Which hazardous waste characteristic is associated with extreme pH values (≤ 2 or ≥ 12.5)?

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

Answer: (C)

Extreme pH values reveal corrosivity. Corrosivity is about liquids that are so acidic (pH ≤ 2) or so basic (pH ≥ 12.5) that they can corrode metals and damage storage containers and materials. Measuring pH provides a quick way to identify this hazardous waste characteristic, since such extreme values indicate the waste can aggressively react with and wear away its surroundings. The other characteristics—ignitability, reactivity, and toxicity—are defined by different criteria (flammability, potential for violent reactions, and harmful health or environmental effects through leaching), and they are not determined by these pH levels.