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                                Washington. DC 2O46O

              Fact Sheet
              Name of Chemical:      PHOSALONE
              Reason for Issuance: REGISTRATION STANDARD
              Date Issued:      NOVEMBER 30,  1937
              Fact Sheet Number: 148

   Generic Name:  S-6-chloro-2,3-#ihydro-2-oxobenzoxazol-3-yl
   (Chemical)    methyl  0,0-diethyl phosphorodithioate

   Common Name:   Phosalone  (ANSI)

   Other Chemical Nomenclature:
      °0,0-diethyl phosphorodithioate S-ester with 6-chloro-
         0,0-diethylphosphorodithioate;            „
      °0,0-di ethyl-S-C 6-chloro-3-(mercaptomethyl)-2-benzoxazolinone]
         phosphorod i th i oat e.

   Trade Names: Azonfene, Benzofos, RP11974,  Rubitox,  and Zolone.

   EPA Shaughnessy Code: 097701

   Chemical  Abstracts Service (CAS) Number:  2310-17-0

   Year  of Initial Registration:  1974

   Pesticide Type: Insecticide/Acaricide

   Chemical  Family: Organophosphate

   U.S.  and  Foreign Producers:  Rhone-Poulenc,  Inc.


   Application Sites:  Nut crops,  citrus crops, pome fruits,
                     stone  fruits, grapes, potatoes, artichokes,
                     roses, and  arborvitae.
   Formulation Types:  Technical,  Emulsifiable Concentrate and
                     Wettable  Powder.
   Application Methods: Foliar: ground and aerial application.

Summary Science Statement
Phosalone may have an adverse impact on birds and aquatic
organisms resulting from all use patterns, excluding ornamentals.
Aquatic and terrestrial field studies are required to determine
the potential risks to these organisms. Laboratory data show
that technical phosalone is highly toxic to fish .and aquatic
The toxicological profile of the end—use products places
them in Toxicity Category II for primary eye irritation,
acute oral and dermal exposures. The end—use products were
only mildly irritating to the skin when tested for dermal
irritation. The products were characterized as weak dermal
sensitizers. Phosalone can cause adverse effects to persons
entering treated fields and to persons involved in the preparation
and application of this pesticide. Preliminary data show
that groundwater contamination is unlikely, but the Agency is
unable to conduct a full assessment due to data gaps.
Chemical/Physical Characteristics of the Technical Material
Physical State: Crystalline solid
Color: White
Molecular weight and formula: 367.8 gms—C 12 H 15 C1NO 4 PS 2
Melting Point: 45—47°C
Density: 1.391 g/ml at 20°C
Vapor Pressure: < 0.5 x 10—6 mm Hg at 24°C and 16.4 x 10-6 at 60°C
Solubility: At 20°C: l.7ppm in water; 20 g/lOO ml in methanol
and ethanol; and lOg/lOOmi in acetone, benzene,
cyclohexanone, acetonitrile, xylene, toluene,
dioxane, chloroform, and methyl chloride.
Stability: Very stable under normal laboratory conditions for
a period of 2 years.

Toxicology Characteristics (Technical Material)
Acute Oral: Toxicity Category II (90 and 125 mg/kg in female and
male rats respectively).
Acute Dermal: Toxicity Category II ( LD5O > 350 mg/kg for both
males and females).
Acute Inhalation: Waived for technical, particles analyzed were
determined not to be within the respirable
range ( < 15 microns).
Primary Dermal Irritation: Toxicity Category IV (PDIS—O.77, mildly
irritating to intact and abraded skin).
Primary Eye Irritation: Data gap.
Skin Sensitization: Data gap.
Delayed neurotoxicity: Negative in hens.
Subchronic Oral (non-rodent): Data gap.
Oncogenicity: Data gap.
Chronic Feeding: NOEL for RBC inhibition in the rat is 25 ppm.
Metabolism: Data gap
Teratogenicity: Data gap
Reproduction: Data gap
Mutagenicity: Data gap for point mutation assay in mammalian
cells, structural chromosomal aberration, and
other genotoxic effects.
Major routes of exposure: Dermal and respiratory exposure to
mixers, loaders, applicators, and
Environmental Characteristics
Phosalone is stable at pH 5 and 7, but is hydrolyzed at a
pH of 9 with a half—life of 9 days. Artificial light accele-
rated degradation in buffered solution at a pH of 5 and in
soil. Aerobic soil metabolism studies demonstrate half—life
values of 1—7 days. Field dissipation studies showed half—life
values of 1—9 weeks. Phosalone was essentially immobile in
a soil column test. Based upon this preliminary data phosalone
appears unlikely to contaminate ground water. It exhibited
moderate accumulation in the bluegill sunfish, with rapid
dissipation in untreated waters.

