WORLD HEALTH ORGANIZATION FOOD AND AGRICULTURE
ORGANISATION MONDIALE DE LA SANTE ORGANISATION POUR L'ALIMENTATION
It must be noted that the issue of a Data Sheet for a
particular pesticide does not imply endorsement of the pesticide by
WHO or FAO for any particular use, or exclude its use for other
purposes not stated. While the information provided is believed to
be accurate according to data available at the time when the sheet
was compiled, neither WHO nor FAO are responsible for any errors or
omissions, or any consequences therefrom.
The issue of this document does Ce document ne constitue pas une
not constitute formal publication. Il ne doit faire
publication. It should not be l'objet d'aucun compte rendu ou
reviewed, abstracted or quoted résumé ni d'aucune citation sans
without the agreement of the l'autorisation de l'Organisation
Food and Agriculture des Nations Unies pour
Organization of the United l'Alimentation et l'Agriculture
Nations or of the World Health ou de l'Organisation Mondiale de
Organization. la Santé.
Primary Use: Insecticide
Secondary Use: None
Chemical Group: Organochlorine compound
Date Issued: June, 1978
1. GENERAL INFORMATION
1.1 COMMON NAME: Chlordane (ISO)
1.1.1 Identity: 1,2,4,5,6,7,8,8-octachloro-2,3,3a,4,7,7a-hexahydro-4,7-
Chlordane is a persistent organochlorine insecticide of moderate
toxicity that may be stored in body fats.
1.3 SELECTED PROPERTIES
1.3.1 Physical characteristics - The technical product is a viscous
amber coloured liquid usually containing 70% cis-, 25% trans-
isomers and less than 1% heptachlor, with a melting point of 103-
1.3.2 Solubility - Insoluble in water, but stable in most organic
solvents, including petroleum oils.
1.3.3 Stability - Unstable in the presence of weak alkalis.
1.3.4 Vapour pressure - The refined product has a vapour pressure of 1
x 10-5 torr at 25°C.
1.4 AGRICULTURE, HORTICULTURE AND FORESTRY
1.4.1 Common formulations - Emulsifiable concentrates 50% and 70%,
kerosin solutions 2% and 20%; dusts and granules 5% and 10%;
wettable powders 40% and 50%; 20% oil solutions for dilution with
1.4.2 Pests mainly controlled - Earthworms in turf, ants, termites,
wireworms, cutworms, thrips, grasshoppers, crickets.
1.4.3 Use pattern - Termites - 1% water emulsions, very good results.
Wireworms - on medium loams use 3 lb per acre - less on light
soils. All formulations satisfactory incorporate in soil.
Cutworms 5 lb to 10 lb of active ingredient per acre depending on
soil type. Crickets 20 lb of 5% dust per acre. Army worm lb per
100 gallons of water spray.
1.4.4 Unintended effects - Should not be used on plants in bloom,
because of toxicity to pollinating insects. Leafy vegetables
may be tainted.
1.5 PUBLIC HEALTH PROGRAMMES
Has been used against mosquitos as a 2% residual spray in
dwellings. Also used for flea control as 2-4% dust.
1.6 HOUSEHOLD USE
Against ants, cockroaches, silver fish, spiders, ticks, wasps
use 2% to 3% spray or 5% dust.
2. TOXICOLOGY AND RISKS
2.1 TOXICOLOGY - MAMMALS
2.1.1 Absorption route - Chlordane may be absorbed from the
gastrointestinal tract, by inhalation or through the intact skin.
