Proper disposal of chemicals
From Sciencemadness Wiki
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.
Contents
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 the nitrating mixture 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 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.[1]
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.
Halogenated compounds like chloroform can be neutralized with a strong base.
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. Many methods described in literature involve slowly bubbling the organic compound with a carrier gas in the Fenton solution, as this increases oxidation and limits splashing. However, because only small amounts of compound gets neutralized at a time, this process takes a while.
Chromic acid and it's derivatives can also be used to destroy hazardous chemical compounds, as it neutralizes them to carbon dioxide and water. However, chromic acid will oxidize alcohols to their respective aldehydes or ketones, which limits it's use in neutralizing most compounds.
Piranha solution is an excellent material for the disposal of organic compounds. The decomposition is highly exothermic and the resulting smoke is very dangerous. As such, this method is generally considered a last resort in disposal, and it's mostly used for cleaning rather than disposal.
Organic salts, such as acetates and oxalates can be pyrolyzed to carbonates and water vapors. The decomposition works best in oxygen-rich atmosphere.
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 paradise 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. Chemicals marked as "Oh yes!" in the table below 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 by making a concrete block. The resulting block can also be covered in another layer of cement, to reduce the diffusion of the heavy metals. Unless the concrete is damaged, broken or 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.
Legal considerations
Releasing hazardous chemicals in the environment is a crime in all jurisdictions and carries heavy fines or even jail time. While properly neutralized reagents may be poured down the drain, dumping very large amounts of said reagents is frowned upon. Incineration is attractive as it's a good method of getting rid of wastes, but unless you're using an incinerator, some material will not be destroyed and instead it will be scattered in air.
Always check the local laws before choosing the disposal method.
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 |
| 1,2,4-Butanetriol trinitrate | Safe detonation in remote area; Strong dilution in organic solvent followed by safe incineration; Hydrolysis with cold sodium hydroxide solution | Detonation above 230 °C | DO NOT DUMP | DO NOT DUMP | Toxic to organisms; nitrate source for plants |
| 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 down the drain, 1,4-dioxane does not undergo significant biodegradation and most will end up in the environment.[2] |
| 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[3] | 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 |
| Activated carbon | Burning, dumping in ground; Desorption by heating it to high temperature and reuse | 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 (powdered form); Less effective as beads or pellets |
| 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 oxide | Not always required, can be dumped in trash | Not useful | Do not dump, may clog plumbing | Yes, but avoid dumping large amounts | Increases level of aluminium in soil, toxic to animals in large quantities |
| 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 azide | Sodium nitrite, nitrous acid | Slowly volatilizes and explodes at 400 °C releasing nitrogen, hydrogen and ammonia gasses | DO NOT DUMP | DO NOT DUMP | Very toxic for wildlife |
| 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 carbonate | Pyrolysis, hydroxides, acids | Decomposes on heating releasing carbon dioxide, ammonia fumes and water vapors | Yes | Oh yes! | Safe, good fertilizer (nitrogen source) |
| Ammonium chloride | Soluble sulfate salts, base + other acid | Decomposes on heating releasing ammonia and hydrogen chloride | Yes | Yes | Safe, good fertilizer (nitrogen source); May prove unsuitable to chloride sensitive plants |
| Ammonium dihydrogen phosphate | Not required; Slaked lime can be used to precipitate calcium phosphate | Decomposes on heating to release ammonia | Yes | Yes | Safe, good fertilizer (nitrogen and phosphorus source) |
| Ammonium formate | Alkali hydroxide, carbonate, sulfate; heating in the presence of a base | Decomposes on heating to release ammonia, carbon monoxide, hydrogen cyanide and water | Yes, if diluted | Yes, if diluted | Dangerous to wildlife in large amounts |
| 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 |
| Ammonium oxalate | Alkali hydroxide, carbonate, sulfate; pyrolysis in the presence of a base | Decomposes on heating to release ammonia, carbon monoxide, oximide, hydrogen cyanide and water vapors | Yes, if diluted | Yes, if diluted | May pose a threat to wildlife in large amounts; Occurs naturally in guano |
| Ammonium permanganate | Dissolution in water, followed by reduction with sulfur dioxide or sodium sulfite, thiosulfate or metabisulfite | Detonates above 60-110 °C, releasing nitrogen, water vapors and a smoke of manganese dioxide | DO NOT DUMP | DO NOT DUMP | Strong oxidizer and explosive, hazardous for wildlife |
| Ammonium persulfate | Pyrolysis, hydrolysis, various reducing agents | Decomposes at 120 °C releasing sulfur and nitrogen oxides, oxygen and ammonia | DO NOT DUMP | DO NOT DUMP | Strong oxidizer, hazardous for wildlife |
| Ammonium sulfate | Not required; Calcium hydroxide can be used to precipitate calcium sulfate | Decomposes on heating to release ammonia, sulfur dioxide, sulfuric acid vapors | Yes | Yes | Safe, good fertilizer (nitrogen and sulfur source); slightly lowers the soil pH |
| Ammonium sulfide | Hydrogen peroxide; hot sulfur dioxide | Decomposes releasing hydrogen sulfide and ammonia | DO NOT DUMP | DO NOT DUMP | Extremely toxic for wildlife; Dangerous for the environment (DSD) |
| Aniline | Oxidation with Fenton's reagent | Gives off carbon oxides, soot, nitrogen and or nitrogen oxides and water vapor | DO NOT DUMP | DO NOT DUMP | Toxic to most wildlife |
| Anthocyanin | Not necessary | Gives off carbon oxides and water vapor | Yes | Yes | Safe, biodegradable; Occurs naturally |
| Anthraquinone | Mixed with a more flammable solvent and safely incinerated; Controlled oxidation with Fenton's reagent | Decomposes at very high temperatures to yield carbon oxides, water vapor, soot, VOCs, etc. | DO NOT DUMP | DO NOT DUMP | Occurs naturally; effects on the environment unknown |
| Asbestos | Pyrolysis; Oxalic acid and ultrasounds[4] | 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 carbonate | Sulfuric acid; Resulting BaSO4 can be dumped in trash | At very high temperatures decomposed to barium oxide and releases carbon dioxide | Not advised | Not advised | May react with acid rain to release soluble barium ions; Occurs naturally |
| Barium chlorate | Reduction with a reducing agent, such as sodium bisulfite, sodium metabisulfite, sodium sulfite, followed by oxidation in open air to sulfate; Addition of excess soluble sulfate to remove any soluble barium ions | Disproportionates into perchlorate and chloride when alone; Burns when mixed with a flammable material | No | No | Toxic for environment |
| Barium chloride | Addition of a soluble sulfate, such as sodium, potassium or magnesium sulfate | Not useful, melts at high temperatures | Neutralize with magnesium sulfate first | Neutralize with magnesium sulfate first | 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 |
| Barium nitrate | Sodium sulfate, potassium magnesium sulfate, sulfuric acid | Breaks down into barium oxide, releasing nitrogen dioxide and oxygen | DO NOT DUMP | DO NOT DUMP | Toxic to wildlife, due to the soluble barium ions |
| Barium sulfate | Not required | Decomposes at > 1600 °C | Yes | Yes | Low toxicity to wildlife due to its poor solubility in water; occurs naturally as the mineral barite |