Ecological Characteristics (Technical grade)
Aviai Oral Toxicity: Slightly toxic to w terfowl (acute oral
toxicity value: mallards > 2150 mg/kg).
Avian Dietary Toxicity: Slightly toxic to waterfowl and upland-
8—Days) game birds (subacute toxicity values:
mallards 1659 ppm and bobwhite quail
2033 ppm).
Freshwater Fish Acute: Very highly toxic to warmwater fish and
Toxicity ( 96—Hours) and highly toxic to coidwater fish (acute
LC values: 0.05 ppm bluegill and 0.63 ppm
rainbow- trout).
Freshwater Invertebrate: Very highly toxic to aquatic invertebrate
Toxicity (48—Hours) (acute EC value: 0.0012 ppm Daphnia magna )
4. Tolerance Reassessment
Tolerances have been established for phosalone on a variety
of raw agricultural commodities, in meat, fat and meat byproducts
(40 CFR 180.263) and in processed food (21 CFR 193.340) and
feed (21 CFR 561.300).
Tolerances for the following commodities are adequately
supported: potatoes, citrus, apples, pears, apricots, cherries,
nectarines, peaches, plums (fresh prunes), dried prunes,
tree nuts, almond hulls, grapes, raisins, artichokes, and the
fat, meat, and meat byproducts of cattle, goats, hogs, horses
and sheep.
Additional data are required to assess the need for food!
feed additive tolerances for the following products processed
from raw agricultural commodities bearing measurable, weathered
residues: potato granules or flakes, chips, and wet and dry
peels, raisin waste and grape juice.

The nature of the residues in both plants and animals
are not adequately understood. If, on receipt of the required
metabolism data, the Agency determines that residues in additi.on
to the parent require regulation, additional methods for data
collection and enforcement may be required.
Crop group tolerances may be proposed for the Pome Fruit
Group at 10 ppm and for the Stone Fruit Group at 15 ppm.
The Agency has established a Provisional Acceptable
Daily Intake (PADI) at 0.0025 mg/kg/day based on a 6—month
dog feeding study in which plasma cholinesterase activity was
depressed. Because a NOEL was not established in this study
a 100 fold uncertainty factor has: been used rather than the
10 fold factor normally applied for cholinesterase inhibition.
5. Summary of Regulatory Positions and Rationales
°Phosalone is not being placed into Special Review at
this time. Although the Agency is concerned about the potential
adverse impact of phosalone on birds and aquatic organisms
resulting from the agricultural use patterns, aquatic and
terrestial field studies are needed in order to evaluate the
potential risks to these species.
°The Agency has sufficient data (analysis of pesticides
with similar uses were found to be in jeopardy) to indicate
that the current use patterns of phosalone may affect endangered
species. Endangered species labeling is reserved pending
concurrence from the Fish and Wildlife Service.
°The Agency is classifying all Phosalone end use products
as Restricted Use Pesticides; except for products packaged
and labeled solely for use around the home. Products containing
phosalone for use on cherries and citrus are restricted due
to avian hazards. All use patterns are restricted due to
aquatic toxicity. The estimated environmental concentrations
exceed the LC5O value for fish and the EC5O value for aquatic
invertebrates, and the NOEL values for avian species.
°The Agency is imposing a 6—month rotational crop restric-
tion for small grains and a 12—month rotational crop restriction
for leafy vegetables and root crops.