2.1.2 Mode of action - The mechanism of toxic action of chlordane is
not fully understood; it causes stimulation of the central
2.1.3 Excretion products - Weekly doses of gamma-chlordane (the trans-
isomer), administered by stomach tube to rabbits, resulted in
47.2% of the total administered dose being excreted in the urine
and 22.7% in the faeces, with only about 4% being retained in
fatty tissues. Unchanged Á-chlordane could be detected only in
subcutaneous fat, while all other tissues contained hydrophilic
metabolites. Two hydrophilic metabolites have been isolated from
urine, these include trans-1-hydroxy-2-chloro-dihydrochlordene and
trans-1,2-dihydroxydihydrochlordene. A third metabolite,
oxychlordane, has also been isolated from the fat and milk of
2.1.4 Toxicity, single dose
Oral: LD50 rats (M) 335 mg/kg
rats (F) 430 mg/kg
Dermal: LD50 rats (M) 840 mg/kg
rats (F) 690 mg/kg
Most susceptible species: man and goat, approximate oral
LD50: 100 mg/kg.
2.1.5 Toxicity, repeated doses
Oral: Daily oral doses of 6.25 25, 50 and 100 mg/kg were
given to rats for 15 days. 6.25 and 25 mg/kg produced no
tremors or convulsions. 50 mg/kg produced toxic symptoms and two
out of five animals died. At 100 mg/kg all animals died.
Intracytoplasmic bodies in the liver cells were found at all
levels and their number was in proportion to the dose given.
Inhalation: No information available on the more recent
formulations. A high vapour toxicity to mice reported with
earlier formulations was due to unreacted hexachloro-
Cumulation of compound: Chlordane fed at 25 mg/kg diet to
calves and sheep reached a maximum level in fat of 18 mg/kg and
12 mg/kg respectively. After feeding was stopped, the residue
was eliminated from calves in 20 weeks and from sheep in four
Cumulation of effect: Chlordane has a cumulative effect on
the liver, initially causing liver enlargement and microsomal
enzyme induction and eventually causing liver damage and bile-
duct proliferation. Damage to the optic nerve has been reported
2.1.6 Dietary studies
Long-term: Groups of 40 rats were given chlordane in their
diet at 0, 2.5, 5, 10, 25, 50, 75, 150 or 300 mg/kg diet.
Changes involving food consumption, growth and mortality were
seen only in the 300 mg/kg diet group. Liver cell changes were
not seen in the group given 2.5-25 mg/kg diet and at 50 mg/kg
diet only "cytoplasmic peripheralization" was present. At
higher doses liver damage was observed in the form of
hypertrophy of centrolobular cells. Cytoplasmic oxyphylia and
hyalinization nuclear karyorhexis or cellular pyknosis, presence
of fat in the cytoplasm and some bile-duct proliferation.
In a second experiment, groups of four to seven male and four to
seven female dogs were fed chlordane for two years at levels of
0, 0.3, 3, 15 and 30 mg/kg diet. Abnormalities of clinical liver
function tests were seen in the 15 and 30 mg/kg groups. In
animals selected for necropsy at the end of the first year,
increased liver weights and associated hepatocellular changes
were found at 30 ppm. At the end of two years, similar changes
were observed at 15 ppm. No adverse effects were seen on
behaviour, appearance, survival, weight gain, blood picture or
the results of periodic physical examination at any level.
2.1.7 Supplementary studies of toxicity
Carcinogenicity: In a number of long-term feeding experiments
with chlordane there has been no evidence of increased
Teratogenicity: In a three generation feeding study in male
and female rats with technical chlordane at levels of 0, 0.3, 3,
15, 30 and 60 mg/kg diet, levels up to and including 30 mg/kg
had no effect on fertility, numbers of young, or litters,
weight, growth or mortality of the young animals up to weaning
age. Autopsy of animals post weaning showed no gross or
microscopic difference between the groups. At 60 mg/kg diet
there was a high mortality in the second F3 generation litters
during the latter part of the nursing period. These animals
showed gross and microscopic pathology comparable to that
characteristic for chlordane intoxication.
Mutagenicity: No information available.
