United States
                Environmental Protection
                       Prevention, Pesticides And
                       Toxic Substances
March 1992
                R.E.D.    FACTS
   Use Profile
     All pesticides sold or used in the United States must be registered by
EPA, based on scientific studies showing that they can be used without
posing unreasonable risks to people or the environment.  Because of
advances in scientific knowledge, the law requires that pesticides which
were first registered years ago be reregistered to ensure that they meet
today's more stringent standards.
     In evaluating pesticides for reregistration, EPA obtains and reviews a
complete set of studies from pesticide producers,  showing the human health
and environmental effects of each pesticide.  The Agency imposes any
regulatory controls that are needed to effectively manage each pesticide's
risks.  EPA then reregisters pesticides that can be used without posing
undue hazards to human health or the environment.
     When a pesticide is eligible for reregistration, EPA announces this and
explains why in a Reregistration Eligibility Document, or RED. This fact
sheet summarizes the information in the RED for heptachlor.

     Heptachlor is a chlorinated hydrocarbon insecticide, presently used in
the United States only to control fire  ants in buried, pad-mounted electric
power transformers and in underground cable television and telephone cable
boxes. The end use product, a granular formulation packaged in small
plastic bags, is  applied by pouring the contents of the plastic bag directly
into a metal or  concrete enclosure, which is rarely opened again.

     Heptachlor was first registered  in the United States in 1952 for use as
a broad spectrum insecticide on many agricultural crops. Heptachlor also
was used for home and garden insect control, for termite control and as a
seed treatment.
     In November 1974, EPA issued a Notice of Intent to Cancel all
registered uses of heptachlor except those for subterranean termite control
and dipping of  non-food plants.  Heptachlor and its  metabolite, heptachlor
epoxide, had been demonstrated to cause cancer and birth defects in
laboratory mice and rats. They also were known to persist in soil for many
years, and to bioaccumulate throughout the food chain.  Most uses of
heptachlor were cancelled in March 1978.

                        In 1989, all heptachlor tolerances (residue limits in foods) were
                   revoked and replaced with action levels (limits set for unavoidable residues
                   in foods resulting from environmental contamination, which are lowered as
                   actual residue levels decline).
                        EPA analyzed the risks and benefits of heptachlor and six other
                   chemicals used for termite control in 1983, and issued a Data Call-In (DCI)
                   requiring more health and exposure data for these termiticides in 1984.
                   EPA also required further data to support the fire  ant control use of
                   heptachlor through a Registration Standard, issued in December 1986.
                        Currently, five heptachlor products are registered.   Only two are
                   eligible for reregistration—a manufacturing use and an end use  product for
                   fire ant control. A third heptachlor product is registered for export only
                   (the legality of this registration is being examined).  The remaining two are
                   termiticide products, which may not be sold or used in the U.S. pending the
                   results  of some required indoor air monitoring studies.  Unless these studies
                   demonstrate that residues cannot be detected inside treated homes, these
                   products' conditional registrations will expire in August  1994.

Human Health   Toxicity
  Assessment        Heptachlor is of moderate toxicity in short term animal feeding
                   studies, and has been placed in Toxicity Category II for this effect.
                   (Toxicity Category I indicates the highest degree of toxicity, and Category
                   IV the  lowest.) Heptachlor is mildly irritating to the skin, and is placed in
                   Toxicity Category IV for dermal effects.
                        Heptachlor is a Class B2, probable human carcinogen, based on long
                   term animal feeding studies in which it produced benign and malignant liver
                   tumors in mice. Heptachlor epoxide also is a Class B2 carcinogen, as it
                   produces liver tumors in mice and female rats. Mutagenicity studies show
                   that heptachlor and heptachlor epoxide affect DNA synthesis in certain
                   human cells.
                   Dietary Exposure
                        There are no remaining food use registrations for heptachlor.
                   Therefore, EPA is imposing no residue chemistry data requirements.
                        All tolerances for heptachlor  and heptachlor epoxide have been
                   converted to action levels, which will be lowered and ultimately rescinded
                   as residues of heptachlor  decline in the environment. Similarly,
                   international Codex Maximum Residue Levels (MRLs) are established for
                   unavoidable residues in meat, milk, poultry, eggs  and vegetable crops.
                   Applicator Exposure
                        The remaining use of heptachlor, to control  fire ants in underground
                   power cable boxes, results in only negligible human exposure when the

