Bifenthrin is a pyrethroid insecticide that is used primarily against red imported fire ants by affecting its nervous system. It has high toxicity to aquatic organisms. Although listed as restricted use chemicals in the United States, it is allowed to be sold for everyday use, provided that the products sold have low concentrations of bifenthrin. The chemicals were discovered and developed by FMC Corporation. Products containing bifenthrin include Transportation, Talstar, Maxxthor, Capture, Brigade, Bifenthrine, Ortho Home Defense Max, Bifen XTS, Bifen IT, Bifen L/P, Torant, Zipak, Scotts LawnPro Step 3, TC Enabled Policy, FMC 54800, Allectus , Ortho Max Pro and OMS3024 and mega wash from the green planet.
Video Bifenthrin
Chemical properties
Bifenthrins are insoluble in water and often lag in the soil. The remaining half life in the soil is between 7 days and 8 months, depending on the type of soil, with low mobility in most soil types. Bifenthrin has the longest residual time known in soil insecticides on the market. It is white, dense wax with a faint sweet smell. It is chemically synthesized in various forms, including powders, granules and pellets. However, it does not happen naturally.
Like other pyrethroids, bifenthrins are chiral; it has a different enantiomer that can have different effects. Bifenthrin is found in two enantiomers: 1S-cis-bifenthrin and 1R-cis-bifenthrin. 1S-cis-Bifenthrin is 3-4 times more toxic to humans than 1R-cis-bifenthrin, while the latter is more than 300 times as effective as pesticides.
Maps Bifenthrin
Toxicodynamics
Two types of pyrethroids are those with -cyanogroup and those without -cyanogroup. Bifenthrin neurotoxicity is based on affinity for the voltage-gated sodium channel (both in insects, as well as in mammals). Pyetroids with -cyanogroup block the sodium-channel closure permanently, causing the membrane to be permanently deposition. The break potential will not be restored, and no further potential action can be generated. Non-cyanogroup pyrethroid, which belongs to bifenthrin, is only capable of temporarily binding sodium channels. This will result after potential and continuous shooting of axons. The resting potential is not affected by this pyrethroid.
Bifenthrin will open the sodium channel for a shorter period of other pyrethroids. Mechanisms in mammals and invertebrates are no different, but the effects on mammals are much less due to higher body temperature, higher body volume, and lower bifenthrin channel affinity to sodium.
Toksokokinetik
A number of studies have been conducted on the life-cycle of bifenthrin in soil, water, and air under different conditions, such as aerobic or anaerobic, and at different temperatures and pH. More likely to stay on the ground and not too much in the water (hydrophobic), or in the air (not possible volatize due to its physical properties). Because water is not soluble in bifenthrin, it will not quickly cause groundwater contamination. However, some contamination may occur by bifenthrins bound to the surface of the water through runoff. For an overview of bifenthrin environmental degradation, see the image below. The main pathway of degradation produces 4'-hydroxy bifenthrin.
Biotransformation
Pyrethroid is much less toxic to mammals than to insects and fish, because mammals have the ability to break ester bonds quickly in bifenthrins and break down the substance into acidic and inactive alcohol components: In humans and rats, bifenthrins are degraded by cytochrome p450-family.
Use
On a large scale, bifenthrins are often used against red-imported fire ants. It is also effective against aphids, worms, ants, gnats, moths, beetles, earwigs, grasshoppers, mites, pests, spiders, fleas, yellow jackets, maggots, thrips, caterpillars, flies, lice, and termites. Mostly used in gardens, nurseries, and homes. In the agricultural sector, it is used in large quantities in certain crops, such as maize. About 70% of all the hops and raspberries grown in the United States are treated with bifenthrins.
Bifenthrin is used by the textile industry to protect wool products from insect attack. It was introduced as an alternative to permethrin-based agents, due to greater efficacy against keratinophagous insects, better wash-fastness, and lower water toxicity.
Bifenthrin is not at all toxic to plants. Although it does not have a great toxicological risk to mammals or birds, bifenthrins may accumulate in food, so it may be harmful to mammals or birds in some scenarios.