| 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 |
| Benzocaine | Oxidation with Fenton's reagent; incineration; down the drain | Generates soot and various VOCs and PAHs | Yes | Not in large quantities | Avoid releasing in environment, effects unknown |
| Benzododecinium bromide | |||||
| 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 |
| Biuret | Not always required | Gives off combustion gasses | Yes | Yes | Safe, biodegradable |
| Biuret reagent | Neutralization with an acid | Gives off combustion gasses | Debatable | No | Copper and sodium ions pose toxicity to plants and animals |
| Black powder | Controlled incineration | Will burn to release a thick cloud of carbon dioxide and sulfur dioxide in open air; will detonate in a sealed container | Not recommended | Yes | Its components are already used as fertilizers and the environmental effect are similar |
| Borax | Not required | Dehydrates | In small quantities | In small quantities | Dangerous to small animals |
| 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 potassium |
| 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 hydride | Neutralization with a concentrated alkali or carbonate solution, alcohols, long chain alcohols are preferred; water vapor can also be used; best performed in an open area | Decomposes to release hydrogen at very high temperatures | DO NOT DUMP | DO NOT DUMP | Corrosive to organisms, toxic to animals |
| 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 required; 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[5][6] | 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 |
| Cellulose | Any disposal method | Burns in air; decomposes to release carbon oxides, water vapors | Not recommended, may clog the plumbing | Yes, but avoid water bodies; bury it in ground instead | Safe, biodegradable; avoid dumping large amounts, as it poses choking hazard to most animals |
| 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[7] |
| 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 |
| Chromic acid | Reducing with a reducing agent, such as sodium metabisulfite, sulfite, bisulfite, ascorbic acid | Decomposes to Cr2O3, releases oxygen and water vapors | DO NOT DUMP | DO NOT DUMP | Cr(VI) ions are carcinogenic and very toxic to organisms |
| Chromium(III) oxide | Not required; can be dumped in the trash | At temperatures ~1000 °C it will become inert against the action of most reagents | 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 |
| Chromium(VI) oxide peroxide | Hydrolysis | Decomposes to harmless Cr(III) | Yes | Yes, but not recommended | Due to its instability, it poses low danger to environment |
| Chromium trioxide | Reducing with a reducing agent, such as sodium metabisulfite, sulfite, bisulfite, ascorbic acid | Decomposes to Cr2O3, releases oxygen | DO NOT DUMP | DO NOT DUMP | Cr(VI) ions are carcinogenic and very toxic to organisms |
| Chromyl chloride | A supersaturated solution of a reducing agent, such as sodium sulfite, metabisulfite or thiosulfate | Not useful, boils off and fumes in contact with air moisture | DO NOT DUMP! | DO NOT DUMP! | Corrosive and deadly to all wildlife; Lowers soil pH; Corrosive to rocks, soil; Carcinogenic |
| 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(II) sulfate | Any soluble hydroxide, carbonate; Taken to disposal centers | Gives off sulfur oxides fumes and sulfuric acid vapors, leaving behind cobalt oxide residue | DO NOT DUMP | DO NOT DUMP | Toxic to wildlife, suspected carcinogen |
| Cobalt (III) oxide | Not required | Not useful | Do not dump | Do not dump | Cobalt is necessary for vitamin B12 production |
| Copper chromite | Not always required; can be dumped in trash | Not useful | Not recommended | Not recommended | Unknown environmental effects |
| Copper citrate | Recover copper via reduction; Discard in trash | Decomposes to copper oxide and releases various gasses | Yes, in small quantities | Yes, in small quantities | High levels of copper are dangerous 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(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) acetate | Reduction with iron or zinc to metallic copper, which is recycled | Gives off carbon oxides, water, acetic acid and acetone vapors | Not recommended | DO NOT DUMP | Unknown effects in the environment; presence of copper ions however is generally considered harmful |
| 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 considered harmful to the environment |
| Copper(II) chloride | Precipitate as carbonate or reduce to copper metal using aluminium, iron 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(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 |
| 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 |
| Decane | Incineration; Oxidation with Fenton's reagent | Ignites in air, gives off carbon dioxide and water vapors, soot | DO NOT DUMP | DO NOT DUMP | Toxic to aquatic life and organisms |
| Devarda's alloy | Dissolved in acid, followed by recovery of copper and zinc Dumped in trash |
Melts between 490 to 560 °C | Not recommended | Do not dump | Toxic to wildlife |
| Dextrin | Any disposal method | Decomposes to release carbon oxides, water vapors | Yes | Yes | Safe, biodegradable |
| Diatomaceous earth | Any disposal method | Not effective | Yes | Yes | Toxic to small animals, otherwise relative safe |
| 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 | Incineration (no peroxides); Adding excess ferrous sulfate, sodium bisulfite or metabisulfite to neutralize the peroxides, followed by incineration; If the bottle has peroxides on the cap, do not open it, instead safely detonate it in a remote or special area | Extremely flammable, burns to release carbon dioxide and water vapors | DO NOT DUMP | DO NOT DUMP | Dangerous to animals |
| Diisopropyl ether | Incineration (no peroxides); Adding excess ferrous sulfate, sodium bisulfite or metabisulfite to neutralize the peroxides, followed by incineration; If the bottle has peroxides on the cap, do not open it, instead safely detonate it in a remote or special area | Extremely flammable, burns to release carbon dioxide and water vapors | DO NOT DUMP | DO NOT DUMP | Dangerous to animals |
| Dimethyl ether | Incineration; can be released in open air | Extremely flammable, burns to release carbon dioxide and water vapors | DO NOT DUMP | DO NOT DUMP | Low toxicity to wildlife |
| Dimethyl sulfoxide | Mixed with a more flammable solvent, followed by incineration; Oxidation with Fenton's reagent if it has too much water | Results in carbon oxides, water vapors and sulfur dioxide | DO NOT DUMP | DO NOT DUMP | Waste water bacteria breaks it down into dimethyl sulfide, which is slightly toxic and has a strong disagreeable odor |
| Dimethylformamide | Oxidation with Fenton's reagent | Gives off toxic fumes | DO NOT DUMP | DO NOT DUMP | Toxic to wildlife |
| Dipicolinic acid | Mixed with a more flammable solvent and followed by incineration | Gives off carbon oxides, water vapors and soot | Yes | Yes | Safe, biodegradable; occurs naturally |
| Disulfur dichloride | Slaked lime or any other base, carbonate or bicarbonate | Boils off | DO NOT DUMP | DO NOT DUMP | Extremely toxic and corrosive |
| Di-tert-butyl ether | Incineration | Extremely flammable, burns to release carbon dioxide and water vapors | DO NOT DUMP | DO NOT DUMP | Displays toxicity to wildlife |
| Dynamite | Will explode | DO NOT DUMP | DO NOT DUMP | Explosive hazard; otherwise good nitrogen source for plants | |
| Erythritol | Not required | Yields carbon oxides, water vapor | Yes | Yes | Low toxicity |
| Erythritol tetranitrate | Cooled aqueous solution of excess sodium hydroxide | Detonates at temperatures > 160 °C | Do not dump | In small amounts | Dangerous to animals due to its vasodilator effects; harmless to plants, nitrogen source for plant life |
| Ethane | Incineration | Flammable, gives off carbon dioxide and water vapors | Not possible | Not possible | Contributes to greenhouse effect |
| Ethanol | Not always required; Incineration | 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; Incineration | Combustion in the presence of air | Do not dump | Do not dump | Toxic to aquatic life |
