ARSENIC, ARSENIC TRIOXIDE, ARSENIC TRICHLORIDE (THREE EXAMPLES)
- Physical and chemical properties
- Arsenic (metal).
- Formula: As.
- Appearance: Gray metal.
- Melting point: Sublimes without melting at 613C.
- Specific Gravity: (H20=1):5.73.
- Solubility in water: Insoluble.
- Arsenic Trioxide.
- Formula: As203, (As406).
- Appearance: White powder.
- Melting point: 315C.
- Specific Gravity (H20=1):3.74.
- Solubility in water: 3.7 grams in 100cc of water at 20c.
- Arsenic Trichloride (liquid).
- Formula: AsC13.
- Appearance: Colorless or pale yellow liquid.
- Melting point: 8.5C.
- Boiling point: 130.2C.
- Specific Gravity (H20=1):2.16 at 20C.
- Vapor Pressure: 10mm Hg at 23.5C.
- Solubility in Water: Decomposes in water.
- Arsenic (metal).
- Fire, explosion and reactivity data.
- Fire: Arsenic, arsenic Trioxide and Arsenic Trichloride are nonflammable.
- Reactivity:
- Conditions Contributing to instability: Heat.
- Incompatibility: Hydrogen gas can react with inorganic arsenic to form the highly toxic gas arsine.
- Monitoring and Measurement Procedures
Samples collected should be full shift (at least 7-hour) samples. Sampling should be done using a personal sampling pump at a flow rate of 2 liters per minute. Samples should be collected on 0.8 micrometer pore size membrane filter (37mm diameter). Volatile arsenicals such as arsenic trichloride can be most easily collected in a midget bubbler filled with 15 ml. of 0.1 N NaOH.
The method of sampling and analysis should have an accuracy of not less than + or - 25 percent (with a confidence limit of 95 percent) for 10 micrograms per cubic meter of air (10 µg/m3) and + or - 35 percent (with a confidence limit of 95 percent) for concentrations of inorganic arsenic between 5 and 10 µg/m3.