The D List Characteristic Wastes

EPA identified four characteristics, or traits, of hazardous waste: ignitability, corrosivity, reactivity, and toxicity (designated with D waste codes). Your waste is thought to be hazardous if it exhibits any of these characteristics (40 CFR 261.20-24). These properties are measurable by standardized and available testing methods that can be found in a manual entitled Test Methods for Evaluating Solid Waste, Physical/Chemical Methods (EPA Publication SW-846).

  1. “A solid waste, as defined in Sec. 261.2 which is not excluded from regulation as a hazardous waste under Sec. 261.4(b), is a hazardous waste if it exhibits any of the characteristics identified in this subpart. It is the generators’ responsibility to determine whether their waste exhibits one or more of the characteristics identified in this subpart.
  2. “A hazardous waste which is identified by a characteristic in this subpart is assigned every EPA Hazardous Waste Number that is applicable as set for in this subpart. This number must be used in complying with the notification requirements of section 3010 of the Act and all applicable recordkeeping and reporting requirements under parts 262 through 2656, 268, and 270 of 40 CFR.”

The Characteristic of Ignitability (40 CFR 261.21)

  • A solid waste exhibits the characteristic of ignitability if a representative sample of the waste has any of the following properties:
  • It is a liquid, other than an aqueous solution, containing less than 24% alcohol by volume.
  • It has a flash point of less than 60 degrees Celsius or 140 degrees Fahrenheit, as determined by a Pensky-Martens Closed Cup Tester, that is, by using the test method specified in ASTM Standard D-93-79 or D-93-80, or a Setaflash Closed Cup Tester, using the test method specified in ASTM Standard D-3278-78. It may also be determined by an equivalent test method approved by the Administrator under procedures set forth in sections 260.20 and 260.21.
  • It is not a liquid and is capable, under standard temperature and pressure, of causing fire through friction, absorption of moisture, or spontaneous chemical changes. When ignited, it burns so vigorously and persistently that it creates a hazard.
  • It is an ignitable compressed gas as defined in 49 CFR 173.300 and saw determined by the test methods described in that regulation.
  • It is an oxidizer as defined in 49 CFR 173.151.

The Characteristic of Corrosivity (40 CFR 261.22)

A solid waste exhibits the characteristic of corrosivity if a representative sample of the waste has any of the following properties:

  • An aqueous liquid is corrosive if it has a pH less than or equal to 2 or greater than or equal to 12.5, that is, as determined by a pH meter using Method 9040 in Test Methods for Evaluating Solid Waste, Physical/Chemical Methods, EPA Publication SW-846.
  • A liquid is corrosive if it corrodes steel (SAE 1020) at a rate greater than 6.35 mm (0.250 in.) per year at a test temperature of 55 degrees Celcius or 130 degrees Fahrenheit. This is as determined by a test method specified in NACE (National Association of Corrosive Engineers) Standard TM-01-69. EPA Publication SW-846 standardized this test.

The Characteristic of Reactivity (40 CFR 261.23)

  • A solid waste exhibits the characteristic of reactivity if a representative sample of the waste has any of the following properties:
  • It is normally unstable and readily undergoes violent change without detonating.
  • It reacts violently with water.
  • It forms potentially explosive mixtures with water.
  • When mixed with water, it generates toxic gases, vapors, or fumes in a quantity sufficient to present a danger to human health or the environment.
  • It is a cyanide or sulfide-bearing waste that, when exposed to pH conditions between 2 and 12.5, can generate toxic gases, vapors, or fumes in a quantity sufficient to present a danger to human health or the environment.
  • It is capable of detonation or explosive reaction if it is subjected to a strong initiating source or if heated under confinement.
  • It is readily capable of detonation or explosive decomposition or reaction at standard temperature and pressure.
  • It is a forbidden explosive as defined in 49 CFR 173.51, or a Class A explosive as defined in 49 CFR 173.53 or a Class B explosive as defined in 49 CFR 173.88

The Characteristic of Toxicity (40 CFR 261.24)

Here the EPA hazardous waste code corresponds to the toxic contaminant causing it to be hazardous, see EPA hazardous waste codes D004 through D043. See the following document, and reference page 24: Hazardous Waste Characteristics A User-Friendly Reference Document.

Toxicity Characteristic Leaching Procedure (TCLP)

The TCLP is the EPA test method that is used to decide if waste will be characterized as toxic. If waste is found to be nontoxic (passes the TCLP test) it may be disposed of in a sanitary landfill. The toxicity of a waste is determined by the Toxicity Characteristic Leaching Procedure (TCLP) (SW-846 Test Method 1311)