2.1.8 Modification of toxicity - The toxicities of bihydroxycoumarin,
phenylbutazone and parathion were reduced after pretreatment with
chlordane. Rats were fed for 28 days from weaning on either (a)
a diet containing 3.5% protein as casein, (b) a diet containing a
normal amount of protein as casein, or (c) a standard laboratory
diet. A single oral dose of chlordane was administered after the
feeding period. The LD50 values for the three groups were 137,
267 or 311 mg/kg body weight respectively. Clinical symptoms and
pathology were the same in all groups.
2.2 TOXICOLOGY - MAN
2.2.1 Absorption - Chlordane may be absorbed from the gastrointestinal
tract, by inhalation or through the intact skin.
2.2.2 Dangerous doses
Single: Convulsions followed by recovery occurred in an infant
ingesting a dose of 10 mg kg and in an adult following ingestion
of 32 mg/kg., The fatal dose for man has been estimated between 6
and 60 g. A dose of 104 mg/kg proved fatal when taken with
Repeated: Multiple doses of 2.4 g are stated to be dangerous.
2.2.3 Observations of occupationally exposed workers - Workers engaged
in the manufacture and formulation of chlordane for periods of up
to 15 years, have exhibited no evidence of harmful effects
attributable to this insecticide.
In a survey of more than 1105 persons who had been engaged in
pest control operations for 1-30 years, three cases of chlordane
poisoning were reported, the only symptoms specified being
dizziness and headache. Isolated cases of poisoning have
resulted from careless handling of chlordane and one death has
been recorded in a fomulator. In these cases exposure was by
inhalation of sprays or by the dermal route.
2.2.4 Observations on exposure of the general population - Dietary
intake of chlordane in the United States of America, England and
Wales has been shown to be negligible. In most cases the residues
were less than the analytical detection limits of 0.02-0.002
2.2.5 Observations of volunteers - No information available.
2.2.6 Reported mishaps - Poisoning with chlordane has occurred by
dermal, inhalation and gastrointestinal absorption. Generalized
congestion, oedema, haemorrhage, irritation and chemical burns of
the gastrointestinal tract have been observed in poisoned people.
2.3 TOXICITY TO NON-MAMMALIAN SPECIES
2.3.1 Fish - Harmful.
2.3.2 Birds - Moderately toxic.
2.3.3 Other species - Harmful to livestock; toxic to pollinating
3. FOR REGULATORY AUTHORITIES - RECOMMENDATIONS ON REGULATION OF
3.1 RECOMMENDED RESTRICTIONS ON AVAILABILITY
(for definition of categories, see introduction)
All formulations above 10%, Category 3.
All formulations 10% or less, Category 5.
3.2 TRANSPORTATION AND STORAGE
Formulations in Category 3 - Should be transported or stored
in clearly labelled impermeable containers, under lock and key,
secure from access by unauthorized persons and children. No food
or drink should be stored in the same compartment.
Fomulations in Category 5 - Should be transported or stored in
clearly labelled, leakproof containers, out of reach of children
and away from food and drink.
Formulations in Category 3 - Full protective clothing (see Part 4)
should be used by all those handling the compound. Adequate
washing facilities should be available at all times during
handling and should be close to the site of handling. Eating,
drinking and smoking should be prohibited during handling and
before washing after handling.
Formulations in Category 5 - No facilities other than those needed
for the handling of any chemical need be required.
3.4 DISPOSAL AND/OR DECONTAMINATION OF CONTAINER
Containers may be decontaminated (for method, see para. 4.2 in
Part 4). Decontaminated containers should not be used for food
and drink. Containers that are not decontaminated should be
burned or should be crushed and buried below the topsoil. Care
must be taken to avoid subsequent contamination of water sources.
3.5 SELECTION, TRAINING AND MEDICAL SUPERVISION OF WORKERS
Formulations in Category 3 - Pre-employment and periodic medical
examination of workers desirable. Workers suffering from active
hepatic or renal disease should be excluded from contact. Special
account should be taken of the workers' mental ability to
comprehend and follow instructions. Training of workers in
techniques to avoid contact essential.
