Proper disposal of chemicals

Most chemicals used by the amateur chemist come from every day use and do not require special treatment before being discarded in the usual way. However there are many chemicals, such as heavy metal compounds or organic solvents, that require special disposal techniques. In the interest of keeping lab costs low, though, it may be a good idea to look into ways to recycle and recover chemicals such as solvents, which can be reclaimed by distillation.

Standard procedures

Acids

Acids should be neutralized with a base, such as carbonate/bicarbonate, hydroxide (calcium hydroxide e.g.) usually as a solution. The soluble salts of halogen acids and oxoacids (except perchloric and chloric acids) can be safely poured down the drain. Special acids and their salts, such as hydrazoic acid and azides must not be poured directly down the drain, they must be treated with nitrous acid to destroy them.

Oxidizing mixtures, such as Aqua regia, piranha solution or mixed acid must also never be poured down the drain, as they're much more dangerous than simple acids, and can wreak havoc on your plumbing. Instead, they must be neutralized first.

Bases

Alkali hydroxides can be left in open air to absorb carbon dioxide as well as corrosive and unpleasant gases, forming carbonates and salts. For quicker results, alkali bases can be neutralized with any acid, though for practical and economical purposes, acetic acid or citric acid are sufficient. Bases may be reused to absorb acidic vapors in a desiccator, which mitigates their dangers. Care must be taken to avoid excess heating with strong bases.

Cyanides

Waste containing cyanide, either from gold refining or from organic extractions of alkaloids from cyanide containing plants, must be neutralized with bleach or hydrogen peroxide, to turn them into less harmful cyanates. Cyanates can be further neutralized to nitrogen and carbon dioxide.

Cyanides must never be poured down the drain.

Heavy metals

Since the biggest hazard comes from the volatile and soluble heavy metal compounds, it's best to convert them into insoluble compounds, which are less toxic.

Heavy metals, such as mercury, can often be neutralized with sulfur, generating mercury(II) sulfide, which is generally insoluble in water and has little reactivity.

Very dangerous heavy metals such as cadmium and arsenic should always be properly disposed of at designated facilities, as their effects on human life and the environment is sometimes catastrophic.

Inorganic anions

Inorganic anions, based on halogens, sulfur, phosphorus, nitrogen, carbon and silicon can be flushed down the drain with lots of water. Examples of these are sulfide, sulfate, chloride, chlorate, nitrate, nitrite, thiocyanate.

Metal ions

A good rule of thumb for transition metals is to convert solutions of their ions to the insoluble carbonate or oxide, often one of the most stable and nontoxic forms of these elements, prior to disposal. Another simple solution is to reduce the ions back to the metal.

Copper salts are dangerous to the environment and should be reduced with iron to elemental copper, that can be reused, and the iron salts produced are less toxic.

Nickel-containing compounds, especially organonickel compounds, are carcinogens, and are also dangerous to many other forms of life. It is a good idea to take these to a proper waste disposal facility.

Cobalt salts may be carcinogenic and should be taken to a proper waste disposal facility.

Aluminium compounds should not be disposed in the sewage. They can, however, be converted to aluminium sulfate, which is safe to dispose of in soil, though it will cause a decrease in pH(it is used as a fertilizer for this purpose). It is a good idea to dispose of aluminium sulfate and a safe basic compound (such as calcium carbonate) at the same time.

Many compounds of chromium, especially chromium(VI), are poisonous and carcinogenic. These should be converted to the +3 oxidation state; hydrogen peroxide as well as sulfites or thiosulfate will do this, which is typically the least harmful, preferably to chromium(III) oxide. Chromium dioxide may be another feasible option, as it is found in cassette tapes and can be recycled with them.

Zinc compounds can be refined to zinc metal using electrowinning. It's not recommended to use zinc compounds as zinc supplemements for soil or livestock, as it may contain traces of cadmium.

Some MSDS sheets recommend that rare earths be converted to their oxalates or carbonates and disposed of in the trash.

Alkali metals are minimally toxic as their salts and may be dumped down the drain.

Organic compounds

Organic solvents should be dumped in labeled waste tanks, such as: halogenated, non-halogenated solvents. Flammable organic solvents that safe in low exposures such as ethanol, methanol, and acetone can often simply be burned outside for disposal, as most often their combustion products are simply carbon dioxide and water. It may be a better idea just to recover them by distillation, though.

