A waste is hazardous if it has one or more of the following characteristics:
1. Ignitability: Wastes that can create fires, those that can readily catch fire, and friction-sensitive substances (for example, paints, degreasers, linseed oil, and gasoline).
2. Corrosiveness: Wastes that are acidic and those capable of corroding metal objects such as drums and tanks (for instance, cleaning fluids, battery acids, and rust removers).
3. Reactivity: Substances that are unstable under normal conditions and that can create explosions and/or toxic fumes, gases, and vapors when mixed with water (for example, sulphur-bearing wastes and cyanides).
4. Toxicity: Substances that are harmful or fatal when ingested or absorbed and that, when improperly disposed of on land, may eventually pollute groundwater (for instance, mercury, certain pesticides, and lead).