Calcium arsenate

  • Tricalcium arsenate
  • Pencal
  • Tricalcium orthoarsenate
  • Cucumber dust
Formula
Ca3(AsO4)2
Structure
Description
White powder.
Uses
The material is used as an insecticide, molluscicide.

Registry Numbers and Inventories.
CAS
7778-44-1
EC (EINECS/ELINCS)
231-904-5
RTECS
CG0830000
RTECS class
Agricultural Chemical and Pesticide; Tumorigen
UN (DOT)
1573
Merck
12,1686
Beilstein/Gmelin
69951 (G)
RCRA
D004
EPA OPP
13501
Swiss Giftliste 1
G-1346
Canada DSL/NDSL
DSL
US TSCA
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
As2Ca3O8
Formula mass
398.07
Melting point, °C
1455.0
Odor Threshold Odor threshold Odorless
Density
3.62 g/cm3
Solubility in water
Insoluble

Hazards and Protection.
Storage
Keep in a cool, dry, dark location in a tightly sealed container or cylinder. Keep away from incompatible materials, ignition sources and untrained individuals. Secure and label area. Protect containers/cylinders from physical damage.
Handling
All chemicals should be considered hazardous. Avoid direct physical contact. Use appropriate, approved safety equipment. Untrained individuals should not handle this chemical or its container. Handling should occur in a chemical fume hood.
Protection
Wear appropriate protective gloves, clothing and goggles.
Respirators
Wear positive pressure self-contained breathing apparatus (SCBA).
Small spills/leaks
Keep material out of water sources and sewers. Land spill: Dig a pit, pond, lagoon, holding area to contain liquid or solid material. Cover solids with a plastic sheet to prevent dissolving in rain or fire fighting water. Water spill: Neutralize with agricultural lime (CaO), crushed limestone (CaCO3), or sodium bicarbonate (NaHCO3). Add ferric chloride (FeCl3). Adjust pH to neutral (pH=7). Use mechanical dredges or lifts to remove immobilized masses of pollutants and precipitates.
Stability
Moisture and carbon dioxide cause slow decomp to calcium carbonate and (phytotoxic) dicalcium hydrogen arsenate. In the presence of acids, water sol, strongly phytotoxic arsenic acid is produced.
Incompatibilities
When water soln of arsenicals are in contact with active metals such as arsenic, iron, aluminum, zinc, highly toxic fumes of arsenic including arsine are released. Arsenic compounds produces toxic fumes of arsenic when heated to decomposition.
Decomposition
Dangerous when heated to decomposition, emits toxic fumes of arsenic including arsine.

Fire.
Fire fighting
Stay upwind; keep out of low areas. Wear self-contained (positive pressure if available) breathing apparatus and full protective clothing.Not flammable. For small fires, use dry chemical, water spray, or foam. For large fires, use water spray, fog, or foam.
Fire potential
Not combustible.
Hazards
When heated to decomposition, calcium arsenate produces toxic fumes of arsenic. Avoid heat.
Combustion products
Poisonous gases may be produced in fire.
Health
3

Health.
Exposure limit(s)
OSHA PEL: 1910.1018 TWA 0.010 mg/m3 NIOSH REL: Ca C 0.002 mg/m3 15-minute See Appendix A NIOSH IDLH: Potential occupational carcinogen 5 mg/m3 (as As)
Carcinogin
O, G-A1, I-1, N-1, CP65
Poison_Class
2
Exposure effects
Patients may rapidly become hypotensive. Rapid heart rate may develop secondary to pain, hypovolemia, cardiac effects of arsenic or anxiety. Toxic delirium and encephalopathy are possible complications. Peripheral neuropathy is common. Seizures may occur. Calcium arsenate is teratogenic and fetotoxic in experimental animals and is likely to be fetotoxic in humans. However at permissible occupational exposure limits, arsenic is NOT likely to be a significant risk to human reproduction. Acute ingestion may cause neonatal death. Arsenic can cross the placenta. <br>Arsenic is excreted in the breast milk. <br>Systemic toxicity was present before any effects were noted on the testes. Fertility does not seem to be affected by arsenic exposure.
   Ingestion
Early symptoms within hours following arsenic ingestion include abdominal pain, vomiting, profuse bloody or watery (rice-water-like) diarrhea, pain in the extremities and muscles, weakness, and flushing of the skin.
   Inhalation
Acute respiratory failure was seen in a patient with severe arsenic poisoning. Pulmonary edema may occur and be life-threatening. Adult respiratory distress syndrome (ards) has been reported.
   Skin
Avoid any skin contact. See Inhalation.
   Eyes
Inflammation of the eye, photophobia, dimness of vision, diplopia, and tearing may occur. A garlic-like odor may be detected on the breath.

First aid
 
   Ingestion
Gastric decontamination - aggressive decontamination with gastric lavage is recommended. Activated charcoal: administer charcoal as a slurry (240 ml water/30 g charcoal). Usual dose: 25 to 100 g in adults/adolescents.
   Inhalation
Move victim to fresh air. Apply artificial respiration if victim is not breathing. Do not use mouth-to-mouth method if victim ingested or inhaled the substance; induce artificial respiration with the aid of a pocket mask equipped with a one-way valve or other proper respiratory medical device. Administer oxygen if breathing is difficult.
   Skin
Remove and isolate contaminated clothing and shoes. Remove material from skin immediately. Immediately flush with running water for at least 20 minutes. For minor skin contact, avoid spreading material on unaffected skin.
   Eyes
Immediately flush with running water for at least 20 minutes.

Transport.
UN number
1573
Response guide
Hazard class
6.1
Packing Group
II
 
USCG CHRIS Code
CCA
 
Std. Transport #
4923218