A good way to destroy halogentated and aromatic compounds is with Fenton's reagent, which breaks them down to simpler non-toxic compounds. It's best however, to avoid dumping large quantities of waste, as the reaction in exothermic and may splash or volatilize some of the waste, so it's best to perform the neutralization in small steps.

Organic salts, such as acetates and oxalates can be pyrolyzed to carbonates and water vapors.

Recycling

Main article: Reagent recycling

Sometimes it is an option to purify waste products into chemicals that are pure enough to be used again. While this can sometimes be time consuming, it can often be more environmentally and economically friendly than discarding the waste in one manner or another is. Before discarding waste, think about what all it contains, and if there is some way that it could be used.

Down the drain vs. into the soil

The availability of these disposal methods varies depending on where you live. If you live in an apartment block, you only have the drain. If you live in a suburban house, you have both. If you live in some quaint rustic shithole like the author of this edit, you only have the "into the soil" option.

Generally, the soil option is safer, because there is no plumbing you should worry about, but some chemicals shouldn't be released into the soil, either. In general, your designated place for pouring chemicals into the soil should be far from any gardens, horticulture or any other agricultural objects. But chemicals marked as "Oh yes!" in the table are harmless and even useful in agriculture as fertilizers. These you can pour down in your garden.

Lists of various chemical compounds that can be safely released in the ground or down the drain can be found here, here or here.

Other

Heavy metal salts or solutions can be mixed with cement, and trapped in the resulted concrete block. The resulting block can also be covered in another layer of cement, to reduce the diffusion of the heavy metals. Unless the resulting concrete is damaged, broken and dissolved in acid, the heavy metal ions will not be released. However, this merely is a method to prevent the heavy metals from being released in the environment, and is not a permanent way of disposal.