| Ethyl formate | Incineration | Gives off carbon dioxide and water vapors | DO NOT DUMP | DO NOT DUMP | Hazardous to environment in large amounts |
| Ethylene glycol | Incineration | Gives off carbon oxides, water vapors and various volatile componds | Not recommended | DO NOT DUMP | Toxic to organisms, dangerous to aquatic life |
| Ethylene glycol dinitrate | Sodium hydroxide, followed by incineration | Detonation | DO NOT DUMP | DO NOT DUMP | Poses threat to animals, weak nitrogen source for plants |
| Ethylene oxide | Incineration; Hydrolysis | Burns, giving off combustion gasses | DO NOT DUMP | DO NOT DUMP | Toxic and dangerous for all wildlife |
| Ethyl iodide | Alkali solution, followed by sodium thiosulfate to remove any free iodine | Decomposes to release iodine fumes | DO NOT DUMP | DO NOT DUMP | Dangerous to wildlife in high concentrations |
| Ethylenediamine | Neutralization with sulfuric acid; mixed with a flammable solvent, followed by an incineration; oxidation with potassium permanganate, followed by addition of sodium bisulfite, and neutralization with sodium hydroxide | Burns in air to release carbon dioxide, water vapor and nitrogen | DO NOT DUMP | Not recommended | Dangerous to aquatic life |
| Fehling's solution | Precipitate copper with hydroxide/phosphate, recycle or safely dispose of; tatrate can be disposed of in any method | Decomposes, releases combustion gasses, leaves behind copper, sodium and potassium carbonate slag | Yes | Yes, but not in large quantities | Too much copper is dangerous for animals |
| Fluorescein | Not always required, any method will do | Decomposes, releases combustion gasses, POCs and VOCs | Yes | Yes | Unknown effects |
| Formaldehyde | Sodium hydroxide | Boils off | DO NOT DUMP | Yes, but only in some places, like farm land | Toxic to small animals, carcinogenic |
| 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 |
| Fructose | Not required | Will decompose to caramel | Yes | Yes | Non-toxic to environment, nourishment for many organisms |
| Furfural | Incineration | Gives off carbon oxides and water vapor | Debatable | Debatable | Low toxicity to wildlife |
| Gasoline | Incineration | Burning gives combustion gasses as well as soot, carbon monoxide and various VOCs | DO NOT DUMP | DO NOT DUMP | Toxic to wildlife; very dangerous for aquatic life |
| Glucose | Not required; can be disposed in any way | Will decompose to caramel and carbon if heated too long | Yes | Yes | Non-toxic to environment, nourishment for many organisms |
| Glycerol | Not required; Incineration | Pyrolysis gives acrolein | Yes | Yes | Safe, biodegradable |
| Haematoxylin | Not required | Gives off carbon oxides, water vapor and soot | Yes | Yes | Safe, biodegradable; occurs naturally |
| Hematein | Not required | Gives off carbon oxides, water vapor and soot | Yes | Yes | Safe |
| Heptane | Incineration; Oxidation with Fenton's reagent | Gives off carbon dioxide and water vapors | DO NOT DUMP | DO NOT DUMP | Toxic to aquatic life and organisms |
| 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 | Slowly breaks down to harmless products |
| Hexamine | Incineration | Burning in air yields carbon oxides, water vapor, nitrogen; Pyrolysis yields formaldehyde, carbon oxides, ammonia and nitrogen fumes, HCN (t > 800°C) | Yes | Yes | Nitrogen source for plants |
| Hexane | Incineration; Oxidation with Fenton's reagent | Results in carbon dioxide and water vapor | DO NOT DUMP | DO NOT DUMP | Toxic to aquatic life |
| Holmium citrate | Recycling | Gives off carbon dioxide and water vapors, leaving holmium(III) oxide behind | Not recommended | Not recommended | Low toxicity to wildlife |
| Hydrazine | Diluted solution of calcium hypochlorite | Gives off toxic fumes; may lead to detonation if temperature is too high | DO NOT DUMP | DO NOT DUMP | Toxic to all life |
| Hydrazine sulfate | Diluted solution of calcium hypochlorite | Gives off toxic fumes; may lead to detonation if temperature s too high | DO NOT DUMP | DO NOT DUMP | Toxic to all life |
| Hydrazoic acid | Sodium nitrite or nitrous acid | Will lead to detonation for concentrated solutions | DO NOT DUMP | DO NOT DUMP | Dangerous to all life |
| Hydrobromic acid | Any base, carbonate, bicarbonate; sodium thiosulfate can also be used | Boils off the acid, resulting in extremely toxic and corrosive fumes; will lead to decomposition to elemental bromine | NO! Neutralize first | NO! Neutralize first | Toxic and very corrosive |
| 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 | Calcium hydroxide, carbonate | DON'T! Results in acidic fumes, which on contact with skin will lead to burns and death | DO NOT DUMP | DO NOT DUMP | Calcium fluoride is more inert than most fluorides and poses little toxicity to wildlife; occurs naturally |
| Hydrogen bromide | Any base, carbonate, bicarbonate; for gaseous form, ammonia can be used, though will result in a dense mist; sodium thiosulfate can be used for removing free bromine | DON'T! Will lead to extremely dangerous and corrosive fumes, which will decompose, resulting bromine vapors | NO! Neutralize first | NO! Neutralize first | Corrosive to organisms and rocks; Bromides have little effect to wildlife |
| Hydrogen chloride | Any base, carbonate, bicarbonate; for gaseous form, ammonia can be used, though will result in a dense ammonium chloride mist | NO | DO NOT DUMP | DO NOT DUMP | Corrosive for rocks, toxic for all wildlife |
| Hydrogen cyanide | Absorbtion in water, base, followed by oxidation with hydrogen peroxide, bleach, sodium thiosulfate to less harmful compounds, continued by oxidation to carbon dioxide and nitrogen gas | Burns if ignited, but excess oxygen is required for complete burning | DO NOT DUMP | DO NOT DUMP | Highly toxic for all wildlife |
| Hydrogen fluoride | Calcium hydroxide, carbonate, bicarbonate; for gaseous form, excess ammonia can be used, though will result in a dense ammonium fluoride mist; further treatment with calcium hydroxide, carbonate will convert it to the more safe CaF2 | NO | DO NOT DUMP | DO NOT DUMP | Corrosive for all life, inorganic materials, toxic for all wildlife |
| Hydrogen iodide | Any base, carbonate, bicarbonate; for gaseous form, ammonia can be used, though will result in a dense mist; sodium thiosulfate can also be used | DON'T! Will lead to extremely dangerous and corrosive fumes, which will decompose, resulting iodine vapors | NO! Neutralize first | NO! Neutralize first | Corrosive to organisms and rocks; Iodides have little toxicity to wildlife |
| Hydrogen peroxide | Manganese dioxide, iron(III) oxide | Diluted solutions will break down harmlessly; Very concentrated solutions may explode if contaminated | Not if concentrated solutions | DO NOT DUMP | Deadly for microbial life, extremely toxic for small animals and aquatic life |
| Hydrogen sulfide | Hydrogen peroxide; sulfur dioxide | Not useful | DO NOT DUMP | Not recommended | Very toxic for animals at high concentrations; Occurs naturally, but at low concentrations |
| Hydroiodic acid | Any alkali or alkaline-earth carbonate, bicarbonate | DON'T! Will lead to extremely dangerous and corrosive fumes, which will decompose, resulting iodine vapors | NO! Neutralize first | NO! Neutralize first | Corrosive to organisms and rocks; Iodides have little toxicity to wildlife |
| Hydroxylamine | Reduction with Zn/HCl; Dilution followed by decomposition with ferrous or ferric salts; Addition of ketone or aldehyde then heated to decompose | Explodes (free base) | DO NOT DUMP | DO NOT DUMP | Toxic for animals at high concentrations |
| Iodoform | Destruction with aqueous sodium hydroxide | Melts and decomposes near boiling point, releasing iodine, hydrogen iodine fumes | Neutralize first | DO NOT DUMP | Dangerous to wildlife, especially if ingested; small animals are harmed easily |
| Iron(II) sulfate | Not always required; Ammonium hydroxide, carbonate/bicarbonate | Breaks down to iron(III) oxide and gives off sulfur dioxide and trioxide fumes | Yes | Yes | Safe, used in agriculture as iron supplement; May cause algal bloom if released in water bodies |
