United StM«           Offio* of P«Htdd« uaa Toxic Sutvttncw
                      Environmental Protection     Offiet of PMtioid* Programs (TS-766C)
                      Agency              WMhington. DC 20460
• vvEPA     Pesticide
                     Fact Sheet
                     Name of Chemical:  Carbofuran
                     Reason for Issuance:  Special Review—Preliminary Determination
                     Date ISSUed: January 5, 1989

                     Fact Sheet Number:  189


        Common Name:  Carbofuran

        Chemical  Name:   2,3-dihydro-2,2-dimethyl-7-benzofuranyl

        Chemical  Family:  Carbamate

        Trade  Name:   Furadan*

        EPA Shaughnessy  Code:  090601

        Chemical  Abstracts Service (CAS) Number:   1563-66-2

        Year of Initial  Registration:  1969

        Pesticide  Type:   Insecticide, neraaticide

        U.S. Producer:   FMC Corporation


        Carbofuran  is currently registered on a variety of fruit
        and field  crops,  vegetables,  tobacco, ornamentals, and
        forest tree seedlings.   Approximately 7 to  10 million
        pounds of  active  ingredient (Ib ai)  are applied to these
        sites per  year.   From 6 to 9  million Ib ai  of the annual
        usage is accounted for  by the granular formulation.  The
        carbofuran granular formulation was  placed  in Special
        Review in  1985 based on the avian hazard.

        Types and Methods of Application:  Aerial and ground.

        Application Rates:  0.1 to 19.9 Ib ai/acre  (granular)
                           0.05  to 10.1 Ib  ai/acre  (flowable)

        Types of Formulations:   Granular, flowable, and wettable
                               powder  formulations and a spike

                              - 2 -


    Chemical Characteristics:

         Physically/ technical carbofuran is a white crystalline
    solid that has a melting point of 153 to 154 °C (pure material).
    Carbofuran is stable under natural or acidic conditions and is
    unstable under alkaline conditions.

    Toxicological Characteristics:

         The Agency evaluated information concerning the hazard
    to humans from carbofuran and its major alternatives.  Based
    on the available data/  carbofuran does not appear to pose
    a  chronic health hazard because it has not shown positive
    oncogenic/  teratogenic/ or reproductive effects.  The data
    base  is complete and is considered acceptable.   The data
    bases for carbofuran's  alternatives  do not suggest adverse
    health effects however  the data bases are not complete so a
    full  conclusion cannot  be drawn.   The Agency has required
    that  these  data be submitted to complete the data bases.

         Based  on data on acute health effects,  the acute oral
    hazard of carbofuran is the same  order of magnitude as
    fonophos,  phorate/ and  terbufos,  but is less than aldicarb/
    and greater than the other major  alternatives.

    Environmental Characteristics:

         The Agency also evaluated the potential for ground
    water contamination from carbofuran.   The environmental
    fate  data indicate that carbofuran is highly mobile and
    has a potential to leach.   Simulation modeling  supports
    this  hypothesis.   The environmental  fate data indicate
    that  under  conditions of low pH and  low temperature,
    residues of carbofuran  could persist after leaching into
    ground water.   Since these conditions are not widespread
    in the United States, most leaching  of carbofuran will
    probably not  result in  significant concentrations at the
    wellhead.   Monitoring information for Long Island, New
    York;  Maryland;  and Massachusetts show the highest and
    most  frequently found residues in ground water.   Concentra-
    tions above 36 parts per billion, the draft  lifetime Health
    Advisory Level/  will probably only occur in  localized/
    worst-case  situations.   The Agency will be requiring the
    registrants to revise the product labels' ground water
    advisory statement.

                           - 3 -

 Ecological Effects:

      To evaluate the avian hazard from the granular formu-
 lation/ the Agency evaluated the risk to birds based on
 (1)  acute avian toxicity/  (2) exposure/  (3)  field studies/
 (4)  bird kill  incidents/  and (5) population  effects.

      Based on  laboratory  data/  the  Agency concluded that
 granular carbofuran  is  acutely  toxic  to  birds/ and that
 a  single granule may kill  a small bird.   Birds are expected
 to be  present  at the time  of carbofuran  application*
 Dietary exposure occurs from direct ingestion  of  granules
 and  exposure from ingestion of  contaminated  soil  invertebrates
 such as earthworms.   Predatory  birds  may be  secondarily
 exposed to carbofuran by  feeding on contaminated  vertebrates
 such as small  birds.

