United States             Prevention, Pesticides         EPA-738-F-94-024
                Environmental Protection       And Toxic Substances         September 1994
                Agency	(7508W)	


                R.E.D.   FACTS
                Sodium  and Zinc


                Salts  of  2-Mercapto-


                     benzothiazole	
     PGStJCJdG      All pesticides sold or distributed in the United States must be
RGTGClistration  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 unreasonable risks to human health or the environment.
                    When a pesticide is eligible for reregistration, EPA announces this and
                explains why in a Reregistration Eligibility Decision (RED) document.  This
                fact sheet summarizes the information in the RED document for
                reregistration case 2380, the sodium and zinc salts of
                2-mercaptobenzothiazole.

   USG ProfilG      This case includes two active ingredients, the sodium and zinc salts of
                2-mercaptobenzothiazole, which are used as fungicides, microbiocides and
                bacteriostats. These salts are used as preservatives for adhesives, latex and
                oil paints, paper products, metal working cutting  fluids and textile fibers.
                    Sodium 2-mercaptobenzothiazole is used in the form of a soluble
                concentrate or liquid to control mold, mildew, bacteria and fungi which
                cause aqueous industrial products to degrade.  The metal working cutting
                fluid use of the sodium salt of 2-mercaptobenzothiazole is the only use
                pattern where effluent containing the chemical is  discharged into aquatic
                environments, potentially exposing non-target aquatic organisms, including
                endangered species. This use pattern exceeds the acute Level of Concern
                (LOG) for endangered aquatic organisms.  The Agency, therefore, has
                determined that effluent containing sodium 2-mercaptobenzothiazole should

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    Regulatory
         History
Human  Health
  Assessment
not be discharged into streams and other waterways where endangered
aquatic organisms are known to reside. When the Agency completes its
Endangered Species Program,  additional precautionary labeling may be
required to mitigate the risk to endangered species.
      Zinc 2-mercaptobenzothiazole is used in the form of a soluble
concentrate or liquid and wettable powder to control mold, mildew, bacteria
and fungi  which degrade aqueous industrial products, fabrics, and yarns;
and slime-forming bacteria and fungi in industrial water systems.
      There are no registered food uses for either the sodium or zinc salts of
2-mercaptobenzothiazole.

      Sodium 2-mercaptobenzothiazole was first registered as a pesticide in
the United States in 1949 in an industrial preservative product.  Currently,
only one product is registered, for use in wood and paper/paper board
treatment  and as a preservative in metal working cutting fluids, emulsions,
textiles and pastes.
      Zinc 2-mercaptobenzothiazole was first registered as a pesticide in the
United States in 1955 in an industrial preservative product.  Currently, two
products are registered for use as preservatives in adhesives, textiles, paints,
coatings and paper products.
      The  parent compound, acid of 2-mercaptobenzothiazole, was
registered  as a pesticide  active ingredient in 1956. However, all products
containing that chemical have since been canceled.

Toxicity
      Zinc 2-mercaptobenzothiazole has  been placed in Toxicity Category
III, which indicates moderate to low acute  toxicity, for acute skin and eye
effects.  However,  the sodium salt is placed in Toxicity Category I,
indicating  the highest degree of acute toxicity, for skin and eye effects
because it is extremely acidic (with a Ph of 11.5).
      The  acid of 2-mercaptobenzothiazole is classified as a non-quantifiable
"Group C" carcinogen; a possible human carcinogen.  A linear, multi-stage
model for  cancer risk assessment was not appropriate because the use of this
pesticide is not likely to  result in repeated human exposure over a significant
portion of the human life span. Margins of Exposure  (MOEs) were
calculated to quantify the risk to applicators/mixers/loaders. The MOEs for
the preservative and metal working cutting fluid uses of zinc and sodium
2-mercaptobenzothiazole exceed 100 (the margin considered acceptable) by
several orders of magnitude. Therefore,  additional exposure studies were
not warranted, and the Agency required data on acute, developmental and
subchronic toxicity and mutagenicity only.
Occupational and Residential Exposure
      The  methods of application for products containing sodium or zinc
2-mercaptobenzothiazole that include open pouring of liquid concentrate,

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                     and open pouring of powder into adhesives and paints, present the potential
                     for dermal and inhalation exposure to applicators.  Dermal exposure is the
                     primary route of exposure of sodium and zinc 2-mercaptobenzothiazole.
                          EPA was concerned about the risks of dermal and inhalation exposure
                     associated with the application of sodium 2-mercaptobenzothiazole for the
                     metal working cutting fluid  use, and required a dermal exposure study to
                     assess the risks to workers.  The study was designed to reflect typical work
                     practice involving the biocide in industrial use. The final assessment of  the
                     study indicated that some absorption into the skin occurred.  However, since
                     there are no special toxicological concerns about the sodium or zinc salts,
                     EPA is not imposing Personal Protective Equipment (PPE) requirements on
                     use  of the products.
                          Post-application exposure from treated paint, adhesives, textiles and
                     other treated industrial products are not considered significant because of the
                     low concentration/dilution factor to the treated products.  There are no
                     residential uses of sodium or zinc 2-mercaptobenzothiazole.  Therefore,  the
                     potential for any significant residential exposure is very low.
                     Human Risk Assessment
                          The sodium and zinc salts are not registered for any food  or feed
                     related uses, so no  dietary risks are posed.  The potential for residential
                     exposure and risk is very low.
                          Workers (mixers, loaders and applicators) may be exposed to these
                     pesticides, especially during open pouring of liquid and powder
                     formulations.  However,  the Agency has determined that use of these
                     pesticides is not likely to result in repeated human exposure over a
                     significant portion of the human life span.  The establishment of active
                     ingredient based PPE requirements is not warranted at this time. The PPE
                     for pesticide handlers will be based on the acute toxicity of the end-use
                     product.