| Iron(II,III) oxide | Not required | Results in iron(III) oxide in the presence of air | Yes, but not advised | Yes | Safe, occurs naturally |
| Iron(III) chloride | Calcium hydroxide (slaked lime) | Gives off hydrogen chloride fumes | DO NOT DUMP | DO NOT DUMP | Extremely toxic to wildlife |
| Iron(III) oxide | Not required | Not useful | Yes, but not advised | Yes | Safe, sometimes used in agriculture as iron supplement; May cause algal bloom if released in water bodies |
| Iron(III) sulfate | Calcium hydroxide (slaked lime) | Breaks down into iron(III) oxide and gives off sulfur oxides | DO NOT DUMP | DO NOT DUMP | Corrosive, toxic to aquatic life |
| Isobutanol | Incineration | Flammable, gives off carbon dioxide and water vapor | DO NOT DUMP | DO NOT DUMP | Dangerous for wildlife and aquatic life |
| Isopropanol | Incineration | Flammable, gives off carbon dioxide and water vapor | DO NOT DUMP | DO NOT DUMP | Dangerous for wildlife and aquatic life |
| Isopropyl nitrite | Neutralization with sodium hydroxide, followed by incineration | Detonation | DO NOT DUMP | DO NOT DUMP | Toxic to wildlife and aquatic life |
| Isopropylamine | Neutralization with any acid; incineration; oxidation with Fenton's reagent | Flammable, burns to release carbon dioxide, water vapors and nitrogen; nitrogen dioxide may also be released | DO NOT DUMP | DO NOT DUMP | Toxic to all wildlife and especially aquatic life |
| Kanthal | Taken to scrap metal centers Dumped in trash |
Melts at 1,500 °C | Do not dump | Do not dump | Toxic to wildlife due to chromium |
| KS Fluid | Immersion underwater to prevent self-ignition, followed by adding a flocculating or a thickening agent to trap the phosphorus inside; resulting mass should be incinerated in a special incinerator | Pyrophoric, releases toxic sulfur dioxide and phosphorus pentoxide fumes | DO NOT DUMP! | DO NOT DUMP! | Pyrophoric, toxic and corrosive to the environment |
| 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! | Extremely toxic to all life, due to the good solubility of lead acetate |
| Lead(II) azide | Nitrous acid, ammonium acetate, sodium dichromate | Decomposes to lead/lead(II) oxide releasing nitrogen gas and may explode during decomposition | DO NOT DUMP | DO NOT DUMP | Very toxic for wildlife |
| Lead(II) chromate | Taken to hazardous waste disposal centers | Breaks down to its component oxides at high temperatures | DO NOT DUMP | DO NOT DUMP | Extremely toxic to the environment |
| Lead(II) nitrate | Precipitation with a sulfide, carbonate or oxalate; wastes are to be taken to hazardous waste disposal centers | Breaks down in to lead oxide and releases nitrogen dioxide fumes | DO NOT DUMP | DO NOT DUMP | Extremely toxic to wildlife due to its good solubility in water |
| Lead(II) oxide | Taken to hazardous waste disposal centers | Not useful | DO NOT DUMP | DO NOT DUMP | Extremely toxic to wildlife |
| Lead(II,IV) oxide | Taken to hazardous waste disposal centers | Not effective | DO NOT DUMP | DO NOT DUMP | Extremely toxic to wildlife |
| Lead(IV) acetate | Precipitate with an excess of carbonate, oxalate or a sulfide; waste is to be taken to hazardous waste disposal centers | Results in lead oxide and acetic acid, carbon dioxide, water vapor | DO NOT DUMP | DO NOT DUMP | Corrosive and very toxic to all organisms |
| Limonene | Incineration; oxidation; not always required | Results in carbon dioxide, water vapor, soot | Yes | Yes | Safe, biodegradable; occurs naturally |
| Lithium aluminium hydride | Neutralization with an alkali or carbonate solution; recycling of lithium ions | Decomposes to release hydrogen | DO NOT DUMP | DO NOT DUMP | Corrosive to organisms, will increase the aluminium concentration in soil or water |
| Lithium chloride | Not required | Hydrated form will give some oxychloride salt | Yes | Yes | Increases the chloride concentration in soil as well as lithium |
| Lithium hydroxide | Any acid, carbon dioxide, sulfur dioxide; recycling is a good choice | Breaks down to lithium oxide and water vapor | Yes | Neutralize first | Lithium has little effect to plant life, but will affect the nervous system of animals when ingested in excess |
| Litmus | Not required; can be poured down the drain | Gives off carbon oxides, water vapor and soot | Yes | Yes | Safe, occurs naturally |
| Magnesium chloride | Not required | Hydrated form gives the oxychloride salt | Yes | Yes | May increase the magnesium and chloride content in the soil significantly |
| Magnesium hydroxide | Not always required; any acid can be used, though a weak one is more economical | Decomposes at 350 °C to magnesium oxide and releases water vapors | Yes | Yes | Raises the soil pH; source of magnesium for plants |
| Magnesium sulfate | Not required | Will dehydrate when heated; Gives off sulfur oxides at very high temperature | Yes | Yes | Source of magnesium for plants |
| Manganese dioxide | Oxalic acid | Converts it into other oxides | DO NOT DUMP | DO NOT DUMP | Toxic to wildlife |
| Manganese heptoxide | Aqueous solutions or suspensions of base, carbonate, bicarbonate | Breaks down to manganese dioxide and gives off ozone; may explode | DO NOT DUMP | DO NOT DUMP | Burns organic material on contact, even wet organic material |
| Manganese(II) sulfate | Dumped in trash | Decomposes at high temperatures | Yes, but in small quantities | Yes, but in small quantities | Classified as dangerous to environment |
| Menthol | Incineration; not required | Releases carbon dioxide, monoxide, water vapors and soot; Burns in rich oxygen atmosphere | Yes | Yes | Safe, biodegradable; Occurs naturally in various plants, like peppermint |
| Mercury sulfide | Taken to hazardous waste disposal centers | Decomposes over 580 °C to yield sulfur oxides and mercury vapors | DO NOT DUMP | DO NOT DUMP | Occurs naturally; Extremely toxic to the environment and all life |
| Mercury(II) sulfate | Taken to hazardous waste disposal centers; Conversion to cinnabar | Decomposes over 450 °C to yield sulfur oxides and mercury vapors | DO NOT DUMP | DO NOT DUMP | Extremely toxic to the environment and all life |
| Mercury(II) thiocyanate | Conversion to mercury(II) sulfide; Taken to hazardous waste disposal centers; | Decomposes over 165 °C to yield a residue known as "Pharaoh's snake", as well as sulfur oxides and mercury vapors | DO NOT DUMP | DO NOT DUMP | Extremely toxic to the environment and all life |
| Methane | Incineration | Releases carbon dioxide and water vapors | Not possible | Not possible | Contributes to global warming |
| Methanol | Incineration | Will give off carbon dioxide and water vapor, as well as some formaldehyde if not enough oxygen | DO NOT DUMP | DO NOT DUMP | Very toxic to wildlife |
| Methyl acetate | Incineration | Gives off carbon dioxide and water vapors | DO NOT DUMP | DO NOT DUMP | Hazardous to environment in large amounts |
| Methyl ethyl ketone | Incineration | Gives off carbon dioxide and water vapors | DO NOT DUMP | DO NOT DUMP | Toxic to wildlife |
| Methyl ethyl ketone peroxide | Reduction with a reducing agent, such as sodium sulfite; Test for peroxides after neutralization; If no peroxides present, incineration or other proper disposal method | Decomposes and explodes | DO NOT DUMP | DO NOT DUMP | Toxic to wildlife |
| Methyl formate | Incineration | Gives off carbon dioxide and water vapors | DO NOT DUMP | DO NOT DUMP | Hazardous to environment in large amounts |
| Methyl iodide | Alkali solution, followed by sodium thiosulfate to remove any free iodine | Decomposes to release iodine fumes | DO NOT DUMP | DO NOT DUMP | Dangerous to wildlife in high concentrations; Occurs naturally in low concentrations |
| Methyl nitrate | Alkali solution, recommended to be cooled first to prevent possible explosion | Will lead to explosion | No | No | Dangerous to wildlife |
| Methyl red | Oxidized with a strong oxidizing solution, such as chromic acid, Fenton's reagent, piranha solution, followed by neutralization and then poured down the drain | Decomposes giving off carbon dioxide, nitrogen, water vapors, VOCs, PAHs | Yes, but not recommended | No, neutralize first | May be harmful to water bodies |
