Which of the following is NOT a hazardous waste characteristic defined by RCRA?

• A. Viscosity
• B. Ignitability
• C. Toxicity
• D. Reactivity

Answer: (A)

The essential idea is how RCRA defines hazardous waste by its characteristics. RCRA identifies four hazardous characteristics: ignitability, corrosivity, reactivity, and toxicity. Viscosity, which measures how thick or runny a liquid is, is not one of these characteristics.

Ignitability refers to wastes that can easily catch fire (flash point below 60°C). Corrosivity covers aqueous wastes with extreme pH values (pH ≤ 2 or ≥ 12.5) or that can corrode metals. Reactivity includes wastes that are unstable, capable of explosive reactions, or that release toxic gases when mixed with water. Toxicity is determined by leaching tests (like TCLP) to see if the waste releases harmful levels of metals or chemicals.

So, viscosity doesn’t determine whether a waste is hazardous under RCRA, even though a waste might be viscous for other reasons.