Chemical disposal table

Substance	Neutralization	Heat treatment	Down the drain	Into the soil	Environmental considerations
1,2-Dichloroethane	Oxidation with Fenton's reagent; Concentrated solution of sodium hydroxide	Flammable, releases corrosive fumes	DO NOT DUMP	DO NOT DUMP	Toxic to wildlife
1,4-Dioxane	Incineration; Oxidation with Fenton's reagent; Chlorination in water with chlorine or hypochlorous acid	Incineration produces carbon dioxide and water vapor	DO NOT DUMP	DO NOT DUMP	Although small amounts can be diluted with large amounts of water and poured dowb the drain, 1,4-dioxane does not undergo significant biodegradation and most will end up in the environment.
2-nitrotoluene	Oxidation with Fenton's reagent	Generates oxidation products and lots of soot	DO NOT DUMP	DO NOT DUMP	Toxic to all wildlife
2,2,4-Trimethylpentane	Incineration	Generates carbon oxides, water vapor and soot	DO NOT DUMP	DO NOT DUMP	Toxic to wildlife and dangerous for water bodies as it floats
2,4-Dinitrobromobenzene	Oxidation with Fenton's reagent	Generates carbon oxides, water vapor, soot and bromine vapors	DO NOT DUMP	DO NOT DUMP	Toxic to all wildlife
Acetaldehyde	Incineration; Sodium pyrosulfite; L-cysteine	Generates carbon oxides and water vapors; some will evaporate when heated	DO NOT DUMP	DO NOT DUMP	Toxic to the wildlife
Acetic acid	Bicarbonates, carbonates, bases, oxides	Flammable (high concentrations), no dangerous combustion products	Yes	Yes	Safe, biodegradable; avoid dumping large amounts, acidifies soil
Acetic anhydride	Bicarbonates, carbonates, bases, oxides	Flammable, no dangerous combustion products	Yes	Yes	Biodegradable; avoid dumping large amounts, acidifies soil
Acetone	Oxidation/incineration, reducing, photolysis	Flammable, no dangerous combustion products	Not advised	Yes	Biodegradable, though not advised for large amounts
Acetone peroxide	Photolysis, detonation in safe area	Explosive, not recommended	Not advised	Not advised	Biodegradable, though not advised
Acetonitrile	Fenton's reagent; Aqueous solution of excess sodium hydroxide	All treatments give some hydrogen cyanide fumes	DO NOT DUMP	DO NOT DUMP	Toxic to all life due to its cyanide/nitrile group; does not quickly break down in environment
Acetylene	Oxidation, photolysis	Dangerously flammable	Not possible	Not possible	Safe, biodegradable
Acetylsalicylic acid	Any base	Not particularly helpful	Yes	Yes	Safe, biodegradable
Alpha-pinene	Not required	Generates smoke, carbon dioxide and water vapor	Yes	Yes	Safe, biodegradable; Occurs naturally
Aluminium chloride	Treatment with water, precipitation with a base	No effect; Water solutions however will give off hydrogen chloride vapors	Not advised	Yes	Lowers the soil pH, corrosive
Aluminium nitrate	Pyrolysis; Aqueous ammonia or alkaline hydroxide solution	Gives off nitrogen oxide fumes	DO NOT DUMP	Not recommended	Lowers soil pH, corrosive
Aluminium sulfate	Any alkaline hydroxide	Releases sulfur oxides at high temperature	Dilute it first; neutralization with a base first is recommended	No	Increases the aluminium concentration in soil and water, lowers pH
Aluminium sulfide	Hydrogen peroxide, bleach	No	NO	NO	Releases hydrogen sulfide on contact with water, which is toxic to organisms
Ammonia	Oxidation, neutralization with acids	At high concentrations may generate nitrogen oxides	Not possible (gaseous), safe to pour (as solution)	Not possible (gaseous), safe to pour (as solution); Good nitrogen source for plants	Biodegradable
Ammonium acetate	Unnecessary	Releases acetonitrile fumes	Yes	Yes	Safe, biodegradable
Ammonium bicarbonate	Pyrolysis, hydroxides, acids	Decomposes on heating releasing carbon dioxide, ammonia fumes and water vapors	Yes	Oh yes!	Safe, good fertilizer (nitrogen source)
Ammonium nitrate	Pyrolysis, hydroxides, carbonates	Emits nitrous oxide, may explode if the temperature is too high	Yes	Oh yes!	Safe, good fertilizer (nitrogen source); May cause algal bloom in water bodies however
Anthocyanin	Not necessary	Gives off carbon oxides and water vapor	Yes	Yes	Safe, biodegradable; Occurs naturally
Asbestos	Pyrolysis; Oxalic acid and ultrasounds	At temperatures over 1000 °C it turns into harmless silicate glass	DO NOT DUMP	DO NOT DUMP	Toxic to animals via inhalation
Ascorbic acid	Unnecessary	Releases carbon oxides and water vapor	Yes	Yes	Safe, biodegradable; Occurs naturally