 product is used according to label directions. The label instructs the
applicator,  while wearing chemical-resistant gloves, to pour the contents of
a 4-ounce plastic bag of granular 7% heptachlor directly into the metal or
concrete cable box, and close it. Neither the applicator nor other people are
likely to come into contact with heptachlor during or after this use.  EPA is
satisfied that the label instructions will mitigate any risk associated with the
use of this product.
Human Risk Assessment
      Although long term exposure to heptachlor or heptachlor epoxide
through the diet could cause cancer in humans, EPA acted to mitigate this
risk by canceling all registered food uses of heptachlor in the 1970s,  and
converting tolerances to action levels in the  1980s.  The only remaining use
of heptachlor, to control fire ants in underground power cable boxes, will
result in minimal, short term exposure to applicators.  EPA finds that the
risk associated with this use is negligible, when the applicator properly
follows  product label directions and precautions.

Environmental Fate
      The available data indicate that heptachlor and heptachlor epoxide are
persistent, immobile, and bind to soil.  However, the remaining use of
heptachlor in enclosed, underground  power cable boxes is not expected to
result in any environmental exposure. Thus, no environmental fate data are
required for reregistration.
Ecological Effects
      Studies available to EPA indicate that heptachlor can bioaccumulate in
fish and freshwater invertebrates.  Heptachlor is very highly toxic to
warmwater and coldwater fish,  and to freshwater invertebrates.  It is highly
toxic to  both upland game birds and waterfowl, and is moderately toxic to
      An ecological risk assessment has not been conducted for heptachlor
because its remaining use is not expected to result in exposure to the
environment.  Risks to nontarget organisms should be negligible. However,
to protect fish, aquatic  invertebrates and birds, a statement must be added to
the heptachlor product label cautioning the user not to contaminate water
when disposing of waste water from cleaning equipment.
Additional Data         Some additional generic product chemistry data are required to
        Required   support the reregistration of technical heptachlor.  In addition, some
                    product-specific chemistry and acute toxicity data are required.  These
                    requirements are detailed in the DCI Notice issued with this RED.

  Product Labeling        The label of the heptachlor end-use fire ant control product must
Changes Required   comply with EPA's current pesticide labeling requirements. In addition,
                            p    The label must continue to include the following protective
                                 clothing statement:  "Wear chemical-resistant gloves when
                                 handling or applying this product."
                            p    The Environmental Hazards section of the label must include the
                                 following new statement:  "This pesticide is toxic to fish, aquatic
                                 invertebrates and birds.  Do not contaminate water when
                                 disposing of equipment waste water."
          For More
     p  Certain registered uses of heptachlor are not likely to cause
unreasonable adverse effects in people or the environment.  Such heptachlor
products, registered to control fire ants in buried,  pad-mounted electric
power transformers and in cable television and telephone pedestals, are
eligible for reregistration.
     p  These heptachlor fire ant control products will be reregistered once
generic data, product-specific data and amended labeling are received and
accepted by EPA.

     EPA is requesting public comments on the Reregistration Eligibility
Document (RED) for heptachlor during a 60-day time period, as announced
in a Notice of Availability published in the Federal Register.  To obtain a
copy of the RED or to submit written comments, please contact the Public
Response and Program Resources Branch, Field Operations Division
(7506C), Office of Pesticide Programs (OPP), US EPA, Washington, DC
20460, telephone  703-305-5805.
     In the future, the heptachlor RED will be available from the National
Technical Information Service (NTIS), 5285 Port Royal Road, Springfield,
VA 22161, telephone 703-487-4650.
     For more information about heptachlor or about EPA's pesticide
reregistration program, please contact the Special Review and Reregistration
Division (7508W), OPP, US EPA, Washington, DC 20460, telephone 703-
308-8000.  For information about reregistration of individual heptachlor
products, please contact the Registration Division (7505C), OPP, US EPA,
Washington, DC 20460,  telephone 703-305-5447.
     For information  about the health effects of pesticides, or for assistance
in recognizing and managing pesticide poisoning symptoms, please contact
the National Pesticides Telecommunications Network (NPTN).  Call toll-
free 1-800-858-7378, 24 hours a day,  seven days a week, or Fax your
inquiry to 806-743-3094.