Which of the following is NOT one of the four characteristics of hazardous wastes as defined by the EPA?

The four characteristics of hazardous waste defined by the Environmental Protection Agency (EPA) include ignitability, corrosivity, reactivity, and toxicity. Radioactivity is not included in these characteristics; rather, it falls under a different classification of waste management, primarily concerned with how materials that emit radiation are handled. While toxic substances can be classified as hazardous, radioactivity itself does not fit within the parameters outlined for hazardous waste characteristics by the EPA.

Toxicity relates directly to a waste's capability to harm living organisms, either through exposure or ingestion. Explosiveness is typically considered under reactivity, which evaluates the potential risks during chemical reactions. Therefore, the characteristic of radioactivity is distinct from the EPA's defined hazardous waste characteristics, making it the correct answer to the question.