°No significant new tolerances or new food uses will be
granted until the Agency has received sufficient data to evaluate
the dietary exposure of p iosalone.
°The Agency will retain the 24—hour reentry interval
imposed in the 1981 Registration Standard. This reentry in-
terval will be retained until the required reeentry data are
received and evaluated. Data will be reviewed on a priority
basis because of reported poisoning incidents in California.
°The Agency will require that end use products bear label
statements to protect mixers, loaders, applicators, flaggers,
and fieldworkers.
°Preliminary data indicate that groundwater contamination
is unlikely. The Agency is requiring environmental fate
studies to fully characterize phosalone’s fate in the environment.
Time Frame
Primary Eye Irritation 9 Months
Dermal Sensitization 9
Acute Inhalation 9 “
Subchronic oral toxicity——Dog (for cholinesterase 12
Oncogenicity-—rat 50
Teratogenicity—-(rat and rabbit) 15
Reproduction—-(rat) 39
Mutagenicity 12
Metabolism study 12
Dermal Absorption (rat) 9
Environmental Fate/Exposure
Aged leaching study 12
Rotational Crop (Confined) 12
Foliar dissipation study 15
Spray Drift 12
Soil Dissipation 27

Fish and Wildlife
Aviari reproduction 24 Months
Actual field testing— birds and mammals (citrus) 30
Simulated or Actual field testing—aquatic organisms 48
Acute toxicity to Estuarine and Marine organisms 12 “
Fish early life stage and aquatic invertebrate
life cycle 15
Acute toxicity to Freshwater Invertebrate 9
Residue Chemistry
Animal and Plant metabolism 18 Months
Storage stability 15
Processing studies for potatoes and grapes 24
Residue data (tea) 18
Product Chemistry 6-15 Months
Dennis H. Edwards, Jr.
Product Manager (12)
Insecticide—Rodentjcjde Branch
Registration Division (TS—767C)
Office of Pesticide Programs
Environmental Protection Agency
401 M Street, S. W.
Washington, D. C. 20460
Office location and telephone number:
Room 211, Crystal Mall #2
1921 Jefferson Davis Highway
Arlington, VA 22202
(703) 557—2386
DISCLAIMER: The information presented in this Chemical Infor-
mation Fact Sheet is for informational purposes Only and may
not be used to fulfill data requirements for pesticide regis-
tration and reregistration.

ACTION: Registration Standard, issued under the provisions
of Sect-ion 3(g) of FIFRA
This document has been reviewed by OPPE, OGC, 0CM,
AA/OPTS, and OPP offices (RD, HED, PMSD, BUD).
This document requires registrants of all products
containing phosalone to generate data to replace missing or
inadequate studies, and to revise labels to reflect the addi-
tional precautions required in the standard. There are 4
FIFRA section 3 end-use products, one technical product, and
1 FIFRA section 24(c) special local need registrations.
The basic producer of phosalone is Rhone—Poulenc, Inc.
Copies of the Standard will be sent by the Registration
Support and Emergency Response Branch (RSERB), RD to EPA
regional offices, Agriculture/Canada, and Health Canada.
Copies of the standard will be sent by OPP8 state coordinator
to each state. Additional copies are available to the public

through NTIS. The public is notified of the availability of the
Registration Standard through per.iodic announcement in the
Federal Register.
The fact sheet, attached, summarizes the Registration Standard.
RSERB maintains a mailing list for the fact sheet. An announcement
will be placed in the Federal Register shortly which will
provide people the opportunity to put their name on the fact
sheet mailing list.
Dennis H. Edwards
Product Manager (12)
Insecticice—Rodenticide Branch
Registration Division (TS—767)
Environmental Protection Agency
Washington, D.C. 20460
Phone: (703) 557—2386