Which class includes liquids with flashpoints at or above 200°F (93.3°C)?

• A. Class II
• B. Class IIIA
• C. Class IIIB
• D. Class I

Answer: (C)

Flammable-liquid classifications are based on flash point, the temperature at which a liquid’s vapors can ignition when an ignition source is present. The system groups liquids as Class I (<100°F), Class II (100–139°F), Class IIIA (140–199°F), and Class IIIB (200°F or higher). Since 200°F is the lower bound for Class IIIB, liquids with flashpoints at or above that temperature belong in Class IIIB. This reflects that they are less flammable at room temperature than the lower classes but still require appropriate precautions to prevent ignition at higher temperatures. The other classes don’t include 200°F, so they don’t apply here.