| Methyl salicylate | Incineration; Not always required | Gives off carbon dioxide and water vapors | Yes | Yes | Low toxicity to environment in small amounts |
| Methyl tert-butyl ether | Incineration | Gives off carbon dioxide and water vapors | DO NOT DUMP | DO NOT DUMP | Classified as hazardous to environment and ground water |
| Methylamine | Incineration | Burns in air, giving off carbon dioxide, nitrogen and water vapors | Not recommended | Not recommended | Amines can be source of nitrogen for plants, but may be harmful to fauna and water bodies |
| Methylene blue | Poured down the drain | Decomposes giving off carbon dioxide, sulfur oxides, nitrogen, water, hydrogen chloride vapors, VOCs, PAHs and other harmful compounds | Yes | Yes, but not recommended | May be harmful to microbial life, fauna and water bodies |
| Mineral oil | Incineration | 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 |
| Mischmetal | Recycled Dumped in trash |
Melts between 790 – 1010°C | Not recommended | Possible, though not recommended | Lanthanides show low toxicity to organisms |
| Monopotassium phosphate | Not required; Excess slaked lime can be used to precipitate calcium phosphate | Decomposes on heating at high temperatures to release water vapors, leaving a residue of potassium and phosphorus oxides | Yes | Yes | Safe, good fertilizer (potassium and phosphorus source) |
| Mu-metal | Recycling Taken to scrap metal centers |
Melts at around 1454°C | DO NOT DUMP! | DO NOT DUMP! | Dangerous to wildlife due to nickel and chromium content |
| N-Methyl-2-pyrrolidone | Mixed with a more flammable solvent, followed by incineration outside or in an incinerator; Oxidation with Fenton's reagent under controlled conditions | Gives off toxic fumes or carbon dioxide, nitrogen oxides, VOCs | DO NOT DUMP | DO NOT DUMP | Toxic to wildlife |
| NaK | Long-chained alcohols, diluted with an alkane | Ignites in air | DO NOT DUMP! | DO NOT DUMP! | Pyrophoric, both alloy and reaction products corrosive to wildlife |
| Naphthalene | Incineration, best done in an incinerator with afterburner; Oxidation with Fenton's reagent | Generates carbon dioxide, water vapors, carbon monoxide, soot, VOCs | DO NOT DUMP | DO NOT DUMP | Toxic to wildlife |
| Neodymium iron boron magnet | Recycled Dumped in trash |
Loses magnetism when heated and melts at high temperatures | Not recommended | Possible, though not recommended | Lanthanides show low toxicity to organisms |
| Neodymium oxalate | Pyrolysis, followed by recycling of Nd slag | Gives off carbon oxides, leaving neodymium oxides and hydroxides behind | Do not dump | Do not dump | Presents toxicity to wildlife due to the oxalate group |
| Nichrome | Recycled Dumped in trash |
Melts at 1400 °C | Do not dump | Do not dump | Nickel and chromium are harmful for wildlife |
| Nickel(II) sulfate | Precipitation with a soluble hydroxide; precipitate should be taken to disposal centers | Gives off sulfur oxide fumes, leaving behind nickel oxide slag | DO NOT DUMP | DO NOT DUMP | Toxic to wildlife, allergen |
| Nicotine | Oxidation; Photolysis; Pyrolysis with selenium | Generates carbon oxides, water vapors, soot, VOCs and toxic nicotine vapors | Acceptable in small quantities | Only as insecticide | Deadly to small animals, toxic and addictive to large organisms; absorbs through skin; biodegradable |
| Nitric acid | Any base, hydroxide, carbonate, bicarbonate | Boils off, while also giving off nitrogen dioxide fumes | Neutralize first | Neutralize first | Corrosive to organisms and rocks; its salts are excellent nitrogen source for plants |
| Nitrocellulose | Controlled incineration; Hydrolysis with aqueous alkali hydroxide | Breaks down to release combustion gasses and self-ignites at 160 °C | DO NOT DUMP | No; however it can be converted to fertilizer by adding aqueous ammonia | Breaks down in the presence of water to give nitric acid, which, after neutralization becomes source of nitrogen for plants |
| Nitrogen dioxide | Bubbling through an alkali solution, peroxide solution | Not useful | Not possible | No | Reacts with air moisture to generate nitric acid and contributes to the acid rain; extremely toxic to animals and plants |
| Nitrogen trichloride | Photolysis; Hydrolysis with hot water; Reduction with sodium thiosulfate | Detonates | DO NOT DUMP | DO NOT DUMP | Corrosive and toxic to wildlife |
| Nitrogen triiodide | Sodium thiosulfate solution | Detonation, giving off corrosive iodine vapors | DO NOT DUMP | DO NOT DUMP | The iodine vapors it gives off during decomposition are dangerous to organisms in short term |
| Nitroglycerin | Photolysis; Hydrolysis with cold sodium hydroxide solution | Violent detonation | DO NOT DUMP | DO NOT DUMP | Toxic to organisms; nitrate source for plants |
| Nitromethane | Incineration | Burns giving off carbon oxides, water vapors and nitrogen gas | DO NOT DUMP | DO NOT DUMP | Dangerous to wildlife |
| Nitrous acid | Any base, hydroxide, carbonate, bicarbonate; percarbonates can also be used | Decomposes, giving off nitrogen oxide fumes | Neutralize first | Neutralize first | Corrosive to organisms and rocks; salts somewhat toxic to animals |
| Nitrous oxide | Gentle reduction with various reducing agents | Breaks down to nitrogen and oxygen at high temperatures | Not possible | Not possible | Low toxicity to wildlife, may induce light narcotic effects and laughing sensation in some organisms |
| Nonane | Incineration; Oxidation with Fenton's reagent | Ignites in air, gives off carbon dioxide and water vapors, soot | DO NOT DUMP | DO NOT DUMP | Toxic to aquatic life and organisms |
| Octane | Incineration; Oxidation with Fenton's reagent | Gives off carbon dioxide and water vapors | DO NOT DUMP | DO NOT DUMP | Toxic to aquatic life and organisms |
| Octyl acetate | Mixed with a more flammable solvent, followed by incineration | Gives off carbon oxides, water vapors and soot | Yes | Yes | Safe, occurs naturally in citrus fruit peels |
| Oxalic acid | Neutralization with any oxide, hydroxide, carbonate, followed by pyrolysis | Releases carbon oxides and water vapor at high temperature | Yes, but dilute it first | No | Toxic to wildlife; Small amounts occur in some plants |
| Ozone | Any compound easily oxidizable that does not ignite, such as carbon monoxide, activated charcoal | Accelerates the decomposition of ozone, but not enough | Not possible | No | Dangerous to wildlife, may oxidize various gaseous compounds, contributing to the acid rain; In the upper atmosphere it acts as UV shield |
| Paraffin wax | Incineration; Dumping in trash | Will burn at high temperatures, releasing carbon oxides, water vapors and soot | Do not dump | Do not dump | Wax, both solid and molten, floats on water bodies and may inhibit the cellular breathing of many organisms |
| Pentaerythritol | Mixed with a flammable solvent and incinerated | Gives off carbon oxides, water vapors, aldehydes | Yes | Yes | Low toxicity to aquatic life; Classified as biodegradable[8] |
| Pentaerythritol tetranitrate | Oxidation with Fenton's reagent; Mixed with a flammable solvent and incinerated; Reduction with powdered iron[9] | Gives off carbon oxides, water vapors, soot | Yes, but not recommended | Yes | Displays relative low toxicity to aquatic life; PETN undergoes safe biodegradation |
| Pentane | Incineration | Flammable, releases carbon oxides, water vapor when burned in air | DO NOT DUMP | DO NOT DUMP | Dangerous to wildlife |
| Perchloric acid | Neutralization with potassium, calcium bases, followed by reduction with metallic iron under UV light in the absence of air | May explode at high temperatures, at high concentrations | Do not dump | Do not dump | Toxic to wildlife, both animals and plants |
| Permanganic acid | Hydrogen peroxide; Caro's acid | Leads to decomposition, resulting in manganese dioxide slag | Do not dump | Do not dump | The resulting manganese dioxide from the decomposition can be toxic if ingested by animals |
| Peroxymonosulfuric acid | Any base, carbonate, bicarbonate | May explode if concentrated | Neutralize first | Neutralize first | Strong oxidizer, it is dangerous and toxic to small organisms |
