Allethrin is a synthetic pyrethroid derivative used as an insecticide. Allethrin is commonly used in many household insecticide products due to its low toxicity towards humans.
Esbiothrin may be used as a reference standard for the determination of the analyte in electric-mosquito coils using gas chromatography (GC) technique.
The allethrins are used to control a wide range of insects in horticultural,
household, public health and animal health situations. They
have some limited use on ornamentals and vegetables (in combination
with synergists).
Generic name for 2-allyl4-hydroxtcyclopenten-1-one ester of chrysanthemummonocarboxylic acid. A synthetic insecticide structurally similar to pyrethrin and used in the same manner. For other synthetic analogs, see barthrin, cyclethrin, ethythrin, furethrin. Pyrethrin I differs in having a 2,4-pentadienyl group in place of the allyl of allethrin.
A clear amber-colored viscous liquid. Insoluble and denser than water. Toxic by ingestion, inhalation, and skin absorption. A synthetic household insecticide that kills flies, mosquitoes, garden insects, etc.
Allethrin is an ester and ketone. Esters react with acids to liberate heat along with alcohols and acids. Strong oxidizing acids may cause a vigorous reaction that is sufficiently exothermic to ignite the reaction products. Heat is also generated by the interaction of esters with caustic solutions. Flammable hydrogen is generated by mixing esters with alkali metals and hydrides. Ketones are reactive with many acids and bases liberating heat and flammable gases (e.g., H2). The amount of heat may be sufficient to start a fire in the unreacted portion of the ketone. Ketones react with reducing agents such as hydrides, alkali metals, and nitrides to produce flammable gas (H2) and heat. Ketones are incompatible with isocyanates, aldehydes, cyanides, peroxides, and anhydrides. They react violently with aldehydes, HNO3, HNO3 + H2O2, and HClO4.
Highly toxic, may be fatal if inhaled, swallowed or absorbed through skin. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.
Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Containers may explode when heated. Runoff may pollute waterways.
Insecticide: Allethrin is used almost exclusively to control flying and crawling insects in homes and industrial locations.
Used extensively in pet animal shampoos, to treat lice in
humans and in home and industrial sprays for flying insects, mosquitos, etc. It is available as mosquito coils,
mats, oil formulations and as an aerosol spray. It may be
hazardous to the environment; special attention should be
given to fish and honey bees. Not currently registered in the
U.S. Not approved for use in EU countries. Depending
on CAS registry number there are probably >100 global
suppliers.
BIOALLETHRIN®; BIOALLETHRIN
TECHNICAL®; d-CISALLETHRIN®; ESBIOTHRIN®;
EXTHRIN® FMC 249®; NIA 249®; OMS 468®;
PYNAMIN®; PYNAMIN-FORTE®; PYRESIN®;
PYRESYN®; PYREXCEL®; PYROCIDE®; SBP 1382/
BIOALLETHRIN CONCENTRATE®
Pyrethroids, also called pyrethrinoids, are neurotoxic
synthetic compounds used as insecticides, with irritant
properties. Cypermethrin and fenvalerate have been
reported as causing positive allergic patch tests, but
only fenvalerate was relevant in an agricultural worker.
Poison by intravenous, intracerebral, and intraperitoneal routes. Moderately toxic by ingestion and skin contact. An allergen. An insecticide. It can cause liver and kidney damage by all routes of entry into the body. Lung congestion may occur due to exposure. Local contact may cause contact dermatitis. Inhalation may cause asthma, coughing, wheezing, running nose and eyes. Mutation data reported. See also ALLYL COMPOUNDS and ESTERS. Slight fire hazard. When heated to decomposition it emits acrid fumes.
Allethrin was the first synthetic pyrethroid. Its stereochemistry is
RS(cyclopentenyl)lRcis-trans. It was further developed as bioallethrin
(RSlRtvuns) and then as S-bioallethrin (SlRtvuns), the most potent of the
three. All are very sensitive to light and are used almost entirely indoors.
Thus, there is only a limited amount of information on their environmental
fate published in the literature. Information on photodegradation
and on metabolism in insects and rodents has been reported.
The allethrins are reasonably stable but they are sensitive to base
hydrolysis forming chrysanthemic acid (2) and 3-allyl-2-methyl-4-
oxocyclopent-2-enol(3, allethrolone). The DT50 of bioallethrin in aqueous
solution is 547 days at pH 7 and 4.3 days at pH 9.
The allethrins are also sensitive to oxidation and to photodecomposition.
Allethrin was converted almost quantitatively into the
cycloproprethronyl derivative (4) by a di-π-methane rearrangement on
irradiation in hexane solution (Bullivant and Pattenden, 1976). In
addition, isomerisation, oxidation and epoxidation of the isobutenyl
group of the chrysanthemic acid moiety by reactions analogous to those
described under phenothrin have been described (Ruzo et al., 1980).
Most products retained the ester linkage but the acid 2 was identified.
A novel product, 1-cyclopropyl-5-methyl-6-oxabicyclo[3.0.1]hexan-2-on-
4-yl chrysanthemate (5), was then reported (Kimmel et al., 1982). This
product proved to be a potent bacterial mutagen (Ames assay). Later
Isobe et al. (1984) reported photo-oxidation products derived from the
alcohol moiety: the alcohol (3) and allethronyl glyoxalate (6). The
latter was mostly present as its hydrate (7).T he ester (8) was also detected
but this was shown not to be a precursor of 6 or 7. These products
are illustrated in Scheme 1. Products formed by oxidation of the acid
moiety and retaining the ester link, such as 9, 10 and 11, are shown in
Scheme 2.
These two sites of weakness in allethrin render it one of the most photolabile
of the synthetic pyrethroids (Ruzo, 1982) and result in a complex
mixture of degradation products.