Environmental   Environmental Fate
   AsSGSSITIGnt        A hydrolysis study has been required on the technical grade of sodium
                     2-mercaptobenzothiazole for industrial use products where effluent is
                     potentially discharged into aquatic environments.  While the Agency has
                     required the study to be based on the industrial use pattern, major
                     environmental exposure to the sodium  salt is not expected.  The Agency  will
                     use  the results of the study to confirm this assessment and the degradation
                     rate of the active ingredient and products formed during hydrolysis.

                     Ecological Effects Risk Assessment
                          2-Mercaptobenzothiazole is almost nontoxic to birds on an acute oral
                     basis and is only slightly toxic to birds on a dietary basis.  However, it is
                     highly toxic to freshwater fish and moderately toxic to aquatic invertebrates.
                     The use patterns of the sodium and zinc salts,  except for sodium

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    Additional Data
            Required
  Product Labeling
Changes Required
2-mercaptobenzothiazole's use in metal working cutting fluids, indicate that
they will not pose risks to avian and aquatic species.
     Unlike agricultural situations, where aquatic organisms can be exposed
to pesticides via runoff or spray drift, nontarget aquatic organisms would be
exposed to industrial microbiocides through a point source discharge.  The
metal working cutting fluids use of the sodium  salt is the only use pattern
which may result in an effluent discharge into aquatic environments.  It
therefore poses the potential for exposure to nontarget aquatic organisms,
including endangered species.
     EPA's aquatic risk assessment indicates that minimal risk is posed to
freshwater aquatic organisms in receiving streams at mean flow rates.
However, under high exposure conditions, a high acute and chronic risk is
posed to  freshwater aquatic organisms.  The high exposure scenario also
exceeds the LOG for endangered freshwater fish and invertebrate species.
Therefore, effluent containing sodium 2-mercaptobenzothiazole should not
be discharged into streams and other waterways where endangered aquatic
organisms are known to reside.

     A hydrolysis study has been required to confirm the environmental
assessment by determining the degradation rate of sodium 2-mercapto-
benzothiazole and products  formed during hydrolysis.   EPA also  is
requiring product-specific data including product chemistry and acute
toxicity studies, revised Confidential Statements of Formula  (CSFs), and
revised product labeling for reregistration of products containing sodium or
zinc salts of 2-mercaptobenzothiazole.

     The labels of all registered pesticide products containing sodium and
zinc salts of 2-mercaptobenzothiazole must comply with EPA's current
pesticide labeling requirements. The following statement also must appear
on the labels of sodium 2-mercaptobenzothiazole  end use products with the
metal working cutting fluid use:
     Effluent Discharge Labeling Statement -  "Do not discharge effluent
     containing this product into lakes, streams,  ponds, estuaries, oceans or
     other waters unless in accordance with the requirements of a National
     Pollutant Discharge Elimination System (NPDES) permit and the
     permitting authority has been notified in writing prior to discharge.
     Do not discharge effluent containing this  product to sewer  systems
     without previously notifying the local sewage treatment plant
     authority. For guidance contact your State Water Board or Regional
     Office of the EPA."
     When the Agency completes the Endangered Species Program,
additional precautionary labeling may be required to mitigate the risk to
endangered species.

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 Regulatory
Conclusion
   For More
Information
     The use of registered products containing sodium or zinc salts of
2-mercaptobenzothiazole will not pose unreasonable risks or adverse effects
to humans or the environment, provided that these products are used in
accordance with the restrictions on product labeling.  Therefore, all uses of
these products are eligible for  reregistration.  Sodium or zinc salts of
2-mercaptobenzothiazole products will be reregistered once the confirmatory
generic data, the required product-specific data, Confidential Statements of
Formula and revised labeling are  received and accepted by  EPA.

     EPA is requesting public comments on the Reregistration Eligibility
Decision (RED) document for sodium and zinc salts of
2-mercaptobenzothiazole 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 document 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 sodium and zinc salts of
2-mercaptobenzothiazole RED document 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 EPA's pesticide reregistration program,
the  sodium and  zinc salts of 2-mercaptobenzothiazole RED, or reregistration
of individual products containing  sodium and zinc salts of
2-mercaptobenzothiazole, please contact the Special Review and
Reregistration Division  (7508W), OPP, US EPA, Washington, DC 20460,
telephone 703-308-8000.
     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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