Final answer:
The Department of Transportation categorizes flammable liquids as Class 3 hazardous materials, requiring careful handling and specific regulations.
Step-by-step explanation:
The Department of Transportation (DOT) defines and regulates hazardous materials in the United States. Flammable liquids are classified by the DOT as Class 3 hazardous materials. The handling of hazardous waste, including flammable liquids, is crucial for ensuring safety and environmental protection.
According to the regulations, appropriate measures must be taken when transporting and disposing of such materials to prevent accidents and environmental contamination. Flammable liquids are those with a flash point of not more than 60 degrees Celsius or 140 degrees Fahrenheit, and they require special attention due to the high risk they pose if they were to ignite or leak.