United States             Office of Pesticides end Toxic Subftaneci
                    Environmental Protection      Office of Pesticide Program* (TS-766C)
                    Agency                Washington, DC  20460
vvEPA       Pesticide
                    Fact Sheet
                    Name of Chemical:
                    Reason for Issuance:
                    Date Issued:
                    Fact Sheet Num
July 16, 1985
 iBer:    61
  1.  Description of Chemical

     Generic name: l-hydroxy-2(lH)-pyridinethione, sodium salt  (CA)
     Common names: Sodium omadine
     Trade names:  Sodium 2-pyridinethiol 1-oxide, Sodium 2-mercaptopyridtne,
                  Sodium l-hydroxypyridine-2-thione, and Omadine* sodium.
     EPA Shaughnessy Code: 088004
     Chemical abstracts Service  (CAS) number:  15922-78-8
     Year of initial registration: 04-10-68
     Pesticide Family: Pyridine
     Pesticide type: Microbiocide
     U.S. and Foreign producers: Olin Corp., Research Center, 270 South
                               Winchester Ave., P.O. Box 30275,
                               New Haven, CT 06511

  2. Use Patterns and Formulations

    Application sites: in metalworklng fluids, paints, inks, adhesives,
         plastics, laundry rinse additive, polymers, floor finishes.

    Types of Formulations: liquid formulations Include the following per-
         centages of sodium omadine: 4Z, 5Z, 5.9Z, 6.4%, and 40Z.  Powder
         formulations include  percentages 2Z and  90Z sodium omadine.

    Types and methods of application: for manufactured materials (i.e.,
         plastics, paints, adhesives, etc.,),  add at any point  during the
         manufacturing process.  As a preservative (i.e., in metalworking
         fluids, and inks) add directly to the solution to preserved.

    Application rates: for metalworking fluids use 4 - 1280 or./lOO Ibs.
         of fluid; for inks use  0.05 - 0.75Z of product/lb. of  ink; for
         paints use 0.1 - 0.25Z  of product/lb. of paint; for plastics and
         polymers use 0.1 -0.2Z  of product/lb. of plastic or polymer.

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3. Science Findings
Summary of science statement: “bottom line” of science information
listed below.
Chemical Characteristics:
Physical state: powder Solubility: 45.42 in water (25°C)
Color: pale yellow 5.4% in ethanol
Melting Point: between 252 — 257°C 19.12 in ethylene glycol
28.6% in methanol
3. Toxicology Characteristics:
Acute Eye Irritation: Tox. CAT III
Skin Irritation: Tox. CAT III
Major routes of exposure: dermal and inhalation
Chronic Toxicology:
Teratology study (rat; dermal application): no teratogenic effects
at 7 mg/kg/day.
Teratology study (rabbit; dermal application): sodium omadine
displayed dose—related maternal toxic effects and potental
teratogenic effects at all dosage levels tested (0.5, 2.0, and
8.0 mg/kg/day). A NOEL could not be determined and malformations
cannot be defined as teratogenic until effects are seen in the
absence of maternal toxicity.
Gene Mutation Study: no mutagenic effects noted at the highest dosage
tested (25ug/plate [ activated) and 3ug/plate [ nonactivatedi).
Environmental Characteristics: as there are no food/feed uses, or other
outdoor uses, environmental fate data do not have to be submitted to the
Agency.
Ecological Characteristics:
Avian Dietary Lc 50 (40% a.i. tested):
Bobwhite quail 3246 ppm
Mallard duck 9119 ppm
Freshwater Fish LC5 (4% a.i. tested):
Bluegill sunfish 66 ppm
Rainbow trout 0.28 ppm
Aquatic invertebrates LC 50 (40% a.i. tested):
Daphnia magna 23 ppb

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Tolerance Assessments: the registered uses of sodium omadine do not
include direct application to a food or feed crop. Therefore, no
tolerances have been established for this chemical.
No problems have been reported to the Agency (i.e., PIMS or data in
reference to Section 6(a)(2) of the Act) with respect to the use of
this chemical.
4. Summary of Regulatory Position and Rationale
There are no use, formulation, manufacturing process or geographical
restrictions for sodium omadine registrations.
Unique warning statement:
Environmental Hazards
This pesticide is toxic to fish and freshwater invertebrates. Do
not discharge effluent containing this product into lakes, ponds,
streams, estuaries, oceans or public water unless this product is
specifically identified and addressed in an NPDES permit. Do not
discharge effluent containing this product to sewer systems without
previously notifying the sewage treatment plant authority. For
guidance contact your State Water board or Regional Office of the
EPA.
A risk assessment has not been conducted on this chemical.
5. Summary of Major Data Gaps
Data Cap Date Study Due
Acute Oral LD rj 12—31—85
Dermal Sensitization 12—31—85
Teratology (rabbit) 12—31—85
Mutagenicity Studies:
Chromosomal 12-31—85
Other Mechanisms 123185
Reproduction — 2 generations 08—31—87
6. Contact Person at EPA
Registration Division (TS—767C)
U.S. Environmental Protection Agency
Office of Pesticide Programs
401 M Street, S.W.
Washington, D.C. 20460
Attn.: Marshall Swindell Telephone: (703)—557—3675
DISCLAIMER: The information presented in this Chemical Information Fact
Sheet is for informational purposes only and may not be used to fulfill
data requirements for pesticide registration and reregistration.

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