     There were 6 field studies  conducted at 11 locations
 that investigated the loss  of birds from label-directed/
 so il-i ncorpora ted uses  of  lt)G and 15G  applied  as  band
 and  in-furrow  applications  and  10G  using specialized
 equipment.  All studies consistently  resulted  in  bird
 mortality,  regardless of application  rate or methods
 which  employed  commonly practiced techniques for  soil
 incorporation  of granules.   Both direct  and  secondary
 poisoning  occurred.

     Bird  kill  incidents from direct  poisoning from carbofuran
 granules  have  occurred  in  several crops  in various areas
 of the  country  and Canada.   The  types  of birds varied  and
 included  both  migratory and  nonmigratory birds.   Bird
 mortality  was  frequently associated with at-planting
 application/ but has  occurred with  other uses  throughout
 the  year.   Direct  poisoning  of  birds  has caused over 40
 reported  bird  kill incidents.

     Secondary  poisoning incidents  have  also occurred  and
 involved  bald eagles, red-tailed hawks,  red-shouldered hawks,
 northern  harriers, and  others.

     The direct  and  secondary bird  kill  incidents  that have
 been reported underestimate  the  number of incidents actually
 taking  place because  of the  problems associated with the
 reporting  of bird kill  incidents  and with carcass  removal
 by predators.

     Populations  of declining or  endangered  species may
 be present  in areas where granular  carbofuran  is  applied.
The  Agency  cited  documented  population declines of the
 red-shouldered  hawk/  loggerhead  shrike,  field  sparrow/
Henslow's  sparrow, and  others.   Statistically  significant
declines have been measured  for  several  species.

                           -  4  -

     While  the  Agency  does not consider granular carbofuran
 to be  the sole  causative  factor in  the  decline of the bird
 species discussed/  carbofuran  is one  of the most highly
 toxic  pesticides  to which  these birds are  exposed.   Given
 its widespread  use  in  agriculture/  carbofuran is likely
 to be  responsible for  bird deaths in  these species.   The
 Agency concluded  that  granular carbofuran  can/  therefore/
 be an  important additive  factor in  the  declines.

     The Fish and Wildlife Service's  Division of  Endangered
 Species and Habitat Conservation (DESHC) indicated  in its
 Biological Opinion  for carbofuran that  the Aplomado
 falcon/ Attwater's  greater prairie  chicken,  and  Aleutian
 Canada goose were the  bird species  jeopardized  by the use
 of carbofuran and indicated  that the  use be  eliminated in
 certain areas.  DESHC  also indicated  that  the bald  eagle,
 whooping crane, and Mississippi  sandhill crane  may  be
 adversely affected.  DESHC recommended  prohibiting  the use
 of carbofuran in certain areas  to avoid impact  on these
 species.                   .

     The Agency has examined other  statutes  that  are  intended
 to protect birds and that  compliment  FIFRA.   The  Migratory
 Bird Treaty Act prohibits  the  taking  "by any means  or in
 any manner" individual  birds of  migratory  species that are
 listed in the Act's regulations.   Birds of more  than  20
 such species have been  reported  killed  by  carbofuran.
 Likewise, the Bald  and  Golden  Eagle Protection  Act  prohibits
 takings of the bald and golden  eacles and  the Endangered
 Species Act prohibits  taking of  threatened or endangered
 species.   A number  of  bald eagles killed by  carbofuran have
 been reported and the  Fish and  Wildlife Service  has  determined
 that carbofuran use  threatens  the continued  existance of
 several endangered  species.

    The Agency has  concluded that, in  general carbofuran
 poses  the greatest  risk to birds  as compared with other
 granular pesticides, including  its  alternatives.   This
 conclusion was based on estimations of  the numbers  of LDSOs
per square foot of  treated ground according  to  labeled use
 rates and methods.'  The field  studies and  reported  bird
 kill incidents for  carbofuran  confirm the  Agency's  conclusion
 that carbofuran poses  a high risk.  This approach for
 comparative risk analysis  can  be  used by the Agency  to
 identify other high  risk pesticides for which regulatory
 action would be appropriate.


