United Stitai Offie* of Ptitictdts and Toxie Sutetinm
Environmental Proraction OHic* of Ptitiad* Proqrimt (TS-766C)
A»»ney Washington. DC 20460
f/EPA Pesticide
Fact Sheet
Name of Chemical: Sodium arsenate
Reason for Issuance: special review
Date Issued: December Id 86
Fact"Sheet Number: 114
1. DESCRIPTION OF CHEMICAL
Common Name: Sodium Arsenate
Chemical Name: Sodium Orthoarsenate - Na2HAs04.7H20
Trade Names: None
EPA Shaughnessy Code: 013505
Chemical Abstracts Service (CAS) Number: 7778-43-0
Year of Ini'tial Registration:
Pesticide Type: Insecticide
Chemical Family: Inorganic Arsenicals
U.S. and Foreign Producers: Osmose Wood Pres. Company
of America, Inc.
2. USE PATTERNS AND FORMULATIONS
Sodium arsenate-is currently registered for use as an
ant bait. These baits are used in approximately 1% of U.S.
homes.
0 Methods of Application: Liquid bait applied where ants are
seen. Applied as a bait station using cardboard, waxpaper,
'cotton, or bottle caps; or apply directly across ant trails
and at entry points as a thin line 3 to 4 inches long.
0 Application Rates: Insecticide- The bait used is a 1.3%
arsenic (metal) solution.
Types of Formulations: Ready to use solution, granular.
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3. SCIENCE FINDINGS
Chemical Characteristics
Sodium arsenate is a pentavalent form of inorganic arsenic.
It is a heptahydrate which normally exists as colorless
crystals with no discernible odor. Sodium arsenate contains
24% arsenic and is soluble in 5.6 gm at 0°C and 100 gin at
100°C in 100 cc of water, soluble in glycerol and slightly
soluble in alcohol. The melting point of calcium arsenate is
130°C , the density is 1.88 and the molecular weight is
312.01. The technical chemical contains 98% and the formula-
tions contain from 0.92% to 3.08% sodium arsenate.
o Toxicological Characteristics
Inorganic arsenical compounds have been classified as Class
A oncogens, demonstrating positive oncogenic effects based
on sufficient human epidemiological evidence.
Inorganic arsenicals have been assayed for mutagenic activity
in a variety of test systems ranging from bacterial cells
to peripheral lymphocytes from humans exposed to arsenic.
The weight of evidence indicates that inorganic arsenical
compounds are mutagenic.
Evidence exists indicating that there is teratogeniC and
fetotoxic potential based on intravenous and intraperitoneal
routes of exposure; however, evidence by the oral route is
insufficient to confirm sodium arsenate’s teratogeniC and
fetotoxic effects.
Inorganic arsenicals are known to be acutely toxic. The
symptoms which follow oral exposure include severe gastro-
intestinal damage resulting in vomiting and diarrhea, and
general vascular collapse leading to shock, coma and death.
Muscular cramps, facial edema, and cardiovascular reactions
are also known to occur following oral exposure to arsenic.
o Environmental Characteristics: The environmental fate of
sodium arsenate is not well documented. Studies to demon-
strate its fate must take into account the fact that
inorganic arsenjcals are natural constituents of the soil,
and that forms of inorganic arsenic may change depending
on environmental conditions. Based on very limited data
sodium arsenate is not predicted to leach significantly.
O Ecological Characteristics: Sodium arsenate is moderately
toxic to birds, slightly toxic to fish and moderately toxic
to aquatic invertebrate species.
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Metabolism: The metabolism of inorganic arseni compounds
in animals is well known. The pentavalent form, such as
sodium arsenate, is metabolized by reduction into the
trivalent form, followed by transformation into organic
forms which are excreted within several days via the urine.
All animals exhibit this metabolism except rats, which retain
arsenic in their bodies for up to 90 days.
o Tolerance Assessment: A tolerance for residues of the
insecticide sodium arsenate on grapes was established
at 3.5 ppm in 40 CFR 180.196.
o Reported Pesticide Incidents: The Agency’s Pesticide
Incident Monitoring System (PIMS) contains many recorded
incidents of accidental poisonings from the use of sodium
arsenate baits. 190 children were involved in 186 reported
incidents; five of these children died and 43 were
hospitalized.
4. SUMMARY OF REGULATOR? POSITION AND RATIONALE
The Agency is proposing to cancel all existing nonwood
registrations of sodium arsenate. Based upon the risk of acute
toxicity poisonings and the other toxicological characteristics
described above the Agency has determined that in light of the
limited benefits for nonwood uses of sodium arsenate the risks of
continued use outweigh the benefits.
° Benefits Analysis: No economic impact is expected as a result
of cancellation of this use. Comparatively priced alter-
natives are available.
5. CONTACT PERSON
Douglas McKinney
Special Review Branch, Registration Division
Office of Pesticide Programs (TS—767C)
401 M Street, S.W.
Washington, D.C. 20460
(703) 557—5488
DISCLAIMER: The information presented in this Pesticide Fact
Sheet is for informational purposes only and may not be used
to fulfill data requirements for pesticide registration or
reregistration.
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