Formulations in Category 5 - Warning of workers to minimize
3.6 ADDITIONAL REGULATIONS RECOMMENDED IF DISTRIBUTED BY AIRCRAFT
All formulations - Pilots and loaders should have special training
in application methods and early symptoms of poisoning and must
wear a suitable respirator. Use of flagmen not recommended.
Flagmen, if used, should wear protective clothing and be located
well away from the dropping zone.
Formulations in Category 3 - Minimum cautionary statement:
"Chlordane is a toxic substance. Avoid contamination of
foodstuffs, empty foodstuff containers and animal feed; and
excessive inhalation of dusts and mists containing this
insecticide. In case of spillage on skin, wash with soap and
water. Keep out of reach of children."
Formulations in Category 5 - Minimum cautionary statement: "This
formulation contains chlordane, a toxic substance. It is poisonous
if swallowed and may cause convulsions. Keep the material out of
reach of children and well away from foodstuffs, animal feed and
3.8 RESIDUES IN FOOD - Maximum residue limits have been recommended
for chlordane by the Joint FAO/WHO Meeting on Pesticide Residues.
These are subject to change at annual reviews.
4. PREVENTION OF POISONING IN MAN AND EMERGENCY AID
4.1 PRECAUTIONS IN USE
4.1.1 General - Chlordane is an organochlorine insecticide of moderate
toxicity that may be absorbed from the gastrointestinal tract, by
inhalation or through the intact skin. It is persistent and may
be stored in body tissue.
4.1.2 Manufacture and formulation - TLV: (ACGIH) 0.5 mg/m3, (USSR) 0.01
mg/m3. Closed systems and forced ventilation may be required to
reduce as much as possible the exposure of workers to the
4.1.3 Mixers and applicators - When opening the container and when
mixing, protective impermeable boots, clean overalls, gloves and
respirator should be worn. Mixing, if not mechanical should
always be carried out with a paddle of appropriate length. When
spraying tall crops or during aerial application a face mask
should be worn as well as an impermeable hood, clothing, boots,
and gloves. The applicator should avoid working in a spray mist
and avoid contact with the mouth.
Particular care is needed when equipment is being washed after
use. All protective clothing should be washed immediately after
use, including the insides of gloves. Splashes must be washed
immediately from the skin or eyes with large quantities of water.
Before eating, drinking or smoking, hands and other exposed skin
should be washed.
4.1.4 Other associated workers (including flagmen in aerial operations)
- Persons exposed to chlordane and associated with its
application should wear protective clothing and observe the
precautions described above in 4.1.3 under "mixers and
4.1.5 Other populations likely to be affected - With good agricultural
practice subject to 4.2 below, other populations should not be
exposed to hazardous amounts of chlordane.
4.2 ENTRY OF PERSONS INTO TREATED AREAS - Unprotected persons
should be kept out of treated areas for at least one day.
4.3 DECONTAMINATION OF SPILLAGE AND CONTAINERS - Residues in
containers should be emptied in a diluted form into a deep
pit, taking care to avoid contamination of groundwaters. The
empty container may be decontaminated by rinsing two or three
times with water and scrubbing the sides. An additional
rinse should be carried out with 5% sodium hydroxide solution
which should remain in the container overnight. Impermeable
gauntlets should be worn during this work and a soakage pit
should be provided for the rinsings. Decontaminated
containers should not be used for food and drink.
Spillage of chlordane and its formulations should be removed
by washing with 5% sodium hydroxide solution and then rinsing
with large quantities of water.
4.4 EMERGENCY AID
4.4.1 Early symptoms of poisoning - Early symptoms of poisoning may
include apprehension and agitation, abdominal pain, vomiting with
blood, coughing, hoarseness, blurred vision, noisy respiration,
incoherent speech and irrational behaviour, muscle twitching may
4.4.2 Treatment before person is seen by a physician, if these symptoms
appear following exposure - The person should stop work
immediately, remove contaminated clothing and wash the affected
skin with soap and water, if available, and flush the area with
large quantities of water. If swallowed, vomiting should be
induced, if the person is conscious.