     The Agency analyzed the benefits of carbofuran  use on
 10 sites.  The percentage  of granular carbofuran  use  on
 these  sites is as follows:   68  percent  for corn,  14  percent
 for sorghum, 5 percent  for soybeans,  2  percent  for  rice, 5
 percent for peanuts, and 2 percent  for  tobacco.   Also, less

                           -  5  -

 than  1  percent  is  used  on  each of  the  following  sites:  cotton/
 cranberries/  sunflowers/ and pineseed  orchards.   These  uses
 encompass  over  95  percent  of the granular  carbofuran  usage
 and about  85  percent  of all  carbofuran formulation  usage.

      If  carbofuran is not  available  for treatment of  the
 10 sites/  the Agency  estimated an  annual grower  impact
 that  ranged from approximately $22.8 to $33.0 million.
 The largest economic  impact  from cancellation of  granular
 carbofuran will be for  rice  since  no registered  alternatives
 are available for  control  of the rice  water weevil.   The
 Agency estimates a grower  impact to  be  $12.2 million
 annually;  a $6.1 million decrease  in Federal deficiency
 payments to rice growers would indicate a  loss to society
 of $6.1  million.

      Corn  is  the major  use site for  carbofuran/  and cost-
 effective/ efficacious  alternatives  are available.  No
 changes  in costs of production/ yields/ or revenues are
 expected.  The corn insecticide market  is  highly  competitive/
 and viable alternatives with similar pesticide performance
 are available at comparable  cost per acre.

      The carbofuran market for corn  has been declining
 since 1978/ and current usage  is approximately one-third
 the level  it was in 1978.  By  1986,  the market share  held
 by carbofuran. dropped to less  than 15  percent where/  in
 terms of acre treatments,  it ranked  fourth out of the five
 major corn insecticides.  The  reasons  for  the decline are
 not clear, but could  include loss  in efficacy, spectrum
 of control, and others.

      Carbofuran is applied to  nonflooded cranberries  in
Washington and Oregon to control the black vine weevil.
Carbofuran is the  only pesticide registered for  black vine
weevil larvae control.  Acephate is an efficacious  insecticide
 for control of the adults.    The impact on cranberries, without
considering acephate's use/  is expected to occur over a
7-year period due  to  the perennial nature of the crop.
Overall impacts cotuld range  from $7 million to $7.7 million
over  this period.

     For the remaining crops/  the Agency does not anti-
cipate major impacts.   The overall economic impact  from
cancellation is not expected to result in significant
changes in either  production costs or outputs.

     The Agency also evaluated aspects of carbofuran use
that are not easily quantifiable.   For example/ only one
carbamate (trimethacarb) would be available for corn
growers who rotate organophosphate and carbamate insecticides
to delay development of resistance in soil pests/ although
the Agency recognizes that some cross-resistance with
organophosphates could occur.  Also, carbofuran has

                               -  6  -

     residual and  systemic  properties  and  a  broad  spectrum  of
     control.  However,  repeated  use of  carbofuran may  lead to
     an apparent increase in  soil microbial  populations  that
     are capable of  reducing  its  effectiveness.


         In weighing  the risks and benefits, the  Agency reviewed
     a number of options other  than cancellation to  reduce  the
     risk to birds.  Among  these measures  were  (1) additional
     precautionary labeling regarding  the  hazard to  birds,  (2)
     limiting carbofuran use  to certain  months  of  the year,
     (3) limiting application geographically, and  (4) implementing
     a risk reduction  program.  The Agency evaluated these
     measures and determined  that they would not adequately
     mitigate the risk.

         As a result, the Agency is proposing  to  cancel granular
     carbofuran use on all sites.  The decision to cancel
    granular carbofuran use,  is, based on the conclusion that
     the risk to birds outweighs the benefits of use.  Because
    of the substantial risks and substantial benefits associated
    with the use of carbofuran on rice  to control the rice
    water weevil,  the Agency has requested specific additional
    information pertaining to the associated risks, benefits,
    usage,  and additional means of control.


    Jay Ellenberger
    Special Review Branch
    Special Review and Reregistration Division
    Office  of Pesticide Programs  (TS-767C)
    401 M Street,  S.W.
    Washington,  D.C.  20460
    (703)  557-7400
    DISCLAIMER:  The information presented in this Pesticide Fact
    Sheet is for informational purpose only and may not be used
    to fulfill data requirements for pesticide registration or