Description
Chlorobenzilate is an organochlorine pesticide belonging to
the same class as dichlorodiphenyltrichloroethane (DDT).
It was originally developed by Ciba–Geigy and introduced
in 1952.
Chemical Properties
viscous yellow liquid or pale yellow crystals
Chemical Properties
Ethyl 4,40
-dichlorobenzilate is a yellow solid
when pure. The technical product is a brownish liquid.
Uses
Nonsystemic pesticide and acaricide.
Uses
Acaricide in spider-mite control; synergist for DDT.
Uses
The primary use of chlorobenzilate is as an acaricide for mite
control on citrus crops and in beehives. It has a narrow
insecticidal action, killing only mites and ticks. Historically,
chlorobenzilate was used as a synergist for DDT. Although
now banned for use in the United States and Europe, it is
believed to be used on crops other than citrus in other
countries.
Definition
ChEBI: Chlorobenzilate is a diarylmethane.
Production Methods
Chlorobenzilate is produced commercially through an esterification reaction involving ethyl chloroacetate and bis(4-chlorophenyl)carbinol. The process begins with the synthesis of bis(4-chlorophenyl)carbinol, typically derived from 4-chlorobenzyl chloride via a Grignard reaction with 4-chlorobenzophenone. This intermediate is then reacted with ethyl chloroacetate in the presence of a base or acid catalyst to form chlorobenzilate.
General Description
Viscous yellow liquid or pale yellow crystals. Light brown crystalline solid.
Air & Water Reactions
Insoluble in water.
Reactivity Profile
CHLOROBENZILATE is hydrolyzed by alkalis and strong acids. Incompatible with lime .
Health Hazard
Moderately toxic by oral route; toxic symptoms similar to DDT and Perthane; ingestionof large dose can produce nausea, vomiting,tremor and convulsions; skin or eye contactcan cause irritation; application of 25 mgproduced moderate irritation of eye inrabbits; adequate evidence of carcinogenicityin experimental animals; produced tumors inrats and mice; evidence of carcinogenicity inhumans remains unknown.
LD50 oral (rat): 700 mg/kg
LD50 oral (mouse): 729 mg/kg.
Fire Hazard
Flash point data for CHLOROBENZILATE are not available; however, CHLOROBENZILATE is probably combustible.
Mechanism of action
Nervous system toxin with contact action. Distrupts the normal flow of Na and K ions across axonal membranes in the central and peripheral nervous systems.
Safety Profile
Suspected carcinogen
with experimental carcinogenic,
neoplastigenic, and tumorigenic data.
Moderately toxic by ingestion. A skin and
eye irritant. A pesticide. When heated to
decomposition it emits toxic fumes of Cl-.
Potential Exposure
It is a buffer in many chemical intermediates; an organochlorine miticide; to kill mites, ticks,
and other insects; as a synergist for DDT.
Incompatibilities: Strong acids, strong bases; lime.
First aid
If this chemical gets into the eyes, remove anycontact lenses at once and irrigate immediately for at least15 min, occasionally lifting upper and lower lids. Seekmedical attention immediately. If this chemical contactsthe skin, remove contaminated clothing and wash immediately with soap and water. Seek medical attention immediately. If this chemical has been inhaled, removefrom exposure, begin rescue breathing (using universal prestopped and CPR if heart action has stopped. Transferpromptly to a medical facility. When this chemical hasbeen swallowed, get medical attention. Give large quantities of water and induce vomiting. Do not make an unconscious person vomit.
Environmental Fate
Biological. Rhodotorula gracilis, a yeast isolated from an insecticide-treated soil,
degraded chlorobenzilate in a basal medium supplemented by sucrose. Metabolites identified by this decarboxylation process were 4,4′-dichlorobenzilic acid, 4,4′-dichlorobenzophenone and carbon dioxide (Miyazaki et al., 1969, 1970).
Soil. Though no products were identified, the half-life of chlorobenzilate in two fine
sandy soils was estimated to be 1.5–5 weeks (Wheeler, 1973).
Photolytic. Chlorobenzilate should not undergo direct photolysis since it does not
absorb UV light at wavelengths greater than 290 nm (Gore et al., 1971).
storage
Color Code—Blue: Health Hazard/Poison: Storein a secure poison location. Prior to working with thischemical you should be trained on its proper handling andstorage. Store in tightly closed containers in a cool, wellventilated area away from strong acids, strong bases. Wherepossible, automatically pump liquid from drums or otherstorage containers to process containers. Sources of ignitionare prohibited where this chemical is used, handled, orstored. A regulated, marked area should be establishedwhere this chemical is handled, used, or stored in compliance with OSHA Standard 1910.1045.
Shipping
UN2996 Organochlorine pesticides, liquid, toxic,
Hazard Class: 6.1; Labels: 6.1-Poisonous materials.UN2761
Organochlorine pesticides, solid, toxic, Hazard Class: 6.1;
Labels: 6.1-Poisonous materials.
Toxicity evaluation
The historical use of chlorobenzilate resulted in its release into
the environment. It has low water solubility (log Kow = 4.74)
and adsorbs strongly to sediment and suspended particulate
matter in aquatic environments. Chlorobenzilate has low soil
mobility due to an estimated Koc of 1500 and thus is not
expected to leach into groundwater. Decomposition via
photolysis or hydrolysis is not considered significant. The halflife
of chlorobenzilate in fine sandy soils was estimated to be
10–35 days, with degradation being primarily microbial. In
silty clay loam and clay soils, the half-life of chlorobenzilate
was estimated to be 10.8–15.1 and 29.5–169.1 days, respectively.
Volatilization from water or soil is not appreciable due
to an estimated Henry’s law constant of 7.2 atmm3 mol
-1. If
released into air, chlorobenzilate will exist in both vapor and particulate phases. The half-life of vapor-phase chlorobenzilate
in ambient air was estimated to be 3.2 days. Chlorobenzilate in
the particulate phase is expected to be removed from the
atmosphere by wet or dry deposition. There is no evidence for
long-range transport of chlorobenzilate. Bioaccumulation in
aquatic organisms is moderate to high due to a reported bioconcentration
factor range of 224–709 in fish.
Incompatibilities
Strong acids, strong bases, lime
Waste Disposal
Consult with environmental
regulatory agencies for guidance on acceptable disposal
practices. Generators of waste containing this contaminant
(≥100 kg/mo) must conform to EPA regulations governing
storage, transportation, treatment, and waste disposal. In
accordance with 40CFR165, follow recommendations for
the disposal of pesticides and pesticide containers. Must be
disposed properly by following package label directions or
by contacting your local or federal environmental control
agency, or by contacting your regional EPA office.
Pesticide Type
Insecticide; Acaricide; Miticide
