Which of the following is a characteristic of hazardous waste as defined by the EPA?

• A. Radioactive
• B. Biodegradable
• C. Non-toxic
• D. Ignitable

Answer: (D)

Hazardous waste is defined by EPA not only by listed hazardous substances but also by certain characteristics, and one of these is ignitability. A waste is ignitable if it can easily catch fire under standard conditions. In practice this means liquids with a flash point at or below 60°C or solids that can ignite easily, or waste that can produce flammable vapors in air. This property is the reason many solvent wastes are regulated as hazardous. Radioactivity is governed by separate radioactive waste rules, not the ignitability characteristic. Biodegradable or non-toxic properties aren’t used to define ignitability; a waste can be ignitable and still have other properties, but ignition tendency is the defining trait in this category. Examples include common solvent wastes like acetone or toluene, which are flammable and thus considered ignitable.