dicofol (Kelthane) Chemical Fact Sheet 12/83
CHEMICAL FACT SHEET FOR:
FACT SHEET NUMBER: 16
DATE ISSUED: DECEMBER 30, 1983
1. DESCRIPTION OF CHEMICAL
- Generic Name: dicofol
- Common Name: dicofol
- Trade Names: Acarin, Carbax, Decofol, Kelthane, Kelthane A,
p,p Kelthane, Mibol, and Mitigan
- Chemical Abstracts Service (CAS) Number: 115-32-2
- EPA Shaughnessey Number: 010501
- Year of Initial Registration: 1957
- Pesticide Type: Acaricide
- U.S. and Foreign Producers: Rohm & Haas, Aceto, Makhteshim Beer-
Shiva, Agan Chemical, Drexel Chemical, Tricon Chem International, and
2. USE PATTERNS AND FORMULATIONS
- Foliar spray on agricultural crops and ornamentals, and in or around
agricultural and domestic buildings for mite control.
- Formulated as emulsifiable concentrates, wettable powders, dusts,
ready-to-use liquids, and aerosol sprays.
3. SCIENCE FINDINGS
- Manufacturing-use dicofol products contain a number of DDT analogs
as manufacturing impurities. These impurities include the o,p' and
p,p' isomers of DDT, DDE, DDD, and a substance called extra-
chlorine DDT or C1-DOT.
- Dicofol is a nonflowable liquid (or waxy solid), ranging from dark
to yellow-brown in color. It is stable under cool and dry
conditions, is practically insoluble in water. but soluble in
organic solvents. Its melting point ranges from 58 C to 78 C. The
chemical does not pose any unusual handling hazards.
- Dicofol has a moderate acute oral toxicity (Toxicity Category III).
- Dicofol has a relatively high degree of acute dermal toxicity
(Toxicity Category II).
- Results from an eye irritation test using a formulation intermediate
indicate that the manufacturlng-use product is probably a severe
eye irritant (Toxicity Category I).
- Toxicity studies on dicofol are as follows:
- Oral LD50 in rats: 684-1495 mg/kg body weight
- Oral LD50 in rabbits: 1810 mg/kg body weight
- Dermal LD50 in rabbits: 2.1 gm/kg body weight
- Eye Irritation: tests with a formulation intermediate showed
corneal damage in some rabbits that persisted for seven days
- Subchronic Oral Toxicity in Rats: NOEL is 20 ppm
- Oncogenicity in Rats: Available data from the National Cancer
Institute suggests that dicofol is a possible oncogen. However,
the study is unacceptable due to the reported decomposition of the
test material during the test.
- Reproduction Study in Rats and Mice: The NOEL for both rats and
mice is 100 ppm.
- Dicofol was stable for 350 days at 10 ppm in field plots under
- Aged dicofol residues are negligibly mobile in sandy loam soil
column leaching studies.
- Field studies show that dicofol persists in soils for at least 4
years after application.
- Dicofol residues may accumulate in fish as well as some rotational
- The DDT analog contaminants in the dicofol products can cause
reproductive impairment in various fish and flesh-eating birds
- Avian dietary LC50: 1237 to 3100 ppm for upland game birds
- Prolonged exposure to low levels (5 to 10 ppm) had no significant
effects on reproduction behavior of mallards.
- Acute 96-hour LC50 for warm water fish: 0.31 to 0.51 ppm.
- Acute 96-hour LC50 for cold water fish: 0.053 to 0.086 ppm.
- Acute LD50 for marine grass shrimp: >0.439 ppm.
- Findings show that dicofol is highly toxic to aquatic organisms.
- Dicofol impairs the reproductive physiology of fish and aquatic
- Dicofol does not seem to be phytotoxic to most plants for which it
- Dicofol has been shown to be relatively nontoxic to honeybees and
alfalfa leafcutting bees.
- Current application rates on labeling exceed the rates associated
with the established tolerances. Tolerances and/or labeling may
need to be revised to correct this discrepancy.
- Residues of the dicofol impurities will have to be examined for the
Summary of Science Findings
- There are insufficient data available to characterize the
environmental fate of dicofol; however, groundwater contamination is
not expected due to dicofol's lack of mobility in soil and low
- There are insufficient data available to determine the oncogenicity,
teratogenicity, mutagenicity, and chronic feeding effects of
- The data show that dicofol is highly toxic to aquatic organisms and
only slightly toxic to birds, mammals, and beneficial insects.
- Dicofol bioaccumulates in some rotational crops and aquatic
- The DDT analog contaminants in dicofol may cause unreasonable
adverse effects in certain bird and fish species.
4. SUMMARY OF REGULATORY POSITION AND RATIONALE
- No use, formulation, or geographical restrictions are required.
General use classification.
- A Special Review of all dicofol end-use products containing detectable
amounts of DDT analogs will be initiated.
- No new registrations will be issued for new dicofol products intended
for outdoor use which would further increase the amount of DDT in the
- Registrants and applicants for registration must submit data regarding
the composition of their products, and in particular the concentration
of DDT contaminants in their manufacturing-use products. Registrants
must indicate the lowest levels that could be achieved, the time frame
needed, and the cost. The Agency is concerned about the presence of
DDT contaminants at levels substantially below 1% of the technical
product because a no-effect-level has not been determined for avian
reproductive effects. Agency files show that currently registered
manufacturing-use products contain from 9 to 15 percent DDT and DDT
- Studies must be conducted by the registrants to measure whether DDT
analog residues will be present on food or feed crops due to the use
of dicofol products. A complete tolerance reassessment will be
conducted after these data and other required residue data are
5. SUMMARY OF MAJOR DATA GAPS
- Product Chemistry: product identity, certification of limits, physical
and chemical properties, and special requirements as mentioned in Item
4, above. Due April, 1984.
- Residue Chemistry: metabolism in plants and animals, residue
analytical methods, updated residue data (including residue data on
DDT analogs) on most crops. Due December, 1986.
- Environmental Fate: degradation studies, soil metabolism studies,
field volatility, field dissipation, accumulation in fish and
rotational crops. Due December, 1986.
- Toxicology: inhalation studies, subchronic feeding, chronic toxicity,
oncogenicity, teratogenicity, mutagenicity, metabolism. Due December,
- Ecological Effects: avian reproduction, aquatic organism testing. Due
- Special Testing For DDT Analog Contaminants: all environmental fate
studies conducted on C1-DDT, chronic testing with C1-DDT on chronic
toxicity on birds, fish, and aquatic invertebrates. Due December,
6. CONTACT PERSON AT EPA
Bruce A. Kapner (TS-767C)
Special Review Branch
Office of Pesticide Programs
401 M Street, S.W.
Washington, D.C. 20460
THE INFORMATION PRESENTED IN THIS CHEMICAL INFORMATION FACT SHEET
IS FOR INFORMATIONAL PURPOSES ONLY AND NOT TO BE USED TO FULFILL
DATA REQUIREMENTS FOR PESTICIDE REGISTRATION AND REREGISTRATION.