticating wild plant and animal species for human benefit has occurred many times all over the planet, and has a major impact on the environment, both positive and negative....
have been conducted, but studies of the nontarget impact from emergency applications of fipronil as barrier sprays for locust control in Madagascar showed adverse impacts of fipronil on termites, which appear to be very severe and long-lived. There were also indications of adverse effects in the short term on several other invertebrate groups, one species of lizard (Mabuya elegans) and several species of birds (including the Madagascar bee-eater).
Nontarget effects on some insects (predatory and detritivorous beetle
Beetle
Coleoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...
s, some parasitic wasps and bees) were also found in field trials of fipronil for desert locust control in Mauritania
Mauritania
Mauritania is a country in the Maghreb and West Africa. It is bordered by the Atlantic Ocean in the west, by Western Sahara in the north, by Algeria in the northeast, by Mali in the east and southeast, and by Senegal in the southwest...
, and very low doses (0.6-2.0 g a.i./ha) used against grasshopper
Grasshopper
The grasshopper is an insect of the suborder Caelifera in the order Orthoptera. To distinguish it from bush crickets or katydids, it is sometimes referred to as the short-horned grasshopper...
s in Niger
Niger
Niger , officially named the Republic of Niger, is a landlocked country in Western Africa, named after the Niger River. It borders Nigeria and Benin to the south, Burkina Faso and Mali to the west, Algeria and Libya to the north and Chad to the east...
caused impacts on nontarget insects comparable to those found with other insecticides used in grasshopper control. The implications of this for other wildlife and ecology of the habitat remain unknown, but appear unlikely to be severe.
Colony collapse disorder
Fipronil is one of the main chemical causes blamed for the spread of colony collapse disorderColony Collapse Disorder
Colony collapse disorder is a phenomenon in which worker bees from a beehive or European honey bee colony abruptly disappear. While such disappearances have occurred throughout the history of apiculture, the term colony collapse disorder was first applied to a drastic rise in the number of...
among bees. It has been found by the Minutes-Association for Technical Coordination Fund in France that even at very low nonlethal doses for bees, the pesticide still impairs their ability to locate their hive, resulting in large numbers of forager bees lost with every pollen-finding expedition.
Toxicity
Fipronil is classed as a WHO Class II moderately hazardous pesticide, and has a rat acute oral of 97 mg/kg.It has moderate acute toxicity by the oral and inhalation routes in rats
RATS
RATS may refer to:* RATS , Regression Analysis of Time Series, a statistical package* Rough Auditing Tool for Security, a computer program...
. Dermal absorption in rats is less than 1% after 24 h and toxicity is considered to be low. It has been found to be very toxic to rabbits.
The photodegradate MB46513 appears to have a higher acute toxicity to mammals than fipronil itself by a factor of about 10.
Toxicity on humans has been tested in few studies, more commonly involving human cells which were used in carcinogenicity studies, but with no adverse effects. Yet, fipronil has been classified as a Group C (possible human) carcinogen based on an increase in thyroid
Thyroid
The thyroid gland or simply, the thyroid , in vertebrate anatomy, is one of the largest endocrine glands. The thyroid gland is found in the neck, below the thyroid cartilage...
follicular cell tumors in both sexes of the rat. Furthermore, fipronil is considered slightly irritating to the skin
Human skin
The human skin is the outer covering of the body. In humans, it is the largest organ of the integumentary system. The skin has multiple layers of ectodermal tissue and guards the underlying muscles, bones, ligaments and internal organs. Human skin is similar to that of most other mammals,...
, while moderately irritating to the eyes in both humans and animals, and there is no evidence suggesting it may cause birth defects.
Two Top Spot products were determined by the New York State Department of Environmental Conservation
New York State Department of Environmental Conservation
The New York State Department of Environmental Conservation is responsible for the conservation, improvement, and protection of natural resources within the U.S. state of New York. It was founded in 1970, replacing the previous Conservation Department...
to pose no significant exposure risks to workers applying the product. However, concerns were raised about human exposure to Frontline spray treatment in 1996, leading to a denial of registration for the spray product. Commercial pet groomers and veterinarian
Veterinarian
A veterinary physician, colloquially called a vet, shortened from veterinarian or veterinary surgeon , is a professional who treats disease, disorder and injury in animals....
s were considered to be at risk from chronic exposure via inhalation and dermal absorption during the application of the spray, assuming they may have to treat up to 20 large dogs per day. Fipronil is not volatile
Volatility (chemistry)
In chemistry and physics, volatility is the tendency of a substance to vaporize. Volatility is directly related to a substance's vapor pressure. At a given temperature, a substance with higher vapor pressure vaporizes more readily than a substance with a lower vapor pressure.The term is primarily...
, so there is little likelihood of humans being exposed to this compound in the air.