Ammonium sulfide solution (CAS 12135-76-1): storage and disposal
Ammonium sulfide solution, commonly about 20%, is a foul smelling alkaline liquid found in school, college and university stores where sulfide tests are taught. It is classified as causing severe skin burns and eye damage, and it releases toxic hydrogen sulfide. Its age, the state of the cap and what sits on neighbouring shelves decide how it is stored and how it leaves the site.
- CAS number
- 12135-76-1
- Form
- Solution
- Storage class
- Alkali
- Signal word
- Danger
- Usual EWC code
- 16 05 06*
Corrosive
What to do this week
- Check the label is readable and write down the opened date if it is not already there.
- Check it is stored as alkali stock and apart from the items listed under "Do not store with".
- 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
Look at the cap and shoulder of the bottle without lifting it. A domed lid or swollen bottle may indicate internal pressure. Leave any suspect bottle undisturbed and report its condition for specialist assessment. Keep it in a corrosive store, low down on a resistant tray, away from acids. The concern is hydrogen sulfide, which sulfides release when they meet acids such as hydrochloric, nitric, sulfuric, phosphoric or perchloric acid. Acids and alkalis also react with heat and spattering, and some oxidisers react strongly with ammonia based alkalis. In a school prep room that means a separate tray from the acid cupboard, rather than a separate shelf above it.
How to tell it has deteriorated
The strong foul smell is normal for this solution, so smell tells you little about age. Colour tells you more, because the solution yellows as it ages, and the deeper the yellow the older the stock is likely to be. The other sign is pressure: a bulging or domed cap, a hiss, or a bottle that has deformed. Staining or crust around the neck, attacked labels and a missing date add to the picture. Do not open a bottle to check whether it has built up pressure. Keep it upright, away from acids and heat, and ask for collection with a note of what you can see.
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 corrosive alkali laboratory pack with compatible chemicals.
Hand over a labelled, closed bottle and expect it to be packed on its own terms. The solution carries UN number 2683, and waste code 16 05 06* applies when it travels in a lab pack. What makes it awkward is the hydrogen sulfide risk: it must be segregated from acids, oxidisers and other incompatible chemicals. Any shared packing arrangement must be confirmed by the specialist collector. Tell the collection team the approximate strength, the volume, the colour and whether the cap looks domed, since a pressurised bottle needs different handling. It must not be poured away, released or treated on site. Do not dilute, neutralise or otherwise treat it in the meantime. Hazardous waste paperwork is prepared from your description.
| EWC code, laboratory chemicals | 16 05 06* |
|---|---|
| Discarded inorganic chemical, not a laboratory pack | 16 05 07* |
| Hazardous waste | Yes |
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
- AcidAcids and alkalis react with strong heat and spattering if they meet.
- OxidiserSome oxidisers react strongly with alkalis, and ammonia based stock is especially at risk.
Named chemicals to keep apart
- Acetic acidAcids and alkalis react with strong heat and spattering if they meet.
- Calcium hypochloriteSome oxidisers react strongly with alkalis, and ammonia based stock is especially at risk.
- Hydrobromic acidSulfides release toxic hydrogen sulfide gas with acids.
- Hydrochloric acidSulfides release toxic hydrogen sulfide gas with acids.
- Hydrogen peroxideSome oxidisers react strongly with alkalis, and ammonia based stock is especially at risk.
- Hydroiodic acidSulfides release toxic hydrogen sulfide gas with acids.
- Nitric acidSulfides release toxic hydrogen sulfide gas with acids.
- Perchloric acidSulfides release toxic hydrogen sulfide gas with acids.
Show 5 more
- Phosphoric acidSulfides release toxic hydrogen sulfide gas with acids.
- Potassium nitrateSome oxidisers react strongly with alkalis, and ammonia based stock is especially at risk.
- Potassium permanganateSome oxidisers react strongly with alkalis, and ammonia based stock is especially at risk.
- Sulfuric acidSulfides release toxic hydrogen sulfide gas with acids.
- Trichloroacetic acidSulfides release toxic hydrogen sulfide gas with acids.
Common quantities we collect
Usually held as: about 20%.
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
- H314 Causes severe skin burns and eye damage.
Precautionary statements
- P260 Do not breathe dust, fume, gas, mist, vapours or spray.
- P264 Wash hands and exposed skin thoroughly after handling.
- P280 Wear protective gloves, protective clothing, eye protection and face protection.
- P301+P330+P331 IF SWALLOWED: Rinse mouth. Do NOT induce vomiting.
- P302+P361+P354 IF ON SKIN: Take off immediately all contaminated clothing. Immediately rinse with water for several minutes.
- P304+P340 IF INHALED: Remove person to fresh air and keep comfortable for breathing.
- P305+P354+P338 IF IN EYES: Immediately rinse with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
- P316 Get emergency medical help immediately.
- P321 Specific treatment (see supplemental first aid instruction on this label).
- P363 Wash contaminated clothing before reuse.
- 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
Why has our ammonium sulfide solution turned yellow?
Yellowing with age is a known behaviour of this solution. It is a sign that the stock is old rather than a reason to act on it. Date it, keep it closed and upright in the corrosive store, and put it forward for collection.
What happens if it is stored near acids?
Sulfides release toxic hydrogen sulfide gas with acids, so it must be separated from hydrochloric, nitric, sulfuric, phosphoric and other acids. Use a different tray or cabinet, rather than a different shelf, and check the store plan when acids are added.
Can the bottle build up pressure?
Yes, the solution may pressurise. If the cap is domed or the bottle is swollen, do not open it. Do not open, move or reposition a swollen bottle. Keep people away from the immediate area and obtain specialist advice, describing the bulging when making the enquiry.
Is old stock collected the same way as fresh?
Yes. Old, yellowed solution is still specialist collection under the same hazardous waste codes. Give an accurate description, the approximate strength and any pressure signs so the specialist collector can determine a safe, chemically compatible packing arrangement.
