Potential Exposure
Pyrethroid insecticide. Those involved in
the manufacture and application of this agricultural chemical.
First aid
If this chemical gets into the eyes, remove any
contact lenses at once and irrigate immediately for at least
15 minutes, occasionally lifting upper and lower lids. Seek
medical attention immediately. If this chemical contacts the
skin, remove contaminated clothing and wash immediately
with soap and water. Seek medical attention immediately. If
this chemical has been inhaled, remove from exposure,
begin rescue breathing (using universal precautions) if
breathing has stopped, and CPR if heart action has stopped.
Transfer promptly to a medical facility. When this chemical
has been swallowed, get Medical attention. Do not induce
vomiting when formulations containing petroleum solvents
are ingested. Otherwise, give large quantities of water and
induce vomiting. Do not make an unconscious person vomit.
Shipping
UN3349 Pyrethroid pesticide, solid toxic,
Hazard Class: 6.1; Labels: 6.1-Poisonous material. UN3352
Pyrethroid pesticide, liquid toxic, Hazard Class: 6.1;
Labels: 6.1-Poisonous materials. UN3082 Environmentally
hazardous substances, liquid, n.o.s., Hazard class: 9;
Labels: 9-Miscellaneous hazardous material, Technical
Name Required
Incompatibilities
May react violently with strong oxidi-
zers, bromine, 90% hydrogen peroxide, phosphorus
trichloride, silver powders, or dust. Incompatible with silver
compounds. Mixture with some silver compounds forms
explosive salts of silver oxalate
Description
Cyphenothrin is a pyrethroid insecticide with public health and industrial applications. It has a low aqueous solubility and is non-volatile. Whilst it is not expected to be persistent in soil systems, it may be persistent in water systems depending on local conditions. Based on its physico-chemical properties it is not expected to leach to groundwaters. It is highly toxic to aquatic life and moderately toxic to honeybees. Cyphenothrin is also moderately toxic to mammals via the oral route.
Chemical Properties
Thick, yellow liquid.
Waste Disposal
Incineration would be an
effective disposal procedure where permitted. If an efficient
incinerator is not available, the product should be mixed
with large amounts of combustible material and contact
with the smoke should be avoided. In accordance with
40CFR165, follow recommendations for the disposal of
pesticides and pesticide containers. Noncombustible con-
tainers should be crushed and buried under more than
40 cm of soil
.
Uses
Cyphenothrin controls insects in household, public health and
industrial situations. It is also used to control insects which attack wood
and fabrics.
Definition
ChEBI: Cyphenothrin is a cyclopropanecarboxylate ester. It has a role as a pyrethroid ester insecticide and an agrochemical. It is functionally related to a chrysanthemic acid.
Production Methods
Cyphenothrin is commercially produced via a process that begins with the preparation of (1R,S)-trans-chrysanthemic acid through esterification of 2,2-dimethyl-3-(2-methylprop-1-enyl)cyclopropanecarboxylic with thionyl chloride, followed by resolution of the (1R)-trans isomer using (S)-alpha-methylbenzylamine. The key coupling occurs via transesterification with 3-phenoxybenzyl alcohol (or its cyanohydrin variant for the alpha-cyano form) under basic conditions to form the ester linkage. Final purification by high-vacuum fractional distillation or crystallisation from hexane yields cyphenothrin.
Mechanism of action
Non-systemic, rapid knockdown with contact and stomach action damaging insects nervous system. Sodium channel modulator.
Metabolic pathway
Cyphenothrin is the name given to the α-RS,1RS-cis-trans isomer mixture
(racemic). The product now used is cyphenothrin which is 95% 1R and
75% trans. It has no field use because the chrysanthemate moiety is very
sensitive to photodegradation. A study in rodents has been reported.
Cyphenothrin is degraded mainly by photo-oxidation and by hydrolysis
and oxidation in plants and animals.
Degradation
Cyphenothrin is stable under normal storage conditions but it is labile
to base, being hydrolysed to trans-2,2-dimethyl-3-(2-methylprop-1-enyl)-
cyclopropanecarboxylic acid (2,trans-chrysanthemic acid) and 3-phenoxybenzaldehyde
(3, 3PBAl) and cyanide ion (Scheme 1). It is sensitive to
light (see phenothrin for expected products).
Pesticide Type
Insecticide
