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Segregation of Waste Chemicals

The proper segregation of waste chemicals is essential to promote safe storage of those chemicals as well as to facilitate the economical disposal of the chemicals. The Environmental Protection Agency (EPA) has published a list of potentially incompatible wastes, waste components, and material along with the harmful consequences of mixing those materials together. This list does not include every possible hazardous chemical reaction, but should be used as a guide in packaging and storing these materials. The list indicates the potential consequences of the mixing of a Group A material with a Group B material. These compatibility listings should not be the only information used when packaging or accumulating waste chemicals. Pay close attention to any waste characterization data you receive on material reactivity and compatibility. Material Safety Data Sheets contain a section devoted to chemical reactivity and incompatibility. The following lists of chemicals in Groups A should be kept separate from those chemicals in Groups B:

Group 1-A Group 1-B

Bases

Potential consequences:  Heat generation; violent reaction

Acids

Group 2-A Group 2-B

Aluminum

Beryllium

Calcium

Lithium

Magnesium

Potassium

Sodium

Zinc powder

Other reactive metals and metal hydrides

Potential consequences: Fire, Explosion, or generation of flammable hydrogen gas.

Any Acid or Bases

Group 3-A Group 3-B

Alcohols

Water

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

Any Concentrated Acids or Bases

Calcium

Lithium

Magnesium

Sodium

Zinc Powder

Any Reactive Metals and Metal Hydrides

Potassium

Sulfonyl chloride

Thionyl chloride

Phosphorus trichloride

Methyl trichloride

Methyl trichlorosilane

Other water-reactive waste

Group 4-A Group 4-B

Alcohols

Aldehydes

Halogenated hydrocarbons

Nitrated hydrocarbons

Unsaturated hydrocarbons

Other organic compounds and solvents

Potential consequences:  Fire, Explosion, or violent reaction.

Any Concentrated Acids or Basses

Reactive Metals and Metal Hydrides

Group 5-A Group 5-B

Cyanides and sulfides

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

Any Acids

Group 6-A Group 6-B

Chlorates

Chlorine

Chlorites

chromic acid

Hypochlorites

Nitrates

Nitric acid, fuming

Perchlorates

Permanganates

Peroxides

Other strong oxidizers

Potential consequences:  Fire, Explosion, or violent reaction.

Acetic acid and other organic acids

Concentrated mineral acids

Reactive Metals and Metal Hydrides

Organic Compounds and Solvents

Other flammable and combustible chemicals

The following two groups are added to facilitate the economical disposal of the wastes.  They are not necessarily reactive.

Group 7-A Group 7-B

Heavy metal Compounds containing arsenic, barium, cadmium, chromium, lead, selenium, silver

Polychlorinated biphenyls (PCBs) Dioxins

Mercury Containing Compounds

Flammable Liquids

Group 8-A Group 8-B

Polychlorinated biphenyls (PCBs)

Dioxins

Mercury Containing Compounds

All other chemicals and each other