Barium chlorate	Reduction with a reducing agent, such as sodium bisulfite, sodium metabisulfite, sodium sulfite	Disproportionates into perchlorate and chloride when alone; Burns when mixed with a flammable material	No	No	Toxic for environment
Barium ferrate	Sulfuric acid	Breaks down to barium and iron oxides, which require further disposal	No	No	Dangerous to wildlife in short term (oxidizer); Releases toxic barium ions in environment
Barium manganate	Sulfuric acid	Breaks down into barium and manganese oxides	Not advised	No	Toxic to wildlife in short term (oxidizer); Will release toxic barium ions in the environment
Basic lead chromate	May be converted to lead(II) carbonate; should be taken to disposal centers	Not useful	DO NOT DUMP	DO NOT DUMP	Toxic to environment due to lead and Cr(VI) content
Benzene	Oxidation with Fenton's reagent; Incineration with afterburner incinerators	Generates dangerous combustion products	DO NOT DUMP	DO NOT DUMP	Avoid releasing in environment
Bis(ethylenediamine)copper(II) perchlorate	Crystallize and ignite safely	Detonates	DO NOT DUMP	No	Copper kills aquatic life and plant roots
Bismuth trioxide	Reduced to bismuth metal	Will oxidize anything (yes, platinum too) when molten	DO NOT DUMP	DO NOT DUMP	May become hazardous for the environment in large quantities
Boric acid	Not required	Will dehydrate it to boron trioxide	In small quantities	In small quantities	Dangerous to small animals
Boron trioxide	Not required	Not useful; may volatilize at high temperatures	In small quantities	In small quantities	Dangerous to small animals
Butane	Incineration	Will burn to release carbon dioxide and water vapors	Not possible	Yes (heavier than air)	May induce greenhouse effect
Butanol	Incineration	Will burn to release carbon dioxide and water vapors	Not recommended	Not recommended	Poses toxicity to wildlife, water bodies
Butyl acetate	Incineration	Will burn to release carbon dioxide and water vapors	Not recommended	Not recommended	Poses toxicity to wildlife, water bodies
Caesium hydroxide	Neutralization with any acid, carbon dioxide	Not useful; highly corrosive when hot to glass, most common metals	Yes, though best to recycle it	Yes	Dangerous to wildlife in short term (highly corrosive); Caesium ions have similar toxicity to those of sodium and potasium
Calcium acetate	Pyrolysis; Not always required	Decomposes to calcium carbonate and acetone at high temperature, which burns in an oxygen-rich atmosphere	Yes	Yes	Biodegradable
Calcium carbide	Lots of water; low chain alcohols	Not useful	DO NOT DUMP	DO NOT DUMP	Dangerous to wildlife in short term (reacts with water); may also release phosphine gas if carbide sample is impure
Calcium carbonate	Any acid; not always required	Not useful; breaks down into calcium oxide and carbon dioxide at high temperatures	Yes, as powder	Yes	Safe, biodegradable; occurs naturally
Calcium chloride	Not required; Any soluble carbonate	Not useful; May release some HCl fumes if wet	Yes	Yes	Chloride ions may be harmful to certain plants
Calcium fluoride	Not required	Unnecessary	Not useful	Yes	Safe to environment, occurs naturally
Calcium gluconate	Not required	Will result in calcium carbonate and give off carbon dioxide and water vapors at high temperatures	Yes	Yes	Not dangerous to wildlife
Calcium hydroxide	Any acid	Will dehydrate to calcium oxide at high temperatures	Yes	No	Will "burn" grassland on contact
Calcium hypochlorite	Sodium bisulfite, sodium metabisulfite, sodium sulfite	Disproportionates into chlorate and chloride; will release chlorine and chlorine dioxide fumes	Yes	DO NOT DUMP	Toxic to all wildlife
Calcium nitrate	Not required; soluble carbonate or sulfate solution can be used if necessary	Not useful	Yes	OH YES	Good source of nitrogen for plants (fertilizer); May cause algal bloom in water bodies
Calcium oxide	Plenty of cold water, carbon dioxide, sodium/potassium bicarbonate	No	Do not dump	Do not dump	Burns grass on contact
Calcium perchlorate	Mixing it with a combustible material, like sugar and incineration	Will decompose at high temperatures to release oxygen	Do not dump	Do not dump	Toxic to plants
