Hazardous Waste

What makes a waste a hazardous waste?

It's might well be one of those "you'll be sorry you asked" answers, at least for the moment. But it's important, and somebody has to understand it. Usually that will be the person whose job explicitly includes managing your company's waste, once you have a real job, that is. But if you're the type of person who likes to have a basic grasp, here are some basics.

One really tidy definition of hazardous waste is "well, 1st it has to be waste (you'd be surprised how many people forget this and start supposing that hazardous waste regulations apply to non-waste chemicals), and 2nd, it has to be hazardous!"

That would be nice and simple if the part about being hazardous was obvious. It's not. Federal regulations provide reams of definitions for what is commonly called hazardous waste, in the law called RCRA (the Resources Conservation and Recovery Act, a major part of EPA law, universally pronounced "rickra" or recra"). Some States add to that pile of definitions, so there are differences between Illinois and Indiana, Tennessee and California..... In Indiana, the RCRA provisions suffice.

FOR STARTERS, "hazardous waste" means chemical waste which must be managed and disposed of according to EPA rules. Wastes containing biological hazards or radioactivity are not "hazardous waste" in this scheme (unless they're mixed with chemical hazardous waste).

Waste is hazardous waste under the RCRA regulation (see also OSW definitions)

if it's a "characteristic waste"
- i.e., it exhibits one of four defined characteristics including
  - ignitability (D001)
  - corrosivity (D002)
  - reactivity (D003), or
  - toxicity (D004 - D043) (all of these are clearly defined in the regs and might not mean what you'd guess they mean), OR
if it's a "listed waste"
- i.e. it's listed on one of the lists! The lists include
  - "source-specific" wastes, aka "K" wastes, from specific industries
  - "non-specific source wastes," which are called "F" wastes
  - commercial chemical products, the "U" and "P" lists (Ps constitute a lot of the so-called "acute hazardous waste." So do some of the Fs.)
unless the waste is exempted explicitly, as are municipal sewage and a small host of other wastes.

Purdue produces all but the K type of hazardous waste.

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. For more details, see 40 CFR §261.21 . Test methods that may be used to determine ignitability include the Pensky-Martens Closed-Cup Method for Determining Ignitability (Method 1010a) (PDF, 1 pp., 19 KB), the Setaflash Closed-Cup Method for Determining Ignitability (Method 1020b) (PDF, 1 pp., 17 KB), and the Ignitability of Solids (Method 1030) (PDF, 13 pp., 116 KB).

Corrosivity

Corrosive wastes are acids or bases (pH less than or equal to 2, or greater than or equal to 12.5) that are capable of corroding metal containers, such as storage tanks, drums, and barrels. Battery acid is an example. For more details, see 40 CFR §261.22. The test method that may be used to determine corrosivity is the Corrosivity Towards Steel (Method 1110a) (PDF, 6 pp., 37 KB).

Reactivity

Reactive wastes are unstable under "normal" conditions. They can cause explosions, toxic fumes, gases, or vapors when heated, compressed, or mixed with water. Examples include lithium-sulfur batteries and explosives. For more details, see 40 CFR §261.23. There are currently no test methods available.

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) (Method 1311) (PDF, 35 pp., 288 KB). The TCLP helps identify wastes likely to leach concentrations of contaminants that may be harmful to human health or the environment. For more details, see 40 CFR §261.24.

F wastes which also count as acute hazardous waste:

The following non-specific source wastes from the 40 CFR 261.31 F waste table are also counted as acute hazardous waste unless excluded (see 260.20 and 260.22)

F020

Wastes (except wastewater and spent carbon from hydrogen chloride purification) from the production or manufacturing use (as a reactant, chemical intermediate, or component in a formulating process) of tri- or tetrachlorophenol, or of intermediates used to produce their pesticide derivatives. (This listing does not include wastes from the production of Hexachlorophene from highly purified 2,4,5- trichlorophenol.)

F021

F022

Wastes (except wastewater and spent carbon from hydrogen chloride purification) from the manufacturing use (as a reactant, chemical intermediate, or component in a formulating process) of tetra-, penta-, or hexachlorobenzenes under alkaline conditions.

F023

Wastes (except wastewater and spent carbon from hydrogen chloride purification) from the production of materials on equipment previously used for the production or manufacturing use (as a reactant, chemical intermediate, or component in a formulating process) of tri- and tetrachlorophenols. (This listing does not include wastes from equipment used only for the production or use of Hexachlorophene from highly purified 2,4,5- trichlorophenol.).

F026

Wastes (except wastewater and spent carbon from hydrogen chloride purification) from the production of materials on equipment previously used for the manufacturing use (as a reactant, chemical intermediate, or component in a formulating process) of tetra-, penta-, or hexachlorobenzene under alkaline conditions.

F027

Discarded unused formulations containing tri-, tetra-, or pentachlorophenol or discarded unused formulations containing compounds derived from these chlorophenols. (This listing does not include formulations containing Hexachlorophene sythesized from prepurified 2,4,5- trichlorophenol as the sole component.).