endosulfan (Thiodan) Chemical Profile 4/85
CHEMICAL NAME: 6,7,8,9,10,10-Hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-
DEC INGRED. CODE:
TRADE NAME(S): Thiodan, Tiovel (56)
FORMULATION(S): Wettable powders (35, 50%), emulsifiable concentrates
(17.5%,35%,50%, and 2 pounds and 3 pounds/gallon),
ULV (25%), granules (2,3,4,5%), dusts (1,2,3,4,5,6%)
TYPE: Organochlorine insecticide - miticide
BASIC PRODUCER(S): FMC Corp. Velsicol Chemical Corp.
Agr. Chem. Group 341 East Ohio Street
2000 Market St. Chicago, IL 60611
Philadelphia, PA 19103
STATUS: Restricted use
PRINCIPAL USES: Controls aphids, thrips, beetles, foliar feeding
larvae, mites, borers, cutworms, bollworms, bugs, whiteflies, leaf-
hoppers, and slugs on deciduous, citrus, and small fruits, vegetables,
forage crops, oil crops, fiber crops, grains, tobacco, coffee, tea,
forest, ornamentals. Controls termites and tsetse fly (56).
Important Pests Controlled: Aphids, beetles, bollworms, spittlebugs,
termites, tsetse fly, leafhoppers, pear psylla, fleabeetles, stemborers,
stinkbugs, boll weevils, loopers, corn earworms, peach twig borers,
armyworms, cyclamen mites, mosquito pupae, and many others (8a).
II. PHYSICAL PROPERTIES
MOLECULAR FORMULA: C9 H6 Cl6 O3 S (62)
MOLECULAR WEIGHT: 406.9 (62)
PHYSICAL STATE: Brown crystalline solid (technical product, at least
94% pure). Endosulfan is a mixture of two stereo-
isomers: alpha-endosulfan, endosulfan (I), m.p. 109
C, is 64-67% of the technical grade; beta-endosulfan,
endosulfan (II), m.p. 213.3 C, is 29-32% (62).
ODOR: Of sulfur dioxide (technical product) (62)
MELTING POINT: 70-100 C (technical product) (62)
VAPOR PRESSURE: 1.2 Pa at 80 C (technical product) (62)
SOLUBILITY: 0.32 mg/l water (alpha-endosulfan), 0.33 mg/l water
(beta-endosulfan) at 22 C (62).
III. HEALTH HAZARD INFORMATION
OSHA STANDARD: None established
NIOSH RECOMMENDED LIMIT: None established
ACGIH RECOMMENDED LIMIT: TWA (Time Weighted Average) = 0.1 mg/m3;
STEL (Short Term Exposure Level) = 0.3 mg/m3
(deleted); skin notation (15c).
A. ACUTE TOXICITY
DERMAL: LD50 = 359 mg (in oil)/kg (rabbit) (62)
ORAL: LD50 = 80-110 mg tech. (in oil)/kg (rat); 76 mg alpha
isomer/kg (rat); 240 mg beta isomer/kg (rat); 76.7 mg
tech./kg (dog) (62).
INHALATION: LC50 (Thiodan 50 WP) = >2 gm/liter of air (rat)
LD50 = 350 mg/m3 when the exposure is four hours
(male rat) (15b)
EYES: Nonirritant (11c)
B. SUBACUTE AND CHRONIC TOXICITY:
In 2-yr feeding trials rats receiving 30 mg/kg diet showed no
ill-effect; in 1-yr feeding trials NEL for dogs was 3 mg/kg diet (62).
Dogs tolerated endosulfan orally for a year at dosages up to 0.75
mg/kg, the highest level tested. Oral dosages of about 0.5
mg/kg/day (dietary level of 10 ppm) for 2 years were associated with
lower survival of female rats and reduced testis weight in males, but
these findings were of doubtful statistical significance.
Consistent histopathological findings were apparent only at a dosage
ten times as great, which produced renal tubular damage and some
hydropic change of the liver (15b).
IV. ENVIRONMENTAL CONSIDERATIONS
Hazardous to birds, fish, and beneficial insects. Moderately
hazardous to honey bees. Biological magnification slight. Not
recommended for use on Concord grapes. Injury reported on alfalfa,
birch and chrysanthemums under greenhouse conditions (1).
It is highly toxic to fish (LC50 (96-hr) for golden ide 2 ug/l
water) but, in practical use, should be harmless to wildlife and to
Fish: Endosulfan is highly toxic. The LC50 of various fish
species was determined to range between 0.001 and 0.05 ppm (11c).
Wildlife Studies: the LD50 values obtained are as follows:
Species Male Female
_______ ____ ______
Bobwhite Quail 50 56
Japanese Quail 106 85
Mallard Ducks 243 205
No significant difference in sex (11c).
It is metabolised, in plants and mammals, to the corresponding
sulphate which is toxicologically similar to endosulfan (the sulphite).
For most fruits and vegetables 50% of the residue is lost in 3-7 days.
There is no accumulation in milk, fat or muscle and it is excreted as
conjugates of the diol and as other highly polar metabolites depending
on the species (62).
Approximate Residual Period: 7-15 days on plant surfaces; 1 season on
unexposed surfaces (1).