| Petroleum ether | Incineration | Burns in the presence of air, to give off carbon dioxide and water vapors | DO NOT DUMP | DO NOT DUMP | Dangerous for wildlife and aquatic environment |
| Phenol | Incineration; Oxidation with Fenton's reagent | Gives off carbon oxides, water vapors, soot and VOCs | DO NOT DUMP | DO NOT DUMP | Dangerous to environment |
| Phenolphthalein | Incineration; Oxidation with Fenton's reagent | Gives off carbon oxides, water vapors, soot and VOCs | Dilute it with plenty of water before release | Not recommended | Dangerous to environment in large amounts |
| Phosgene | Alkaline metal hydroxide, ammonia | NO | DO NOT DUMP | DO NOT DUMP | Extremely toxic for all organisms |
| Phosphine | Bleach (best bet); hydrogen peroxide; oxygen; ozone; | May ignite in the presence of air | DO NOT DUMP | DO NOT DUMP | Extremely toxic for all organisms, used to kill pests |
| 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 wildlife; Reaction with water will lead to phosphoric acid, highly corrosive and dangerous. |
| Phosphorus triiodide | Sodium thiosulfate solution | Decomposes, releasing corrosive fumes | DO NOT DUMP! | DO NOT DUMP! | Very toxic and corrosive to organisms and rocks |
| Picric acid | Hydrolysis with aqueous sodium hydroxide; oxidation with Fenton's reagent; Containers with dry picric acid should be taken by professionals and safely detonated in a remote location | Gives off carbon dioxide, water vapors, soot, VOCs | DO NOT DUMP | DO NOT DUMP | Very toxic to environment |
| 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 | Resistant to most corrosive chemicals, cannot be digested by wildlife |
| Portland cement | Hydration, followed by recycling, dumping in trash, ground, etc. | Not useful | DO NOT DUMP | DO NOT DUMP | Non-hydrated cement is hazardous to environment, animals and plants; hydrated solid is generally non-toxic; Production of cement is extremely harmful to environment |
| Potassium antimony tartrate | Pyrolysis, followed by taking the resulting slag to disposal facilities | Gives off carbon oxides and water vapors, leaving potassium antimony oxide slag behind | Do not dump | Do not dump | Hazardous to wildlife |
| Potassium bicarbonate | Any acid will do | Above 292 °C decomposes to potassium carbonate and above 891 °C will yield potassium oxide and carbon dioxide, which is quickly reabsorbed as it cools | Yes | OH YES | Excess may increase the concentration of potassium in the dumping area |
| Potassium bisulfate | Any base, carbonate, bicarbonate | Decomposes to high temperatures releasing water vapors and sulfur trioxide | Yes | Neutralize first | Decreases the soil pH, high levels of sodium are toxic for plants |
| Potassium bromide | Not required | May give off bromine vapors in the presence of water at high temperatures | Yes | Yes | Bromide ions pose little toxicity to wildlife in small amounts |
| Potassium carbonate | Any acid will do | No, very high temperatures decompose it to potassium oxide and carbon dioxide, which is quickly reabsorbed as it cools | Yes | OH YES | Excess may increase the soil level of potassium in the dumping area |
| Potassium chlorate | Reduction with metabisulfite, sulfite or bisulfite; a mixture of sulfuric acid and ferric ammonium sulfate can also be used | Melts and disproportionates to potassium perchlorate and potassium chloride | Small amounts can be dumped, as household bleach already contains a small percentage of chlorates, especially if it's old; Do not dump large quantities | No | Toxic to plants, was used as a weedkiller in the past |
| Potassium chloride | Not required | Melts, not useful | Yes | Yes, unless the soil is chloride sensitive | Presence of chlorides may have a harmful effect to some plants |
| Potassium chromate | Neutralization with a reducing agent, such as ascorbic acid sodium metabisulfite, sulfite, bisulfite | Decomposes above 1000 °C, releasing oxygen | DO NOT DUMP | DO NOT DUMP | Cr(VI) ions are powerful carcinogens and very toxic to organisms |
| Potassium dichromate | Reducing with a reducing agent, such as sodium metabisulfite, sulfite, bisulfite, ascorbic acid | Breaks down, releasing oxygen | DO NOT DUMP | DO NOT DUMP | Cr(VI) ions are carcinogenic and very toxic to organisms |
| 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 hexachlorostannate | |||||
| 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 | Not required | May release iodine vapors in the presence of water | Yes | Yes | Low toxicity to wildlife |
| Potassium manganate | Any reducing agents, such as oxalic acid, hydrogen peroxide | Breaks down to manganese oxide and alkali | DO NOT DUMP | DO NOT DUMP | Deadly to small organisms, dangerous to organisms in short term |
| Potassium metabisulfite | Bleach | Breaks down to release sulfur oxides | Yes | Yes | Dangerous to small organisms |
| 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 | Reduction with metallic iron under UV light in the absence of air | Oxidizes flammable materials, burning them | Do not dump | Do not dump | Hazardous to aquatic life |
| 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 peroxochromate | Sodium sulfite; Addition of water and acid | Detonates, releasing potassium chromate fumes | DO NOT DUMP | DO NOT DUMP | Cr(VI) is harmful for he environment |
| 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 persulfate | Pyrolysis, various reducing agents | Decomposes | Do not dump | Do not dump | Strong oxidizer, toxic for wildlife |
| Potassium sodium tartrate | Not always required; can be disposed anyway | Releases combustion gasses and leaves behind sodium and potassium carbonate | Yes | Yes | Safe, low toxicity |
| Potassium sulfate | Not required | Releases sulfur oxides at very high temperatures | Yes | OH YES | Safe, good potassium source for plants |
| Potassium sulfite | Not required, simply pour down the drain; Bleach or hydrogen peroxide can be used if desired | Decomposes to release sulfur dioxide | Yes | Yes, but not recommended | Oxidation of aqueous potassium sulfite to sulfate reduces the amount of dissolved oxygen from water bodies |
| Propane | Incineration | Burns in the presence of oxygen | Not possible | Not possible | Contributes to the greenhouse effect |
| Propylene carbonate | Incineration, first mix it with a more flammable solvent | Burns in the presence of oxygen | Yes | Yes | Low toxicity to organisms |
| Propylene glycol | Not required, though it can be mixed with a flammable solvent and burned | Generates carbon oxides and water vapor, as well as other toxic pyrolysis compounds | Yes | Yes | Little toxic effect on aquatic wildlife |
| Prussian blue | Hydrogen peroxide, bleach | May give off carbon oxides and nitrogen gasses at high temperatures, as well as cyanide | Yes | Yes | Contact with strong acids may release hydrogen cyanide |
| Pumice | Not required; dump it in trash; mix it with concrete | Not useful | Yes (powder or fine grains only, with plenty of water) | Yes | Low toxicity to organisms |
| Pyranine | Not always required | Breaks down to combustion gasses and soot | Yes | Yes | Low toxicity to organisms |
| Pyridine | Incineration; Oxidation with Fenton's reagent | Gives off carbon oxides, water vapors, soot, amines and nitrogen | DO NOT DUMP | DO NOT DUMP | Toxic to wildlife |
| RDX | Incineration, done outside; Oxidation with Fenton's reagent; Hot aqueous solution containing sodium hydroxide and sodium tetraborate | Ignites, gives off carbon oxides, nitrogen oxides, water vapors, soot | Do not dump | Do not dump | Displays moderate toxicity to aquatic life; RDX can be degradated by the fungus Phanaerocheate chrysosporium |
| Rosocyanine | Not required | Breaks down to carbon oxides and water vapors | Yes | Yes | Low toxicity to organisms |
| Safrole | Incineration; Not always required | Breaks down to combustion gasses, soot | Yes | Yes | Low toxicity to wildlife, occurs naturally |
| Salicylic acid | Not always required | Breaks down to phenol; at higher temperatures gives off carbon oxides, water vapors, soot and VOCs | Yes | Yes | Low toxicity to environment, occurs naturally |
