Potassium arsenate

  • Potassium dihydrogen arsenate
  • Macquer's salt
Formula
H2AsKO4
Structure
Description
Colorless crystalline solid.
Uses
Used in textile, tanning, and paper industries, in insecticidal formulations (especially fly paper).

Registry Numbers and Inventories.
CAS
7784-41-0
EC (EINECS/ELINCS)
232-065-8
RTECS
CG1100000
RTECS class
Tumorigen
UN (DOT)
1677
Merck
12,7767
Beilstein/Gmelin
14110 (G)
RCRA
D004
Canada DSL/NDSL
NDSL
US TSCA
Listed
Austrailia AICS
Listed
Korea ECL
Listed

Properties.
Formula
AsH2KO4
Formula mass
180.03
Melting point, °C
275
Density
2.867 g/cm3 (20 C)
Solubility in water
Slightly soluble
Refractive index
1.5723

Hazards and Protection.
Storage
Keep containers tightly closed in a well ventilated area away from food products. Keep away from heat and water.
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
No data.
Incompatibilities
Reacts as bases to neutralize acids.
Decomposition
Dangerous when heated to decomposition, emits toxic fumes of arsenic including arsine.

Fire.
Fire fighting
Extinguish fire using agent suitable for type of surrounding fire. (Material itself does not burn or burns with difficulty.) Use water in flooding quantities as fog. Use alcohol foam, dry chemical or carbon dioxide.
Fire potential
Nonflammable.
Hazards
Containers may explode when heated. Runoff may pollute waterways.
Combustion products
Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes.

Health.
Exposure limit(s)
TLV (as As): ppm; 0.2 mg/m3 (ACGIH 1991-1992).
Carcinogin
O, G-A1, I-1, N-1, CP65
Exposure effects
Abnormally low blood pressure and rapid heart rate are common early signs. Fever and rapid breathing may occur. Elevated blood pressure has been associated with chronic environmental arsenic exposure. Altered mental status, seizures, toxic delirium, encephalopathy, and delayed peripheral neuropathy are complications of acute arsenic poisoning. Inorganic arsenic crosses the placenta and may result in spontaneous abortion or stillbirth with either acute or chronic poisoning.
   Ingestion
Acute toxicity results in early symptoms of abdominal pain, severe vomiting and diarrhea, as well as dryness of the oral and nasal cavities.
   Inhalation
Respiratory tract irritation may occur. Cardiogenic or noncardiogenic pulmonary edema and respiratory failure may develop in severe poisonings.
   Skin
Skin findings may include hyperpigmentation, keratoses, and epidermoid carcinomas. Mee's lines of the nails are common. Trivalent arsenic compounds are corrosive to the skin. Arsenic trioxide and pentoxide are sensitizers.
   Eyes
As(III) is corrosive to the eyes, mouth, and mucous membranes. Perforation of the nasal septum can occur.

First aid
 
   Ingestion
Immediately induce evacuation of intestinal tract by inducing vomiting, giving gastric lavage and saline cathartic; see physician at once; consider possible development of arsenic poisoning.
   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
Flush with water to remove dust.

Transport.
UN number
1677
Response guide
Hazard class
6.1
Packing Group
II
 
USCG CHRIS Code
PAS
 
Std. Transport #
4923277