Calcium sulfate	Not rquired; soluble carbonate solution can be used if gypsum is not desired as waste product	Becomes anhydrous at high temperatures (drierite); decomposes to calcium oxide at very high temperatures	Yes, with lots and lots of water	Yes	Anhydrous or hemihydrate form may burn grass on contact
Carbon dioxide	Not required; Alkali hydroxides	Not necessary	Not possible (gaseous form), safe to pour (water solution)	Not possible (gaseous form), safe to pour (water solution)	Contributes to global warming
Carbon disulfide	Incineration, followed by scrubbing of sulfur dioxide (optional)	Burns in presence of oxygen, releasing carbon dioxide and sulfur dioxide	DO NOT DUMP	DO NOT DUMP	Toxic to wildlife
Carbon monoxide	Oxidation with ozone; adsorbtion on activated charcoal; absorbtion in a solution of cuprous chloride in hydrochloric acid or cuprous chloride in ammonia	Not useful; burns in the presence of oxygen and hydrogen	Not possible	Not possible	Toxic to animals
Carbon tetrachloride	Sodium hydroxide excess; oxidation with Fenton's reagent	Results in phosgene in the presence of air	DO NOT DUMP	DO NOT DUMP	Extremely toxic to wildlife, sinks at the bottom of water bodies
Carbonic acid	Any base	Releases carbon dioxide fumes	Yes	Yes	Toxic to aquatic life in large quantities
Charcoal	Burning, dumping in ground	Results in carbon dioxide and ash	DO NOT DUMP	OH YES!	Unless it adsorbed dangerous volatile compounds or heavy metals, it can be used as a fertilizer
Chevreul's salt	Oxidation with hydrogen peroxide to sulfate, followed by precipitation or reduction of copper ions to metal or hydroxide/oxide	Gives off water vapors when heated and sulfur oxides at very high temperatures	Not recommended	Not recommended	Little is known about its environmental effect; it is used as a fungicide and molluscicide
Chloric acid	Reducing with sodium sulfite, metabisulfite, bisulfite	Breaks down to perchloric acid and chlorine oxides	DO NOT DUMP	DO NOT DUMP	Strong oxidizing, toxic and corrosive to all wildlife and everything organic
Chloroauric acid	Reduction with a reducing agent, such as ascorbic acid, metabisulfite, sulfur dioxide	Gives off hydrogen chloride gases and leaves gold powder behind	DO NOT DUMP	DO NOT DUMP	Dangerous to wildlife; Best to try to recycle it
Chlorobutanol	Reducing with alkali hydroxide or magnesium, followed by incineration	Gives off hydrogen chloride fumes during burning/pyrolysis	Not recommended	Not recommended	Toxic to wildlife
Chloroform	Destruction with aqueous sodium hydroxide, which can be aided by methanol or acetone; Oxidation with Fenton's reagent	Boils to form vapor, should not be attempted indoors	DO NOT DUMP	DO NOT DUMP	May cause ozone depletion, dangerous to aquatic life
Chromium(III) oxide	Not required; can be dumped in the trash	Not useful	Do not dump	Not recommended	Low reactivity, low danger for environment
Chromium(III) sulfate	Precipitation with a soluble hydroxide, followed by calcination to chromium(III) oxide	Not useful	Do not dump	Do not dump	Dangerous to wildlife in large amounts
Citric acid	Any base, carbonate, bicarbonate, alkaline-earth oxide	Gives off carbon dioxide and water vapors	Yes	Yes	In wet environment it acts as fungi growth environment
Cobalt(II) chloride	Any soluble hydroxide, carbonate	May give off hydrogen chloride fumes in the presence of water	DO NOT DUMP	DO NOT DUMP	Toxic to wildlife; classified as "Substance of very high concern" in the EU
Cobalt (III) oxide	Not required	Not useful	Do not dump	Do not dump	Cobalt is necessary for vitamin B12 production
Copper(I) chloride	Oxidizing with air/oxygen or H2O2 to the more soluble CuCl2, followed by reduction to metallic copper with iron or zinc.	May hydrolyze in the presence of water and air to give off hydrogen chloride fumes	DO NOT DUMP	DO NOT DUMP	Oxidizes to copper(II) chloride in the presence of air, which is toxic and corrosive in water
Copper(II) acetylsalicylate	Pyrolysis, incineration, oxidation with Fenton's reagent	Gives off carbon oxides and water vapors, as well as soot and VOCs	Not recommended	Not recommended	Unknown effects in the environment; presence of copper ions however is generally considered harmful
Copper(II) carbonate	Not required; can be neutralized with an acid and reduced to metallic copper	Will give off carbon dioxide fumes and leave CuO residues	Do not dump	DO NOT DUMP	Copper ions are considere harmful to the environment
