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dicofol (Kelthane) Chemical Fact Sheet 12/83

                         CHEMICAL FACT SHEET FOR:
                                 DICOFOL

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
  Ida, Inc.


                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


Chemical Characteristics

- 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.


Toxicological Properties

- 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.


Environmental Characteristics

- Dicofol was stable for 350 days at 10 ppm in field plots under
  aerobic conditions.
- 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
  crops.


Ecological Characteristics

- The DDT analog contaminants in the dicofol products can cause
  reproductive impairment in various fish and flesh-eating birds
  (eggshell thinning).
- Avian dietary LC50:  1237 to 3100 ppm for upland game birds
  (slightly toxic).
- 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
  invertebrates.
- Dicofol does not seem to be phytotoxic to most plants for which it
  is registered.
- Dicofol has been shown to be relatively nontoxic to honeybees and
  alfalfa leafcutting bees.


Tolerance Assessment

- 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
  tolerance reassessment.


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
  leaching potential.
- There are insufficient data available to determine the oncogenicity,
  teratogenicity, mutagenicity, and chronic feeding effects of
  dicofol.
- 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
  organisms.
- 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
  environment.
- 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
  analog contamination
- 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
  submitted.


               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,
  1986.
- Ecological Effects: avian reproduction, aquatic organism testing.  Due
  December, 1986.
- 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,
  1986.


                   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

(703) 557-7400


DISCLAIMER:
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.