The Resource Conservation and Recovery Act (RCRA) of 1976, Solid Waste Disposal Act Amendment of 1980, and the Hazardous and Solid Waste Amendment of 1984 regulated in 40CFR 260-268

and Arkansas Regulation 23 define the standards for Hazardous Waste.

The analytical testing identified for the indicated RCRA parts is in accordance with "SW846 Test Methods for Evaluating Solid Waste".

Part 261 of the regulation is composed of: Subpart A, General which identifies those solid wastes which are subject to regulations as hazardous waste; Subpart B, Criteria of Identifying the Characteristics of Hazardous Waste and for the Listing Hazardous Wastes; Subpart C, Characteristics of Hazardous Waste, and Subpart D - List of Hazardous wastes.

In Subpart B, RCRA regulations list specific industrial wastestreams and identify them as "Listed Wastes". These wastes are considered hazardous if they meet one of the narrative listings descriptions found in the regulations and do not meet any of the exclusions described in 40 CFR 261.4. Listed wastes are divided into four different categories:

F listed waste -- wastes from non-specific industrial process, such as spent solvents used for cleaning or degreasing;
K listed waste -- wastes that are from specific industry sources, such as certain petroleum refining wastes and veterinary pharmaceuticals;
P listed waste -- unused, acutely hazardous commercial chemical products, such as aldin, a chemical used as an agricultural insecticide;
U list waste -- unused, commercial chemical products, such as DDT and formaldehyde.

The definitions and determinations for these listing can be found in 40 CFR Part 261.31 through 261.33.