Copper(II) chloride	Precipitate as carbonate or reduce to copper metal using aluminium, iorn or zinc	Loses water and hydrogen chloride, turns brown	DO NOT DUMP	Yes, but far from any agricultural plants	Kills aquatic life and plant roots
Copper(II) hydroxide	Reduction to metallic copper	Loses water, yielding CuO	Do not dump	Only as agricultural product	Copper ions are considered harmful to most wildlife
Copper(II) nitrate	Any alkali or ammonium hydroxide, carbonate	Gives off nitrogen oxide and nitric acid fumes, leaving copper oxides/hydroxides slag	DO NOT DUMP	DO NOT DUMP	Copper ions may be harmful to wildlife; the nitrate group is a nitrogen source for plants
Copper(II) oxide	Dissolving it in an acid, followed by reduction to metallic copper	Not useful	DO NOT DUMP	DO NOT DUMP	Generally considered harmful to wildlife
Copper oxychloride	Reduction with a iron or zinc to metallic copper	Gives off HCl fumes and leaves behind CuO slag	DO NOT DUMP	DO NOT DUMP	Generally toxic to wildlife
Copper(II) phosphate	Not always required	May decompose to copper oxide and phosphorus oxides at high temperatures, or elemental phosphorus in the presence of a reducing agent	Not recommended	Not recommended	Due to low solubility, it has lower toxicity than other copper compounds
Copper(II) sulfate	Reduction with aluminium, iron or zinc to metallic copper	Loses water when heated, releases sulfur trioxide at high temperatures, leaving behind CuO	Not recommended	Only as agricultural product	Shows toxicity to pests, wildlife
Copper chromite	Not always required	Not useful	Not recommended	Not recommended	Unknown environmental effects
Curcumin	Not required	Releases carbon oxides and water vapors, as well as soot	Yes	Yes	Safe, biodegradable; occurs naturally
Cyclohexane	Incineration; oxidation with Fenton's reagent	Flammable, burns in the presence of oxygen to release carbon oxides, water vapors, soot and VOCs	DO NOT DUMP	DO NOT DUMP	Toxic to wildlife
Dichloromethane	Destruction with aqueous sodium hydroxide, iron can also be used; Oxidation with Fenton's reagent	Boils to form vapor; pyrolysis at high temperatures yielding chlorine, hydrochloric acid and carbon monoxide	DO NOT DUMP	DO NOT DUMP	May cause ozone depletion, dangerous to aquatic life
Diethyl ether
Diisopropyl ether
Dimethyl sulfoxide
Dimethylformamide
Dipicolinic acid
Disulfur dichloride
Erythritol	Not required	Yields carbon oxides, water vapor	Yes	Yes	Low toxicity
Ethane
Ethanol	Not required	Yields carbon oxides, water vapor	Yes	Not recommended	Deadly to small animals on direct contact, dangerous to aquatic and soil life
Ethyl acetate	Sodium hydroxide	Combustion in the presence of air	Do not dump	Do not dump	Toxic to aquatic life
Ethylene glycol
Ethylene glycol dinitrate
Ethylenediamine
Formaldehyde
Formic acid	Sodium hydroxide	Gives off carbon monoxide and water vapors	DO NOT DUMP	DO NOT DUMP	Deadly to insects and aquatic life; reason why it's used to kill varroa
Furfural‎	Incineration	Gives off carbon oxides and water vapor	Debatable	Debatable
Glycerol
Hematein
Heptane
Hexamethylene triperoxide diamine	Adding a mixture of zinc sulfate, copper(II) chloride with Zn and Cu powder in a 5:5:1 ratio to the peroxide solution, in the presence of small amounts of sulfuric acid	Do not use heat, as it will lead to detonation	DO NOT DUMP	Debatable
Hexamine		Burning in an oxygen atmosphere yields carbon oxides, water vapor, nitrogen; Pyrolysis generates formaldehyde, carbon oxides, ammonia and nitrogen fumes; at temperatures >800°C also yields hydrogen cyanide	Yes	Yes
Hexane
Holmium citrate
Hydrazine
Hydrazine sulfate
Hydrazoic acid	Sodium nitrite or nitrous acid	Will lead to detonation for concentrated solutions	DO NOT DUMP	DO NOT DUMP	Dangerous to wildlife
Hydrobromic acid
Hydrochloric acid	Any alkali or alkaline-earth carbonate, bicarbonate	DON'T! Results in acidic vapors, extremely dangerous and corrosive	NO! Neutralize first	NO!	Toxic to wildlife and corrosive to minerals
Hydrofluoric acid
Hydrogen chloride	Any base, carbonate, bicarbonate; for gaseous form, ammonia can be used, though will result in a dense ammonium chloride mist	No	No	Do not dump	Corrosive for rocks, toxic for all wildlife
Hydrogen iodide