| Schweizer's reagent | Any acid | Breaks down to copper(I) oxide, gives off water vapors and ammonia | DO NOT DUMP | DO NOT DUMP | Copper ions and ammonia are toxic to most animals, especially small ones; ammonia can be a source of nitrogen for plants |
| sec-Butanol | Incineration, if no peroxides present; If peroxides are present, neutralize them with a reducing agent such as ferrous sulfate, sodium bisulfite or metabisulfite in excess, then incinerate; If the bottle has peroxides on the cap, do not open it, instead safely detonate it in a remote or special area | Will burn to release carbon dioxide and water vapors | Do not dump | Do not dump | Poses toxicity to wildlife, water bodies |
| Silicon carbide | Not required | Surface oxidation at high temperatures in oxygen; decomposes at its melting point | Not recommended, may clog the plumbing | Yes | Inert, safe for the environment |
| 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 | Photolysis; Reduction with a more reactive metal or a reducing agent like ascorbic acid; Recycling of silver | Breaks down to metallic silver, oxygen and nitrogen dioxide at high temperatures | DO NOT DUMP | DO NOT DUMP | Toxic to wildlife in short term |
| Silver sulfate | Photolysis; Reduction with a more reactive metal or a reducing agent like ascorbic acid; Recycling of silver | Breaks down to metallic silver, oxygen and/or sulfur dioxide/trioxide at high temperatures | DO NOT DUMP | DO NOT DUMP | Toxic to wildlife |
| Smokeless powder | Controlled incineration; dumping in soil | Ignites | Not recommended | Yes, but in low amounts | Somewhat good as a fertilizer, though expensive; Acts as a slow-release nitrogen source for plants |
| Sodium acetate | Not always required | Results in sodium carbonate and acetone at high temperatures, then carbon dioxide and water vapors | Yes | Not recommended | High levels of sodium are toxic for plants |
| Sodium acetylsalicylate | Pyrolysis; Not always required | Gives off carbon dioxide, water vapors and soot | Yes | Not recommended | Sodium is toxic for plants |
| Sodium azide | Sodium nitrite, nitrous acid | Breaks down to sodium metal and gives off nitrogen gas | DO NOT DUMP | DO NOT DUMP | Very toxic for wildlife |
| Sodium benzoate | Not always required | May give off benzene vapors | Yes | Yes, but not in large quantities | Too much sodium is harmful to plants; Reaction with certain compounds may release traces of benzene; otherwise safe, occurs naturally |
| Sodium bicarbonate | Any acid or base; not generally required | Converts to sodium carbonate | Yes | No | High levels of sodium are toxic for plants |
| Sodium bisulfate | Any base, carbonate, bicarbonate | Not useful | Yes | Do not dump | Decreases the soil pH, high levels of sodium are toxic for plants |
| Sodium bisulfite | Not required; Bleach or hydrogen peroxide can be used if desired | Decomposes to release sulfur dioxide | Yes | Yes, but not recommended | High levels of sodium are toxic for plants |
| Sodium carbonate | Any acid; Not generally required | Not useful | Yes | No | High levels of sodium are toxic for plants |
| Sodium chlorate | Reduction with metabisulfite, sulfite or bisulfite; a mixture of sulfuric acid and ferric ammonium sulfate can also be used | Melts and disproportionates to sodium perchlorate and sodium chloride | Small amounts can be dumped, as household bleach already contains a small percentage of chlorates, especially if it's old; Do not dump large quantities though | No | Toxic to plants, was used as a weedkiller in the past |
| Sodium chloride | Not required | Not useful | Yes | No | High levels of sodium are toxic for plants |
| 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 formate | Pyrolysis in a kiln | Decomposes to sodium carbonate, releasing carbon monoxide and water vapors | Yes | Not recommended due to its sodium content | High levels of sodium are toxic to plants |
| 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 | Any reducing agent, such as sodium metabisulfite, bisulfite, sulfite, thiosulfate; Hydrogen peroxide | Disproportionates to sodium chlorate and sodium chloride, giving off chlorine | Yes | DO NOT DUMP | Very toxic to organisms, especially aquatic ones; High levels of sodium are toxic for plants |
| Sodium metabisulfite | Bleach | Breaks down to release sulfur oxides | Yes | No | Toxic to most fauna; High levels of sodium are toxic for plants |
| Sodium nitrate | Not always required; Ammonium sulfate | Not useful; may convert to sodium nitrite | Yes | No | While it is a good source of nitrogen for plants, high levels of sodium are generally undesired in soils |
| Sodium nitrite | Oxidation with sodium percarbonate, oxygen, ozone to nitrate; Thermal decomposition followed by conversion to sodium carbonate or sulfate | Decomposes to form sodium oxide/hydroxide and releases nitrogen oxides fumes | Yes, but not recommended | No | Unlike nitrates, nitrites are poor source of nitrogen for plants; High levels of sodium are generally undesired in soils; Nitrites are toxic for most animals |
| Sodium percarbonate | Any acid; Iron(III) oxide or manganese dioxide can also be added for complete neutralization; Generally not required though | Decomposes to release water vapors and oxygen, leaving behind sodium carbonate | Yes | No | Hydrogen peroxide in harmful for organisms; High levels of sodium are toxic for plants |
| Sodium perchlorate | Reduction with metallic iron under UV light in the absence of air | Burns in a mixture with flammable materials | DO NOT DUMP | DO NOT DUMP | Toxic to wildlife |
| Sodium peroxide | Any acid and manganese dioxide | Not useful | DO NOT DUMP | DO NOT DUMP | Corrosive and toxic for wildlife |
| Sodium pyrosulfate | |||||
| 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 | Not required | Not useful | Yes | No | High levels of sodium are toxic for plants |
| Sodium sulfite | Not required; Bleach can be used if desired | Decomposes to release sulfur dioxide | Yes | Yes, but not recommended | High levels of sodium are toxic for plants |
| Sodium thiosulfate | Bleach | Gives off sulfur oxide gasses | Yes | Yes, but not in large quantities | Breaks down rapidly in the environment due to air and microorganisms, yielding sulfides and sulfates. |
| Solochrome cyanine R | |||||
| Sorbitol | Not needed | Melts; Releases carbon dioxide and water vapor at high temperatures | Yes | Yes | Cannot be digested by most organisms, but has no dangerous effects on wildlife; |
| Starch | Any disposal method | Decomposes to release carbon oxides, water vapors | Yes | Yes | Safe, biodegradable; Nourishment for almost all organisms |
| Strontium carbonate | Any acid; Not required; Can be safely dumped in trash | Breaks down to strontium oxide and carbon dioxide at high temperatures; reverts as it cools | Yes | Yes | Strontium has little effect on environment |
| Strontium oxide | Lots of water; any diluted acid | Not useful | Neutralize first | Neutralize first | Will burn grass on contact; strontium has little effect on environment |
| 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 | Any base, carbonate, bicarbonate, best as aqueous solution/suspension | Boils off | DO NOT DUMP | DO NOT DUMP | Extremely corrosive and toxic to all organisms |
| Sulfur dioxide | Any base, bleach (solution); hydrogen sulfide, ammonia (gaseous) | Not useful | Not possible (gas) | Not possible (gas) | Contributes to acid rain |
| Sulfur trioxide | Dry calcium carbonate; ammonia | Not useful | DO NOT DUMP | DO NOT DUMP | Deadly and extremely corrosive to all life; contact with moist air produces sulfuric acid mist; contributes to acid rain |
| Sulfur hexafluoride | Not required | May lead to sulfur dioxides and fluorine at very high temperatures | Not possible | Yes | Strong greenhouse effect |
| Sulfuric acid | Any base, carbonate, bicarbonate; | Not useful | Only if it's followed by large amounts of water; Though best to neutralize it first | DO NOT DUMP | Corrosive and deadly to wildlife; Lowers soil pH; Corrosive to rocks |
| Sulfuryl chloride | Any base, carbonate, bicarbonate; | Not useful | Neutralize it first | Neutralize it first | Corrosive and deadly to all wildlife; Lowers soil pH; Corrosive to rocks, soil |