Toxicology
Toxicity in animals
- Mosquito
Bifenthrin is an effective pesticide to be used against malaria and filaria vector mosquitoes. This is still effective when resistance to other pyrethroids is found. Mosquito nets and indoor walls can be treated with bifenthrin to expel more mosquitoes. Bifenthrin is an effective insecticide used, but the high risk only works for a short time. Mosquitoes can develop resistance to it as well.
- Aquatic life
Bifenthrin is almost insoluble in water, so almost all bifenthrins will stay in sediment, but are very harmful to aquatic life. Even in small concentrations, fish and other aquatic animals are affected by bifenthrin. One of the reasons for high fish sensitivity is that fish have a slow metabolism. Bifenthrin will last longer in the fish system. Another reason for high fish sensitivity is the effect of bifenthrin as an ATPase inhibitor. Gills require ATP to control osmotic oxygen balance. If the fish is no longer able to take oxygen because ATP can not be used again, the fish will die. In cold water, bifenthrin is even more dangerous. pH and calcium concentration are also factors that affect toxicity. Vertebrates are less sensitive to the effects of bifenthrin as an ATPase inhibitor.
- Bee
In bees, the lethal concentration (LC 50 ) of bifenthrin is about 17 mg/l. At subletal concentrations, bifenthrins reduce bee fecundity, reducing the rate at which bee larvae develop into adulthood, and increase their adulthood.
- List of LD values ​​ 50
Toxicity in mammals
- Chemical consequences
Bifenthrins and other synthetic pyrethroids are used in agriculture in increasing quantities because of the high efficiency of these substances in killing insects, low toxicity for mammals, and good biodegradability. However, because of its success, they are used more often (also indoors) and high bifenthrin exposure to humans can occur.
- Carcinogenicity
The US EPA classifies bifenthrins as Category C, possibly human carcinogens. This rating is based on an increased rate of bladder tumors in rats, adenomas and adenocarcinomas of the liver in male mice, and bronchoalveolar adenoma and pulmonary adenocarcinoma in some female mice.
- Neurotoxicity for humans
Bifenthrin exposure can be achieved either with skin contact or consumption. The skin contact is non-toxic, apart from a slight tingling sensation at a particular contact location. Ingestion is poisonous, though only slightly. Bifenthrin commercially available (Ortho Home Defense Max, for example), however, can cause toxic effects on these concentrations, because additional chemicals that enhance sustainability either potentiate bifenthrin or are toxic on their own. Symptoms of excessive exposure are nausea, headache, hypersensitivity to touch and sound, and irritation to the skin and eyes.
Rule
The EPA monitors and regulates the use of pesticides in the United States. Bifenthrins are classified as restricted-use pesticides, meaning they are legally allowed to be sold only by certified pesticide applicators. For everyday use, it is allowed to be sold in lower concentrations.
Bifenthrin has been approved for use against Rasberry ants in the Houston, Texas area, under a special "crisis exception" from the Texas Department of Agriculture and the EPA. These chemicals are only approved for use in the Texas region experiencing a "confirmed infestation" of newly invasive ant species imported.
EPA has classified bifenthrin as a class C carcinogen, possibly human carcinogens based on tests with mice, which show an increase in the development of certain tumors.
Acute and chronic reference doses (RfD) for bifenthrins have been established, based on animal studies. The reference dose resembles an estimate of the quantity of chemicals that a person can be exposed to each day (or a one-time exposure to acute RfD) without the risk of adverse health effects. The acute reference dose (RfD) for bifenthrin is 0.328 mg/kg body weight/day. The chronic reference dose (RfD) for bifenthrin is 0.013 mg/kg body weight/day.
Bifenthrin is included in the biocide ban proposed by the Swedish Chemistry Agency, due to its carcinogenic effects. It was approved by the European Parliament in 2009. Pesticides containing bifenthrin were withdrawn from use in the European Union. They have been restored.
References
External links
- Common fact sheet Bifrenthrin - National Pesticide Information Center
- Pyrethrins and Pyrethroids Fact Sheet - National Pesticide Information Center
- Bifenthrin in Pesticide Properties DataBase (PPDB)
Source of the article : Wikipedia
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