Hydrogen peroxide	Manganese dioxide, iron(III) oxide	Except for very concentrated solutions	Not for concentrated solutions	DO NOT DUMP	Deadly for microbial life, extremely toxic for small animals
Hydrogen sulfide
Hydroiodic acid
Iron(II) sulfate
Iron(II,III) oxide
Iron(III) chloride	Calcium hydroxide	Gives off hydrogen chloride fumes	DO NOT DUMP	DO NOT DUMP	Extremely toxic to wildlife
Iron(III) oxide
Iron(III) sulfate
Isobutanol
Isopropanol
Isopropyl nitrite
Lead(II) acetate	Alkali carbonate or hydroxide; Lead precipitate should be taken to disposal facilities	Results in lead oxides; Yields carbon oxides, water vapors	DO NOT DUMP!	DO NOT DUMP!
Lead(II) chromate
Lead(II) nitrate
Lead(II) oxide
Lead(II,IV) oxide
Lead(IV) acetate
Limonene
Lithium aluminium hydride
Lithium chloride
Lithium hydroxide
Magnesium chloride	Not required	Hydrated form gives the oxychloride salt	Yes	Yes	May increase the magnesium and chloride content in the soil significantly
Magnesium sulfate
Manganese dioxide
Manganese heptoxide
Methane
Methanol
Methyl ethyl ketone
Methyl formate
Methyl nitrate	Alkali solution, recommended to be cooled	Will lead to explosion	No	No	Dangerous to wildlife
Methyl salicylate
Methyl tert-butyl ether
Mineral oil		Will burn at high temperatures, releasing carbon oxides, water vapors and soot	No	No	Oils float on water bodies and inhibit the cellular breathing of many organisms
Naphthalene
Neodymium oxalate
Nicotine
Nitric acid
Nitrocellulose
Nitrogen dioxide	Bubbling through an alkali solution, peroxide solution	Not useful	Not possible	No	Will react with atmospheric moisture to generate nitric acid and contributes to the acid rain; extremely toxic to animals and plants
Nitrogen trichloride
Nitrogen triiodide	Sodium thiosulfate	Leads to detonation	DO NOT DUMP	DO NOT DUMP
Nitroglycerin
Nitromethane
Nitrous oxide
Octyl acetate
Oxalic acid	Calcium oxide, hydroxide, carbonate	Releases carbon oxides and water vapor at high temperature	Yes	No	Toxic to wildlife
Ozone	Any compound easily oxidizable that does not ignite, such as carbon monoxide, activated charcoal	Aceelerates the decomposition of ozone, but not enough	Not possible	No	Dangerous to wildlife, may oxidize various gaseous compounds, contributing to the acid rain
Pentaerythritol
Pentane	Burning	Flammable, releases carbon oxides, water vapor when burned in air	NO	NO	Dangerous to wildlife
Perchloric acid
Permanganic acid	Hydrogen peroxide	Leads to decomposition	Do not dump	Do not dump	The resulting manganese dioxide from the decomposition can be toxic if ingested by animals
Peroxymonosulfuric acid
Petroleum ether
Phenol
Phosgene	Alkaline metal hydroxide, ammonia	No	DO NOT DUMP	DO NOT DUMP	Extremely toxic for all organisms
Phosphoric acid	Any metal oxide, hydroxide, carbonate	Not very useful	Yes, if it's diluted	Neutralize it first, good source of phosphorus, unless contaminated	Deadly to small animals; excess in water bodies may cause algal bloom
Phosphorus pentoxide‎‎	Alkaline solution, lots of water	Will volatilize at very high temperatures	No, reaction with water is highly exothermic and may generate acidic steam	Neutralize first	Corrosive and dangerous on direct contact with wilflife; Reaction with water will lead to phosphoric acid, highly corrosive and dangerous.
Picric acid
Polytetrafluoroethylene	Not required; Can simply be dumped in trash	Generates toxic fluorine, hydrogen fluoride, fluorocarbons and carbon oxide vapors	DO NOT DUMP	DO NOT DUMP	Resistent to most corrosive chemicals, cannot be digested by wildlife
Potassium antimony tartrate
Potassium bromide
Potassium carbonate	Any acid will do	No	Yes	OH YES	Excess may increase the soil level of potassium in the dumping area
Potassium chlorate
Potassium chloride
Potassium dichromate
Potassium ferrate	Any acid, hot water	Breaks down to iron(III) oxide and potassium hydroxide, best in the presence of moisture	Yes, but recommended to neutralize first	Yes, but recommended to neutralize first	Dangerous to wildlife in short term
Potassium hydroxide	Any acid, carbon dioxide	Not useful	Yes	Neutralize first; neutralized is a good source of potassium for plants	Dangerous to wildlife in short term
Potassium iodide
Potassium manganate
Potassium metabisulfite
Potassium nitrate	Not required	Gives off nitrogen oxides at very high temperatures; burns in presence of organic compounds, releasing carbon oxides, nitrogen and leaving behind alkaline slag	Yes	OH YES	Excellent fertilizer, though may lead to uncontrolled algae growth if dumped in water bodies