V. EMERGENCY AND FIRST AID PROCEDURES
The chemical information provided below has been condensed
from original source documents, primarily from "Recognition and
Management of Pesticide Poisonings", 3rd ed. by Donald P. Morgan,
which have been footnoted. This information has been provided in
this form for your convenience and general guidance only. In
specific cases, further consultation and reference may be required
and is recommended. This information is not intended as a sub-
stitute for a more exhaustive review of the literature nor for the
judgement of a physician or other trained professional.
If poisoning is suspected, do not wait for symptoms to develop.
Contact a physician, the nearest hospital, or the nearest Poison
FREQUENT SYMPTOMS AND SIGNS OF POISONING BY ORGANOCHLORINE PESTICIDES
APPREHENSION, EXCITABILITY, DIZZINESS, HEADACHE, DISORIENTATION,
WEAKNESS, PARESTHESIAE, muscle twitching, tremor, tonic and clonic
CONVULSIONS (often epileptiform), and unconsciousness are the major
manifestations. Soon after ingestion, nausea and vomiting commonly
occur. When chemicals are absorbed dermally, apprehension, twitching,
tremors, confusion, and convulsions may be the first symptoms.
Respiratory depression is caused by the pesticide and by the petroleum
solvents in which these pesticides are usually dissolved. Pallor
occurs in moderate to severe poisoning. Cyanosis may result as
convulsive activity interferes with respiration (25).
SKIN CONTACT: Remove contaminated clothing and wash skin
thoroughly with soap and water. Call a physician
INGESTION: Give a saline emetic (tablespoon of salt in glass of
water) and repeat until returns are clear. Call a
physician immediately (11c).
EYE CONTACT: Flush with plenty of water. Call a physician
NOTES TO PHYSICIAN:
Endosulfan is a central nervous system stimulant. There is no
specific antidote. If patient is convulsing, give pentobarbital (0.25
to 0.50 gram) intravenously. Otherwise phenobarbital (0.06 to 0.10
gram) may be given orally. Do not use oily laxatives as they increase
absorption. Patient should be under medical observation for at least
24 hours in any case of suspected intoxication. Electroencephalogram
may show abnormal alpha wave activity (11c).
Diazepam is the treatment of choice for convulsions. If ingested,
induce emesis, then administer magnesium sulfate and observe (56).
VI. FIRE AND EXPLOSION INFORMATION
GENERAL: While dry Thiodan formulations will not support combustion,
there is the possibility of them giving off sulfur dioxide fumes if a
fire occurs where they are stored. For liquid Thiodan formulations
observe flammable caution statements. No explosive hazard (for technical
EXTINGUISHER TYPE: Water spray, CO2, dry chemical, fog (16).
Generally compatible except with alkaline materials (1).
Incompatible with calcium arsentate, lime, or zinc sulfate plus lime.
Compatible with other pesticides with which it might be used (11c).
VIII. PROTECTIVE MEASURES
STORAGE AND HANDLING: Do not breathe dust or spray mist. Do not get in
eyes, on skin, or on clothing. Wash hands immediately after handling.
Do not store Thiodan Miscible at temperatures below 20 F. Provide
general ventilation plus local exhaust at point of potential fume
emission. Protect E.C. from freezing (56).
PROTECTIVE CLOTHING: During commercial or prolonged exposure, wear
clean clothing fastened at neck and wrists for dust protection, change
clothing daily; wear clean synthetic rubber gloves and a mask or
respirator of a type passed by MESA for endosulfan protection.
Protective clothing also required for workers entering treated fields
within 24 hours of application (56).
PROTECTIVE EQUIPMENT: During commercial or prolonged exposure, wear a
mask or respirator of type passed by MESA for endosulfan protection
IX. PROCEDURES FOR SPILLS AND LEAKS
IN CASE OF EMERGENCY, CALL, DAY OR NIGHT
PESTICIDE TEAM SAFETY NETWORK/CHEMTREC
Using respirator sweep up spill and use if possible or package for
X. LITERATURE CITED
1. Harding, W.C. 1979. Pesticide profiles, part one: insecticides
and miticides. Univ. Maryland, Coop. Ext. Serv. Bull. 267.
8a. Thomson, W. T. 1976. Agricultural chemicals - book 1:
insecticides, acaricides, and ovicides. Revised ed. Thomson
Publ., Indianapolis, IN. 232 pp.
11c. FMC Corporation. 1974. Product manual: Thiodan. Middleport,
15b. American Conference of Governmental Industrial Hygienists. 1971.
Documentation of the threshold limit values for substances in
workroom air with supplements for those substances added or
changed since 1971, 3rd ed., 4th printing (1977). Cincinnati,
OH. 484 pp.
15c. American Conference of Governmental Industrial Hygienists. 1984.
TLVs: threshold limit values for chemical substances and
physical agents in the work environment and biological exposure
indices with intended changes for 1984-85. Cincinnati, OH.
16. Agway, Inc., Chemical Division. Material safety data sheet.
25. Morgan, D.P. 1982. Recognition and management of pesticide
poisonings, 3rd ed. U.S. Environmental Protection Agency,
Washington, DC. 120 pp.
56. Farm Chemicals Handbook, 70th ed. 1984. R. T. Meister, G. L.
Berg, C. Sine, S. Meister, and J. Poplyk, eds. Meister
Publishing Co., Willoughby, OH.
62. The Pesticide Manual: A World Compendium, 7th ed. 1983. C.R.
Worthing, ed. The British Crop Protection Council, Croydon,
England. 695 pp.