5. FOR MEDICAL AND LABORATORY PERSONNEL
5.1 MEDICAL DIAGNOSIS AND TREATMENT IN CASES OF POISONING
5.1.1 General information - An organochlorine insecticide of moderate
toxicity which may be absorbed through the intact skin quite
rapidly, as well as by inhalation and from the gastrointestinal
tract. Poisoning incidents have occurred by all routes of
exposure. Its mode of action is stimulation of the central
nervous system. Tremors and convulsions are typical signs of
poisoning with this compound. The metabolite oxychlordane which
may be formed in animal tissues is considerably more toxic than
the parent compound. Chlordane may persist in body fats.
5.1.2 Symptoms and signs - Symptoms of poisoning may
include apprehension and agitation, coughing, hoarseness, noisy
respiration and moist rales, abdominal pain, diarrhoea, blood
stained vomiting, incoherent speech and irrational behaviour.
Inflammation of the mucus membranes of the mouth and pharynx may
follow oral ingestion. More advanced signs may include tremor,
tonic and clonic convulsions, diffuse broncho-pneumonia, delirium
5.1.3 Laboratory - Blood levels of chlordane associated with poisoning
are not known. The finding of chlordane or its metabolites in
urine will confirm exposure. After exposure there may be changes
in both EEG and ECG recordings. Changes in liver function, as
measured by plasma enzyme levels, may occur if liver damage is
5.1.4 Treatment - If the pesticide has been ingested, gastric lavage
should be performed with two to four litres of water, followed by
saline purgatives. Barbiturates (preferably phenobarbitone or
phentobarbitone) or diazepam should be given intramuscularly or
intravenously in sufficient dosage to control restlessness or
convulsions. Mechanical respiratory assistance with oxygen may
be required. Calcium gluconate, 10% in 10 ml injected
intramuscularly four-hourly may be helpful. Contraindicated are
oily purgatives, epinephrine and other adrenergic drugs and
central stimulants of all types.
5.1.5 Prognosis - If the acute effects are survived the prognosis is
reasonably good, however, complications such as bronchopneumonia,
liver damage and optic nerve damage might occur.
5.1.6 References of previously reported cases - Stormont, R. T. &
Clonley, B. E. (1955) Jour. Amer. Med. Ass., 158 (15), 1364;
Derbes, V. J. et al. (1955) Jour. Amer. Med. Ass., 158 (15),
1367; Hayes, W. J. (1963) Clinical Handbook on Economic Poisons,
US Dept. Hlth, Educ. & Welfare, Atlanta, Georgia.
5.2 SURVEILLANCE TESTS - There are no readily available
surveillance methods. Monitoring of the excretion of
chlordane and its metabolites in urine may give some
indication of the degree of exposure, although anuria has
occurred in some cases of chlordane poisoning.
5.3 LABORATORY METHODS
5.3.1 Detection and assay of compound - References only are given.
Chlordane residues may be estimated colorimetrically by the
reaction of chlordane, methanolic KOH and diethanolamine with
heat to yield a red colour with an absorbance maximum at 550
mu. The sensitivity by this method is in the order of 0.006-
Ordas et al. (1956) J. Ag. Food Che., 4, 444, or Analytical
methods for pesticides plant growth regulators and food
additives. Edited by G. Zweig, Vol. II, Insecticides,
Academic Press, New York and London (1964) Bowery, T.G., p.
Methods involving GLC are given in Analytical methods for
pesticides and plant growth regulators, Vol. VI, Gas
chromatographic analysis, edited by G. Zweig and J. Sherma,
Academic Press, New York and London, 1972, p. 315; and Yeo &
Bevenue (1969) J. Ass. Off. Anal. Chem., 52, 1206.
5.3.2 Other tests in cases of poisoning - No specific tests, see
5.1.3 - Laboratory.