United States
Environmental Protection
Agency
Office of Prevention, Pesticides
And Toxic Substances
(7508W)
EPA-738-F-93-003
June 1993
R.E.D. FACTS
Pesticide
Reregistration
10, 10'-OXYBISPHENOX-
ARSINE (OBPA)
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
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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the hydrolysis study (which was later rescinded).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
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potential human risks from exposure to OBPA pesticides are likely to be
minimal.
Environmental
Assessment
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
organisms.
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.
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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
EPA."
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).
Regulatory
Conclusion
For More
Information
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
eligible.
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
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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.
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