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calcium arsenate (Pencal, Security) EPA Environmental Fact Sheet 8/90

EPA Environmental Fact Sheet                                       8/90


                   I. DESCRIPTION OF CHEMICAL

- COMMON NAME:  Calcium arsenate
- CHEMICAL NAME:  Calcium Orthoarsenate - Ca3(AsO4)2
- TRADE NAMES:  Pencal, Security
- EPA SHAUGHNESSY CODE:  013501
- CHEMICAL ABSTRACTS SERVICE (CAS) NUMBER:  7778-44-1
- PESTICIDE TYPE:  Crop herbicide, Insecticide and molluscicide
- PESTICIDE FAMILY:  Inorganic arsenicals
- U.S. AND FOREIGN PRODUCERS:  Woolfolk Chemical Works, Inc., Commercial
  Chemical Co.

                 II. USE PATTERNS AND FORMULATIONS

   Calcium arsenate was registered as a foliar insecticide on various 
small fruits and berries and certain vegetable crops.  It was applied at 
a rate of 4.5 lb. active ingredient/acre.  As a molluscicide, calcium 
arsenate bait was composed o f 80% bran, 10% molasses and 10% calcium 
arsenate. It was applied to the soil near plants for protection.

                    III. SCIENTIFIC FINDINGS

CHEMICAL CHARACTERISTICS

   Calcium arsenate is a pentavalent form of inorganic arsenic. It 
normally exists as white crystals with no discernable odor. Calcium 
arsenate contains 38% arsenic and is very slightly soluble in cold water 
and soluble in dilute acids.  The melting point is 1045 degrees C; the 
specific gravity is 3.62 and the molecular weight is 398.08.

TOXICOLOGICAL CHARACTERISTICS

   Inorganic arsenical compounds have been classified as Group A, or 
known human carcinogens.

   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 inorganic arsenical compounds are mutagenic.

   Evidence exists there is teratogenic and fetotoxic potential based on 
intravenous and intraperitoneal routes of exposure; however, evidence by 
the oral route is insufficient to confirm calcium arsenate's teratogenic 
and fetotoxic effects.

   Inorganic arsenicals are known to be acutely toxic.  The symptoms 
which follow oral exposure include severe gastrointestinal 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.


ENVIRONMENTAL CHARACTERISTICS

   Studies to demonstrate calcium arsenate's fate must take into account 
the fact that inorganic arsenicals are natural constituents of the soil, 
and that forms of inorganic arsenicals may change depending on 
environmental conditions.  Based on limited data, calcium arsenate is 
not predicted to leach significantly.


ECOLOGICAL CHARACTERISTICS

   Calcium arsenate is moderately toxic to birds, slightly toxic to fish 
and moderately toxic to aquatic invertebrate species.


                       IV. BACKGROUND

   On October 18, 1978, EPA issued a Notice of Rebuttable Presumption 
Against Registration (RPAR) -- now called Special Review -- of pesticide 
products containing inorganic arsenic (as well as creosote, coal tar, 
coal tar neutral oils, and pentachlorophenol).

   On January 2, 1987, EPA proposed to cancel most registrations for 
inorganic arsenicals, including the food uses of calcium arsenate, based 
on acute toxicity from accidental ingestion and oncogenic risks posed to 
workers.  The final determination to cancel these registrations was 
issued June 30, 1988 (53 FR 24787).  In that Notice, the sale, 
distribution and use of food use products containing calcium arsenate, 
among other inorganic arsenical products, was prohibited after August 1, 
1988.

                 V.  PROP0SED TOLERANCE EVOCATION

   EPA is proposing to revoke all tolerances for calcium arsenate, which 
are found at 40 CR 180.192.  No action levels will be recommended to 
replace the tolerances proposed for revocation.

               VI.  REGULATORY POSITION AND RATIONALE

   Calcium arsenate was registered for food use as an insecticide on 
various field and orchard crops.  The cancellation of these 
registrations, based on acute toxicity, were announced in a June 30, 
1988 Federal Register Notice.  In that Notice, the sale, distribution 
and use of calcium arsenate, including any exiting stocks provision, was 
prohibited after August 1, 1988. It was noted in that Federal Register 
Notice that most registrations had been either suspended or voluntarily 
cancelled before the 1988 cancellation Notice.  It is believed all 
treated commodities have passed through channels of trade.  Thus there 
would be no seizure of legally treated goods.

   No economic impact is expected as a result of cancellation of these 
uses since it is estimated that there has been no use for several years.

                        VII. CONTACT PERSON

Lisa Engstrom,
Special Review and Reregistration Division (H7508C),
Office of Pesticide Programs,
Environmental Protection Agency,
401 M St., SW.,
Washington, DC  20460.