Arsenic

  • Gray arsenic
Formula As
Structure
Description A silver-grey brittle, crystalline, metallic-looking substance odorless.
Uses Alloying constituent.

Registry Numbers and Inventories.
CAS 7440-38-2
EC (EINECS/ELINCS) 231-148-6
EC Index Number 033-001-00-X
EC Class Toxic
RTECS CG0525000
RTECS class Tumorigen; Drug; Mutagen; Reproductive Effector; Human Data
UN (DOT) 1558
Merck 12,832
Beilstein/Gmelin 16247 (G)
RCRA D004
Swiss Giftliste 1 G-1999
Canada DSL/NDSL DSL
US TSCA Listed
Austrailia AICS Listed
New Zealand Listed
Korea ECL Listed

Properties.
Formula As
Formula mass 74.92
Melting point, °C 817
Vapor pressure, mmHg 3.1 (400 C)
Vapor density (air=1) 5.7
Critical temperature 1400
Critical pressure 220
Density 5.727 g/cm3 (20 C)
Solubility in water Insoluble
Refractive index 3.54
Thermal expansion 1.44E-5/K (20 C)
Heat of fusion 27.7 kJ/mol

Hazards and Protection.
Storage Protect container against physical damage. Store in well ventilated area away from food or food products and combustible materials.
Handling Use of approved respirators is required for applications where adequate ventilation cannot be provided. Activi- ties which generate dust or fume should be avoided. When melted, the temperature should be kept as low as possible.
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. Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete. Water spill: Use natural barriers or oil spill control booms to limit spill travel. Use natural deep water pockets, excavated lagoons, or sand bag barriers to trap material at bottom. Remove trapped material with suction hoses.
Stability Slight - as dust. Reactive only under extreme conditions.
Incompatibilities Reacts incandescently with bromine trifluoride, even at 10C Reacts readily in the cold with arsenic React vigorously with fluorine at ordinary temperatures.
Decomposition When arsenic is heated in air it will burn and form a white smoke consisting of arsenic trioxide (as2o3).

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 foam, dry chemical, or carbon dioxide.
Fire potential Moderate in form of dust when exposed to heat or flame or by chemical reaction with powerful oxidizing agents.
Hazards Containers may explode when heated.
Combustion products Contain highly toxic arsenic trioxide and other forms of arsenic.
NFPA Health 3
  Flammability 2  

Health.
Exposure limit(s) TLV (as As): ppm; 0.01 mg/m3 A1 (ACGIH 1997). MAK: class III A1 (1997).
Carcinogin O, G-A1, I-1, N-1, CP65
Poison_Class 1*
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 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. 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 1558
Response guide 152
Hazard class 6.1
Packing Group II  
USCG CHRIS Code ARX  
Std. Transport # 4923207