Appendix V to Part 264 - Examples of Potentially Incompatible Waste  


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  • Appendix V to Part 264 - 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

    Acetylene sludge

    Alkaline caustic liquids

    Alkaline cleaner

    Alkaline corrosive liquids

    Alkaline corrosive battery fluid

    Caustic wastewater

    Lime sludge and other corrosive alkalies

    Lime wastewater

    Lime and water

    Spent caustic

    Group 1-B

    Acid sludge

    Acid and water

    Battery acid

    Chemical cleaners

    Electrolyte, acid

    Etching acid liquid or solvent

    Pickling liquor and other corrosive acids

    Spent acid

    Spent mixed acid

    Spent sulfuric acid

    Potential consequences: Heat generation; violent reaction.

    Group 2-A

    Aluminum

    Beryllium

    Calcium

    Lithium

    Magnesium

    Potassium

    Sodium

    Zinc powder

    Other reactive metals and metal hydrides

    Group 2-B

    Any waste in Group 1-A or

    1 -B

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

    Group 3-A

    Alcohols

    Water

    Group 3-B

    Any concentrated waste in Groups 1-A or 1-B

    Calcium

    Lithium

    Metal hydrides

    Potassium

    SO2 Cl2, SOCl2, PCl3, CH3 SiCl3

    Other water-reactive waste

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

    Group 4-A

    Alcohols

    Aldehydes

    Halogenated hydrocarbons

    Nitrated hydrocarbons

    Unsaturated hydrocarbons

    Other reactive organic compounds and solvents

    Group 4-B

    Concentrated Group 1-A or 1-B wastes

    Group 2-A wastes

    Potential consequences: Fire, explosion, or violent reaction.

    Group 5-A

    Spent cyanide and sulfide solutions

    Group 5-B

    Group 1-B wastes

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

    Group 6-A

    Chlorates

    Chlorine

    Chlorites

    Chromic acid

    Hypochlorites

    Nitrates

    Nitric acid, fuming

    Perchlorates

    Permanganates

    Peroxides

    Other strong oxidizers

    Group 6-B

    Acetic acid and other organic acids

    Concentrated mineral acids

    Group 2-A wastes

    Group 4-A wastes

    Other flammable and combustible wastes

    Potential consequences: Fire, explosion, or violent reaction.

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

    [46 FR 2872, Jan. 12, 1981]