United States
               Environmental Protection
                      Office of Prevention, Pesticides
                      And Toxic Substances
June 1993
               R.E.D.   FACTS

     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, describing 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 10,  10'-
Oxybisphenoxarsine (OBPA).

     OBPA is a bacteriostat, disinfectant (bacteriocide/ germicide) and
fungicide. It is registered to prevent the growth of microorganisms in
plastics which are fabricated into shower curtains, floor coverings, wall
coverings, coated fabrics, marine upholstery, automotive vinyl trim, vinyl
molding, tarpaulins, awnings, gaskets, weather  stripping, caulking, ditch
liners and swimming pool liners. OBPA also is used as a preservative in
adhesives, coatings and specialty products, in paper and paper and plastic
products, in textiles, fibers and cordage, in carpets, and in other pesticides.
     OBPA formulations are either liquids or non-dusting powders, and
range in concentration from 0.6 to 5 percent.
   Regulatory       OBPA was initially registered as a pesticide in the United States in
      History  1965. EPA issued a Registration Standard for OBPA in October 1981
               (NTIS PB82-172271). The Registration Standard required additional
               product chemistry data, a hydrolysis study and an activated sludge
               metabolism study, which was later waived. In September 1991, EPA
   Use Profile

                   issued a Data Call-in (DCI) requiring product chemistry data and a repeat of
                   the hydrolysis study  (which was later rescinded).
                        EPA has now completed its review of the OBPA data base, including
                   the data submitted in response to the DCI.

Human Health        OBPA shows a high degree of acute toxicity when administered orally
  Assessment   and to the skin and eyes. It has been placed in Toxicity Category I
                   indicating the highest degree of acute toxicity for these effects.
                        In subacute feeding studies using rats, animals at the highest dose
                   levels had retarded growth, liver effects and an accumulation of arsenic in
                   the liver and kidneys. In a subacute inhalation study, rats  and guinea pigs
                   sacrificed 48 hours after their last exposure to OBPA had mild to moderate
                   heart effects and the  rats had liver effects.  Animals kept four months longer
                   with no further exposure showed no effects of OBPA.
                        OBPA does not appear to cause developmental or reproductive
                   toxicity, and shows no mutagenic activity.  Metabolism studies show that
                   arsenic accumulates  in the liver and kidneys as a result of  exposure to
                   OBPA, however this  arsenic is cleared from the body after two weeks.
                   Dietary Exposure
                        OBPA is not registered for use on food,  feed or processed
                   commodities.  Therefore, dietary exposure or risk is not expected.
                   Occupational and  Residential Exposure
                        Although occupational and residential exposure to OBPA occurs, such
                   exposure is indirect and/or extremely low level. Direct occupational
                   exposure during production of pesticide or plastic products containing
                   OBPA is mitigated by the use of closed systems and appropriate protective
                   gloves and eyewear.  Indirect residential and other human  exposure to
                   OBPA in treated plastics is low because only a small percent of OBPA is
                   added to these products, and only small amounts of OBPA are released,
                   very slowly.
                   Human Risk Assessment
                        OBPA does not pose human dietary risks since no food-related uses
                   are registered and dietary exposure is not anticipated.
                        The potential for occupational exposure to OBPA is  minimal provided
                   that OBPA is used in a closed system and that appropriate  Personal
                   Protective Equipment (PPE) is worn. Residential exposure to OBPA is
                   indirect and low level. No additional uses are proposed that would
                   significantly increase human exposure to OBPA.  Therefore, the

                    potential human risks from exposure to OBPA pesticides are likely to be
Environmental Fate
     No further environmental fate data are needed because of the very
limited environmental exposure expected from current uses of OBPA.  The
Registration Standard required an activated sludge study, which was later
waived, and a hydrolysis study.  The hydrolysis study was found deficient,
but the Agency  later determined that an additional hydrolysis study was not
needed based on the fact that OBPA-treated  materials will not result in
significant levels of residues being released into the  environment.  An
extractability study on pool liners and vinyl  baby  pants showed that leaching
would not result in residues that exceed the  50 ppb maximum limit
established for arsenic in drinking water.

Ecological Effects
     Studies usually required to determine  effects on birds, fish and other
nontarget organisms are waived because of OBPA's indoor, industrial use pattern.
Avian and aquatic toxicity  information is needed only to assess the need for
precautionary label statements.
     Since OBPA is  highly corrosive,  it would be very highly toxic to birds.
Existing acute oral rat studies confirm that OBPA is highly toxic to terrestrial
     Aquatic studies show that OBPA is very highly toxic to both freshwater and
marine fish, and to freshwater aquatic  and marine invertebrates, on an acute basis.

Ecological Effects  Risk  Assessment
     OBPA is an indoor, non-food, industrial use pesticide which is incorporated
into plastics, textiles, adhesives, etc.. The Agency does not conduct risk
assessments for nontarget organisms for indoor uses without effluent.  Should
residues of OBPA in  effluent ever exceed  1.75 ppm, aquatic organisms would be
acutely at risk.
Additional Data        EPA is requiring product-specific data, including product chemistry
        Required   and acute toxicity studies, as well as revised Confidential Statements of
                    Formula and revised labeling for reregistration of pesticide products
                    containing OBPA.

  Product Labeling        The labels of all registered pesticide products containing OBPA must
Changes Required   comply with EPA's current pesticide labeling requirements.  End-use and
                       manufacturing use products also must bear the following label statement in
                       the Environmental Hazards section:
                            "This pesticide is toxic to fish, aquatic invertebrates, birds, and
                            mammals.  Do not discharge effluent containing this product into
                            lakes, streams,  ponds, estuaries, oceans, or public waters unless this
                            product is specifically identified and addressed in an NPDES permit.
                            Do not discharge effluent containing this product into sewer systems
                            without previously notifying the sewage treatment plant authority.
                            For guidance contact your State Water Board or Regional Office of
                            In addition, labels must consistently reflect any potential eye and skin
                       hazard (Danger, Warning or Caution Signal Words) and recommend
                       appropriate protective equipment (protective eyeware [goggles or face
                       shield], waterproof gloves, long sleeved shirts and long-legged pants, shoes
                       and socks).
          For More
     The use of currently registered pesticide products containing OBPA in
accordance with approved labeling will not pose unreasonable risks or
adverse effects to humans or the environment.  Therefore, all uses of these
products are eligible for reregistration.
     These OBPA products will be reregistered once the required product-
specific data, revised Confidential Statements of Formula and revised
labeling are received and  accepted by EPA.  Products which contain other
active ingredients in addition to OBPA will be eligible for reregistration
only when all of their other active ingredients also are determined to be

     EPA is requesting public comments on the Reregistration Eligibility
Document (RED) for OBPA 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 Pesticide
Docket, Public Response  and Program Resources Branch, Field Operations
Division (7506C),  Office of Pesticide Programs (OPP), US EPA,
Washington, DC 20460, telephone 703-305-5805.
     Following the comment period, the OBPA 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 OBPA 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 products containing OBPA, please contact Product Manager -
Cynthia Giles-Parker, Registration Division (7505C), OPP, US EPA,
Washington, DC 20460, telephone 703-305-5540.
     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, between 8:00 am and 6:00 pm Central Time, Monday
through Friday.