This document summarizes the key characteristics of hazardous waste. It identifies four main properties - ignitability, corrosivity, reactivity, and toxicity. Ignitable wastes are easily flammable. Corrosive wastes can eat through containers due to their high pH levels. Reactive wastes are unstable and can experience violent changes. Toxic wastes are measured by their lethal dose (LD50), which indicates the amount needed to kill 50% of a test sample. The document provides examples and testing methods for each of the four hazardous waste properties.