How many categories of hazardous waste are defined under RCRA?

The Resource Conservation and Recovery Act (RCRA) defines four categories of hazardous waste. These categories help in the classification, management, and regulatory oversight of hazardous waste to ensure environmental safety and human health protection. The four categories are:

1. Listed Waste: This is further divided into three subcategories: F-list (non-specific wastes), K-list (wastes from specific industries), and P and U lists (discarded commercial chemical products).

2. Characteristic Waste: This includes wastes that exhibit certain hazardous traits, such as ignitability, corrosivity, reactivity, and toxicity.

3. Mixed Waste: This category includes wastes that contain both radioactive and hazardous waste components.

4. Universal Waste: A regulatory category intended for specific hazardous wastes that are commonly generated, such as batteries, pesticides, and certain types of bulbs, which are managed under streamlined regulations.

Understanding these categories is crucial for compliance with hazardous waste regulations and for ensuring that hazardous substances are handled and disposed of correctly.