What Makes a Product Hazardous Waste?

EPA's regulations establish two ways of identifying solid wastes as hazardous under the Resource Conservation and Recovery Act (RCRA). A waste may be considered hazardous if it exhibits certain hazardous properties (“characteristics”) or if it is included on a specific list of wastes EPA has determined are hazardous (“listing” a waste as hazardous) because they are found to pose substantial present or potential hazards to human health or the environment.

EPA's regulations in the Code of Federal Regulations (40 CFR) define four hazardous waste characteristic properties: ignitability, corrosivity, reactivity, or toxicity (see 40 CFR 261.21-261.24).

Characteristic Hazardous Wastes

A RCRA characteristic hazardous waste is a solid waste that exhibits at least one of four characteristics defined in 40 CFR Part 261 subpart C — ignitability (D001), corrosivity (D002), reactivity (D003), and toxicity (D004 - D043).

  • Ignitability– Ignitable wastes can create fires under certain conditions, are spontaneously combustible, or have a flash point less than 60 °C (140 °F). Examples include waste oils and used solvents.
  • Corrosivity – Corrosive wastes are acids or bases (pH less than or equal to 2, or greater than or equal to 12.5) and/or are capable of corroding metal containers, such as storage tanks, drums, and barrels. Battery acid is an example.
  • Reactivity – Reactive wastes are unstable under "normal" conditions. They can cause explosions, undergo violent reactions, generate toxic fumes, gases, or vapors or explosive mixtures when heated, compressed, or mixed with water. Examples include lithium-sulfur batteries and explosives.
  • Toxicity – Toxic wastes are harmful or fatal when ingested or absorbed (e.g., containing mercury, lead, etc.). When toxic wastes are land disposed, contaminated liquid may leach from the waste and pollute ground water. Toxicity is defined through a laboratory procedure called the Toxicity Characteristic Leaching Procedure (TCLP).

Listed Wastes

By definition, EPA determined that some specific wastes are hazardous. These wastes are incorporated into lists published by the EPA. These lists are organized into three categories:

The F-list (non-specific source wastes). This list identifies wastes from common manufacturing and industrial processes, such as solvents that have been used in cleaning or degreasing operations. Because the processes producing these wastes can occur in different sectors of industry, the F-listed wastes are known as wastes from non-specific sources.

The K-list (source-specific wastes). This list includes certain wastes from specific industries, such as petroleum refining or pesticide manufacturing. Certain sludges and wastewaters from treatment and production processes in these industries are examples of source-specific wastes.

The P-list and the U-list (discarded commercial chemical products). These lists include specific commercial chemical products in an unused form. Some pesticides and some pharmaceutical products become hazardous waste when discarded.


  • Used oil may only be stored in tanks or containers.

  • Containers and tanks must be in good condition and not leaking.

  • Containers and tanks must be labeled "Used Oil."

  • Spills must be cleaned up, and contaminated materials disposed of properly.

  • Oil filters may not be disposed of at landfills. They must be recycled by an oil filter processor or municipal refuse incinerator (Chapter 62-710, F.A.C.).

  • Used oil must have secondary containment for containers, existing tanks or above ground tanks.


U.S. EPA’s Universal Waste Rule (40 CFR Part 273) provides an alternative set of management standards for certain specific wastes in lieu of regulation under 40 CFR Parts 260 through 272. Currently, it applies to recycling of batteries, some pesticides, and mercury containing devices and lamps. Facilities that manage these wastes as Universal Waste (UW) do not need to count that waste toward their generator status or use hazardous waste manifests for shipping UW. Florida’s Chapter 62-737, F.A.C., is broader in scope than EPA’s UW Rule and therefore governs the management of mercury-containing lamps and devices in Florida.