What information is used when a boiling point is not available for a material?

When a boiling point is not available for a particular material, the 20% evaporated point of a distillation performed in accordance with ASTM D 86 is utilized as a reliable reference. ASTM D 86 is a standard test method for determining the boiling range characteristics of petroleum products and similar materials. This method allows for the assessment of how the material behaves thermally during distillation, providing insights into its volatility and phase changes. The 20% evaporated point specifically indicates the temperature at which 20% of the substance has been vaporized, which can offer an approximation of the boiling point and help in understanding the material's behavior under similar conditions. This is particularly useful in safety assessments and when dealing with flammable substances, as it can give clues about the temperatures to be aware of during handling and storage.

Other potential answers, such as the freezing point, average boiling point of similar substances, or historical data from previous experiments can provide some context but do not directly apply in the same way that the 20% evaporated point does in this context. These alternatives may not provide the specific thermal behavior needed for accurate assessments related to safety and handling.