| Tannerite | VERY controlled incineration | Burns, almost never detonates | DO NOT DUMP! | DO NOT DUMP! | While ammonium nitrate is a good nitrogen source for plants, the aluminium and other impurities are generally harmful for wildlife |
| Terbium(III) oxide | Unnecessary, simply dump in trash | Releases absorbed water or carbon dioxide | Unnecessary | Yes | Effects unknown, may stimulate plant growth |
| Terbium acetate | No required, simply dump in trash or recycle | Breaks down at high temperatures to release carbon oxides | Yes | Yes | Effects unknown |
| Terbium sulfate | No required, simply dump in trash | Breaks down at high temperatures to release sulfur oxides | Yes | Yes | Effects unknown |
| tert-Butanol | Incineration, oxidation with Fenton's reagent, strongly diluted and poured down the drain | Will burn to release carbon dioxide and water vapors | Dilute first | Dilute first | Poses moderate toxicity to wildlife, water bodies |
| Tetraamine copper(II) complex | Pyrolysis; any acid | Gives off water vapors and ammonia, leaving copper oxide behind | Yes, unless there's copper or brass plumbing | No | Copper ions pose toxicity to most organisms |
| Tetraaminecopper(II) persulphate | Controlled detonation; Any acid | Detonation, releasing ammonia, sulfur dioxide copper oxide | Do not dump | Do not dump | Copper ions are toxic to small animals |
| Tetrachlorocupric acid | Any base, carbonate, bicarbonate | Gives off hydrochloric acid fumes, leaving copper oxide behind | DO NOT DUMP | DO NOT DUMP | Corrosive and toxic for wildlife |
| Tetrahydrofuran | Incineration (no peroxides); Adding excess ferrous sulfate, sodium bisulfite or metabisulfite to neutralize the peroxides, followed by incineration; If the bottle has peroxides on the cap, do not open it, instead safely detonate it in a remote or special area | Burns, giving off combustion gasses | DO NOT DUMP | DO NOT DUMP | Toxic and dangerous for wildlife |
| Tetralin | Mixed with a more flammable solvent and incinerated | Ignites at high temperatures and generates carbon oxides, water vapors, carbon monoxide, soot, VOCs | DO NOT DUMP | DO NOT DUMP | Harmful to wildlife and water bodies |
| Thionyl chloride | Any base, carbonate, bicarbonate; | Not useful; Decomposes to release sulfur dioxide and chlorine | NO! Neutralize it first! | NO! Neutralize it first! | Corrosive and deadly to all wildlife; Lowers soil pH; Corrosive to rocks, soil |
| Tin(II) chloride | Excess base, carbonate, bicarbonate; Should be taken to waste disposal centers | Gives off hydrochloric acid fumes in the presence of moisture | DO NOT DUMP | DO NOT DUMP | Corrosive and toxic to wildlife |
| Tin(IV) chloride | Any base, carbonate, bicarbonate; Should be taken to waste disposal centers | Gives off hydrochloric acid fumes in moist air | DO NOT DUMP | DO NOT DUMP | Corrosive and toxic to wildlife |
| Titanium dioxide | Not required; Can be dumped in trash | Not useful; Fuses in the presence of alkaline and alkaline-earth oxides and hydroxides to titanates | Yes, but not recommended | Yes, but not recommended | May lead to staining water bodies and soil in a white color |
| Toluene | Oxidation with Fenton's reagent; Incineration, best done with an afterburner | Flammable, burns in air to release carbon oxides, water vapors, soot, VOCs | DO NOT DUMP | DO NOT DUMP | Toxic to wildlife and very dangerous to aquatic life, as well as soil |
| Trichloroethylene | Sodium hydroxide; Oxidation with Fenton's reagent | Not useful | DO NOT DUMP | DO NOT DUMP | Toxic to wildlife |
| Trichloroisocyanuric acid | Sodium thiosulfate, sulfite, bisulfite, metabisulfite | Breaks down to release chlorine | Yes | DO NOT DUMP | Toxic to wildlife |
| Triethylamine | Diluted with another solvent, followed by incineration; Neutralization with an acid and destroyed via oxidation | Burns in air | DO NOT DUMP | DO NOT DUMP | Toxic to most lifeforms, dangerous to water bodies |
| Trimethyl borate | Incineration; Hydrolysis with water | Burns in air | Not recommended | Not recommended | Effects unknown to environment |
| Trinitrotoluene | Oxidation with Fenton's reagent | Burns and decomposes to release combustion gasses and soot | DO NOT DUMP | DO NOT DUMP | Extremely toxic to the environment, especially for animals |
| Tris(ethylenediamine)nickel perchlorate | Safe detonation; Residual perchlorates can be destroyed by adding metallic iron under UV light, in the absence of air. | Detonates | Do not dump | Do not dump | Nickel and perchlorates are toxic to environment |
| Tungsten carbide | Not required; can be dumped in trash or taken to waste disposal centers | Not useful (refractory) | DO NOT DUMP | Yes (if pure); No (if it contains cobalt) | Toxic to the environment if it contains cobalt |
| 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 |
| Urea nitrate | Cooled basic solution (NaOH, KOH, Ca(OH)2) | Decomposes when burned; May explode if heated at high temperatures | Yes | OH YES! | Safe, good fertilizer; May cause uncontrolled algae growth in water bodies |
| Urea peroxide | Water, , iron(III) oxide, manganese dioxide | Decomposes when heated to high temperatures, releasing water vapor | Yes | Yes, though not recommended in large quantities | Irritant and corrosive to large organisms, kills small organisms |
| Vanadium pentoxide | Not required; should be taken to disposal facilities | Not useful; Turns into oxides of lower states at high temperatures | DO NOT DUMP | DO NOT DUMP | Vanadium ions pose toxicity for wildlife |
| Water | Not required | Leads to steam | YES | YES | It's...water |
| Xylene | Oxidation with Fenton's reagent; Incineration, best with an afterburner | Burns in air, to release combustion gasses, soot and VOCs | DO NOT DUMP | DO NOT DUMP | Toxic to wildlife and hazardous to water bodies |
| Xylitol | Not required | Melts when heated; not useful | Yes | Yes | Cannot be digested by most lifeforms, otherwise little to no toxicity to most organisms; It is however known to be fatal to dogs and some birds |
| Zeolite | Not required | Calcinates at high temperatures | Yes, but not recommended | Yes | Unless contaminated with hazardous compounds, it poses little danger to environment |
| Zinc carbonate | Not required | Breaks down to zinc oxide and carbon oxide at high temperatures | Yes | Yes | Unless contaminated, good source of zinc for plants, though a bit too alkaline |
| Zinc chloride | Any base, carbonate, bicarbonate | Gives off hydrochloric acid fumes if moist | Neutralize first | Neutralize first | Chlorides are dangerous for chloride-sensitive plants in large quantities |
| Zinc chromate | Reducing with a reducing agent, such as sodium metabisulfite, sulfite, bisulfite, ascorbic acid | Not very useful | DO NOT DUMP | DO NOT DUMP | Cr(VI) is toxic for wildlife |
| 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 in large quantities |
| Zinc peroxide | Hydrolysis with water; Any acid | May explode at over 212 °C | Best to neutralize it first | No | Peroxides are deadly to small animals |
| Zinc phosphate | Not required | Not useful | No | Yes | Source of zinc and phosphorus for wildlife |
| Zinc sulfate | Not always required; Zinc metal can be recovered through electrowinning and the diluted sulfuric acid neutralized with a base | Not useful | Yes | Yes | Unless contaminated, is a good source of zinc for plants |
| Zinc sulfide | Hydrogen peroxide | May give off hydrogen sulfide in the presence of water at high temperatures | DO NOT DUMP | DO NOT DUMP | Toxic to wildlife |
| Zirconyl chloride |
References
- ↑ http://woelen.homescience.net/science/chem/exps/rules.html
- ↑ http://www.atsdr.cdc.gov/toxprofiles/tp187-c5.pdf
- ↑ http://link.springer.com/article/10.1007%2FBF02318626
- ↑ http://pubs.rsc.org/en/Content/ArticleLanding/2007/EM/b709571f#!divAbstract
- ↑ http://www.google.com/patents/US2519284
- ↑ Chemical Technology and Emission Control, 2012, M.B. Hocking, p. 216
- ↑ http://www.drugfuture.com/chemdata/cuprous-sulfite.html
- ↑ http://www.inchem.org/documents/sids/sids/115775.pdf
- ↑ http://pubs.acs.org/doi/abs/10.1021/es7029703?journalCode=esthag
