Code of Federal Regulations Title 29. Labor § 29.1910.1018—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 613C.

4. Specific Gravity: (H20=1):5.73.

5. Solubility in water:  Insoluble.

B. Arsenic Trioxide.

1. Formula:  As203, (As406).

2. Appearance:  White powder.

3. Melting point:  315C.

4. Specific Gravity (H20=1):3.74.

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

C. Arsenic Trichloride (liquid).

1. Formula:  AsC13.

2. Appearance:  Colorless or pale yellow liquid.

3. Melting point:  −8.5C.

4. Boiling point:  130.2C.

5. Specific Gravity (H20=1):2.16 at 20C.

6. Vapor Pressure:  10mm Hg at 23.5C.

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 NaOH.

The method of sampling and analysis should have an accuracy of not less than ±25 percent (with a confidence limit of 95 percent) for 10 micrograms per cubic meter of air (10 μg/m³) and ±35 percent (with a confidence limit of 95 percent) for concentrations of inorganic arsenic between 5 and 10 μg/m³.