584-79-2

Yellow Oil

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.

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(584-79-2) 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.

Insoluble in water.

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.

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.

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®

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.