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Chemical collection and stock control for UK schools, universities and hospitals

Sodium cobaltinitrite (CAS 13600-98-1): storage and disposal

Old school, college and university stores often hold a small bottle of sodium cobaltinitrite, kept for the yellow precipitate test for potassium. The solid is classified as an oxidiser, a skin and breathing sensitiser, an eye and respiratory irritant and a suspected carcinogen. Few people use it now, so a single forgotten bottle is usually what turns up at collection time.

CAS number
13600-98-1
Form
Solid
Storage class
Oxidiser
Signal word
Danger
Usual EWC code
16 05 06*
  • Oxidising pictogramOxidising
  • Harmful or irritant pictogramHarmful or irritant
  • Serious health hazard pictogramSerious health hazard

What to do this week

  1. Check the label is readable and write down the opened date if it is not already there.
  2. Check it is stored as oxidiser stock and apart from the items listed under "Do not store with".
  3. If you no longer need it, add it to your disposal list so it goes on the next collection.

Safe storage in a school or lab

Because it was bought for one test and rarely used since, the bottle in a school prep room tends to live at the back of a shelf with other analysis reagents. It should be moved to the oxidiser space instead, on non-combustible shelving, apart from flammable, acid, alkali, toxic and corrosive stock. The suspected cancer classification, together with the allergic skin and breathing hazards, means it should not be handled casually. Keep the lid tight, wear gloves and eye protection, and avoid raising the fine powder. Date the bottle on arrival and write on the stock record who last used it, since reagents like this change hands slowly.

How to tell it has deteriorated

It is a yellow brown powder, and a sound bottle keeps that colour and flows freely. Damp air can cake it or leave a wet looking lump, and a change in colour or a smell is a reason to leave the cap alone. This substance gives few specific visible signs, so the container does the talking: a faded label, a stained or cracked cap, a crust around the neck, corrosion on nearby shelf fittings and contamination with paper or organic dust. The last of these matters most for an oxidiser. A bottle with no date of receipt is treated as old stock and recorded as it is.

How it must be disposed of

By specialist collection only. It never goes down the drain or into general waste. It is normally packed in a oxidising laboratory pack with compatible chemicals.

No one should try to treat the powder, wash a spill away or sweep it up with paper towels, and none of it goes into a sink, a drain, a general waste bin or a skip. Waste code 16 05 06* is the usual entry for a school or college holder. The allergic reactions make the outside of the bottle matter, so note any powder on the cap or label when you describe it. Record the container size, the amount left and what shares its shelf. It is grouped in a lab pack with oxidisers only, and kept clear of flammable, acid and organic stock.

Waste codes and transport details for Sodium cobaltinitrite
EWC code, laboratory chemicals16 05 06*
Discarded inorganic chemical, not a laboratory pack16 05 07*
Hazardous wasteYes

The code depends on where the waste came from and what it is mixed with. Use the waste code finder to see why.

Do not store with

  • FlammableOxidisers can ignite flammable materials or make a fire far more intense.
  • AcidMany oxidisers release toxic gas or become unstable in contact with acid.
  • AlkaliSome oxidisers react strongly with alkalis, and ammonia based stock is especially at risk.
  • ToxicToxic and oxidising stock are stored apart. A reaction could release toxic vapours.
  • CorrosiveCorrosive stock can react with oxidisers, releasing heat or fumes.

Named chemicals to keep apart

  • Acetic acidMany oxidisers release toxic gas or become unstable in contact with acid.
  • AcetoneOxidisers can ignite flammable materials or make a fire far more intense.
  • Ammonia solutionSome oxidisers react strongly with alkalis, and ammonia based stock is especially at risk.
  • EthanolOxidisers can ignite flammable materials or make a fire far more intense.
  • FormalinToxic and oxidising stock are stored apart. A reaction could release toxic vapours.
  • HexaneOxidisers can ignite flammable materials or make a fire far more intense.
  • Hydrochloric acidMany oxidisers release toxic gas or become unstable in contact with acid.
  • Mercury(II) chlorideToxic and oxidising stock are stored apart. A reaction could release toxic vapours.
Show 9 more
  • MethanolOxidisers can ignite flammable materials or make a fire far more intense.
  • Nitric acidMany oxidisers release toxic gas or become unstable in contact with acid.
  • Potassium hydroxideSome oxidisers react strongly with alkalis, and ammonia based stock is especially at risk.
  • Sodium cyanideToxic and oxidising stock are stored apart. A reaction could release toxic vapours.
  • Sodium hydroxideSome oxidisers react strongly with alkalis, and ammonia based stock is especially at risk.
  • Sulfuric acidMany oxidisers release toxic gas or become unstable in contact with acid.
  • Thionyl chlorideCorrosive stock can react with oxidisers, releasing heat or fumes.
  • TolueneOxidisers can ignite flammable materials or make a fire far more intense.
  • Zinc chlorideCorrosive stock can react with oxidisers, releasing heat or fumes.