Potassium perchlorate
Potassium permanganate	Hydrogen peroxide	Decomposes to manganese dioxide at high temperatures	DO NOT DUMP	DO NOT DUMP	The resulting manganese dioxide from the decomposition can be toxic if ingested by animals
Potassium peroxymonosulfate	Alkaline solution, sodium carbonate	Decomposes, releasing oxygen	Recommended be neutralized first	Must be neutralized first	Dangerous to the environment in short term
Potassium sulfate
Propane
Propylene carbonate
Propylene glycol	Not required	Generates carbon oxides and water vapor, as well as other toxic pyrolysis compounds	Yes	Yes	Little toxic effect on aquatic wildlife
Prussian blue
Pyranine
Pyridine
Rosocyanine
Safrole
Salicylic acid
Schweizer's reagent
Silicon dioxide	Not required	At high temperatures results in melting; Can be used to indurate crystalline silica	Not recommended, may clog the plumbing	Yes	Finely divided silica is dangerous for fauna
Silver nitrate
Sodium acetate
Sodium acetylsalicylate
Sodium azide	Sodium nitrite, nitrous acid	Breaks down in sodium metal and nitrogen gas	DO NOT DUMP	DO NOT DUMP	Very toxic for wildlife
Sodium benzoate
Sodium bicarbonate
Sodium bisulfate	Any base, carbonate, bicarbonate	No	Yes	Do not dump	Decreases the soil pH
Sodium carbonate
Sodium chloride	Not required	Not useful	Yes	No	Toxic to plants due to sodium ions
Sodium ferrate	Diluted organic solutions will reduce it to its constituent oxides	Breaks down to its constituent oxides, both dry and as solution	Yes	Not recommended due to its sodium content	Dangerous to organisms due to its strong oxidizing properties
Sodium hydroxide	Any acid, carbon dioxide	Not useful	Yes	Do not dump	Dangerous to wildlife in short term; toxic to plants due to sodium ions
Sodium hypochlorite
Sodium metabisulfite
Sodium nitrate
Sodium perchlorate
Sodium peroxide
Sodium silicate	Any acid	Not useful	Not recommended	Only in places without plant or animal life (construction sites, quarries, etc.)	Sodium ions are toxic to plant roots
Sodium sulfate
Sodium thiosulfate	Bleach	No	Yes	Yes	Breaks down rapidly in the environment due to air and microorganisms, yielding sulfides and sulfates.
Sorbitol	Not needed	Releases carbon dioxide and water vapor	Yes	Yes	None
Strontium carbonate
Strontium oxide
Sucrose	Not always required	Turns into caramel if gently heated and soot at high temperatures	Yes	Yes	Source of food for many small animals
Sulfur dichloride
Sulfur dioxide
Sulfur trioxide
Sulfur hexafluoride	Not required	May lead to sulfur dioxides and fluorine at very high temperatures	Not possible	Yes	Strong greenhouse effect
Sulfuric acid
Terbium(III) oxide	Unnecessary, simply dump in trash	Releases absorbed water or carbon dioxide	Unnecessary		Effects unknown, may stimulate plant growth
Terbium sulfate
Tetraamine copper(II) complex
Tetraaminecopper(II) persulphate
Tetrachlorocupric acid
Tetrahydrofuran
Tin(IV) chloride
Titanium dioxide	Not required; Can be dumped in trash	Leads to fusing in the presence of alkaline and alkaline-earth oxides and hydroxides	Yes, but not recommended	Yes, but recommended	May lead to staining water bodies and soil in a white color
Toluene
Trichloroethylene
Trichloroisocyanuric acid
Trimethyl borate
Tris(ethylenediamine)nickel perchlorate
Tungsten carbide
Urea	Not required	Generates carbon oxides, nitrogen fumes; May corrode metal container, if done in one	Yes	OH YES	May cause uncontrolled algae growth in water bodies
Vanadium pentoxide
Water	Not required	Leads to steam	YES	YES	It's...water
Xylene
Xylitol	Not required	Melts when heated; not useful	Yes	Yes	Cannot be digested by most lifeforms
Zinc carbonate
Zinc chloride
Zinc chromate
Zinc oxide	Not required; Weak acids can be used to dissolve zinc oxide stains to soluble zinc compounds	Turns the oxide yellow at high temperatures; process is reversible	Not recommended	Yes, but not recommended	May pose a threat to aquatic life
Zinc peroxide
Zinc phosphate	Not required	Not useful	No	Yes	Source of zinc and phosphorus for wildlife
Zinc sulfate
Zinc sulfide

References

Relevant Sciencemadness threads

• Lab Waste Disposal
• Waste disposal
• Safe disposal/handling of lead in a domestic setting