What determines the Category of a chemical?

• A. Flash Point
• B. Boiling Point
• C. Density
• D. Odor

Answer: (A)

The property that determines how a chemical is categorized for flammability is the flash point. This is the lowest temperature at which the liquid emits enough vapor to form an ignitable mixture with air. The lower the flash point, the more readily the substance can ignite, so it falls into a higher flammability category. Boiling point, density, and odor don’t reliably indicate how easily vapors will ignite under normal conditions, so they’re not used to set the flammability category. For example, a liquid with a very low flash point like acetone is considered highly flammable, while a liquid with a higher flash point is less hazardous in terms of ignition risk.