{"data":{"id":"us/40-cfr-appendix-v-to-part-265","jurisdiction":"us","citation":"40 CFR Appendix V to Part 265","heading":"Appendix V to Part 265—Examples of Potentially Incompatible Waste","body":"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.\nBelow 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.\nThis 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.\nIt 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).\nIn the lists below, the mixing of a Group A material with a Group B material may have the potential consequence as noted.\nGroup 1-A Group 1-B\nAcetylene sludge Acid sludge\nAlkaline caustic liquids Acid and water\nAlkaline cleaner Battery acid\nAlkaline corrosive liquids Chemical cleaners\nAlkaline corrosive battery fluid Electrolyte, acid\nCaustic wastewater Etching acid liquid or solvent\nLime sludge and other corrosive alkalies\nLime wastewater Pickling liquor and other corrosive acids\nLime and water Spent acid\nSpent caustic Spent mixed acid\nSpent sulfuric acid\nPotential consequences: Heat generation; violent reaction.\nGroup 2-A Group 2-B\nAluminum Any waste in Group 1-A or 1-B\nBeryllium\nCalcium\nLithium\nMagnesium\nPotassium\nSodium\nZinc powder\nOther reactive metals and metal hydrides\nPotential consequences: Fire or explosion; generation of flammable hydrogen gas.\nGroup 3-A Group 3-B\nAlcohols Any concentrated waste in Groups 1-A or 1-B\nWater Calcium\nLithium\nMetal hydrides\nPotassium\nSO2 Cl2, SOCl2, PCl3, CH3 SiCl3\nOther water-reactive waste\nPotential consequences: Fire, explosion, or heat generation; generation of flammable or toxic gases.\nGroup 4-A Group 4-B\nAlcohols Concentrated Group 1-A or 1-B wastes\nAldehydes Group 2-A wastes\nHalogenated hydrocarbons\nNitrated hydrocarbons\nUnsaturated hydrocarbons\nOther reactive organic compounds and solvents\nPotential consequences: Fire, explosion, or violent reaction.\nGroup 5-A Group 5-B\nSpent cyanide and sulfide solutions Group 1-B wastes\nPotential consequences: Generation of toxic hydrogen cyanide or hydrogen sulfide gas.\nGroup 6-A Group 6-B\nChlorates Acetic acid and other organic acids\nChlorine Concentrated mineral acids\nChlorites Group 2-A wastes\nChromic acid Group 4-A wastes\nHyphochlorites Other flammable and combustible wastes\nNitrates\nNitric acid, fuming\nPerchlorates\nPermanganates\nPeroxides\nOther strong oxidizers\nPotential consequences: Fire, explosion, or violent reaction.\nSource: “Law, Regulations, and Guidelines for Handling of Hazardous Waste.” California Department of Health, February 1975.","path":["Title 40—Protection of Environment","CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY","SUBCHAPTER I—SOLID WASTES","PART 265—INTERIM STATUS STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-40.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:26:04Z","sha256":"70d90c8171a73dbd8bed8576f7104c1f0fb82cc0f9f717b4e77a67dde83788ed","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-appendix-iv-to-part-265","next":"us/40-cfr-appendix-vi-to-part-265"},"notice":"GroundRules: Original legal text. Not legal advice."}