1. Regulations
  2. title 40
  3. chapter I-i27
  4. part 265
  5. subpart FF
  6. appendix AppendixV

Appendix V - Appendix V to Part 265—Examples of Potentially Incompatible Waste

Many hazardous wastes, when mixed with other waste or materials at a hazardous waste facility, can produce effects which are harmful to human health and the environment, such as (1) heat or pressure, (2) fire or explosion, (3) violent reaction, (4) toxic dusts, mists, fumes, or gases, or (5) flammable fumes or gases.

Below are examples of potentially incompatible wastes, waste components, and materials, along with the harmful consequences which result from mixing materials in one group with materials in another group. The list is intended as a guide to owners or operators of treatment, storage, and disposal facilities, and to enforcement and permit granting officials, to indicate the need for special precautions when managing these potentially incompatible waste materials or components.

This list is not intended to be exhaustive. An owner or operator must, as the regulations require, adequately analyze his wastes so that he can avoid creating uncontrolled substances or reactions of the type listed below, whether they are listed below or not.

It is possible for potentially incompatible wastes to be mixed in a way that precludes a reaction (e.g., adding acid to water rather than water to acid) or that neutralizes them (e.g., a strong acid mixed with a strong base), or that controls substances produced (e.g., by generating flammable gases in a closed tank equipped so that ignition cannot occur, and burning the gases in an incinerator).

In the lists below, the mixing of a Group A material with a Group B material may have the potential consequence as noted.

Group 1-A Group 1-B Acetylene sludgeAcid sludge Alkaline caustic liquidsAcid and water Alkaline cleanerBattery acid Alkaline corrosive liquidsChemical cleaners Alkaline corrosive battery fluidElectrolyte, acid Caustic wastewaterEtching acid liquid or solvent Lime sludge and other corrosive alkalies Lime wastewaterPickling liquor and other corrosive acids Lime and waterSpent acid Spent causticSpent mixed acid Spent sulfuric acid

Potential consequences: Heat generation; violent reaction.

Group 2-A Group 2-B AluminumAny waste in Group 1-A or 1-B Beryllium Calcium Lithium Magnesium Potassium Sodium Zinc powder Other reactive metals and metal hydrides

Potential consequences: Fire or explosion; generation of flammable hydrogen gas.

Group 3-A Group 3-B AlcoholsAny concentrated waste in Groups 1-A or 1-B WaterCalcium Lithium Metal hydrides Potassium SO2Cl2, SOCl2, PCl3, CH3SiCl3Other water-reactive waste

Potential consequences: Fire, explosion, or heat generation; generation of flammable or toxic gases.

Group 4-A Group 4-B AlcoholsConcentrated Group 1-A or 1-B wastes AldehydesGroup 2-A wastes Halogenated hydrocarbons Nitrated hydrocarbons Unsaturated hydrocarbons Other reactive organic compounds and solvents

Potential consequences: Fire, explosion, or violent reaction.

Group 5-A Group 5-B Spent cyanide and sulfide solutionsGroup 1-B wastes

Potential consequences: Generation of toxic hydrogen cyanide or hydrogen sulfide gas.

Group 6-A Group 6-B ChloratesAcetic acid and other organic acids ChlorineConcentrated mineral acids ChloritesGroup 2-A wastes Chromic acidGroup 4-A wastes HyphochloritesOther flammable and combustible wastes Nitrates Nitric acid, fuming Perchlorates Permanganates Peroxides Other strong oxidizers

Potential consequences: Fire, explosion, or violent reaction.

Source: “Law, Regulations, and Guidelines for Handling of Hazardous Waste.” California Department of Health, February 1975.

[45 FR 33232, May 19, 1980, as amended at 71 FR 40276, July 14, 2006]

SOURCE: 45 FR 33232, May 19, 1980, unless otherwise noted.