Common quantities we collect

Usually held as: solid.

Part-used bottles and full containers are both fine. Tell us the size and how many, and an estimate is enough for a first price.

Where it is commonly held

Hazard statements

  • H272 May intensify fire; oxidiser.
  • H315 Causes skin irritation.
  • H317 May cause an allergic skin reaction.
  • H319 Causes serious eye irritation.
  • H334 May cause allergy or asthma symptoms or breathing difficulties if inhaled.
  • H335 May cause respiratory irritation.
  • H351 Suspected of causing cancer.
Precautionary statements
  • P203 Obtain, read and follow all safety instructions before use.
  • P210 Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking.
  • P220 Keep away from clothing and other combustible materials.
  • P233 Keep container tightly closed.
  • P260 Do not breathe dust, fume, gas, mist, vapours or spray.
  • P261 Avoid breathing dust, fume, gas, mist, vapours or spray.
  • P264 Wash hands and exposed skin thoroughly after handling.
  • P264+P265 Wash hands and exposed skin thoroughly after handling. Do not touch eyes.
  • P271 Use only outdoors or in a well-ventilated area.
  • P272 Contaminated work clothing should not be allowed out of the workplace.
  • P280 Wear protective gloves, protective clothing, eye protection and face protection.
  • P284 In case of inadequate ventilation wear respiratory protection.
  • P302+P352 IF ON SKIN: Wash with plenty of water.
  • P304+P340 IF INHALED: Remove person to fresh air and keep comfortable for breathing.
  • P305+P351+P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
  • P318 If exposed or concerned, get medical advice.
  • P319 Get medical help if you feel unwell.
  • P321 Specific treatment (see supplemental first aid instruction on this label).
  • P332+P317 If skin irritation occurs: Get medical help.
  • P333+P317 If skin irritation or rash occurs: Get medical help.
  • P337+P317 If eye irritation persists: Get medical help.
  • P342+P316 If experiencing respiratory symptoms: Get emergency medical help immediately.
  • P362+P364 Take off contaminated clothing. And wash it before reuse.
  • P370+P378 In case of fire: Use suitable extinguishing media to extinguish.
  • P403 Store in a well-ventilated place.
  • P403+P233 Store in a well-ventilated place. Keep container tightly closed.
  • P405 Store locked up.
  • P501 Dispose of contents and container in accordance with local, regional, national and international regulations.

Substance as classified, dilutions may differ.

Questions

What is sodium cobaltinitrite used for in a school?

Chiefly as the reagent that gives a yellow precipitate with potassium ions in analysis exercises. Many schools no longer run that test, so the bottle often sits unused and ends up as a collection item.

Which hazards should I tell staff about?

It is an oxidiser, may cause an allergic skin reaction and asthma symptoms if inhaled, irritates skin, eyes and the respiratory tract, and is suspected of causing cancer. Staff with known allergies should not handle it.

Where should it be kept in the meantime?

In the oxidiser space on non-combustible shelving, apart from flammable, acid, alkali, toxic and corrosive stock, with the lid tight and the label legible. Keep it clear of paper, wood and organic materials.

Does an old bottle need special treatment?

It gives few visible signs of age. Check the cap, label and shelf for damp, caking or contamination, and record the date if known. If the bottle is undated or contaminated, report it and leave it where it is.

Guidance only. Check your own risk assessment and your supplier's safety data sheet.

Hazard data source: PubChem GHS Classification, retrieved 31 Oct 2026. Formula CoN6Na3O12. EC number 237-077-7.

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