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Subchapter 7. General Industry Safety Orders
Group 16. Control of Hazardous Substances
Article 110. Regulated Carcinogens
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§5214. Inorganic Arsenic, Appendix B

Substance Technical Guidelines

Arsenic, Arsenic Trioxide, Arsenic Trichloride

(Three Examples)

I. Physical and Chemical Properties

A. Arsenic (metal).

1. Formula: As.

2. Appearance: Gray metal.

3. Melting point: Sublimes without melting at 613oC.

4. Specific Gravity: (H2O = 1): 5.73.

5. Solubility in water: Insoluble.

B. Arsenic Trioxide.

1. Formula: As2O3 (As4O6).

2. Appearance: White powder.

3. Melting point: 315oC.

4. Specific Gravity (H2O = 1): 3.74.

5. Solubility in water: 3.7 grams in 100cc of water at 20o C.

C. Arsenic Trichloride (liquid).

1. Formula: AsCl3.

2. Appearance: Colorless or pale yellow liquid.

3. Melting point: -8.5o C.

4. Boiling point: 130.2o C.

5. Specific Gravity (H2O = 1): 2.16 at 20o C.

6. Vapor pressure: 10mm Hg at 23.5o C.

7. Solubility in Water: Decomposes in water.

II. Fire, Explosion and Reactivity Data.

A. Fire: Arsenic, Arsenic Trioxide and Arsenic Trichloride are nonflammable.

B. Reactivity:

1. Conditions Contributing to Instability: Heat.

2. Incompatibility: Hydrogen gas can react with inorganic arsenic to form the highly toxic gas arsine.

III. 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 sodium hydroxide.

The method of sampling and analysis should have an accuracy of not less than plus or minus 25 percent (with a confidence limit of 95 percent) for 0.01 mg per cubic meter of air (10 mg/m3) and plus or minus 35 percent (with a confidence limit of 95 percent) for concentrations of inorganic arsenic between 0.005 and 0.01 mg/m3.

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